This paper highlights the crucial role of Indonesia’s GNSS receiver network in advancing Equatorial Plasma Bubble(EPB)studies in Southeast and East Asia,as ionospheric irregularities within EPB can disrupt GNSS signa...This paper highlights the crucial role of Indonesia’s GNSS receiver network in advancing Equatorial Plasma Bubble(EPB)studies in Southeast and East Asia,as ionospheric irregularities within EPB can disrupt GNSS signals and degrade positioning accuracy.Managed by the Indonesian Geospatial Information Agency(BIG),the Indonesia Continuously Operating Reference Station(Ina-CORS)network comprises over 300 GNSS receivers spanning equatorial to southern low-latitude regions.Ina-CORS is uniquely situated to monitor EPB generation,zonal drift,and dissipation across Southeast Asia.We provide a practical tool for EPB research,by sharing two-dimensional rate of Total Electron Content(TEC)change index(ROTI)derived from this network.We generate ROTI maps with a 10-minute resolution,and samples from May 2024 are publicly available for further scientific research.Two preliminary findings from the ROTI maps of Ina-CORS are noteworthy.First,the Ina-CORS ROTI maps reveal that the irregularities within a broader EPB structure persist longer,increasing the potential for these irregularities to migrate farther eastward.Second,we demonstrate that combined ROTI maps from Ina-CORS and GNSS receivers in East Asia and Australia can be used to monitor the development of ionospheric irregularities in Southeast and East Asia.We have demonstrated the combined ROTI maps to capture the development of ionospheric irregularities in the Southeast/East Asian sector during the G5 Geomagnetic Storm on May 11,2024.We observed simultaneous ionospheric irregularities in Japan and Australia,respectively propagating northwestward and southwestward,before midnight,whereas Southeast Asia’s equatorial and low-latitude regions exhibited irregularities post-midnight.By sharing ROTI maps from Indonesia and integrating them with regional GNSS networks,researchers can conduct comprehensive EPB studies,enhancing the understanding of EPB behavior across Southeast and East Asia and contributing significantly to ionospheric research.展开更多
The Red Sea-Gulf of Suez-Cairo-Alexandria Clysmic-Trend in northern Egypt is the main earthquake zone in the country,with a moderate-to-high seismic hazard and a history of significant earthquakes caused by rifting an...The Red Sea-Gulf of Suez-Cairo-Alexandria Clysmic-Trend in northern Egypt is the main earthquake zone in the country,with a moderate-to-high seismic hazard and a history of significant earthquakes caused by rifting and active faulting.To improve our understanding of the tectonic and seismic processes in this area,more comprehensive imaging of the crustal structure is required.This can be achieved by increasing the number of receiver functions(RFs)recorded by the seismic stations in northern Egypt and the southeastern Mediterranean.Data handling and processing should also be automated to increase process efficiency.In this study,we developed a capsule neural network for automated selection of RFs.The model was trained on a dataset containing RFs(both selected and unselected)from five broadband stations in northern Egypt.Stations SLM,SIWA,KOT,NBNS,and NKL are located in the unstable shelf region of Egypt,where limited knowledge of the deep crustal structure is available.The proposed capsule neural network achieved an average precision of 80%on the test set.The automated selection of RFs using a capsule neural network has the potential to significantly improve the efficiency and accuracy of RF analysis,as demonstrated by the stacking test.This could lead to a better understanding of crustal structure and tectonic processes in northern Egypt and the southeastern Mediterranean.展开更多
In DSP-based SerDes application,it is essential for AFE to implement a pre-ADC equalization to provide a better sig-nal for ADC and DSP.To meet the various equalization requirements of different channel and transmitte...In DSP-based SerDes application,it is essential for AFE to implement a pre-ADC equalization to provide a better sig-nal for ADC and DSP.To meet the various equalization requirements of different channel and transmitter configurations,this paper presents a 112 Gbps DSP-Based PAM4 SerDes receiver with a wide band equalization tuning AFE.The AFE is realized by implementing source degeneration transconductance,feedforward high-pass branch and inductive feedback peaking TIA.The AFE offers a flexible equalization gain tuning of up to 17.5 dB at Nyquist frequency without affecting the DC gain.With the pro-posed AFE,the receiver demonstrates eye opening after digital FIR equalization and achieves 6×10^(-9) BER with a 29.6 dB inser-tion loss channel.展开更多
A Receiver Operating Characteristic(ROC)analysis of a power is important and useful in clinical trials.A Classical Conditional Power(CCP)is a probability of a classical rejection region given values of true treatment ...A Receiver Operating Characteristic(ROC)analysis of a power is important and useful in clinical trials.A Classical Conditional Power(CCP)is a probability of a classical rejection region given values of true treatment effect and interim result.For hypotheses and reversed hypotheses under normal models,we obtain analytical expressions of the ROC curves of the CCP,find optimal ROC curves of the CCP,investigate the superiority of the ROC curves of the CCP,calculate critical values of the False Positive Rate(FPR),True Positive Rate(TPR),and cutoff of the optimal CCP,and give go/no go decisions at the interim of the optimal CCP.In addition,extensive numerical experiments are carried out to exemplify our theoretical results.Finally,a real data example is performed to illustrate the go/no go decisions of the optimal CCP.展开更多
Construction of LNG receiving terminals The scale of receiving terminals is expanding rapidly At the end of 1999,the state approved the Guangdong LNG Pilot Project,which opened the prelude to the construction of LNG r...Construction of LNG receiving terminals The scale of receiving terminals is expanding rapidly At the end of 1999,the state approved the Guangdong LNG Pilot Project,which opened the prelude to the construction of LNG receiving terminals.In 2006,China's first LNG receiving terminal,namely Dapeng LNG Receiving Terminal in Shenzhen,Guangdong Province,was put into operation,marking the beginning of the use of overseas natural gas in China.展开更多
The objective of this study is to establish a thermodynamic model of an ORC(organic Rankine cycle)for power electricity.A case study was proposed in an area where direct solar irradiation is abundant.The number of hel...The objective of this study is to establish a thermodynamic model of an ORC(organic Rankine cycle)for power electricity.A case study was proposed in an area where direct solar irradiation is abundant.The number of heliostats used in the system as a function of the DNI(direct normal irradiation)was studied.The efficiencies of ORC and receiver,the power of turbine,pump,evaporator and receiver as a function of thermodynamic parameters such as temperature,pressure at the level of different components of the system are studied.The results obtained show that the number of heliostats used decreases when the DNI increases.For a DNI of 700 W/m^(2) to 500 W/m^(2),the number of heliostats goes from 280 to 60.ORC efficiency and turbine power increase respectively from 11%to 22%and from 20 kW to 50 kW when the condenser temperature decreases.Also it is noted an increase of receiver efficiency when evaporator temperature increases.展开更多
The geodetic detrending(GD)methodology was introduced in the past decade and has opened the door to the global monitoring of ionospheric scintillation using global navigation satellite system(GNSS)receivers.The perfor...The geodetic detrending(GD)methodology was introduced in the past decade and has opened the door to the global monitoring of ionospheric scintillation using global navigation satellite system(GNSS)receivers.The performance of GD has been demonstrated in geodetic receivers.However,extending scintillation monitoring to low-cost commercial receivers remains a challenge.Low-cost devices could serve as valuable complements to specialised and much more expensive scintillation monitoring receivers.In this paper,first,a feasibility study was conducted using the GD technique,demonstrating that the scintillation indices derived from the observations of two lowcost receivers(Septentrio Mosaic X5 and UBLOX ZED-F9P)have a resolution similar to that achieved by geodetic receiver models,whose price is one order of magnitude higher.Second,measurements of GNSS signals at different frequencies from the Galileo and global positioning system(GPS)satellites were analysed in a specific experiment over six days of null scintillation.Next,the noise level in the scintillation parameters derived from the experiment was evaluated,which shows that for low-cost receivers,the minimum scintillation detection threshold increases only negligibly compared to geodetic-grade receivers.Moreover,the geometry-free(GF)combination of L1 with a second signal of different frequency was investigated as an alternative to detrending GNSS signals.Finally,for determining the ionospheric fluctuations produced by scintillation,the limitations of using the GF combination versus the uncombined measurements were highlighted.It is concluded that the minimum resolution of scintillation indices derived from low-cost receiver measurements makes it possible to distinguish values associated with periods of scintillation activity from those produced by residual noise from mismodeling.For both geodetic and low-cost receivers,the scintillation detection threshold obtained with uncombined carrier-phase measurements is smaller than that achieved with the classic GF combination.展开更多
Orbital angular momentum(OAM)can achieve multifold increase of spectrum efficiency,but the hollow divergence characteristic and Line-of-Sight(LoS)path requirement impose the crucial challenges for vortex wave communic...Orbital angular momentum(OAM)can achieve multifold increase of spectrum efficiency,but the hollow divergence characteristic and Line-of-Sight(LoS)path requirement impose the crucial challenges for vortex wave communications.For air-to-ground vortex wave communications,where there exists the LoS path,this paper proposes a multi-user cooperative receive(MUCR)scheme to break through the communication distance limitation caused by the characteristic of vortex wave hollow divergence.In particular,we derive the optimal radial position corresponding to the maximum intensity,which is used to adjust the waist radius.Based on the waist radius and energy ring,the cooperative ground users having the minimum angular square difference are selected.Also,the signal compensation scheme is proposed to decompose OAM signals in air-to-ground vortex wave communications.Simulation results are presented to verify the superiority of our proposed MUCR scheme.展开更多
BACKGROUND Emerging evidence suggests that serum levels of pepsinogen(PG),gastrin-17(G17),carcinoembryonic antigen(CEA),carbohydrate antigen 19-9(CA19-9),and CA72-4 may aid in distinguishing gastric cancer(GC)from gas...BACKGROUND Emerging evidence suggests that serum levels of pepsinogen(PG),gastrin-17(G17),carcinoembryonic antigen(CEA),carbohydrate antigen 19-9(CA19-9),and CA72-4 may aid in distinguishing gastric cancer(GC)from gastric ulcer(GU).AIM To assess serum PG,G17,CEA,CA19-9,and CA72-4 in diagnosing GU and optimizing GC detection.METHODS A retrospective analysis was conducted from 263 patients treated at the Third People’s Hospital of Hefei,who were classified into three groups:Chronic non-atrophic gastritis(CG),GU,and GC.Fasting serum levels of PG,G17,CEA,CA19-9,and CA72-4 were measured and compared across the groups.RESULTS Serum levels of PGII and G17 were significantly elevated in both the GU and GC groups compared to the CG group(P<0.01),whereas the PGI/PGII ratio was markedly decreased(P<0.01).Levels of CEA,CA19-9,and CA72-4 were significantly higher in the GC group than in the CG and GU groups(P<0.01).Receiver operating characteristic curve analysis identified the optimal diagnostic cut-off values for GU and GC as follows:PGI(169.855 pmol/L),PGII(30.555μg/L),PGI/PGII ratio(16.529),G17(6.435 pmol/L),CEA(2.005 ng/mL),CA19-9(16.65 U/mL),and CA72-4(2.075 U/mL).The area under the curve for combined detection was 0.826(P<0.001),indicating good diagnostic performance.CONCLUSION Serological biomarkers effectively distinguish GC from GU,with combined detection of PGII,PGI/PGII ratio,G17,and tumor markers enhancing diagnostic accuracy.展开更多
The Rydberg atom-based receiver, as a novel type of antenna, demonstrates broad application prospects in the field of microwave communications. However, since Rydberg atomic receivers are nonlinear systems, mismatches...The Rydberg atom-based receiver, as a novel type of antenna, demonstrates broad application prospects in the field of microwave communications. However, since Rydberg atomic receivers are nonlinear systems, mismatches between the parameters of the received amplitude modulation(AM) signals and the system's linear workspace and demodulation operating points can cause severe distortion in the demodulated signals. To address this, the article proposes a method for determining the operational parameters based on the mean square error(MSE) and total harmonic distortion(THD) assessments and presents strategies for optimizing the system's operational parameters focusing on linear response characteristics(LRC) and linear dynamic range(LDR). Specifically, we employ a method that minimizes the MSE to define the system's linear workspace, thereby ensuring the system has a good LRC while maximizing the LDR. To ensure that the signal always operates within the linear workspace, an appropriate carrier amplitude is set as the demodulation operating point. By calculating the THD at different operating points, the LRC performance within different regions of the linear workspace is evaluated, and corresponding optimization strategies based on the range of signal strengths are proposed. Moreover, to more accurately restore the baseband signal, we establish a mapping relationship between the carrier Rabi frequency and the transmitted power of the probe light, and optimize the slope of the linear demodulation function to reduce the MSE to less than 0.8×10^(-4). Finally, based on these methods for determining the operational parameters, we explore the effects of different laser Rabi frequencies on the system performance, and provide optimization recommendations. This research provides robust support for the design of high-performance Rydberg atom-based AM receivers.展开更多
In this paper,an interference cancellation based neural receiver for superimposed pilot(SIP)in multi-layer transmission is proposed,where the data and pilot are non-orthogonally superimposed in the same time-frequency...In this paper,an interference cancellation based neural receiver for superimposed pilot(SIP)in multi-layer transmission is proposed,where the data and pilot are non-orthogonally superimposed in the same time-frequency resource.Specifically,to deal with the intra-layer and inter-layer interference of SIP under multi-layer transmission,the interference cancellation with superimposed symbol aided channel estimation is leveraged in the neural receiver,accompanied by the pre-design of pilot code-division orthogonal mechanism at transmitter.In addition,to address the complexity issue for inter-vendor collaboration and the generalization problem in practical deployments,respectively,this paper also provides a fixed SIP(F-SIP)design based on constant pilot power ratio and scalable mechanisms for different modulation and coding schemes(MCSs)and transmission layers.Simulation results demonstrate the superiority of the proposed schemes on the performance of block error rate and throughput compared with existing counterparts.展开更多
In this paper,we investigate a distributed multi-input multi-output and orthogonal frequency division multiplexing(MIMO-OFDM) dual-functional radar-communication(DFRC) system,which enables simultaneous communication a...In this paper,we investigate a distributed multi-input multi-output and orthogonal frequency division multiplexing(MIMO-OFDM) dual-functional radar-communication(DFRC) system,which enables simultaneous communication and sensing in different subcarrier sets.To obtain the best tradeoff between communication and sensing performance,we first derive Cramer-Rao Bound(CRB) of targets in detection area,and then maximize the transmission rate by jointly optimizing the power/subcarriers allocation and the selection of radar receivers under the constraints of detection performance and total transmit power.To tackle the non-convex mixed integer programming problem,we decompose the original problem into a semidefinite programming(SDP) problem and a convex quadratic integer problem and solve them iteratively.The numerical results demonstrate the effectiveness of our proposed algorithm,as well as the performance improvement brought by optimizing radar receivers selection.展开更多
To enable simultaneous transmit and receive(STAR)on the same frequency in a densely deployed space with multi-interference sources,this work proposes a digitally-assisted analog selfinterference cancellation method,wh...To enable simultaneous transmit and receive(STAR)on the same frequency in a densely deployed space with multi-interference sources,this work proposes a digitally-assisted analog selfinterference cancellation method,which can acquire reference signals through flexible wired/wireless switching access.Based on this method,the Minimum Mean Square Error algorithm with known channel state information is derived in detail,determining the upper limit of the cancellation performance,and the Adaptive Dithered Linear Search algorithm for real-time engineering cancellation is given.The correctness of theoretical analysis is verified by the practical self-interference channel measured by a vector network analyzer.Furthermore,we have designed and implemented the corresponding multiinterference cancellation prototype with the digitallyassisted structure,capable of handling multiple interferences(up to three)and supporting a large receive bandwidth of 100 MHz as well as a wide frequency coverage from 30 MHz to 3000 MHz.Prototype test results demonstrate that in the presence of three interferences,when the single interference bandwidth is 0.2/2/20 MHz(corresponding to the receive bandwidth of 2/20/100 MHz),the cancellation performance can reach 46/32/22 dB or more.展开更多
Large dynamic range and ultra-wideband receiving abilities are significant for many receivers. With these abilities, receivers can obtain signals with different power in ultra-wideband frequency space without informat...Large dynamic range and ultra-wideband receiving abilities are significant for many receivers. With these abilities, receivers can obtain signals with different power in ultra-wideband frequency space without information loss. However, conventional receiving scheme is hard to have large dynamic range and ultra-wideband receiving simultaneously because of the analog-to-digital converter(ADC) dynamic range and sample rate limitations. In this paper, based on the modulated sampling and unlimited sampling, a novel receiving scheme is proposed to achieve large dynamic range and ultra-wideband receiving. Focusing on the single carrier signals, the proposed scheme only uses a single self-rest ADC(SR-ADC) with low sample rate, and it achieves large dynamic range and ultra-wideband receiving simultaneously. Two receiving scenarios are considered, and they are cooperative strong signal receiving and non-cooperative strong/weak signals receiving. In the cooperative receiving scenario, an improved fast recovery method is proposed to obtain the modulated sampling output. In the non-cooperative receiving scenario, the strong and weak signals with different carrier frequencies are considered, and the signal processing method can recover and estimate each signal. Simulation results show that the proposed scheme can realize large dynamic range and ultra-wideband receiving simultaneously when the input signal-to-noise(SNR) ratio is high.展开更多
Existing Generalized Receive Spatial Modulation(GRSM)with Symbol-Level Precoding(SLP)forces the received signals(excluding noise)at unintended antennas to be zero,which restricts the generation of strong constructive ...Existing Generalized Receive Spatial Modulation(GRSM)with Symbol-Level Precoding(SLP)forces the received signals(excluding noise)at unintended antennas to be zero,which restricts the generation of strong constructive interference to intended receive antennas and thus limits the performance improvement over conventional GRSM with Zero-Forcing(ZF)precoding.In this paper,we propose a novel GRSM-SLP scheme that relaxes the zero receive power constraint and achieves superior performance by integrating Intelligent Reflecting Surfaces(IRSs).Specifically,our advanced GRSM-RSLP jointly exploits SLP at the transmitter and passive beamforming at the IRS to maximize the power difference between intended and unintended receive antennas,where the received signals at unintended antennas are relaxed to lie in a sphere centered at origin with a preset radius that depends on the Signal-to-Noise Ratio(SNR)value.The precoding matrix and passive beamforming vectors are optimized alternately by considering both phase shift keying and quadrature amplitude modulation signaling.It is worth emphasizing that GRSM-RSLP is a universal solution,also applicable to systems without IRS,although it performs better in IRS-assisted systems.We finally conduct extensive simulations to prove the superiority of GRSM-RSLP over GRSM-ZF and GRSM-SLP.Simulation results show that the performance of GRSM-RSLP is significantly influenced by the number of unintended antennas,and the larger the number,the better its performance.In the best-case scenario,GRSM-RSLP can achieve SNR gains of up to 10.5 dB and 12.5 dB over GRSM-SLP and GRSM-ZF,respectively.展开更多
As a novel signaling technology,the power splitting receiver(PSR)simultaneously employs both the coherent and non-coherent signal processing.In order to improve its communication performance,an intelligent reflecting ...As a novel signaling technology,the power splitting receiver(PSR)simultaneously employs both the coherent and non-coherent signal processing.In order to improve its communication performance,an intelligent reflecting surface(IRS)is introduced into its signal propagation path.Consequently,an IRSaided PSR is concerned for a point-to-point(P2P)data link,where both the single-antenna and multiantenna deployments on the receiver are discussed.We aim at maximizing the capacity of the concerned P2P data-link by jointly optimizing the passive beamforming of IRS and the splitting ratio of PSR,either in single-antenna or multi-antenna case.However,owing to the coupling of multiple variables,the optimization problems are non-convex and challenging,especially in the later multi-antenna case.The proposed alternating-approximating algorithm(A-A),aided by semi-definite relaxation(SDR)and successive convex approximation(SCA)methods,etc.,successfully overcomes these challenges.We compare the IRS-aided PSR system that optimized by our proposed algorithm to the systems without IRS or PSR,and the systems without joint optimization.The simulation results show that our proposal has a better performance.展开更多
BACKGROUND With the increasing global incidence of mental illness,depression has become a serious problem among college students.AIM To investigate the relationship between depression and its correlates in Chinese ado...BACKGROUND With the increasing global incidence of mental illness,depression has become a serious problem among college students.AIM To investigate the relationship between depression and its correlates in Chinese adolescents and to identify diagnostic predictors of depression,examine the effects of binge eating,physical activity,and body dissatisfaction on depression among college students and to determine a diagnostic cutoff value for depression based on body dissatisfaction.METHODS We conducted a cross-sectional survey of 1286 college students in South China.Physical activity level,depressive symptoms,and binge eating behavior were assessed using the Physical Activity Scale-3,Zung Self-Rating Depression Scale,and Dutch Eating Behavior Questionnaire,respectively.The absolute difference between actual body mass index(BMI)and ideal BMI was used to indicate the level of body dissatisfaction.Structural equation modeling(SEM)and receiver operating characteristic(ROC)curve analysis were used to examine the relationships between these variables and depression.RESULTS The findings showed that female college students reported higher levels of depression.Physical activity,body dissatisfaction,and binge eating behavior were significantly associated with depression.SEM revealed that body dissatisfaction played a mediating role.A body dissatisfaction score of 1.73 was identified as the diagnostic cutoff value for predicting depression,with an area under the ROC curve of 70.0%,providing a basis for targeted interventions.CONCLUSION This study demonstrated a significant positive correlation between body dissatisfaction and depression.Low levels of physical activity and binge eating behaviors were found to heighten the risk of depression.Therefore,promoting physical activity and healthy eating habits among adolescents is essential.Additionally,the identification of a diagnostic threshold for body dissatisfaction represents a novel finding with important implications for early screening.Future longitudinal studies are recommended to further refine this diagnostic criterion.展开更多
Based on the observational data from 60 short-period stations deployed in the Jishishan M6.2 earthquake epicenter and adjacent regions(Gansu Province,2023),this study inverted the near-surface S-wave velocity structur...Based on the observational data from 60 short-period stations deployed in the Jishishan M6.2 earthquake epicenter and adjacent regions(Gansu Province,2023),this study inverted the near-surface S-wave velocity structure through teleseismic receiver function analysis by using the amplitude of direct P-wave.The results reveal that the epicentral area(Liugou Township and surroundings)exhibits markedly low S-wave velocities of 400-600 m/s,with a mean value of(500±50)m/s.In contrast,intermountain basins-Guanting Basin and Dahejia Basin-demonstrate significantly elevated velocities,exceeding the epicentral zone by 100-300 m/s,with values concentrated at 600-900 m/s.Notably,localized areas such as Jintian Village and Caotan Village maintain stable S-wave velocities of(700±30)m/s.The western margin tectonic belt of Jishishan displays distinctive velocity differentiation:A pronounced velocity gradient zone along the 35.8°N latitude boundary separates northern areas(<550 m/s)from southern regions(>750 m/s).These findings demonstrate significant spatial heterogeneity in shallow S-wave velocity structures,primarily controlled by three factors:(1)topographic-geomorphic units,(2)stratigraphic lithological contrasts,and(3)anthropogenic modifications.The persistent low-velocity anomalies(<600 m/s)in the epicentral zone and northern Yellow River T2 terrace likely correlate with Quaternary unconsolidated sediments,enhanced groundwater circulation,and bedrock weathering.These results provide critical geophysical constraints for understanding both the seismogenic environment of the Jishishan earthquake and its damage distribution patterns.Furthermore,they establish a foundational framework for regional seismic intensity evaluation,site amplification analysis,and secondary hazard risk assessment.展开更多
An optimizing method for designing the wireless power receiving coil(RC)is proposed in this paper to address issues such as insufficient and fluctuating power supply in the near-infrared capsule robot.An elec-tromagne...An optimizing method for designing the wireless power receiving coil(RC)is proposed in this paper to address issues such as insufficient and fluctuating power supply in the near-infrared capsule robot.An elec-tromagnetic and circuit analysis is conducted to establish the magnetic induction intensity and equivalent circuit models for the wireless power transmission system.Combining these models involves using the number of layers in each dimension as the optimization variable.Constraints are imposed based on the normalized standard deviation of the receiving-end load power and spatial dimensions.At the same time,the optimization objective aims to maximize the average power of the receiving-end load.This process leads to formulating an optimization model for the RC.Finally,three-dimensional RCs with three different sets of parameters are wound,and the receiving-end load power of these coils is experimentally tested under various drive currents.The experimental values of the receiving-end load power exhibit a consistent trend with theoretical values,with experimental values consistently lower than theoretical values.The optimized coil parameters are determined by conducting comparative exper-iments,with a theoretical value of 4.6%for the normalized standard deviation of the receiving-end load power and an average experimental value of 9.6%.The study addressed the power supply issue of near-infrared capsule robots,which is important for early diagnosing and treating gastrointestinal diseases.展开更多
In the RSSI-based positioning algorithm,regarding the problem of a great conflict between precision and cost,a low-power and low-cost synergic localization algorithm is proposed,where effective methods are adopted in ...In the RSSI-based positioning algorithm,regarding the problem of a great conflict between precision and cost,a low-power and low-cost synergic localization algorithm is proposed,where effective methods are adopted in each phase of the localization process and fully use the detective information in the network to improve the positioning precision and robustness.In the ranging period,the power attenuation factor is obtained through the wireless channel modeling,and the RSSI value is transformed into distance.In the positioning period,the preferred reference nodes are used to calculate coordinates.In the position optimization period,Taylor expansion and least-squared iterative update algorithms are used to further improve the location precision.In the positioning,the notion of cooperative localization is introduced,in which the located node satisfying certain demands will be upgraded to a reference node so that it can participate in the positioning of other nodes,and improve the coverage and positioning precision.The results show that on the same network conditions,the proposed algorithm in this paper is similar to the Taylor series expansion algorithm based on the actual coordinates,but much higher than the basic least square algorithm,and the positioning precision is improved rapidly with the reduce of the range error.展开更多
基金JSPS KAKENHI Grant Number16H06286 supports global GNSS ionospheric maps (TEC,ROTI,and detrended TEC maps) developed by the Institute for SpaceEarth Environmental Research (ISEE) of Nagoya Universitysupport of the 2024 JASSO Follow-up Research Fellowship Program for a 90-day visiting research at the Institute for Space-Earth Environmental Research (ISEE),Nagoya University+3 种基金the support received from Telkom University under the“Skema Penelitian Terapan Periode I Tahun Anggaran 2024”the Memorandum of Understanding for Research Collaboration on Regional Ionospheric Observation (No:092/SAM3/TE-DEK/2021)the National Institute of Information and Communications Technology (NICT) International Exchange Program 2024-2025(No.2024-007)support for a one-year visiting research at Hokkaido University
文摘This paper highlights the crucial role of Indonesia’s GNSS receiver network in advancing Equatorial Plasma Bubble(EPB)studies in Southeast and East Asia,as ionospheric irregularities within EPB can disrupt GNSS signals and degrade positioning accuracy.Managed by the Indonesian Geospatial Information Agency(BIG),the Indonesia Continuously Operating Reference Station(Ina-CORS)network comprises over 300 GNSS receivers spanning equatorial to southern low-latitude regions.Ina-CORS is uniquely situated to monitor EPB generation,zonal drift,and dissipation across Southeast Asia.We provide a practical tool for EPB research,by sharing two-dimensional rate of Total Electron Content(TEC)change index(ROTI)derived from this network.We generate ROTI maps with a 10-minute resolution,and samples from May 2024 are publicly available for further scientific research.Two preliminary findings from the ROTI maps of Ina-CORS are noteworthy.First,the Ina-CORS ROTI maps reveal that the irregularities within a broader EPB structure persist longer,increasing the potential for these irregularities to migrate farther eastward.Second,we demonstrate that combined ROTI maps from Ina-CORS and GNSS receivers in East Asia and Australia can be used to monitor the development of ionospheric irregularities in Southeast and East Asia.We have demonstrated the combined ROTI maps to capture the development of ionospheric irregularities in the Southeast/East Asian sector during the G5 Geomagnetic Storm on May 11,2024.We observed simultaneous ionospheric irregularities in Japan and Australia,respectively propagating northwestward and southwestward,before midnight,whereas Southeast Asia’s equatorial and low-latitude regions exhibited irregularities post-midnight.By sharing ROTI maps from Indonesia and integrating them with regional GNSS networks,researchers can conduct comprehensive EPB studies,enhancing the understanding of EPB behavior across Southeast and East Asia and contributing significantly to ionospheric research.
文摘The Red Sea-Gulf of Suez-Cairo-Alexandria Clysmic-Trend in northern Egypt is the main earthquake zone in the country,with a moderate-to-high seismic hazard and a history of significant earthquakes caused by rifting and active faulting.To improve our understanding of the tectonic and seismic processes in this area,more comprehensive imaging of the crustal structure is required.This can be achieved by increasing the number of receiver functions(RFs)recorded by the seismic stations in northern Egypt and the southeastern Mediterranean.Data handling and processing should also be automated to increase process efficiency.In this study,we developed a capsule neural network for automated selection of RFs.The model was trained on a dataset containing RFs(both selected and unselected)from five broadband stations in northern Egypt.Stations SLM,SIWA,KOT,NBNS,and NKL are located in the unstable shelf region of Egypt,where limited knowledge of the deep crustal structure is available.The proposed capsule neural network achieved an average precision of 80%on the test set.The automated selection of RFs using a capsule neural network has the potential to significantly improve the efficiency and accuracy of RF analysis,as demonstrated by the stacking test.This could lead to a better understanding of crustal structure and tectonic processes in northern Egypt and the southeastern Mediterranean.
基金supported by National Key R&D Program of China No.2022YFB2803401.
文摘In DSP-based SerDes application,it is essential for AFE to implement a pre-ADC equalization to provide a better sig-nal for ADC and DSP.To meet the various equalization requirements of different channel and transmitter configurations,this paper presents a 112 Gbps DSP-Based PAM4 SerDes receiver with a wide band equalization tuning AFE.The AFE is realized by implementing source degeneration transconductance,feedforward high-pass branch and inductive feedback peaking TIA.The AFE offers a flexible equalization gain tuning of up to 17.5 dB at Nyquist frequency without affecting the DC gain.With the pro-posed AFE,the receiver demonstrates eye opening after digital FIR equalization and achieves 6×10^(-9) BER with a 29.6 dB inser-tion loss channel.
基金supported by the National Social Science Fund of China(Grand No.21XTJ001).
文摘A Receiver Operating Characteristic(ROC)analysis of a power is important and useful in clinical trials.A Classical Conditional Power(CCP)is a probability of a classical rejection region given values of true treatment effect and interim result.For hypotheses and reversed hypotheses under normal models,we obtain analytical expressions of the ROC curves of the CCP,find optimal ROC curves of the CCP,investigate the superiority of the ROC curves of the CCP,calculate critical values of the False Positive Rate(FPR),True Positive Rate(TPR),and cutoff of the optimal CCP,and give go/no go decisions at the interim of the optimal CCP.In addition,extensive numerical experiments are carried out to exemplify our theoretical results.Finally,a real data example is performed to illustrate the go/no go decisions of the optimal CCP.
文摘Construction of LNG receiving terminals The scale of receiving terminals is expanding rapidly At the end of 1999,the state approved the Guangdong LNG Pilot Project,which opened the prelude to the construction of LNG receiving terminals.In 2006,China's first LNG receiving terminal,namely Dapeng LNG Receiving Terminal in Shenzhen,Guangdong Province,was put into operation,marking the beginning of the use of overseas natural gas in China.
文摘The objective of this study is to establish a thermodynamic model of an ORC(organic Rankine cycle)for power electricity.A case study was proposed in an area where direct solar irradiation is abundant.The number of heliostats used in the system as a function of the DNI(direct normal irradiation)was studied.The efficiencies of ORC and receiver,the power of turbine,pump,evaporator and receiver as a function of thermodynamic parameters such as temperature,pressure at the level of different components of the system are studied.The results obtained show that the number of heliostats used decreases when the DNI increases.For a DNI of 700 W/m^(2) to 500 W/m^(2),the number of heliostats goes from 280 to 60.ORC efficiency and turbine power increase respectively from 11%to 22%and from 20 kW to 50 kW when the condenser temperature decreases.Also it is noted an increase of receiver efficiency when evaporator temperature increases.
基金funding from European Union(MCIN/AEI/10.13039/501100011033/FEDER)(Nos.PID2022-138485OB-I00 and CNS2022-135383)European Space Agency(RT-WMIS)(No.4000137762/22/NL/GLC/ov)funding support from the China Scholarship Council(No.202006020025)。
文摘The geodetic detrending(GD)methodology was introduced in the past decade and has opened the door to the global monitoring of ionospheric scintillation using global navigation satellite system(GNSS)receivers.The performance of GD has been demonstrated in geodetic receivers.However,extending scintillation monitoring to low-cost commercial receivers remains a challenge.Low-cost devices could serve as valuable complements to specialised and much more expensive scintillation monitoring receivers.In this paper,first,a feasibility study was conducted using the GD technique,demonstrating that the scintillation indices derived from the observations of two lowcost receivers(Septentrio Mosaic X5 and UBLOX ZED-F9P)have a resolution similar to that achieved by geodetic receiver models,whose price is one order of magnitude higher.Second,measurements of GNSS signals at different frequencies from the Galileo and global positioning system(GPS)satellites were analysed in a specific experiment over six days of null scintillation.Next,the noise level in the scintillation parameters derived from the experiment was evaluated,which shows that for low-cost receivers,the minimum scintillation detection threshold increases only negligibly compared to geodetic-grade receivers.Moreover,the geometry-free(GF)combination of L1 with a second signal of different frequency was investigated as an alternative to detrending GNSS signals.Finally,for determining the ionospheric fluctuations produced by scintillation,the limitations of using the GF combination versus the uncombined measurements were highlighted.It is concluded that the minimum resolution of scintillation indices derived from low-cost receiver measurements makes it possible to distinguish values associated with periods of scintillation activity from those produced by residual noise from mismodeling.For both geodetic and low-cost receivers,the scintillation detection threshold obtained with uncombined carrier-phase measurements is smaller than that achieved with the classic GF combination.
基金supported in part by National Natural Science Foundation of China under Grant 62441115 and 62201427in part by the Ministry of Industry and Information Technology of the People’s Republic of China under Grant CBG01N23-01-04.
文摘Orbital angular momentum(OAM)can achieve multifold increase of spectrum efficiency,but the hollow divergence characteristic and Line-of-Sight(LoS)path requirement impose the crucial challenges for vortex wave communications.For air-to-ground vortex wave communications,where there exists the LoS path,this paper proposes a multi-user cooperative receive(MUCR)scheme to break through the communication distance limitation caused by the characteristic of vortex wave hollow divergence.In particular,we derive the optimal radial position corresponding to the maximum intensity,which is used to adjust the waist radius.Based on the waist radius and energy ring,the cooperative ground users having the minimum angular square difference are selected.Also,the signal compensation scheme is proposed to decompose OAM signals in air-to-ground vortex wave communications.Simulation results are presented to verify the superiority of our proposed MUCR scheme.
基金Supported by Chinese Medicine Research Project of Anhui Chinese Medicine Society,No.2024ZYYXH135.
文摘BACKGROUND Emerging evidence suggests that serum levels of pepsinogen(PG),gastrin-17(G17),carcinoembryonic antigen(CEA),carbohydrate antigen 19-9(CA19-9),and CA72-4 may aid in distinguishing gastric cancer(GC)from gastric ulcer(GU).AIM To assess serum PG,G17,CEA,CA19-9,and CA72-4 in diagnosing GU and optimizing GC detection.METHODS A retrospective analysis was conducted from 263 patients treated at the Third People’s Hospital of Hefei,who were classified into three groups:Chronic non-atrophic gastritis(CG),GU,and GC.Fasting serum levels of PG,G17,CEA,CA19-9,and CA72-4 were measured and compared across the groups.RESULTS Serum levels of PGII and G17 were significantly elevated in both the GU and GC groups compared to the CG group(P<0.01),whereas the PGI/PGII ratio was markedly decreased(P<0.01).Levels of CEA,CA19-9,and CA72-4 were significantly higher in the GC group than in the CG and GU groups(P<0.01).Receiver operating characteristic curve analysis identified the optimal diagnostic cut-off values for GU and GC as follows:PGI(169.855 pmol/L),PGII(30.555μg/L),PGI/PGII ratio(16.529),G17(6.435 pmol/L),CEA(2.005 ng/mL),CA19-9(16.65 U/mL),and CA72-4(2.075 U/mL).The area under the curve for combined detection was 0.826(P<0.001),indicating good diagnostic performance.CONCLUSION Serological biomarkers effectively distinguish GC from GU,with combined detection of PGII,PGI/PGII ratio,G17,and tumor markers enhancing diagnostic accuracy.
基金Project supported by the National Natural Science Foundation of China (Grant No. U22B2095)the Civil Aerospace Technology Research Project (Grant No. D010103)。
文摘The Rydberg atom-based receiver, as a novel type of antenna, demonstrates broad application prospects in the field of microwave communications. However, since Rydberg atomic receivers are nonlinear systems, mismatches between the parameters of the received amplitude modulation(AM) signals and the system's linear workspace and demodulation operating points can cause severe distortion in the demodulated signals. To address this, the article proposes a method for determining the operational parameters based on the mean square error(MSE) and total harmonic distortion(THD) assessments and presents strategies for optimizing the system's operational parameters focusing on linear response characteristics(LRC) and linear dynamic range(LDR). Specifically, we employ a method that minimizes the MSE to define the system's linear workspace, thereby ensuring the system has a good LRC while maximizing the LDR. To ensure that the signal always operates within the linear workspace, an appropriate carrier amplitude is set as the demodulation operating point. By calculating the THD at different operating points, the LRC performance within different regions of the linear workspace is evaluated, and corresponding optimization strategies based on the range of signal strengths are proposed. Moreover, to more accurately restore the baseband signal, we establish a mapping relationship between the carrier Rabi frequency and the transmitted power of the probe light, and optimize the slope of the linear demodulation function to reduce the MSE to less than 0.8×10^(-4). Finally, based on these methods for determining the operational parameters, we explore the effects of different laser Rabi frequencies on the system performance, and provide optimization recommendations. This research provides robust support for the design of high-performance Rydberg atom-based AM receivers.
文摘In this paper,an interference cancellation based neural receiver for superimposed pilot(SIP)in multi-layer transmission is proposed,where the data and pilot are non-orthogonally superimposed in the same time-frequency resource.Specifically,to deal with the intra-layer and inter-layer interference of SIP under multi-layer transmission,the interference cancellation with superimposed symbol aided channel estimation is leveraged in the neural receiver,accompanied by the pre-design of pilot code-division orthogonal mechanism at transmitter.In addition,to address the complexity issue for inter-vendor collaboration and the generalization problem in practical deployments,respectively,this paper also provides a fixed SIP(F-SIP)design based on constant pilot power ratio and scalable mechanisms for different modulation and coding schemes(MCSs)and transmission layers.Simulation results demonstrate the superiority of the proposed schemes on the performance of block error rate and throughput compared with existing counterparts.
基金supported by the National Key R&D Program of China (2023YFB2905605)the National Natural Science Foundation of China (62072229)。
文摘In this paper,we investigate a distributed multi-input multi-output and orthogonal frequency division multiplexing(MIMO-OFDM) dual-functional radar-communication(DFRC) system,which enables simultaneous communication and sensing in different subcarrier sets.To obtain the best tradeoff between communication and sensing performance,we first derive Cramer-Rao Bound(CRB) of targets in detection area,and then maximize the transmission rate by jointly optimizing the power/subcarriers allocation and the selection of radar receivers under the constraints of detection performance and total transmit power.To tackle the non-convex mixed integer programming problem,we decompose the original problem into a semidefinite programming(SDP) problem and a convex quadratic integer problem and solve them iteratively.The numerical results demonstrate the effectiveness of our proposed algorithm,as well as the performance improvement brought by optimizing radar receivers selection.
基金supported in part by the National Natural Science Foundation of China under Grant 62071094in part by the National Key Laboratory of Wireless Communications Foundation under Grant IFN202402in part by the Postdoctoral Fellowship Program(Grade C)of China Postdoctoral Science Foundation under Grant GZC20240217.
文摘To enable simultaneous transmit and receive(STAR)on the same frequency in a densely deployed space with multi-interference sources,this work proposes a digitally-assisted analog selfinterference cancellation method,which can acquire reference signals through flexible wired/wireless switching access.Based on this method,the Minimum Mean Square Error algorithm with known channel state information is derived in detail,determining the upper limit of the cancellation performance,and the Adaptive Dithered Linear Search algorithm for real-time engineering cancellation is given.The correctness of theoretical analysis is verified by the practical self-interference channel measured by a vector network analyzer.Furthermore,we have designed and implemented the corresponding multiinterference cancellation prototype with the digitallyassisted structure,capable of handling multiple interferences(up to three)and supporting a large receive bandwidth of 100 MHz as well as a wide frequency coverage from 30 MHz to 3000 MHz.Prototype test results demonstrate that in the presence of three interferences,when the single interference bandwidth is 0.2/2/20 MHz(corresponding to the receive bandwidth of 2/20/100 MHz),the cancellation performance can reach 46/32/22 dB or more.
文摘Large dynamic range and ultra-wideband receiving abilities are significant for many receivers. With these abilities, receivers can obtain signals with different power in ultra-wideband frequency space without information loss. However, conventional receiving scheme is hard to have large dynamic range and ultra-wideband receiving simultaneously because of the analog-to-digital converter(ADC) dynamic range and sample rate limitations. In this paper, based on the modulated sampling and unlimited sampling, a novel receiving scheme is proposed to achieve large dynamic range and ultra-wideband receiving. Focusing on the single carrier signals, the proposed scheme only uses a single self-rest ADC(SR-ADC) with low sample rate, and it achieves large dynamic range and ultra-wideband receiving simultaneously. Two receiving scenarios are considered, and they are cooperative strong signal receiving and non-cooperative strong/weak signals receiving. In the cooperative receiving scenario, an improved fast recovery method is proposed to obtain the modulated sampling output. In the non-cooperative receiving scenario, the strong and weak signals with different carrier frequencies are considered, and the signal processing method can recover and estimate each signal. Simulation results show that the proposed scheme can realize large dynamic range and ultra-wideband receiving simultaneously when the input signal-to-noise(SNR) ratio is high.
基金supported in part by the National Key R&D Program of China under Grant 2023YFB2904500in part by the National Natural Science Foundation of China under Grant 62471183in part by the Fundamental Research Funds for the Central Universities under Grant 2024ZYGXZR076.
文摘Existing Generalized Receive Spatial Modulation(GRSM)with Symbol-Level Precoding(SLP)forces the received signals(excluding noise)at unintended antennas to be zero,which restricts the generation of strong constructive interference to intended receive antennas and thus limits the performance improvement over conventional GRSM with Zero-Forcing(ZF)precoding.In this paper,we propose a novel GRSM-SLP scheme that relaxes the zero receive power constraint and achieves superior performance by integrating Intelligent Reflecting Surfaces(IRSs).Specifically,our advanced GRSM-RSLP jointly exploits SLP at the transmitter and passive beamforming at the IRS to maximize the power difference between intended and unintended receive antennas,where the received signals at unintended antennas are relaxed to lie in a sphere centered at origin with a preset radius that depends on the Signal-to-Noise Ratio(SNR)value.The precoding matrix and passive beamforming vectors are optimized alternately by considering both phase shift keying and quadrature amplitude modulation signaling.It is worth emphasizing that GRSM-RSLP is a universal solution,also applicable to systems without IRS,although it performs better in IRS-assisted systems.We finally conduct extensive simulations to prove the superiority of GRSM-RSLP over GRSM-ZF and GRSM-SLP.Simulation results show that the performance of GRSM-RSLP is significantly influenced by the number of unintended antennas,and the larger the number,the better its performance.In the best-case scenario,GRSM-RSLP can achieve SNR gains of up to 10.5 dB and 12.5 dB over GRSM-SLP and GRSM-ZF,respectively.
基金supported by National Key R&D Program of China with Grant number 2019YFB1803400in part by Sichuan Science and Technology Program under Grant 2024NSFSC0472。
文摘As a novel signaling technology,the power splitting receiver(PSR)simultaneously employs both the coherent and non-coherent signal processing.In order to improve its communication performance,an intelligent reflecting surface(IRS)is introduced into its signal propagation path.Consequently,an IRSaided PSR is concerned for a point-to-point(P2P)data link,where both the single-antenna and multiantenna deployments on the receiver are discussed.We aim at maximizing the capacity of the concerned P2P data-link by jointly optimizing the passive beamforming of IRS and the splitting ratio of PSR,either in single-antenna or multi-antenna case.However,owing to the coupling of multiple variables,the optimization problems are non-convex and challenging,especially in the later multi-antenna case.The proposed alternating-approximating algorithm(A-A),aided by semi-definite relaxation(SDR)and successive convex approximation(SCA)methods,etc.,successfully overcomes these challenges.We compare the IRS-aided PSR system that optimized by our proposed algorithm to the systems without IRS or PSR,and the systems without joint optimization.The simulation results show that our proposal has a better performance.
基金Supported by Starting Research Fund from the Gannan Medical University,No.QD202121。
文摘BACKGROUND With the increasing global incidence of mental illness,depression has become a serious problem among college students.AIM To investigate the relationship between depression and its correlates in Chinese adolescents and to identify diagnostic predictors of depression,examine the effects of binge eating,physical activity,and body dissatisfaction on depression among college students and to determine a diagnostic cutoff value for depression based on body dissatisfaction.METHODS We conducted a cross-sectional survey of 1286 college students in South China.Physical activity level,depressive symptoms,and binge eating behavior were assessed using the Physical Activity Scale-3,Zung Self-Rating Depression Scale,and Dutch Eating Behavior Questionnaire,respectively.The absolute difference between actual body mass index(BMI)and ideal BMI was used to indicate the level of body dissatisfaction.Structural equation modeling(SEM)and receiver operating characteristic(ROC)curve analysis were used to examine the relationships between these variables and depression.RESULTS The findings showed that female college students reported higher levels of depression.Physical activity,body dissatisfaction,and binge eating behavior were significantly associated with depression.SEM revealed that body dissatisfaction played a mediating role.A body dissatisfaction score of 1.73 was identified as the diagnostic cutoff value for predicting depression,with an area under the ROC curve of 70.0%,providing a basis for targeted interventions.CONCLUSION This study demonstrated a significant positive correlation between body dissatisfaction and depression.Low levels of physical activity and binge eating behaviors were found to heighten the risk of depression.Therefore,promoting physical activity and healthy eating habits among adolescents is essential.Additionally,the identification of a diagnostic threshold for body dissatisfaction represents a novel finding with important implications for early screening.Future longitudinal studies are recommended to further refine this diagnostic criterion.
基金project is supported in part by Broadband Seismic 3D Array Detection(PhaseⅠ),Deep Earth Probe and Mineral Resources Exploration-National Science and Technology Major Project(Grant No.2024ZD1000300)National Natural Science Foundation of China(42204061)Gansu Jishishan 6.2 magnitude earthquake scientific investigation(DQJB23Y45)program。
文摘Based on the observational data from 60 short-period stations deployed in the Jishishan M6.2 earthquake epicenter and adjacent regions(Gansu Province,2023),this study inverted the near-surface S-wave velocity structure through teleseismic receiver function analysis by using the amplitude of direct P-wave.The results reveal that the epicentral area(Liugou Township and surroundings)exhibits markedly low S-wave velocities of 400-600 m/s,with a mean value of(500±50)m/s.In contrast,intermountain basins-Guanting Basin and Dahejia Basin-demonstrate significantly elevated velocities,exceeding the epicentral zone by 100-300 m/s,with values concentrated at 600-900 m/s.Notably,localized areas such as Jintian Village and Caotan Village maintain stable S-wave velocities of(700±30)m/s.The western margin tectonic belt of Jishishan displays distinctive velocity differentiation:A pronounced velocity gradient zone along the 35.8°N latitude boundary separates northern areas(<550 m/s)from southern regions(>750 m/s).These findings demonstrate significant spatial heterogeneity in shallow S-wave velocity structures,primarily controlled by three factors:(1)topographic-geomorphic units,(2)stratigraphic lithological contrasts,and(3)anthropogenic modifications.The persistent low-velocity anomalies(<600 m/s)in the epicentral zone and northern Yellow River T2 terrace likely correlate with Quaternary unconsolidated sediments,enhanced groundwater circulation,and bedrock weathering.These results provide critical geophysical constraints for understanding both the seismogenic environment of the Jishishan earthquake and its damage distribution patterns.Furthermore,they establish a foundational framework for regional seismic intensity evaluation,site amplification analysis,and secondary hazard risk assessment.
基金the Project of the Science and Technology Commission of Shanghai Municipality(No.20142201300)the National Facility for Translational Medicine(Shanghai)Open Project Foundation(No.TMSK-2021-302)the China Postdoctoral Science Foundation(No.2023M732267)。
文摘An optimizing method for designing the wireless power receiving coil(RC)is proposed in this paper to address issues such as insufficient and fluctuating power supply in the near-infrared capsule robot.An elec-tromagnetic and circuit analysis is conducted to establish the magnetic induction intensity and equivalent circuit models for the wireless power transmission system.Combining these models involves using the number of layers in each dimension as the optimization variable.Constraints are imposed based on the normalized standard deviation of the receiving-end load power and spatial dimensions.At the same time,the optimization objective aims to maximize the average power of the receiving-end load.This process leads to formulating an optimization model for the RC.Finally,three-dimensional RCs with three different sets of parameters are wound,and the receiving-end load power of these coils is experimentally tested under various drive currents.The experimental values of the receiving-end load power exhibit a consistent trend with theoretical values,with experimental values consistently lower than theoretical values.The optimized coil parameters are determined by conducting comparative exper-iments,with a theoretical value of 4.6%for the normalized standard deviation of the receiving-end load power and an average experimental value of 9.6%.The study addressed the power supply issue of near-infrared capsule robots,which is important for early diagnosing and treating gastrointestinal diseases.
基金National Natural Science Foundation of China,grant number 62205120,funded this research.
文摘In the RSSI-based positioning algorithm,regarding the problem of a great conflict between precision and cost,a low-power and low-cost synergic localization algorithm is proposed,where effective methods are adopted in each phase of the localization process and fully use the detective information in the network to improve the positioning precision and robustness.In the ranging period,the power attenuation factor is obtained through the wireless channel modeling,and the RSSI value is transformed into distance.In the positioning period,the preferred reference nodes are used to calculate coordinates.In the position optimization period,Taylor expansion and least-squared iterative update algorithms are used to further improve the location precision.In the positioning,the notion of cooperative localization is introduced,in which the located node satisfying certain demands will be upgraded to a reference node so that it can participate in the positioning of other nodes,and improve the coverage and positioning precision.The results show that on the same network conditions,the proposed algorithm in this paper is similar to the Taylor series expansion algorithm based on the actual coordinates,but much higher than the basic least square algorithm,and the positioning precision is improved rapidly with the reduce of the range error.
