Blood oxygenation and flow are both important parameters in a living body. In this Letter, we introduce a simple configuration to simultaneously measure blood flow and oxygenation using an off-the-shelf spectrometer. ...Blood oxygenation and flow are both important parameters in a living body. In this Letter, we introduce a simple configuration to simultaneously measure blood flow and oxygenation using an off-the-shelf spectrometer. With the integration time of 10 ms, flow phantom measurements, a liquid blood phantom test, and an arm cuff occlusion paradigm were performed to validate the feasibility of the system. We expect this proof-of-concept study would be widely adopted by other researchers for acquiring both blood flow and oxygenation changes due to its straightforward configuration and the possibility of multimodal measurement.展开更多
Utilizing commercial off-the-shelf(COTS) components in satellites has received much attention due to the low cost. However, commercial memories suffer severe reliability problems in radiation environments. This paper ...Utilizing commercial off-the-shelf(COTS) components in satellites has received much attention due to the low cost. However, commercial memories suffer severe reliability problems in radiation environments. This paper studies the low-density parity-check(LDPC) coding scheme for improving the reliability of multi-level-cell(MLC) NAND Flash memory in radiation environments. Firstly, based on existing physical experiment works, we introduce a new error model for heavyion irradiations; secondly, we explore the optimization of writing voltage allocation to maximize the capacity of the storage channel; thirdly, we design the degree distribution of LDPC codes that is specially suitable for the proposed model; finally, we propose a joint detection-decoding scheme based on LDPC codes, which estimates the storage channel state and executes an adaptive log-likelihood ratio(LLR) calculation to achieve better performance. Simulation results show that, compared with the conventional LDPC coding scheme, the proposed scheme may almost double the lifetime of the MLC NAND Flash memory in radiation environments.展开更多
Joint Radar and Communications(JRC)can implement two Radio Frequency(RF)functions using a single of resources,providing significant hardware,power and spectrum savings for wireless systems requiring both functions.Fre...Joint Radar and Communications(JRC)can implement two Radio Frequency(RF)functions using a single of resources,providing significant hardware,power and spectrum savings for wireless systems requiring both functions.Frequency-Hopping(FH)MIMO radar is a popular candidate for JRC because the achieved communication symbol rate can greatly exceed the radar pulse repetition frequency.However,practical transceiver imperfections can cause many existing theoretical designs to fail.In this work,we reveal for the first time the non-trivial impact of hardware imperfections on FH-MIMO JRC and model the impact analytically.We also design new waveforms and correspondingly develop a low-complexity algorithm to jointly estimate the hardware imperfections of unsynchronized receiver.In addition,using low-cost software-defined radios and Commercial Off-The-Shelf(COTS)products,we build the first FH-MIMO JRC experimental platform with simultaneous over-the-air radar and communication validation.Confirmed by simulation and experimental results,the proposed designs achieve high performance for both radar and communications.展开更多
In a component-based software development life cycle, selection of preexisting components is an important task. Every component that has to be reused has an associated risk of failure of not meeting the functional and...In a component-based software development life cycle, selection of preexisting components is an important task. Every component that has to be reused has an associated risk of failure of not meeting the functional and non-functional requirements. A component's failure would lead a developer to look for some other alternative of combinations of COTS, in-house and engineered components among possible candidate combinations. This means design itself can readily change. The very process of design of a software system and component selection seems to be heavily dependent on testing results. Instability of design, further, becomes more severe due to requirements change requests. Therefore, this instability of design has to be essentially mitigated by using proper design and testing approaches, otherwise, it may lead to exorbitantly high testing cost due to the repeated testing of various alternatives. How these three activities: Component-based software design, component selection and component-based software testing are interrelated? What process model is most suited to address this concern? This work explores the above questions and their implication in terms of nature of a process model that can be convincing in case of component-based software development.展开更多
Sensorless sensing using wireless signals has been rapidly conceptualized and developed recently. Among numerous applications of WiFi-based sensing, human presence detection acts as a primary and fundamental function ...Sensorless sensing using wireless signals has been rapidly conceptualized and developed recently. Among numerous applications of WiFi-based sensing, human presence detection acts as a primary and fundamental function to boost applications in practice. Many complicated approaches have been proposed to achieve high detection accuracy, but they frequently omit various practical constraints such as real-time capability, computation efficiency, sampling rates, deployment efforts, etc. A practical detection system that works in realworld applicati ons is lacki ng. In this paper, we design and implement WiSH, a real-time system for con tactless human detection that is applicable for whole-day usage. WiSH employs lightweight yet effective methods and thus enables detection under practical conditions even on resource-limited devices with low signal sampling rates. We deploy WiSH on commodity desktops and customized tiny no des in different everyday scenarios. The experimental results dem on strate the superior performance of WiSH, which has a detection accuracy of >98% using a sampling rate of 20 Hz with an average detection delay of merely 1.5 s. Thus, we believe WiSH is a promising system for real-world deployment.展开更多
The remarkable success of Chimeric Antigen Receptor(CAR-T)cells in B-cell malignancies has not yet translated to solid tumors.Several factors explain this gap.Solid tumors actively exclude and suppress infiltrating ly...The remarkable success of Chimeric Antigen Receptor(CAR-T)cells in B-cell malignancies has not yet translated to solid tumors.Several factors explain this gap.Solid tumors actively exclude and suppress infiltrating lymphocytes through a complex microenvironment.Their surface antigens are often heterogeneous,making it hard to find a target expressed uniformly on all malignant cells.And the current manufacturing paradigm,autologous and ex vivo,remains logistically challenging and expensive.Recent engineering efforts have taken different tacks.One approach aims at off-the-shelf CAR-T cells,using gene editing to eliminate alloreactivity while preserving function.Another seeks to redesign the CAR itself,for instance with logic-gated circuits that sharpen tumor recognition and limit off-tumor toxicity.A third strategy targets the Tumor Microenvironment(TME)directly,either by remodeling it or by using delivery systems that improve T cell infiltration.Meanwhile,in vivo CAR-T generation,which reprograms T cells inside the patient with targeted nanoparticles or viral vectors,could eventually bypass ex vivo manufacturing altogether.These lines of work are gradually converging,and together they point toward a future in which CAR-T therapy might become effective,safe,and accessible for a wider range of cancers.展开更多
基金partially supported by the SGER grant NRF-2015R1D1A1A02062382(J.G.Kim)Global Ph.D.Fellowship Program NRF-2015H1A2A1032268(M.Seong)through the National Research Foundation of Korea(NRF) funded by the Ministry of EducationGIST Research Institute in 2018
文摘Blood oxygenation and flow are both important parameters in a living body. In this Letter, we introduce a simple configuration to simultaneously measure blood flow and oxygenation using an off-the-shelf spectrometer. With the integration time of 10 ms, flow phantom measurements, a liquid blood phantom test, and an arm cuff occlusion paradigm were performed to validate the feasibility of the system. We expect this proof-of-concept study would be widely adopted by other researchers for acquiring both blood flow and oxygenation changes due to its straightforward configuration and the possibility of multimodal measurement.
基金supported by the National Basic Research Project of China(973)(2013CB329006)National Natural Science Foundation of China(NSFC,91538203)the new strategic industries development projects of Shenzhen City(JCYJ20150403155812833)
文摘Utilizing commercial off-the-shelf(COTS) components in satellites has received much attention due to the low cost. However, commercial memories suffer severe reliability problems in radiation environments. This paper studies the low-density parity-check(LDPC) coding scheme for improving the reliability of multi-level-cell(MLC) NAND Flash memory in radiation environments. Firstly, based on existing physical experiment works, we introduce a new error model for heavyion irradiations; secondly, we explore the optimization of writing voltage allocation to maximize the capacity of the storage channel; thirdly, we design the degree distribution of LDPC codes that is specially suitable for the proposed model; finally, we propose a joint detection-decoding scheme based on LDPC codes, which estimates the storage channel state and executes an adaptive log-likelihood ratio(LLR) calculation to achieve better performance. Simulation results show that, compared with the conventional LDPC coding scheme, the proposed scheme may almost double the lifetime of the MLC NAND Flash memory in radiation environments.
文摘Joint Radar and Communications(JRC)can implement two Radio Frequency(RF)functions using a single of resources,providing significant hardware,power and spectrum savings for wireless systems requiring both functions.Frequency-Hopping(FH)MIMO radar is a popular candidate for JRC because the achieved communication symbol rate can greatly exceed the radar pulse repetition frequency.However,practical transceiver imperfections can cause many existing theoretical designs to fail.In this work,we reveal for the first time the non-trivial impact of hardware imperfections on FH-MIMO JRC and model the impact analytically.We also design new waveforms and correspondingly develop a low-complexity algorithm to jointly estimate the hardware imperfections of unsynchronized receiver.In addition,using low-cost software-defined radios and Commercial Off-The-Shelf(COTS)products,we build the first FH-MIMO JRC experimental platform with simultaneous over-the-air radar and communication validation.Confirmed by simulation and experimental results,the proposed designs achieve high performance for both radar and communications.
文摘In a component-based software development life cycle, selection of preexisting components is an important task. Every component that has to be reused has an associated risk of failure of not meeting the functional and non-functional requirements. A component's failure would lead a developer to look for some other alternative of combinations of COTS, in-house and engineered components among possible candidate combinations. This means design itself can readily change. The very process of design of a software system and component selection seems to be heavily dependent on testing results. Instability of design, further, becomes more severe due to requirements change requests. Therefore, this instability of design has to be essentially mitigated by using proper design and testing approaches, otherwise, it may lead to exorbitantly high testing cost due to the repeated testing of various alternatives. How these three activities: Component-based software design, component selection and component-based software testing are interrelated? What process model is most suited to address this concern? This work explores the above questions and their implication in terms of nature of a process model that can be convincing in case of component-based software development.
基金supported in part by the National Key Research Plan(No.2016YFC0700100)the National Natural Science Foundation of China(Nos.61832010,61332004,and 61572366)
文摘Sensorless sensing using wireless signals has been rapidly conceptualized and developed recently. Among numerous applications of WiFi-based sensing, human presence detection acts as a primary and fundamental function to boost applications in practice. Many complicated approaches have been proposed to achieve high detection accuracy, but they frequently omit various practical constraints such as real-time capability, computation efficiency, sampling rates, deployment efforts, etc. A practical detection system that works in realworld applicati ons is lacki ng. In this paper, we design and implement WiSH, a real-time system for con tactless human detection that is applicable for whole-day usage. WiSH employs lightweight yet effective methods and thus enables detection under practical conditions even on resource-limited devices with low signal sampling rates. We deploy WiSH on commodity desktops and customized tiny no des in different everyday scenarios. The experimental results dem on strate the superior performance of WiSH, which has a detection accuracy of >98% using a sampling rate of 20 Hz with an average detection delay of merely 1.5 s. Thus, we believe WiSH is a promising system for real-world deployment.
文摘The remarkable success of Chimeric Antigen Receptor(CAR-T)cells in B-cell malignancies has not yet translated to solid tumors.Several factors explain this gap.Solid tumors actively exclude and suppress infiltrating lymphocytes through a complex microenvironment.Their surface antigens are often heterogeneous,making it hard to find a target expressed uniformly on all malignant cells.And the current manufacturing paradigm,autologous and ex vivo,remains logistically challenging and expensive.Recent engineering efforts have taken different tacks.One approach aims at off-the-shelf CAR-T cells,using gene editing to eliminate alloreactivity while preserving function.Another seeks to redesign the CAR itself,for instance with logic-gated circuits that sharpen tumor recognition and limit off-tumor toxicity.A third strategy targets the Tumor Microenvironment(TME)directly,either by remodeling it or by using delivery systems that improve T cell infiltration.Meanwhile,in vivo CAR-T generation,which reprograms T cells inside the patient with targeted nanoparticles or viral vectors,could eventually bypass ex vivo manufacturing altogether.These lines of work are gradually converging,and together they point toward a future in which CAR-T therapy might become effective,safe,and accessible for a wider range of cancers.
