With the continuous improvement of national scientific and technological level, various control systems derived therefrom are also widely used. Distributed Control System (DCS) control system is a typical example and ...With the continuous improvement of national scientific and technological level, various control systems derived therefrom are also widely used. Distributed Control System (DCS) control system is a typical example and plays a very important role in the production of petrochemical industry. This paper introduces the related concepts of DCS system and its application status in petrochemical enterprises. Aiming at the existing problems, the paper presents an optimization plan for the transformation, and implements the transformation to realize the localization of the control system. After the transformation, the system is stable and reliable, meeting the design expectation of the project and achieving the goal of localization of the control system. Finally, the development trend of DCS is prospected to provide reference for the industry.展开更多
A high speed LIGBT with localized lifetime control by using high dose and low en ergy helium implantation(LC-LIGBT) is proposed.Compared with conventional LIGB Ts,particle irradiation results show that trade-off relat...A high speed LIGBT with localized lifetime control by using high dose and low en ergy helium implantation(LC-LIGBT) is proposed.Compared with conventional LIGB Ts,particle irradiation results show that trade-off relationship between turn- off time and forward voltage drop is improved.At the same time,the forward volta ge drop and turn-off time of such device are researched,when localized lifetime control region place near the p+-n junction,even in p+ anode.The results s how for the first time,helium ions,which stop in the p+ anode,also contribute to the forward voltage drop increasing and turn-off time reducing.展开更多
The attitude control problem of a spacecraft underactuated by two single-gimbal control moment gyros （SGCMGs） is investigated. Small-time local controllability （STLC） of the attitude dynamics of the spacecraft-SGC...The attitude control problem of a spacecraft underactuated by two single-gimbal control moment gyros （SGCMGs） is investigated. Small-time local controllability （STLC） of the attitude dynamics of the spacecraft-SGCMGs system is analyzed via nonlinear controllability theory. The conditions that guarantee STLC of the spacecraft attitude by two non-coaxial SGCMGs are obtained with the momentum of the SGCMGs as inputs, implying that the spacecraft attitude is STLC when the total angular momentum of the whole system is zero. Moreover, our results indi- cate that under the zero-momentum restriction, full attitude stabilization is possible for a spacecraft using two non-coaxial SGCMGs. For the case of two coaxial SGCMGs, the STLC property of the spacecraft cannot be determined. In this case, an improvement to the previous full attitude stabilizing control law, which requires zero-momentum presumption, is proposed to account for the singu- larity of SGCMGs and enhance the steady state performance. Numerical simulation results demonstrate the effectiveness and advantages of the new control law.展开更多
Background:To protect neurological tissues,underdosing occurs in most cases of T4 nasopharyngeal carcinoma(NPC) with intracranial extension.In this study,we aimed to evaluate the effect of dosimetric inadequacy on loc...Background:To protect neurological tissues,underdosing occurs in most cases of T4 nasopharyngeal carcinoma(NPC) with intracranial extension.In this study,we aimed to evaluate the effect of dosimetric inadequacy on local control and late neurological toxicities for patients treated with intensity-modulated radiotherapy(IMRT) plus chemotherapy.Methods:We prospectively enrolled patients who had non-metastaticT4 NPC with intracranial extension treated between January 2009 and November 2013.The prescribed dose was 66.0-70.4 Gy to the primary planning target volume(primary gross tumor volume [GTVp;i.e.,the nasopharyngeal tumor] +5.0 mm).Dose-volume histogram parameters were calculated,including minimum point dose(D_(min)) and dose to 95% of the target volume(D95).All patients received chemotherapy with the cisplatin,5-fluorouracil,and docetaxel regimen.Survivals were estimated using the Kaplan-Meier method and compared using the log-rank test.Results:In total,41 patients were enrolled.The local partial response rate was 87.8% after induction chemotherapy.With a median follow-up of 51 months,7 patients experienced failure in the nasopharynx;the 3-year local failure-free survival and overall survival rates of the 41 patients were 87.4% and 90.2%,respectively.The actual mean D_(min) to the GTVp was 55.2 Gy(range 48.3-67.3 Gy),and D95 was 61.6 Gy(range 52.6-69.0 Gy).All doses received by neurological organs remained well within their dose constraints.No patients developed temporal lobe necrosis or other neurological dysfunctions.Conclusions:With relative underdosed IMRT plus effective chemotherapy,the patients achieved satisfactory local control with few late toxicities of the central nervous system.Determining the acceptable extent of dosimetric inadequacy requires further exploration.展开更多
Objective： To study the effect of tumor infiltrating lymphocytes at cancer nest on local control of rectal cancer after preoperative radiotherapy. Methods： From Jan. 1999 to Oct. 2007, a total of 107 patients with r...Objective： To study the effect of tumor infiltrating lymphocytes at cancer nest on local control of rectal cancer after preoperative radiotherapy. Methods： From Jan. 1999 to Oct. 2007, a total of 107 patients with rectal cancer were reviewed. They were treated by preoperative radiotherapy, 30 Gy/10 fractions/12 days. Two weeks later, the patient underwent a surgical operation. Their pathological samples were kept in our hospital before and after radiotherapy. Lymphocyte infiltration （LI） degree, pathologic degradation and fibrosis degree after radiotherapy in paraffin section were evaluated under microscope. Results： After followed-up of 21 months （2-86 months）, a total of 107 patients were reviewed. Univariate analysis showed that lymphocyte infiltration （LI）, fibrosis and pathologic changes after radiotherapy were significant factors on local control. Logistic regression analysis showed that LI after radiotherapy was a significant effect factor on local control. Conclusion： LI, fibrosis and pathologic degradation after radiotherapy are significant for local control of rectal cancer after preoperative radiotherapy. LI after radiotherapy was a significantly prognostic index for local control of rectal cancer after preoperative radiotherapy.展开更多
Because model switching system is a typical form of Takagi-Sugeno（T-S） model which is an universal approximator of continuous nonlinear systems, we describe the model switching system as mixed logical dynamical （ML...Because model switching system is a typical form of Takagi-Sugeno（T-S） model which is an universal approximator of continuous nonlinear systems, we describe the model switching system as mixed logical dynamical （MLD） system and use it in model predictive control （MPC） in this paper. Considering that each local model is only valid in each local region,we add local constraints to local models. The stability of proposed multi-model predictive control （MMPC） algorithm is analyzed, and the performance of MMPC is also demonstrated on an inulti-multi-output（MIMO） simulated pH neutralization process.展开更多
We consider first order quasilinear hyperbolic systems with vertical characteristics. It was shown in [4] that such systems can be exactly controllable with the help of internal controls applied to the equations corr...We consider first order quasilinear hyperbolic systems with vertical characteristics. It was shown in [4] that such systems can be exactly controllable with the help of internal controls applied to the equations corresponding to zero eigenvalues. However, it is possible that, for physical or engineering reasons, we can not put any control on the equations corresponding to zero eigenvalues. In this paper, we will establish the exact controllability only by means of physically meaningfnl internal controls applied to the equations corresponding to non-zero eigenvalues. We also show the exact controllability for a very simplified model by means of switching controls.展开更多
In this paper, a decentralized proportional-derivative （PD） controller design for non-uniform motion of a Hamiltonian hybrid system is considered. A Hamiltonian hybrid system with the capability of producing a non-u...In this paper, a decentralized proportional-derivative （PD） controller design for non-uniform motion of a Hamiltonian hybrid system is considered. A Hamiltonian hybrid system with the capability of producing a non-uniform motion is developed. The structural properties of the system are investigated by means of the theory of Hamiltonian systems. A relationship between the parameters of the system and the parameters of the proposed decentralized PD controller is shown to ensure local stability and tracking performance. Simulation results are included to show the obtained non-uniform motion.展开更多
This research presents an improved real-time face recognition system at a low<span><span><span style="font-family:" color:red;"=""> </span></span></span><...This research presents an improved real-time face recognition system at a low<span><span><span style="font-family:" color:red;"=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">resolution of 15 pixels with pose and emotion and resolution variations. We have designed our datasets named LRD200 and LRD100, which have been used for training and classification. The face detection part uses the Viola-Jones algorithm, and the face recognition part receives the face image from the face detection part to process it using the Local Binary Pattern Histogram (LBPH) algorithm with preprocessing using contrast limited adaptive histogram equalization (CLAHE) and face alignment. The face database in this system can be updated via our custom-built standalone android app and automatic restarting of the training and recognition process with an updated database. Using our proposed algorithm, a real-time face recognition accuracy of 78.40% at 15</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">px and 98.05% at 45</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">px have been achieved using the LRD200 database containing 200 images per person. With 100 images per person in the database (LRD100) the achieved accuracies are 60.60% at 15</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">px and 95% at 45</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">px respectively. A facial deflection of about 30</span></span></span><span><span><span><span><span style="color:#4F4F4F;font-family:-apple-system, " font-size:16px;white-space:normal;background-color:#ffffff;"="">°</span></span><span> on either side from the front face showed an average face recognition precision of 72.25%-81.85%. This face recognition system can be employed for law enforcement purposes, where the surveillance camera captures a low-resolution image because of the distance of a person from the camera. It can also be used as a surveillance system in airports, bus stations, etc., to reduce the risk of possible criminal threats.</span></span></span></span>展开更多
In this paper, a formation control algorithm and an obstade avoidance control algorithm for mobile robots are developed based on a relative motion sensory system such as a pan/tilt camera vision system, without the ne...In this paper, a formation control algorithm and an obstade avoidance control algorithm for mobile robots are developed based on a relative motion sensory system such as a pan/tilt camera vision system, without the need for global sensing and between robots. This is achieved by employing the velocity variation, instead of actual velocities, as the control inputs. Simulation and experimental results have demonstrated the effectiveness of the proposed control methods.展开更多
This paper describes a cooperative decentralized architecture for reactive real-time route guidance. The architecture is cooperative in the sense that it allows adjacent local controllers to exchange information regar...This paper describes a cooperative decentralized architecture for reactive real-time route guidance. The architecture is cooperative in the sense that it allows adjacent local controllers to exchange information regarding the traffic conditions in their territories. A set of local decision rules and associated heuristic functions to support the cooperative architecture are specified. A protocol governing the knowledge exchange among local adjacent controllers is developed. A simulation-assignment modeling framework is used for assessing the effectiveness of this cooperative architecture under various levels of controller knowledge and network traffic congestion. The cooperative decentralized system is tested under various scenarios of knowledge and cooperation and network traffic demand levels. The cooperative system is compared against the shortest path algorithm as a benchmark.展开更多
在医疗行业数字化转型加速的背景下,医院信息系统(Hospital Information System,HIS)面临日益严峻的网络安全挑战。文章针对医院内外网边界防护的特殊需求,以等保2.0三级要求和HIPAA安全规则为基准,提出基于网闸技术的动态安全隔离方案...在医疗行业数字化转型加速的背景下,医院信息系统(Hospital Information System,HIS)面临日益严峻的网络安全挑战。文章针对医院内外网边界防护的特殊需求,以等保2.0三级要求和HIPAA安全规则为基准,提出基于网闸技术的动态安全隔离方案。通过分析相关医院网络环境中的案例,发现传统防火墙在防范勒索软件横向传播、医疗设备固件漏洞利用等高级威胁时存在协议解析盲区。网闸作为网络安全的重要防线,通过独特的隔离机制与数据摆渡技术,在涉密保护、企业防护等领域具有不可替代性。未来,随着攻击手段的演进,网闸需持续优化性能并拓展应用场景,以应对更复杂的安全挑战。展开更多
文摘With the continuous improvement of national scientific and technological level, various control systems derived therefrom are also widely used. Distributed Control System (DCS) control system is a typical example and plays a very important role in the production of petrochemical industry. This paper introduces the related concepts of DCS system and its application status in petrochemical enterprises. Aiming at the existing problems, the paper presents an optimization plan for the transformation, and implements the transformation to realize the localization of the control system. After the transformation, the system is stable and reliable, meeting the design expectation of the project and achieving the goal of localization of the control system. Finally, the development trend of DCS is prospected to provide reference for the industry.
文摘A high speed LIGBT with localized lifetime control by using high dose and low en ergy helium implantation(LC-LIGBT) is proposed.Compared with conventional LIGB Ts,particle irradiation results show that trade-off relationship between turn- off time and forward voltage drop is improved.At the same time,the forward volta ge drop and turn-off time of such device are researched,when localized lifetime control region place near the p+-n junction,even in p+ anode.The results s how for the first time,helium ions,which stop in the p+ anode,also contribute to the forward voltage drop increasing and turn-off time reducing.
基金supported by the National Natural Science Foundation of China (No.10902003)
文摘The attitude control problem of a spacecraft underactuated by two single-gimbal control moment gyros （SGCMGs） is investigated. Small-time local controllability （STLC） of the attitude dynamics of the spacecraft-SGCMGs system is analyzed via nonlinear controllability theory. The conditions that guarantee STLC of the spacecraft attitude by two non-coaxial SGCMGs are obtained with the momentum of the SGCMGs as inputs, implying that the spacecraft attitude is STLC when the total angular momentum of the whole system is zero. Moreover, our results indi- cate that under the zero-momentum restriction, full attitude stabilization is possible for a spacecraft using two non-coaxial SGCMGs. For the case of two coaxial SGCMGs, the STLC property of the spacecraft cannot be determined. In this case, an improvement to the previous full attitude stabilizing control law, which requires zero-momentum presumption, is proposed to account for the singu- larity of SGCMGs and enhance the steady state performance. Numerical simulation results demonstrate the effectiveness and advantages of the new control law.
基金support of the Department of Radiation Oncology,Fudan University Shanghai Cancer Centersupported by Science and Technology Commission of Shanghai Municipality(14411962400)
文摘Background:To protect neurological tissues,underdosing occurs in most cases of T4 nasopharyngeal carcinoma(NPC) with intracranial extension.In this study,we aimed to evaluate the effect of dosimetric inadequacy on local control and late neurological toxicities for patients treated with intensity-modulated radiotherapy(IMRT) plus chemotherapy.Methods:We prospectively enrolled patients who had non-metastaticT4 NPC with intracranial extension treated between January 2009 and November 2013.The prescribed dose was 66.0-70.4 Gy to the primary planning target volume(primary gross tumor volume [GTVp;i.e.,the nasopharyngeal tumor] +5.0 mm).Dose-volume histogram parameters were calculated,including minimum point dose(D_(min)) and dose to 95% of the target volume(D95).All patients received chemotherapy with the cisplatin,5-fluorouracil,and docetaxel regimen.Survivals were estimated using the Kaplan-Meier method and compared using the log-rank test.Results:In total,41 patients were enrolled.The local partial response rate was 87.8% after induction chemotherapy.With a median follow-up of 51 months,7 patients experienced failure in the nasopharynx;the 3-year local failure-free survival and overall survival rates of the 41 patients were 87.4% and 90.2%,respectively.The actual mean D_(min) to the GTVp was 55.2 Gy(range 48.3-67.3 Gy),and D95 was 61.6 Gy(range 52.6-69.0 Gy).All doses received by neurological organs remained well within their dose constraints.No patients developed temporal lobe necrosis or other neurological dysfunctions.Conclusions:With relative underdosed IMRT plus effective chemotherapy,the patients achieved satisfactory local control with few late toxicities of the central nervous system.Determining the acceptable extent of dosimetric inadequacy requires further exploration.
文摘Objective： To study the effect of tumor infiltrating lymphocytes at cancer nest on local control of rectal cancer after preoperative radiotherapy. Methods： From Jan. 1999 to Oct. 2007, a total of 107 patients with rectal cancer were reviewed. They were treated by preoperative radiotherapy, 30 Gy/10 fractions/12 days. Two weeks later, the patient underwent a surgical operation. Their pathological samples were kept in our hospital before and after radiotherapy. Lymphocyte infiltration （LI） degree, pathologic degradation and fibrosis degree after radiotherapy in paraffin section were evaluated under microscope. Results： After followed-up of 21 months （2-86 months）, a total of 107 patients were reviewed. Univariate analysis showed that lymphocyte infiltration （LI）, fibrosis and pathologic changes after radiotherapy were significant factors on local control. Logistic regression analysis showed that LI after radiotherapy was a significant effect factor on local control. Conclusion： LI, fibrosis and pathologic degradation after radiotherapy are significant for local control of rectal cancer after preoperative radiotherapy. LI after radiotherapy was a significantly prognostic index for local control of rectal cancer after preoperative radiotherapy.
文摘Because model switching system is a typical form of Takagi-Sugeno（T-S） model which is an universal approximator of continuous nonlinear systems, we describe the model switching system as mixed logical dynamical （MLD） system and use it in model predictive control （MPC） in this paper. Considering that each local model is only valid in each local region,we add local constraints to local models. The stability of proposed multi-model predictive control （MMPC） algorithm is analyzed, and the performance of MMPC is also demonstrated on an inulti-multi-output（MIMO） simulated pH neutralization process.
文摘We consider first order quasilinear hyperbolic systems with vertical characteristics. It was shown in [4] that such systems can be exactly controllable with the help of internal controls applied to the equations corresponding to zero eigenvalues. However, it is possible that, for physical or engineering reasons, we can not put any control on the equations corresponding to zero eigenvalues. In this paper, we will establish the exact controllability only by means of physically meaningfnl internal controls applied to the equations corresponding to non-zero eigenvalues. We also show the exact controllability for a very simplified model by means of switching controls.
文摘In this paper, a decentralized proportional-derivative （PD） controller design for non-uniform motion of a Hamiltonian hybrid system is considered. A Hamiltonian hybrid system with the capability of producing a non-uniform motion is developed. The structural properties of the system are investigated by means of the theory of Hamiltonian systems. A relationship between the parameters of the system and the parameters of the proposed decentralized PD controller is shown to ensure local stability and tracking performance. Simulation results are included to show the obtained non-uniform motion.
文摘This research presents an improved real-time face recognition system at a low<span><span><span style="font-family:" color:red;"=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">resolution of 15 pixels with pose and emotion and resolution variations. We have designed our datasets named LRD200 and LRD100, which have been used for training and classification. The face detection part uses the Viola-Jones algorithm, and the face recognition part receives the face image from the face detection part to process it using the Local Binary Pattern Histogram (LBPH) algorithm with preprocessing using contrast limited adaptive histogram equalization (CLAHE) and face alignment. The face database in this system can be updated via our custom-built standalone android app and automatic restarting of the training and recognition process with an updated database. Using our proposed algorithm, a real-time face recognition accuracy of 78.40% at 15</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">px and 98.05% at 45</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">px have been achieved using the LRD200 database containing 200 images per person. With 100 images per person in the database (LRD100) the achieved accuracies are 60.60% at 15</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">px and 95% at 45</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">px respectively. A facial deflection of about 30</span></span></span><span><span><span><span><span style="color:#4F4F4F;font-family:-apple-system, " font-size:16px;white-space:normal;background-color:#ffffff;"="">°</span></span><span> on either side from the front face showed an average face recognition precision of 72.25%-81.85%. This face recognition system can be employed for law enforcement purposes, where the surveillance camera captures a low-resolution image because of the distance of a person from the camera. It can also be used as a surveillance system in airports, bus stations, etc., to reduce the risk of possible criminal threats.</span></span></span></span>
文摘In this paper, a formation control algorithm and an obstade avoidance control algorithm for mobile robots are developed based on a relative motion sensory system such as a pan/tilt camera vision system, without the need for global sensing and between robots. This is achieved by employing the velocity variation, instead of actual velocities, as the control inputs. Simulation and experimental results have demonstrated the effectiveness of the proposed control methods.
文摘This paper describes a cooperative decentralized architecture for reactive real-time route guidance. The architecture is cooperative in the sense that it allows adjacent local controllers to exchange information regarding the traffic conditions in their territories. A set of local decision rules and associated heuristic functions to support the cooperative architecture are specified. A protocol governing the knowledge exchange among local adjacent controllers is developed. A simulation-assignment modeling framework is used for assessing the effectiveness of this cooperative architecture under various levels of controller knowledge and network traffic congestion. The cooperative decentralized system is tested under various scenarios of knowledge and cooperation and network traffic demand levels. The cooperative system is compared against the shortest path algorithm as a benchmark.
文摘在医疗行业数字化转型加速的背景下,医院信息系统(Hospital Information System,HIS)面临日益严峻的网络安全挑战。文章针对医院内外网边界防护的特殊需求,以等保2.0三级要求和HIPAA安全规则为基准,提出基于网闸技术的动态安全隔离方案。通过分析相关医院网络环境中的案例,发现传统防火墙在防范勒索软件横向传播、医疗设备固件漏洞利用等高级威胁时存在协议解析盲区。网闸作为网络安全的重要防线,通过独特的隔离机制与数据摆渡技术,在涉密保护、企业防护等领域具有不可替代性。未来,随着攻击手段的演进,网闸需持续优化性能并拓展应用场景,以应对更复杂的安全挑战。
