Benefiting from strong decoding capabilities,soft-decision decoding has been used to replace hard-decision decoding in various communication systems,and NAND flash memory systems are no exception.However,soft-decision...Benefiting from strong decoding capabilities,soft-decision decoding has been used to replace hard-decision decoding in various communication systems,and NAND flash memory systems are no exception.However,soft-decision decoding relies heavily on accurate soft information.Owing to the incremental step pulse programming(ISPP),program errors(PEs)in multi-level cell(MLC)NAND flash memory have different characteristics compared to other types of errors,which is very difficult to obtain such accurate soft information.Therefore,the characteristics of the log-likelihood ratio(LLR)of PEs are investigated first in this paper.Accordingly,a PE-aware statistical method is proposed to determine the usage of PE mitigation schemes.In order to reduce the PE estimating workload of the controller,an adaptive blind clipping(ABC)scheme is proposed subsequently to approximate the PEs contaminated LLR with different decoding trials.Finally,simulation results demonstrate that(1)the proposed PE-aware statistical method is effective in practice,and(2)ABC scheme is able to provide satisfactory bit error rate(BER)and frame error rate(FER)performance in a penalty of negligible increasing of decoding latency.展开更多
Online programming platforms are popular in programming education.However,there has been no research investigating students’real opinions and expectations of the error feedback mechanisms,leaving educators without a ...Online programming platforms are popular in programming education.However,there has been no research investigating students’real opinions and expectations of the error feedback mechanisms,leaving educators without a solid data foundation when attempting to improve the error feedback mechanisms.This paper makes a survey of 834 students across various programming courses and investigates student perceptions of error feedback mechanisms on online programming platforms.It explores the effectiveness of existing feedback,student satisfaction,and preferences for potential improvements,focusing on automatic error localization and program repair mechanisms.Results reveal a significant portion of students are dissatisfied with current feedback due to its limited informativeness.Students also express a clear demand for stronger feedback mechanisms,such as error localization and repair hints.Nevertheless,they prefer feedback that subtly guides them toward solutions,rather than providing direct and explicit answers,valuing the opportunity to enhance their debugging skills.The findings suggest a need for balanced,educational-focused feedback mechanisms that aid learning while promoting independent problem-solving.展开更多
<strong>Background: </strong>Medication errors are the iceberg of patient safety in hospitals and leading cause of morbidity and mortality among patients. <strong>Objectives:</strong> The study...<strong>Background: </strong>Medication errors are the iceberg of patient safety in hospitals and leading cause of morbidity and mortality among patients. <strong>Objectives:</strong> The study aim was to evaluate the effect of an educational program of medication safety on the knowledge of critical care nurses regarding intravenous medication errors. <strong>Methods Design: </strong>There are one group pretest and posttest designs. <strong>Subject:</strong> A convenient sample of all registered nurses (52) works in Palestine Medical Complex. <strong>Data collection tools:</strong> A self-administered knowledge determination questionnaire consists of both qualitative and quantitative statements to measure level of knowledge, used as data collection tool in pre and post educational sessions, with educational booklet as intervention tool. <strong>Statistical analysis:</strong> Data were analyzed with Statistical Package for the Social Sciences Software Version 18. The results are presented as frequency & percentage as appropriate at alpha level of P < 0.05;inferential statistics were generated. Paired t-test was used to perform the comparisons. <strong>Results:</strong> There was statistically significant difference in the knowledge level for the intensive care unit’s nurses regarding the intravenous medication administration during pre and post education program. Statistical analysis showed that there was a statistically significant between age, educational degree, critical units/wards, years of nursing experience and previous medication administration education program of the nurses and their knowledge during different phases of program intervention.<strong> Conclusion:</strong> Educational program on medication safety improves the knowledge of critical care nurses regarding intravenous medication errors. This study recommends that medication errors should be periodically assessed by improving clinical guidelines of medication administration.展开更多
Software defect prevention is an important way to reduce the defect introduction rate.As the primary cause of software defects,human error can be the key to understanding and preventing software defects.This paper pro...Software defect prevention is an important way to reduce the defect introduction rate.As the primary cause of software defects,human error can be the key to understanding and preventing software defects.This paper proposes a defect prevention approach based on human error mechanisms：DPe HE.The approach includes both knowledge and regulation training in human error prevention.Knowledge training provides programmers with explicit knowledge on why programmers commit errors,what kinds of errors tend to be committed under different circumstances,and how these errors can be prevented.Regulation training further helps programmers to promote the awareness and ability to prevent human errors through practice.The practice is facilitated by a problem solving checklist and a root cause identification checklist.This paper provides a systematic framework that integrates knowledge across disciplines,e.g.,cognitive science,software psychology and software engineering to defend against human errors in software development.Furthermore,we applied this approach in an international company at CMM Level 5 and a software development institution at CMM Level 1 in the Chinese Aviation Industry.The application cases show that the approach is feasible and effective in promoting developers＇ ability to prevent software defects,independent of process maturity levels.展开更多
In this paper, an optimal tracking control scheme is proposed for a class of discrete-time chaotic systems using the approximation-error-based adaptive dynamic programming （ADP） algorithm. Via the system transformat...In this paper, an optimal tracking control scheme is proposed for a class of discrete-time chaotic systems using the approximation-error-based adaptive dynamic programming （ADP） algorithm. Via the system transformation, the optimal tracking problem is transformed into an optimal regulation problem, and then the novel optimal tracking control method is proposed. It is shown that for the iterative ADP algorithm with finite approximation error, the iterative performance index functions can converge to a finite neighborhood of the greatest lower bound of all performance index functions under some convergence conditions. Two examples are given to demonstrate the validity of the proposed optimal tracking control scheme for chaotic systems.展开更多
Efficient solvers for optimization problems are based on linear and semidefinite relaxations that use floating point arithmetic. However, due to the rounding errors, relaxation thus may overestimate, or worst, underes...Efficient solvers for optimization problems are based on linear and semidefinite relaxations that use floating point arithmetic. However, due to the rounding errors, relaxation thus may overestimate, or worst, underestimate the very global optima. The purpose of this article is to introduce an efficient and safe procedure to rigorously bound the global optima of semidefinite program. This work shows how, using interval arithmetic, rigorous error bounds for the optimal value can be computed by carefully post processing the output of a semidefinite programming solver. A lower bound is computed on a semidefinite relaxation of the constraint system and the objective function. Numerical results are presented using the SDPA (SemiDefinite Programming Algorithm), solver to compute the solution of semidefinite programs. This rigorous bound is injected in a branch and bound algorithm to solve the optimisation problem.展开更多
Decoding by alternating direction method of multipliers(ADMM) is a promising linear programming decoder for low-density parity-check(LDPC) codes. In this paper, we propose a two-step scheme to lower the error floor of...Decoding by alternating direction method of multipliers(ADMM) is a promising linear programming decoder for low-density parity-check(LDPC) codes. In this paper, we propose a two-step scheme to lower the error floor of LDPC codes with ADMM penalized decoder.For the undetected errors that cannot be avoided at the decoder side, we modify the code structure slightly to eliminate low-weight code words. For the detected errors induced by small error-prone structures, we propose a post-processing method for the ADMM penalized decoder. Simulation results show that the error floor can be reduced significantly over three illustrated LDPC codes by the proposed two-step scheme.展开更多
The concept of cointegration describes an equilibrium relationship among a set of time-varying variables, and the cointegrated relationship can be represented through an error-correction model (ECM). The error-correct...The concept of cointegration describes an equilibrium relationship among a set of time-varying variables, and the cointegrated relationship can be represented through an error-correction model (ECM). The error-correction variable, which represents the short-run discrepancy from the equilibrium state in a cointegrated system, plays an important role in the ECM. It is natural to ask how the error-correction mechanism works, or equivalently, how the short-run discrepancy affects the development of the cointegrated system? This paper examines the effect or local influence on the error-correction variable in an error-correction model. Following the argument of the second-order approach to local influence suggested by reference [5], we develop a diagnostic statistic to examine the local influence on the estimation of the parameter associated with the error-correction variable in an ECM. An empirical example is presented to illustrate the application of the proposed diagnostic. We find that the short-run discre pancy may have strong influence on the estimation of the parameter associated with the error-correction model. It is the error-correction variable that the short-run discrepancies can be incorporated through the error-correction mechanism.展开更多
目前的勘探方案预期效果评价指标常未能反映物理过程且参数较难确定.此外,勘探方案优化框架中的勘探点布置策略往往依赖位置关系并需事先确定勘探范围.为解决上述问题,以不排水抗剪强度参数为例,提出并采用安全系数的均方根误差折减率期...目前的勘探方案预期效果评价指标常未能反映物理过程且参数较难确定.此外,勘探方案优化框架中的勘探点布置策略往往依赖位置关系并需事先确定勘探范围.为解决上述问题,以不排水抗剪强度参数为例,提出并采用安全系数的均方根误差折减率期望(expected reduction rate of the root mean square error,ERRS)量化因融合参考勘探数据而导致的安全系数评估结果向参考安全系数集中效果的期望提升程度,并将其作为勘探方案预期效果评价的指标.此外,结合该指标和贪心算法构建了以优化勘探位置和数量为目的的勘探方案优化框架.ERRS指标计算过程采用乔列斯基分解中点法和改进贝叶斯更新方法离散参数完全及条件随机场实现,并基于多重二阶响应面代理模型替代确定性空间变异边坡稳定性分析,有效提高指标计算精度和效率.不排水饱和黏土边坡案例显示:提出的ERRS指标能够在无需确定复杂参数的情况下,获得与其他指标接近的评价结果;所构建的勘探方案优化框架能够在不事先确定勘探范围的情况下,得到指定勘探数量下更优的勘探点布置,进而获得更节省成本且预期效果较好的勘探方案.提出的指标和优化框架可为实际边坡工程场地勘探方案评价及优化设计提供参考.展开更多
为了实现复杂型面工件的柔性加工,研制了一套机器人柔性加工系统,完成了具有复杂型面水龙头的自动化磨削抛光过程。设计了具有力控制功能及接触轮在线调整功能的磨削单元,可以实现在线误差实时补偿及自动更换机器人TCP(Tool Center Poin...为了实现复杂型面工件的柔性加工,研制了一套机器人柔性加工系统,完成了具有复杂型面水龙头的自动化磨削抛光过程。设计了具有力控制功能及接触轮在线调整功能的磨削单元,可以实现在线误差实时补偿及自动更换机器人TCP(Tool Center Point);设计了具有力控制功能及轮径在线检测与补偿功能的抛光单元,不仅能够实时补偿机器人系统各种误差,而且当抛光轮半径变化很大时,仍能够保证工件与抛光轮接触;采用机器人离线编程技术,设计了离线编程软件,提高了机器人编程效率及精度;采用三维激光扫描技术,能够自动实现工件校准及在线装卡误差检测与补偿,保证产品加工一致性。该系统技术先进且简单实用,能够满足产品生产要求。展开更多
基金This work was supported by Key Project of Sichuan Province(no.2017SZYZF0002)Marie Curie Fellowship(no.796426).
文摘Benefiting from strong decoding capabilities,soft-decision decoding has been used to replace hard-decision decoding in various communication systems,and NAND flash memory systems are no exception.However,soft-decision decoding relies heavily on accurate soft information.Owing to the incremental step pulse programming(ISPP),program errors(PEs)in multi-level cell(MLC)NAND flash memory have different characteristics compared to other types of errors,which is very difficult to obtain such accurate soft information.Therefore,the characteristics of the log-likelihood ratio(LLR)of PEs are investigated first in this paper.Accordingly,a PE-aware statistical method is proposed to determine the usage of PE mitigation schemes.In order to reduce the PE estimating workload of the controller,an adaptive blind clipping(ABC)scheme is proposed subsequently to approximate the PEs contaminated LLR with different decoding trials.Finally,simulation results demonstrate that(1)the proposed PE-aware statistical method is effective in practice,and(2)ABC scheme is able to provide satisfactory bit error rate(BER)and frame error rate(FER)performance in a penalty of negligible increasing of decoding latency.
基金supported by the National Natural Science Foundation of China under Grant No.92582204,No.62577007,and No.62177003the Fundamental Research Funds for the Central Universities under Grant No.JKF-2025011975129.
文摘Online programming platforms are popular in programming education.However,there has been no research investigating students’real opinions and expectations of the error feedback mechanisms,leaving educators without a solid data foundation when attempting to improve the error feedback mechanisms.This paper makes a survey of 834 students across various programming courses and investigates student perceptions of error feedback mechanisms on online programming platforms.It explores the effectiveness of existing feedback,student satisfaction,and preferences for potential improvements,focusing on automatic error localization and program repair mechanisms.Results reveal a significant portion of students are dissatisfied with current feedback due to its limited informativeness.Students also express a clear demand for stronger feedback mechanisms,such as error localization and repair hints.Nevertheless,they prefer feedback that subtly guides them toward solutions,rather than providing direct and explicit answers,valuing the opportunity to enhance their debugging skills.The findings suggest a need for balanced,educational-focused feedback mechanisms that aid learning while promoting independent problem-solving.
文摘<strong>Background: </strong>Medication errors are the iceberg of patient safety in hospitals and leading cause of morbidity and mortality among patients. <strong>Objectives:</strong> The study aim was to evaluate the effect of an educational program of medication safety on the knowledge of critical care nurses regarding intravenous medication errors. <strong>Methods Design: </strong>There are one group pretest and posttest designs. <strong>Subject:</strong> A convenient sample of all registered nurses (52) works in Palestine Medical Complex. <strong>Data collection tools:</strong> A self-administered knowledge determination questionnaire consists of both qualitative and quantitative statements to measure level of knowledge, used as data collection tool in pre and post educational sessions, with educational booklet as intervention tool. <strong>Statistical analysis:</strong> Data were analyzed with Statistical Package for the Social Sciences Software Version 18. The results are presented as frequency & percentage as appropriate at alpha level of P < 0.05;inferential statistics were generated. Paired t-test was used to perform the comparisons. <strong>Results:</strong> There was statistically significant difference in the knowledge level for the intensive care unit’s nurses regarding the intravenous medication administration during pre and post education program. Statistical analysis showed that there was a statistically significant between age, educational degree, critical units/wards, years of nursing experience and previous medication administration education program of the nurses and their knowledge during different phases of program intervention.<strong> Conclusion:</strong> Educational program on medication safety improves the knowledge of critical care nurses regarding intravenous medication errors. This study recommends that medication errors should be periodically assessed by improving clinical guidelines of medication administration.
文摘Software defect prevention is an important way to reduce the defect introduction rate.As the primary cause of software defects,human error can be the key to understanding and preventing software defects.This paper proposes a defect prevention approach based on human error mechanisms：DPe HE.The approach includes both knowledge and regulation training in human error prevention.Knowledge training provides programmers with explicit knowledge on why programmers commit errors,what kinds of errors tend to be committed under different circumstances,and how these errors can be prevented.Regulation training further helps programmers to promote the awareness and ability to prevent human errors through practice.The practice is facilitated by a problem solving checklist and a root cause identification checklist.This paper provides a systematic framework that integrates knowledge across disciplines,e.g.,cognitive science,software psychology and software engineering to defend against human errors in software development.Furthermore,we applied this approach in an international company at CMM Level 5 and a software development institution at CMM Level 1 in the Chinese Aviation Industry.The application cases show that the approach is feasible and effective in promoting developers＇ ability to prevent software defects,independent of process maturity levels.
基金supported by the Open Research Project from SKLMCCS (Grant No. 20120106)the Fundamental Research Funds for the Central Universities of China (Grant No. FRF-TP-13-018A)+1 种基金the Postdoctoral Science Foundation of China (Grant No. 2013M530527)the National Natural Science Foundation of China (Grant Nos. 61304079, 61125306, and 61034002)
文摘In this paper, an optimal tracking control scheme is proposed for a class of discrete-time chaotic systems using the approximation-error-based adaptive dynamic programming （ADP） algorithm. Via the system transformation, the optimal tracking problem is transformed into an optimal regulation problem, and then the novel optimal tracking control method is proposed. It is shown that for the iterative ADP algorithm with finite approximation error, the iterative performance index functions can converge to a finite neighborhood of the greatest lower bound of all performance index functions under some convergence conditions. Two examples are given to demonstrate the validity of the proposed optimal tracking control scheme for chaotic systems.
文摘Efficient solvers for optimization problems are based on linear and semidefinite relaxations that use floating point arithmetic. However, due to the rounding errors, relaxation thus may overestimate, or worst, underestimate the very global optima. The purpose of this article is to introduce an efficient and safe procedure to rigorously bound the global optima of semidefinite program. This work shows how, using interval arithmetic, rigorous error bounds for the optimal value can be computed by carefully post processing the output of a semidefinite programming solver. A lower bound is computed on a semidefinite relaxation of the constraint system and the objective function. Numerical results are presented using the SDPA (SemiDefinite Programming Algorithm), solver to compute the solution of semidefinite programs. This rigorous bound is injected in a branch and bound algorithm to solve the optimisation problem.
基金supported in part by National Nature Science Foundation of China under Grant No.61471286,No.61271004the Fundamental Research Funds for the Central Universitiesthe open research fund of Key Laboratory of Information Coding and Transmission,Southwest Jiaotong University(No.2010-03)
文摘Decoding by alternating direction method of multipliers(ADMM) is a promising linear programming decoder for low-density parity-check(LDPC) codes. In this paper, we propose a two-step scheme to lower the error floor of LDPC codes with ADMM penalized decoder.For the undetected errors that cannot be avoided at the decoder side, we modify the code structure slightly to eliminate low-weight code words. For the detected errors induced by small error-prone structures, we propose a post-processing method for the ADMM penalized decoder. Simulation results show that the error floor can be reduced significantly over three illustrated LDPC codes by the proposed two-step scheme.
基金This project was supported by the National Natural Science Foundation (No. 79800012 and No. 79400014).
文摘The concept of cointegration describes an equilibrium relationship among a set of time-varying variables, and the cointegrated relationship can be represented through an error-correction model (ECM). The error-correction variable, which represents the short-run discrepancy from the equilibrium state in a cointegrated system, plays an important role in the ECM. It is natural to ask how the error-correction mechanism works, or equivalently, how the short-run discrepancy affects the development of the cointegrated system? This paper examines the effect or local influence on the error-correction variable in an error-correction model. Following the argument of the second-order approach to local influence suggested by reference [5], we develop a diagnostic statistic to examine the local influence on the estimation of the parameter associated with the error-correction variable in an ECM. An empirical example is presented to illustrate the application of the proposed diagnostic. We find that the short-run discre pancy may have strong influence on the estimation of the parameter associated with the error-correction model. It is the error-correction variable that the short-run discrepancies can be incorporated through the error-correction mechanism.
文摘目前的勘探方案预期效果评价指标常未能反映物理过程且参数较难确定.此外,勘探方案优化框架中的勘探点布置策略往往依赖位置关系并需事先确定勘探范围.为解决上述问题,以不排水抗剪强度参数为例,提出并采用安全系数的均方根误差折减率期望(expected reduction rate of the root mean square error,ERRS)量化因融合参考勘探数据而导致的安全系数评估结果向参考安全系数集中效果的期望提升程度,并将其作为勘探方案预期效果评价的指标.此外,结合该指标和贪心算法构建了以优化勘探位置和数量为目的的勘探方案优化框架.ERRS指标计算过程采用乔列斯基分解中点法和改进贝叶斯更新方法离散参数完全及条件随机场实现,并基于多重二阶响应面代理模型替代确定性空间变异边坡稳定性分析,有效提高指标计算精度和效率.不排水饱和黏土边坡案例显示:提出的ERRS指标能够在无需确定复杂参数的情况下,获得与其他指标接近的评价结果;所构建的勘探方案优化框架能够在不事先确定勘探范围的情况下,得到指定勘探数量下更优的勘探点布置,进而获得更节省成本且预期效果较好的勘探方案.提出的指标和优化框架可为实际边坡工程场地勘探方案评价及优化设计提供参考.
文摘为了实现复杂型面工件的柔性加工,研制了一套机器人柔性加工系统,完成了具有复杂型面水龙头的自动化磨削抛光过程。设计了具有力控制功能及接触轮在线调整功能的磨削单元,可以实现在线误差实时补偿及自动更换机器人TCP(Tool Center Point);设计了具有力控制功能及轮径在线检测与补偿功能的抛光单元,不仅能够实时补偿机器人系统各种误差,而且当抛光轮半径变化很大时,仍能够保证工件与抛光轮接触;采用机器人离线编程技术,设计了离线编程软件,提高了机器人编程效率及精度;采用三维激光扫描技术,能够自动实现工件校准及在线装卡误差检测与补偿,保证产品加工一致性。该系统技术先进且简单实用,能够满足产品生产要求。
