Timing is everything: using fluidics to understand the role of temporal dynamics in cellular systems

In biology, it is not only the magnitude of a chemical stimulus that determines cellular response; it is becoming increasingly clear that the timing of the stimulus is vastly important as well. Currently there is a paucity of data regarding cell behavior under dynamic stimulation conditions that are representative of what occurs in vivo. This is, at least in part, attributed to the lack of appropriate tools for generating time-varying stimulatory signals in highly diverse patterns. Fluidics on the macro and micro scale has provided a practical platform for dynamically stimulating cells in a highly controllable manner at physiological and supra-physiological time scales (seconds to a few hours). These fluidic systems have contributed substantially to our understanding of how cells process and react to dynamic stimulatory environments; while these setups provide the means to analyze and manipulate cellular behavior in these types of environments on the single-cell level and on a high-throughput level, improvements can be made to these platforms to enhance their utility for high-impact biological investigations of temporal dynamics.     

Human and organizational factors in computer and information security: Pathways to vulnerabilities

The purpose of this study was to identify and describe how human and organizational factors may be related to technical computer and information security (CIS) vulnerabilities. A qualitative study of CIS experts was performed, which consisted of 2, 5-member focus groups sessions. The participants in the focus groups each produced a causal network analysis of human and organizational factors pathways to types of CIS vulnerabilities. Findings suggested that human and organizational factors play a significant role in the development of CIS vulnerabilities and emphasized the relationship complexities among human and organizational factors. The factors were categorized into 9 areas: external influences, human error, management, organization, performance and resource management, policy issues, technology, and training. Security practitioners and management should be aware of the multifarious roles of human and organizational factors and CIS vulnerabilities and that CIS vulnerabilities are not the sole result of a technological problem or programming mistake. The design and management of CIS systems need an integrative, multi-layered approach to improve CIS performance (suggestions for analysis provided).     

基于反馈约束的SRAM接口时序分析方法

FPGA验证作为保证FPGA产品功能和可靠性的重要手段已经备受关注。对接口芯片时序的验证通常通过布局布线后仿真来进行,但布局布线后仿真需要耗费大量的时间。本文介绍了一种基于反馈的SRAM接口时序验证的方法,将FPGA输入输出连接成一个回路,验证结果表明,与动态仿真验证相比,该种静态时序验证方法可以较早、快速、精确定位FPGA接口时序设计存在的问题。缩短了验证时间,提高了验证效率、准确性和覆盖率。     

用MAXPLUSII进行静态时序分析

本文阐述了HDL设计中后端时序分析的一些概念，重点介绍了使用MAXPLUSII的静态时序分析工具TIMING ANALYZER对设计进行仿真分析的方法。     

Money is not everything: A typology of crowdfunding project creators

While studies focus on how crowdfunding promotes the launch of innovative products or services through two-sided (creator-investor) platforms and digital tools, knowledge on the creator-side motivation is limited. To address this knowledge gap, our study identifies four types of crowdfunding project creators—social entrepreneur, fund seeker, indie producer, and daring dreamer—based on four motivations—achievement, monetary need, prosociality, and relationship building. We also examine how crowdfunding projects’ characteristics differ by the creator type and which characteristics are critical for enhancing projects’ performance. The study extends crowdfunding literature by deepening knowledge of creator-side motivation and contributes to crowdfunding practices by suggesting platform operators ways to attract and promote different types of project creators.     

基于北斗/GPS的网络授时系统设计

针对电脑主机多采用BIOS内时钟而导致系统时间不精确的问题,提出一种基于北斗/GPS芯片的网络授时系统设计;该系统采用可编程逻辑器件(FPGA)作为主控芯片,接收北斗/GPS双模芯片提供的UTC时间码流,解码并通过网口发送到PC机上作为精准时间;同时多个设备间相互连接,实现多设备之间的数据传输,增强系统的稳定性和可靠性,传输速率可达100 Mbps;实验证明:北斗/GPS接收信号稳定,传输的时间信息准确,北斗/GPS所解时间信息误差不超过80 ns,设备与PC机100 Mbps传输速率误差在1~2 ms,系统稳定、可靠。     

Quantitative relationship between time margin and human reliability

Operator reliability in complex systems is influenced by various performance shaping factors (PSFs). Time is a particularly important PSF; however, empirical studies of human reliability analysis (HRA) are rarely focused on modeling the effect of time PSF on human error probability (HEP). This study contributes to HRA literature by investigating the empirical relationship between time margin and HEP. Time margin is defined as the difference between the time available to complete a task and the time required to successfully complete the task, divided by the required time. We investigate and compare two models (logistic and linear) to explain HEP based on time margin. The empirical HEP data for model testing were extracted from a microworld simulator (Study 1) and a full-scope simulator (Study 2) in two existing studies relevant to procedural tasks in nuclear power plants. For Study 1, both models exhibited an acceptable, equivalent explanatory power; for Study 2, although both models exhibited an acceptable explanatory ability, the logistic model explained more variance in HEP. Our findings indicate the potential of the logistic model in explaining and predicting HEP based on time margin in time-critical tasks.     

通过抖动建模和分解计算高速计算机系统的误码率

随着计算机速度的显著提高,定时抖动已经成为影响高速计算机性能的基本因素,文章全面介绍了如何根据抖动中的具体参数进行抖动可视化和抖动建模,进而进行抖动分解,运用统计学的方法,将高速计算机系统中的抖动进行时域和频域的分析,通过计算抖动来估算系统的误码率。最后对随机抖动和确定性抖动分量分离给出了一种实际可行的抖动分解和测试方法。     

基于PERT技术的人员调度研究

人员成本占软件项目总成本的大部分,但是现有的Pert技术未能体现人员计划管理这重要的一环,不合理的活动指派时间可能导致人员闲置或者项目延迟.本文提出一种解决方法,基于Pert技术,结合人员闲置、项目延迟和缓冲区计算活动负责人的指派时间,以此指导项目管理,可有效减少总开销.     

虚拟环境中人体因素问题的研究进展

虚拟现实技术目前在各个领域中得到了广泛的应用。该文根据国内外相关的文献资料,将虚拟环境中人体因素问题分为两个方面：一是虚拟系统的时间延时对操作者完成目标捕获与操作、用手完成的虚拟操作以及目标搜索与识别等任务时的影响,同时分析了导致系统时间延时的因素;二是长时间处于虚拟环境中的副作用,如视觉问题、失定向与恶心等,并归纳了系统、使用者以及任务的特性对副作用的影响。在此基础上,阐述具体的解决对策。最后,提出几点看法以供讨论。     

The influence of temperament style on a student’s choice of and performance in a computer programming course

This study is an attempt to determine whether it is necessary to include temperament style when compiling an instrument to predict a student’s chances of success in a computer programming course. Temperament style is seen as the combination of qualities which constitute the natural disposition of an individual and which affect actions, thinking and emotions. The DISC model, as adapted by Boyd [Boyd, C. F. (1994). Different children, different needs: the art of adjustable parenting. Oregon: Questar Publishers Inc.], views people as behaving along two orthogonal dimensions: the speed at which a person moves through life, and his/her general focus when doing things, i.e. on people or on tasks. This study proved that both of these dimensions have an influence on the performance of students in a computer programming course while one of them also has an influence on a student’s choice to pursue a programming course.     

Understanding challenges in the front lines of home health care: A human-systems approach

A human-systems perspective is a fruitful approach to understanding home health care because it emphasizes major individual components of the system – persons, equipment/technology, tasks, and environments – as well as the interaction between these components. The goal of this research was to apply a human-system perspective to consider the capabilities and limitations of the persons, in relation to the demands of the tasks and equipment/technology in home health care. Identification of challenges and mismatches between the person(s) capabilities and the demands of providing care provide guidance for human factors interventions. A qualitative study was conducted with 8 home health Certified Nursing Assistants and 8 home health Registered Nurses interviewed about challenges they encounter in their jobs. A systematic categorization of the challenges the care providers reported was conducted and human factors recommendations were proposed in response, to improve home health. The challenges inform a human-systems model of home health care.     

Visualizing disaster attitudes resulting from terrorist activities

The purpose of this study was to analyze people’s attitudes to disasters by investigating how people feel, behave and think during disasters. We focused on disasters induced by humans, such as terrorist attacks. Two types of textual information were collected – from Internet blogs and from research papers. The analysis enabled forecasting of attitudes for the design of proactive disaster advisory scheme. Text was analyzed using a text mining tool, Leximancer. The outcome of this analysis revealed core themes and concepts in the text concerning people’s attitudes. The themes and concepts were sorted into three broad categories: Affect, Behaviour, and Cognition (ABC), and the data was visualized in semantic maps. The maps reveal several knowledge pathways of ABC for developing attitudinal ontologies, which describe the relations between affect, behaviour and cognition, and the sequence in which they develop. Clearly, terrorist attacks induced trauma and people became highly vulnerable.     

微博用户的时间行为研究

人类日常行为活动在生活的各个方面普遍存在。个体行为活动类型多样且个体之间行为差异明显,人类行为显示出高度复杂性。利用微博用户发布微博所产生的时间数据来研究用户的时间行为模式,研究发现个体用户时间间隔的统计特征主要服从幂律、指数和双模3种分布函数;并提出了基于任务队列的个体用户行为动力学模型,解释了用户发布微博的时间间隔分布特征。     

基于TRACEr失误辨识方法的电网调度人因风险认知分析

辨识和分析电网调度中的人为失误对于防范和控制人因风险、保障电网安全稳定运行至关重要。人为失误预测和确认方法在复杂系统的设计、评估和运行中已得到了广泛应用。结合电网调度业务知识和认知心理学模型,对认知差错追溯和预测技术(Technique for Ret-rospective and Predictive Analysis of Cognitive Errors,TRACEr)进行了分析和改进,研究了其在电网调度人为风险分析中的应用。运用提出的人为失误分析方法,对电网调度中的人因风险案例进行了分析,结果表明,基于TRACEr失误辨识方法能较为全面地分析电网调度员的人为失误,并为失误的补救和防范提供有效的改进措施。     

基于视频的矿井中人体运动区域检测

将人体运动区域检测技术应用到矿井视频中可以检测矿井下矿工的运动情况,进一步可以智能检测矿工的异常行为,根据反馈的检测结果实现实时报警和联动控制,减少矿井事故的发生。针对矿井场景下的人体运动区域检测,提出了一种实现人体运动区域提取的融合方法TD-HF(Time Difference and Haar Feature),该方法融合了时间差分法和基于Haar特征的人体检测算法。实验表明,所提方法在检测率和误识率方面均比单纯的基于AdaBoost算法的分类器更胜一筹,并且在检测时间上满足实时性要求,适用于矿井视频这种特殊场景下的人体运动区域检测。     

能量模型数据挖掘的研究

本文通过数据挖掘自身的特点,有效地结合相关算法并基于人体运动捕捉数据,给出这两个问题的有效解决方法。主要工作如下：（1）提出了基于能量模型的算法。相对于现有文献中使用的关节的几何位置,本文提出了的人体能量模型能够有效地降低动作数据的维度,并且能够正确地反映原动作的特征。在此基础上,使用相关系数来表示人体运动过程中各关节之间的相关性,并据此提取出原动作的低维度索引,实验表明该索引能够有效地体现原动作的特征。使用支持向量机结合低维度索引可以有效地讲输入动作划分到一个动作大类中,在此基础上使用基于Keogh下界的线性索引算法可以精确、快速地检索到与输入动作DTW距离最近的候选动作。（2）提出了基于公共子序列距离的数据挖掘算法。相对于现有文献中使用的欧式距离,本文使用的基于最长公共子序列的度量方法能够有效地降低噪声对于挖掘结果的不利影响。使用启发式搜索可以将搜索所需要的时间降低为使用朴素式搜索算法的60%以下,并且随着序列的长度的增加、计算量的增大,前者相对于后者运行时间的百分比有明显的减小趋势,利用这一特性,该算法可以在长序列的主旨模式挖掘中,大规模地减少算法的运行时间。在各长度的候选模式集合中,使用层次化聚类分析可以有效地合并相似度较高的候选模式,以达到合理约简模式、消除相邻重叠模式对结果不利影响的目的。使用最小描述长度原则可以根据模式的长度以及出现频率对候选模式表达整个原序列的能力进行有效地评估,从而达到支持非固定长度主旨模式挖掘的目的。     

An experimental study on estimating human error probability (HEP) parameters for PSA/HRA by using human model simulation

A framework of Human Error Probability (HEP) parameters, which is needed for Human Reliability Analysis (HRA) within a practice of Probabilistic Safety Assessment (PSA) of Nuclear Power Plant is first proposed. Then a laboratory experiment was conducted in order to construct a computer simulation model (human model) that describes human cognitive behaviour on detecting and diagnosing plant anomaly causes. An inter-comparison between experimental data and human model simulation was performed to estimate Human Cognitive Reliability (HCR) curves, in order to confirm the applicability of a human model for estimating these HEP parameters for PSA/HRA practice.     

If the State provided free computer literacy, would it find takers? Evidence and propositions from the Akshaya project in India

The Akshaya project from Kerala has been a much discussed case for the community of practitioners and scholars working on technology and development. A unique feature of the project is its state-wide e-literacy goal in which one member of every household was trained in the telecenters set up under Akshaya at public expense. Using a survey of 1,750 households in the experimental area of Malappuram and a comparison group of neighbouring Kozhikode, this work investigates the extent of e-literacy and discusses the performance of service delivery using telecenters. While the question of whether public funds should be spent on projects such as telecenters or e-literacy continues to be an ongoing debate, the evidence here is that even though structural factors such as service delivery mechanisms and publicity make an impact on technology adoption, the overall participation in free e-literacy services among poor households remains low.