近海复杂环境因素对闸墩混凝土裂缝的影响

近海大体积混凝土结构所处的外界环境以及地质条件比较复杂,对于带裂缝水闸结构来说,因所处的地理位置、气候变化以及潮汐升降水位等因素的缘故,水闸闸墩裂缝处于张合状态,这降低了水闸结构的稳定性,甚至会影响水闸结构的寿命。沿海环境温度变化对混凝土裂缝宽度变化的实际监测分析,对于混凝土结构安全耐久性评价具有一定价值,依托典型软土地基永定新河防潮闸工程,利用测缝计对闸墩裂缝宽度变化进行健康监测。主要研究运行期环境因素(以空气温度、水温以及潮汐水位为主)对闸墩裂缝的影响,采用健康安全监测软件,通过对数据的挖掘处理,得出环境温度和水位是影响闸墩水下裂缝宽度变化的敏感性因素的结论,为以后水闸闸墩裂缝的安全维护和裂缝的预防提供思路。     

Performance on agile teams: Relating iteration objectives and critical decisions to project management success factors

ContextWhile project management success factors have long been established via the golden triangle, little is known about how project iteration objectives and critical decisions relate to these success factors. It seems logical that teams’ iteration objectives would reflect project management success factors, but this may not always be the case. If not, how are teams’ objectives for iterations differing from the golden triangle of project management success factors?ObjectiveThis study identifies iteration objectives and the critical decisions that relate to the golden triangle of project management success factors in agile software development teams working in two-week iterations.MethodThe author conducted semi-structured interviews with members across three different agile software development teams using a hybrid of XP and Scrum agile methodologies. Iteration Planning and Retrospective meetings were also observed. Interview data was transcribed, coded and reviewed by the researcher and two independently trained research assistants. Data analysis involved organizing the data to identify iteration objectives and critical decisions to identify whether they relate to project management success factors.ResultsAgile teams discussed four categories of iteration objectives: Functionality, Schedule, Quality and Team Satisfaction. Two of these objectives map directly to two aspects of the golden triangle: schedule and quality. The agile teams’ critical decisions were also examined to understand the types of decisions the teams would have made differently to ensure success, which resulted in four categories of such decisions: Quality, Dividing Work, Iteration Amendments and Team Satisfaction.ConclusionThis research has contributed to the software development and project management literature by examining iteration objectives on agile teams and how they relate to the golden triangle of project management success factors to see whether these teams incorporate the golden triangle factors in their objectives and whether they include additional objectives in their iterations. What’s more, this research identified four critical decisions related to the golden triangle. These findings provide important insight to the continuing effort to better assess project management success, particularly for agile teams.     

Fuzzy arithmetic based reliability allocation approach during early design and development

During early design and development stages, every engineering system has to meet its specific reliability goals. The target reliability of the system is achieved through application of an effective reliability apportionment technique to its subsystems. There are various traditional methods exist to perform the reliability allocation based on engineering factors that are assessed in a subjective manner. The conventional reliability allocation approach requires the assessment of factors like complexity, cost, and maintenance. This may not be realistic in real applications if they are assessed in a crisp manner by the domain experts of their varied expertise and background.In this paper, we treat allocation factors as fuzzy numbers, which are evaluated in fuzzy linguistic terms. As a result, fuzzy proportionality factor scales are proposed for the subsystems. In order to accomplish fuzzy division to evaluate the fuzzy proportionality factor, an approximation method based on linear programming for trapezoidal fuzzy numbers is also proposed in this paper. For the evaluation of weighting factors from fuzzy proportionality factors, centroid method of defuzzification is being employed. The allocated reliability of each subsystem is computed with the help of weighting factor thereafter. An example is provided to illustrate the potential application of the proposed fuzzy based reliability allocation approach.     

多点多板多分型面注塑模具的简化设计

应用锁扣装置、组合拉杆结构，减少导柱数量，简化了多点多板多分型面注塑模具的设计。     

催化热裂解工艺机遇及影响因素

分析了催化热裂解过程的反应机理及乙烯和丙烯形成的反应，乙烯和丙均可通过热裂解和催化裂解生成，讨论了影响乙烯，丙烯产率的因素：与USY和REY相比，使用ZSM－5催化剂能够提高乙烯，丙烯产率，磷改性ZRP－1经碱土金属改性后，可进一步提高乙烯和丙烯的产率，提高反应温度和降低剂油比，能够提高热裂解和催化裂解的比例，有利于乙烯产率的提高；增强蒸汽量能够减少焦炭产率，提高乙烯和丙烯产率。     

Texaco煤气化装置长周期运行影响因素分析

介绍了Texaco煤气化工艺流程,从原料煤种、水煤浆浓度、操作工艺、关键设备等几个方面讨论了影响装置长周期运行的因素,提出了延长气化装置运行周期的措施。     

Fundamentals of systems ergonomics/human factors

Ergonomics/human factors is, above anything else, a systems discipline and profession, applying a systems philosophy and systems approaches. Many things are labelled as system in today's world, and this paper specifies just what attributes and notions define ergonomics/human factors in systems terms. These are obviously a systems focus, but also concern for context, acknowledgement of interactions and complexity, a holistic approach, recognition of emergence and embedding of the professional effort involved within organization system. These six notions are illustrated with examples from a large body of work on rail human factors.     

Effects of personal,psychosocial and occupational factors on low back pain severity in workers

Low back pain (LBP) remains the most common work-related musculoskeletal disorder (WMSD). While most of the LBP research has focused on occupational risk factors, other underlying causal mechanisms may exist since not all workers performing the same task develop an injury. Previous research has identified three primary risk factor categories for LBP (occupational, personal and psychosocial factors); however, few studies have investigated the impact of cross categorical risk factor interactions on LBP. The objective of this study was to investigate the effects of occupational, personal and psychosocial factors, and their interactions, on LBP severity in a population of workers currently suffering from LBP. Sixty LBP patients recruited for the study through local physicians and local announcements, completed questionnaires relating to identified occupational, personal and psychosocial risk factors, and completed an Oswestry Disability Index (ODI). Multiple regression models for predicting LBP severity were developed for each risk factor category and for a combined risk factor model (which included factors from all three risk factor categories) that included two-way interactions. Results showed that the final model consisted of both main effects and interaction terms between risk factor categories and had an adjusted R² value of 0.85, a significant improvement over models developed for the individual categories. These findings illustrate the need to consider all three broad categories of risk factors simultaneously in predicting injury status and in developing effective potential intervention efforts.     

基于Monte Carlo随机模拟的综合交通网络布局评价与决策方法

针对综合交通网络评价指标权重及属性值具有主观性和随机性的特点,提出了基于模拟运算的布局规划方案排序选优的群体随机决策方法.仿真生成满足集结的多个专家对指标重要性偏好排序统计分布的权重,同时考虑交通需求的不确定性对指标值的影响,结合客观熵权计算方案的综合评价值,由多次模拟得到的排序优势度确定方案的优劣差异.根据设计的仿真流程通过算例说明了方法应用的有效性,评价中考虑了主客观因素及随机性特征,可以为网络布局提供科学决策依据.