An Experimental Low-Cost, Low-Data-Rate Rapid Structural Assessment Network

In this paper, we present the design, implementation, and experimental evaluation of a wireless sensor network for real-time structural ldquohealthrdquo monitoring. We use simple custom-built gages to detect cracks in critical structural elements. The main data reports require no structural analysis for interpretation, have a low data rate, and are naturally resilient to loss. We show how a variety of low-cost, off-the-shelf data acquisition/communication devices can be used to support remote monitoring by a control center. The heterogeneous hardware is accommodated by the use of open technology standards and a software architecture that is portable, modular, and highly configurable. We present an experimental evaluation of our structural-assessment network done using a full-scale three-story reinforced concrete building that was tested under lateral forces emulating forces induced by earthquakes. Our results show that a set of 12 strategically positioned sensors achieved a 100% detection rate for cracks crossing sensors and a zero false-alarm rate (in the sense that all signals exceeding a preset threshold were traced to cracks exceeding a specified total width).     

How much do I tell thee? Strategies for managing information to parents among American adolescents from Chinese, Mexican, and European backgrounds.

Strategies for managing information about activities to parents, including partial disclosure, avoidance, lying, and full disclosure, were examined in 479 American adolescents (M = 16.38 years, SD = 0.77) varying in generational status and from Mexican, Chinese, and European backgrounds. Information management strategies for personal, prudential, and overlapping (multifaceted) activities as defined within social domain theory were examined. With age, parental education, and generational status controlled, Chinese American adolescents partially disclosed more to mothers about personal and multifaceted activities than did Mexican American adolescents and more to fathers about personal activities than did European American teens. In contrast, European and Mexican American adolescents fully disclosed more to mothers about personal activities than did Chinese-origin adolescents. Strategies varied by generation among Chinese American youth; second-generation adolescents avoided discussing activities with parents more than did immigrants. Adolescents who fully disclosed about all activities and lied less about multifaceted and personal activities reported stronger endorsement of obligations to assist their families, more trust in parents, and less problem behavior. More depressed mood was associated with more lying about personal activities. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of three‐dimensional virtual reality and traditional training methods on mental workload and training performance

Industries will implement effective training programs to improve training performance, and an ideal training performance occurs under proper mental workload (MWL). Virtual reality (VR) has recently been widely utilized in training; however, only a few studies have investigated its effects on MWL and training performance simultaneously. The purpose of this study is to investigate the effects of VR training and traditional training methods, such as technical manuals (TM) and multimedia films (MF), on training performance and MWL. The results of the performance measurement show that VR training is considered the best training method compared to TM and MF, particularly in the case of complex tasks. The results of physiological measurements (GSR [galvanic skin response], LF% [low frequency], and LF/HF [high frequency] ratio) show a significant difference between reading TM and using computer (MF and VR), wherein the latter has a lower MWL. However, no significant difference in subjective MWL assessment (NASA‐TLX [task load index]) and HF% measurement is found.     

Adaptive Resource Allocation for Service-Based Systems

Due to its major advantages, service-oriented architecture (SOA) has been adopted in various distributed systems, such as web services, grid computing systems, utility computing systems and cloud computing systems. These systems are referred as service-based systems (SBS). In order to effectively use these systems in various applications, one major challenge which must be addressed is to manage the quality of services (QoS) to satisfy users’ requirements. In SBS, multiple services are often hosted by the same server and compete for the limited system resources of the server, such as CPU-time, memory and network bandwidth. In addition, service compositions, resource status of servers, workflow priorities and QoS requirements are usually dynamically changing in runtime. Hence, it is necessary to have effective techniques to allocate the system resources to each service provided by a server in order to satisfy the QoS requirements of multiple workflows in SBS. In this paper, a resource allocation approach is presented to adaptively allocating the system resources of servers to their services in runtime in order to satisfy one of the most important QoS requirements, the throughput, of multiple workflows in SBS.     

专业认证背景下铸造工艺课程设计教学改革的探讨

工程教育专业认证是保证、改进教育质量的重要途经,是以专业全体学生的学习结果为认证的主要目标。铸造工艺课程设计是综合性较强的专业核心课程,对于学生综合能力培养具有重要作用。本文基于对重庆大学材料成型及控制工程专业铸造工艺课程设计课程目标达成情况的分析,对课程教学的教学设计、组织形式、实施方法以及学业成绩评价等方面进行了改进,突出"以学生为中心"的工程应用水平和创新能力的培养。     

Comparing the top-down and bottom-up approaches of function point analysis: a case study

Function point analysis is a widely cited method for estimating software project size, which is an important activity of project management. At the beginning stage of planning, the top-down approach can be applied. Having obtained more systems specifications at later stages, the bottom-up approach might also be used to improve the accuracy of the estimation. However, the bottom-up approach is not a conventional way of function point analysis. There was no empirical evidence showing the difference between the fully informed top-down approach and the bottom-up approach. Through the implementation of a function point analysis system in an in-house software development department, this paper compares the results of the two approaches. This comparison study shows that the bottom-up approach does not contribute a significant added value to a fully-informed top-down approach. Therefore, the fully-informed top down approach has been chosen as a method for building a software metric database in the organization. More important, the observations and experience gained from this project may help in-house development organizations to establish their own function point analysis systems.     

Reverse engineering of engine intake ports by digitization and surface approximation

This paper describes a research development for the design of engine intake ports using reverse engineering techniques. The background is typical of many automotive applications where digitization and reverse engineering become necessary when the design is subject to changes during production or testing. After careful analysis of the problem, CMM contact measurement was selected to digitize the complex intake ports. Part segmentation and semi-automatic scanning were applied to the digitization process. For the purpose of data reduction and surface approximation, a new approach to the fitting of rational B-splines was developed. This is because rational B-splines have more flexibility and can approximate complex geometry more accurately than traditional Bezier or B-splines. Furthermore, skinning—a cross-sectional design technique—was utilized to construct the surface to reduce the computation cost. Surface merging was also implemented to maintain the surface boundary continuity. Finally, the enclosed surface volume is produced and can be transferred to commercial CAD/CAM systems through IGES translation. Examples with complex intake ports were described to validate the approach.