A Donor–Acceptor Polymer with a Peculiar Negative‐Charge‐“Trapping” Characteristic

Voltammetric and spectrophotometric measurements of poly(3,3″‐dipentoxy‐3′‐dicyanoethenyl‐2,2′:5′,2″‐terthiophene) (polyCN) films, in connection with other experimental evidence, reveal a normal oxidative, but a peculiar reductive behavior consisting of trapping of the negative charge during the cathodic scan. Another interesting property of polyCN films is the tendency to form strong intramolecular and intermolecular associations, probably charge‐transfer (CT) complexes. These properties could account for the fact that the photovoltaic performance does not improve when polyCN is blended with a polythiophene donor.     

Homophily of Network Ties and Bonding and Bridging Social Capital in Computer-Mediated Distributed Teams

This research studied homophily of network ties in distributed teams in both task-related instrumental networks and non-task related expressive networks. Homophily of network ties was examined in terms of demographic and social characteristics, including gender, race, geographic location, and group assignment. Social network data were collected from 32 students enrolled in a distance learning class from two universities. MQAP regression analysis showed that homophily in gender and in race had no significant impact on the development of either instrumental or expressive ties. In instrumental networks, both homophily in group assignment and in location had significant impact on the development of network ties. In expressive networks, homophily in location had significant impact on the development of network ties, but the impact of homophily in group membership was only marginally significant. Further analysis of bonding ties with people of the same group and bridging ties with people from different groups showed that bonding social capital can exert significant influence on performance.     

In Google We Trust: Users' Decisions on Rank, Position, and Relevance

An eye tracking experiment revealed that college student users have substantial trust in Google's ability to rank results by their true relevance to the query. When the participants selected a link to follow from Google's result pages, their decisions were strongly biased towards links higher in position even if the abstracts themselves were less relevant. While the participants reacted to artificially reduced retrieval quality by greater scrutiny, they failed to achieve the same success rate. This demonstrated trust in Google has implications for the search engine's tremendous potential influence on culture, society, and user traffic on the Web.     

基于Windows Server2008的IPV6 FTP服务器的设计与实现

基于Windows Server2008设计并实现了支持IPV4和IPV6协议的FTP服务器。对IPV4环境中的应用程序向IPV6迁移进行了实质性的探索和研究。该文是使用Windows Server2008 IIS70搭建FTP服务器,并用SmartFTP实现访问。     

On challenges of model transformation from UML to Alloy

The Unified Modeling Language (UML) is the de facto language used in the industry for software specifications. Once an application has been specified, Model Driven Architecture (MDA) techniques can be applied to generate code from such specifications. Since implementing a system based on a faulty design requires additional cost and effort, it is important to analyse the UML models at earlier stages of the software development lifecycle. This paper focuses on utilizing MDA techniques to deal with the analysis of UML models and identify design faults within a specification. Specifically, we show how UML models can be automatically transformed into Alloy which, in turn, can be automatically analysed by the Alloy Analyzer. The proposed approach relies on MDA techniques to transform UML models to Alloy. This paper reports on the challenges of the model transformation from UML class diagrams and OCL to Alloy. Those issues are caused by fundamental differences in the design philosophy of UML and Alloy. To facilitate better the representation of Alloy concepts in the UML, the paper draws on the lessons learnt and presents a UML profile for Alloy.     

A Theory of Constraints approach to interorganizational systems implementation

Interorganizational systems (IOS) may provide substantial benefits, however many organizations are reluctant to implement them. This empirical research takes a novel approach and develops a model of IOS feasibility, which is based on the Theory of Constraints (TOC). It introduces the notion of maximal infeasibility, which is the highest among the values of five factors: economic infeasibility, organizational infeasibility, technological infeasibility, risks, and lack of financial resources. The highest value was selected because implementation is hindered even if only one of the feasibility requirements is not fulfilled. Data collected from 139 medium and large Israeli business organizations validated the model, and indicated that strategic motivation is the main driving force for an organization to initiate or to join an IOS, while the main barriers are organizational infeasibility issues such as lack of management support or uninterested potential partners. Adopting a TOC approach to IOS implementation may assist organizations to overcome these obstacles and increase the chance of a successful implementation. An earlier shorter version of this paper was presented at WEB 2006, a pre-ICIS workshop on e-business, in Milwaukee, WI.     

Value enhancement in a dynamic environment—a constraint management expert system for the oil refinery industry

This paper analyses a case study of a dynamic expert system which was developed according to the theory of constraints (TOC) approach, and implemented at the Ashdod refinery of Oil Refineries Ltd in Israel, as part of an overall improvement process based on the focused management philosophy. The unique feature of the system is its ability to cope with dynamic bottlenecks typical of the continuous process industry, as well as frequent shifts from an external market constraint to internal capacity constraints. The paper examines the development and implementation stages, describes the expert system along with the new process control, and evaluates its impact. The system creates a dynamic, effective and immediate link between the production planning and the operation control, which enables the oil refinery to maximize its profits. During the first two years of its use, the system generated over $3 million of estimated benefits. Finally, we suggest practical implications to assist organizations in developing and utilizing similar applications, emphasizing knowledge gathering and maintenances, which are the major challenges facing expert systems projects.     

Driving behaviors in early stage dementia: A study using in-vehicle technology

According to the Alzheimer's Association (2011), (1) in 8 people age 65 and older, and about one-half of people age 85 and older, have Alzheimer's disease in the United States (US). There is evidence that drivers with Alzheimer's disease and related dementias are at an increased risk for unsafe driving. Recent advances in sensor, computer, and telecommunication technologies provide a method for automatically collecting detailed, objective information about the driving performance of drivers, including those with early stage dementia. The objective of this project was to use in-vehicle technology to describe a set of driving behaviors that may be common in individuals with early stage dementia (i.e., a diagnosis of memory loss) and compare these behaviors to a group of drivers without cognitive impairment. Seventeen drivers with a diagnosis of early stage dementia, who had completed a comprehensive driving assessment and were cleared to drive, participated in the study. Participants had their vehicles instrumented with a suite of sensors and a data acquisition system, and drove 1–2 months as they would under normal circumstances. Data from the in-vehicle instrumentation were reduced and analyzed, using a set of algorithms/heuristics developed by the research team. Data from the early stage dementia group were compared to similar data from an existing dataset of 26 older drivers without dementia. The early stage dementia group was found to have significantly restricted driving space relative to the comparison group. At the same time, the early stage dementia group (which had been previously cleared by an occupational therapist as safe to drive) drove as safely as the comparison group. Few safety-related behavioral errors were found for either group. Wayfinding problems were rare among both groups, but the early stage dementia group was significantly more likely to get lost.