Open-Source Change Logs

A recent editorial in Empirical Software Engineering suggested that open-source software projects offer a great deal of data that can be used for experimentation. These data not only include source code, but also artifacts such as defect reports and update logs. A common type of update log that experimenters may wish to investigate is the ChangeLog, which lists changes and the reasons for which they were made. ChangeLog files are created to support the development of software rather than for the needs of researchers, so questions need to be asked about the limitations of using them to support research. This paper presents evidence that the ChangeLog files provided at three open-source web sites were incomplete. We examined at least three ChangeLog files for each of three different open-source software products, namely, GNUJSP, GCC-g++, and Jikes. We developed a method for counting changes that ensures that, as far as possible, each individual ChangeLog entry is treated as a single change. For each ChangeLog file, we compared the actual changes in the source code to the entries in the ChangeLog> file and discovered significant omissions. For example, using our change-counting method, only 35 of the 93 changes in version 1.11 of Jikes appear in the ChangeLog file—that is, over 62% of the changes were not recorded there. The percentage of omissions we found ranged from 3.7 to 78.6%. These are significant omissions that should be taken into account when using ChangeLog files for research. Before using ChangeLog files as a basis for research into the development and maintenance of open-source software, experimenters should carefully check for omissions and inaccuracies.     

Corrosion of NiTi Wires with Cracked Oxide Layer

Corrosion behavior of superelastic NiTi shape memory alloy wires with cracked TiO₂ surface oxide layers was investigated by electrochemical corrosion tests (Electrochemical Impedance Spectroscopy, Open Circuit Potential, and Potentiodynamic Polarization) on wires bent into U-shapes of various bending radii. Cracks within the oxide on the surface of the bent wires were observed by FIB–SEM and TEM methods. The density and width of the surface oxide cracks dramatically increase with decreasing bending radius. The results of electrochemical experiments consistently show that corrosion properties of NiTi wires with cracked oxide layers (static load keeps the cracks opened) are inferior compared to the corrosion properties of the straight NiTi wires covered by virgin uncracked oxides. Out of the three methods employed, the Electrochemical Impedance Spectroscopy seems to be the most appropriate test for the electrochemical characterization of the cracked oxide layers, since the impedance curves (Nyquist plot) of differently bent NiTi wires can be associated with increasing state of the surface cracking and since the NiTi wires are exposed to similar conditions as the surfaces of NiTi implants in human body. On the other hand, the potentiodynamic polarization test accelerates the corrosion processes and provides clear evidence that the corrosion resistance of bent superelastic NiTi wires degrades with oxide cracking.     

Color–concept associations: A cross‐occupational and ‐cultural study and comparison

This study used a questionnaire survey to examine color–concept associations in two occupational groups from Hebei Province in China: steel workers (n = 139) and managerial staff (n = 74). The color stereotypes held by these two groups were also compared to those held by three other cultural groups studied elsewhere (Hong Kong Chinese, Yunnan Chinese, and Americans). The participants were presented with 16 concepts and asked to choose one of 10 colors to represent each concept. The chi‐square test results showed that each concept was significantly associated with at least one color. Both the steel workers and the managerial staff primarily associated green with “go” and “safe” and red with “stop” and “danger.” The cross‐group comparisons indicated that the steel workers and the managerial staff produced stronger color associations than those produced by the Yunnan Chinese and the Hong Kong Chinese subjects, but weaker than those produced by the US subjects. Our findings build on existing knowledge of population stereotypes for color–concept associations and provide guidelines for the design of color displays and products for global users. © 2013 Wiley Periodicals, Inc. Col Res Appl, 39, 630–635, 2014     

Growing a list

It is easy to find expert knowledge on the Internet on almost any topic, but obtaining a complete overview of a given topic is not always easy: information can be scattered across many sources and must be aggregated to be useful. We introduce a method for intelligently growing a list of relevant items, starting from a small seed of examples. Our algorithm takes advantage of the wisdom of the crowd, in the sense that there are many experts who post lists of things on the Internet. We use a collection of simple machine learning components to find these experts and aggregate their lists to produce a single complete and meaningful list. We use experiments with gold standards and open-ended experiments without gold standards to show that our method significantly outperforms the state of the art. Our method uses the ranking algorithm Bayesian Sets even when its underlying independence assumption is violated, and we provide a theoretical generalization bound to motivate its use.     

石家庄勒泰中心

<正>项目名称:石家庄勒泰中心业主:勒泰商业地产集团建设地点:河北省石家庄市中山东路39号设计单位:捷德国际建筑师事务所业态构成:商业,酒店,办公,公寓用地面积:6hm2建筑面积:62.4万m2材料应用:石材,金属镶板,玻璃,预制混凝土外立面主创设计师:Tammy Mc Kerrow结构/机电/施工图配合:华东建筑设计研究院有限公司(ECADI)景观设计:Earth Asia照明设计:Grenald Waldron Associates(GWA)标识设计:Dutton Bray水景设计:Oase设计时间:2010年建成时间:2012年图纸版权:捷得国际建筑师事务所摄影:Kerunlp     

Impact of Functionalized Polystyrenes as the Electron Injection Layer on Gold and Aluminum Surfaces: A Combined Theoretical and Experimental Study

At metal/organic interfaces, the insertion of an organic monolayer can significantly modify the surface properties of the substrate, especially in terms of charge injection across the interface. Herein, we study the formation of an insulating monolayer of morpholine or amine-functionalized polystyrene on Al(111) and Au(111) surfaces and its impact on surface work-function and charge injection. First-principles calculations based on Density Functional Theory have been carried out and point to a significant decrease in the work-function of modified metal surfaces; this is in very good agreement with ultraviolet photoemission spectroscopy measurements performed on the Au(111) surface. In addition, a bilayer cathode, consisting of a thin film of high-work-function metal, such as Al and Au, and a layer of amine-functionalized polystyrene, was also fabricated and tested in organic light-emitting diodes. Such bilayer structures exhibit substantially enhanced efficiency when compared with controls without the functionalized polymers. Our combined theoretical and experimental investigation gives insight into how a thin layer of a commodity polymer can be used to transform rather high-work-function metals into high-performance cathodes to provide efficient electron injection.     

Real-time PCR detection of the thermostable direct hemolysin and thermolabile hemolysin genes in a Vibrio parahaemolyticus cultured from mussels and mussel homogenate associated with a foodborne outbreak

Molecular methods have become vital epidemiological tools in the detection and characterization of bacteria associated with a foodborne outbreak. We used both culture and real-time PCR to detect a Vibrio parahaemolyticus isolate associated with a foodborne outbreak. The outbreak occurred in July 2002 in Polk County, Florida, and originated at a Chinese buffet, with one person being hospitalized. The hospital isolated V. parahaemolyticus from the patient but destroyed the sample after diagnosis. From an onsite visit of the restaurant, food samples that possibly contributed to the outbreak were collected and sent to the Florida Department of Health, Tampa Branch Laboratory. Crab legs, crabsticks, and mussel samples were homogenized and incubated according to the Food and Drug Administration Bacteriological Analytical Manual culture protocol. Three sets of primers and a TaqMan probe were designed to target the tdh, trh, and tlh genes and used for real-time PCR. This study was successful in isolating V. parahaemolyticus from a mussel sample and detecting two of its genes (tdh and tlh) in food and pure culture by real-time PCR.     

找好接班人:CIO谋求上位的第一步

对CIO们而言,制订一个灵活的继任者计划,帮助公司培养未来IT领导人。直接关乎自己职业宏图的拓展。毕竟,在没有得到一个足够优秀的人才来接替你的工作之前,CEO怎么会将你调任到其他新岗位呢？     

Application of molecular identification tools for Lactobacillus, with a focus on discrimination between closely related species: A review

Lactobacillus is among the most important GRAS food lactic acid bacteria, with nearly 140 species at present, mostly of industrial importance. Being part of the natural flora of a range of food products like raw milk, fermented dairy products, fruits, vegetables, meat products they also serve as starters for a number of fermented food products either to enhance the quality or to add health benefits. These groups of economically important species are often alike in phenotypic and physiological characteristics, probably due to their co-evolution in the same ecological niches; hence they are difficult to be differentiated. This demands advanced methods for their proper identification and characterization. With the advancement of molecular biology, a range of DNA-based molecular techniques has replaced the largely cumbersome phenotypic methods. This review summarizes the various molecular techniques available for detection and identification within the genus Lactobacillus, with special emphasis on the four groups of closely resembling species: L. casei group, L. acidophilus group, L. delbrueckii subspecies, and L. plantarum group. This review also provides insights into current trends for alternative molecular markers other than 16S rRNA to resolve the ambiguity within phylogenetically close species in the genus Lactobacillus.