An experimental evaluation and possible extensions of SyPet

Program synthesis is an automated programming technique that automatically constructs a program which satisfies given specifications. SyPet is a recently published novel component-based synthesis tool that assembles a straight-line Java method body that invokes a sequence of methods from a given set of libraries to implement desired functionality that is defined by a given test suite. In this report, we experimentally evaluate the correctness and performance of the publicly available SyPet implementation, at the black-box level, focusing on the size of test suites. We then demonstrate how SyPet can be extended to support some other applications, such as synthesizing non-straight-line methods and program repair. Finally, we conjecture an alternative technique that is conceptually simpler for synthesizing straight-line methods and present a few initial experimental results.Electrical and Computer Engineerin

What Causes My Test Alarm? Automatic Cause Analysis for Test Alarms in System and Integration Testing

Driven by new software development processes and testing in clouds, system and integration testing nowadays tends to produce enormous number of alarms. Such test alarms lay an almost unbearable burden on software testing engineers who have to manually analyze the causes of these alarms. The causes are critical because they decide which stakeholders are responsible to fix the bugs detected during the testing. In this paper, we present a novel approach that aims to relieve the burden by automating the procedure. Our approach, called Cause Analysis Model, exploits information retrieval techniques to efficiently infer test alarm causes based on test logs. We have developed a prototype and evaluated our tool on two industrial datasets with more than 14,000 test alarms. Experiments on the two datasets show that our tool achieves an accuracy of 58.3% and 65.8%, respectively, which outperforms the baseline algorithms by up to 13.3%. Our algorithm is also extremely efficient, spending about 0.1s per cause analysis. Due to the attractive experimental results, our industrial partner, a leading information and communication technology company in the world, has deployed the tool and it achieves an average accuracy of 72% after two months of running, nearly three times more accurate than a previous strategy based on regular expressions.Comment: 12 page

Analysis of Functionalities of Commercial Websites Used for Procurement: Implications on Design and Operations

This research analyzes the functionalities of commercial websites used for electronic procurement and links them with the benefits as perceived by users and with relevant operations. Findings from a Data Envelopment Analysis (DEA) used on data collected from 88 corporate buyers working in a wide range of industries and using the World Wide Web to support the procurement process show that adding advanced functionalities to informational websites can reduce their efficiency, which suggest that commercial websites are more often used to reduce buyers’ search costs than their processing costs. Possible explanations and implications of such findings on the design of commercial websites used for business-to-business transactions and on operations for both vendors and buyers are discussed

Electron transport through Al-ZnO-Al: an {\it ab initio} calculation

The electron transport properties of ZnO nano-wires coupled by two aluminium electrodes were studied by {\it ab initio} method based on non-equilibrium Green's function approach and density functional theory. A clearly rectifying current-voltage characteristics was observed. It was found that the contact interfaces between Al-O and Al-Zn play important roles in the charge transport at low bias voltage and give very asymmetric I-V characteristics. When the bias voltage increases, the negative differential resistance occurs at negative bias voltage. The charge accumulation was calculated and its behavior was found to be well correlated with the I-V characteristics. We have also calculated the electrochemical capacitance which exhibits three plateaus at different bias voltages which may have potential device application.Comment: 10 pages, 6 figure

Prediction Of Air Pollutant From Poultry Houses By A Modified Gaussian Plume Model

Concentrated animal feeding operations release a variety of potential pollutants, such as ammonia and particulate matters (PM). Field measurements are time consuming, costly, and only provide a limited amount of spatial and temporal information. Air dispersion models can serve as an alternative solution, especially if coupled with field sampling. The Gaussian plume model (GPM) is a mathematical model that assumes steady state condition. Previous studies have used the GPM to evaluate and analyze source. However, much less is known about utilizing GPM to simulate plumes from horizontal sources, such as the exhaust fans from poultry houses. The purpose of this study is to modify and validate a GPM to predict air pollutant emissions from the poultry houses. Two major assumptions were applied on the model, 1) a virtual releasing point was proposed behind the ventilation fan, and 2) ventilation fan was considered as the dominant wind direction in the model for short distance (< 50 m). The modified model was validated with field experimental data. Performance and sensitivity of the model were also evaluated. Fraction of predictions within a factor of two of observations (FAC2) of NH3 and PM were 0.609 and 0.625. Model-predicted concentrations of NH3 were 1.5 times of the measured values on average. Model-predicted concentrations of PM was 0.98 times of the observed values on average

Photoinduzierte Mikrostrukturierung und Anisotropie in Bakteriorhodopsin-Filmen

Im Rahmen dieser Dissertation wurden zwei Effekte von Bakteriorhodopsin untersucht. Im ersten Teil der Arbeit wurde die photoinduzierte Mikrostrukturierung erforscht und ihre Anwendung zur Darstellung von Beugungsgittern gezeigt. Im zweiten Teil wurde die photoinduzierte Anisotropie untersucht und für die Datenspeicherung mit mehreren Informationen angewendet