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Combined classifier for cross-project defect prediction： an extended empirical study

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Frontiers of Computer Science 2018年第2期12卷 280-296页

作者： Yun ZHANG David lo Xin XIA Jianling SUN College of Computer Science and Technology Zhejiang University Hangzhou 310027 China School of Information Systems Singapore Management University Singapore 641674 Singapore

To facilitate developers in effective allocation of their testing and debugging efforts, many software defect prediction techniques have been proposed in the literature. These techniques can be used to predict classes that are more likely to be buggy based on the past history of classes, methods, or certain other code elements. These techniques are effective provided that a sufficient amount of data is available to train a prediction model. However, sufficient training data are rarely available for new software projects. To resolve this problem, cross-project defect prediction, which transfers a prediction model trained using data from one project to another, was proposed and is regarded as a new challenge in the area of defect prediction. Thus far, only a few cross-project defect prediction techniques have been proposed. To advance the state of the art, in this study, we investigated seven composite algorithms that integrate multiple machine learning classifiers to improve cross-project defect prediction. To evaluate the performance of the composite algorithms, we performed experiments on 10 open-source software systems from the PROMISE repository, which contain a total of 5,305 instances labeled as defective or clean. We compared the composite algorithms with the combined defect predictor where logistic regression is used as the meta classification algorithm （CODEPlogistic）, which is the most recent cross-project defect prediction algorithm in terms of two standard evaluation metrics： cost effectiveness and F-measure. Our experimental results show that several algorithms outperform CODEPlogistic：Maximum voting shows the best performance in terms of F-measure and its average F-measure is superior to that of CODEPlogistic by 36.88%. Bootstrap aggregation （Bagging J48） shows the best performance in terms of cost effectiveness and its average cost effectiveness is superior to that of CODEPlogistic by 15.34%.

关键词： defect prediction cross-project classifier combination

Automated Android application permission recommendation

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Science China(Information Sciences) 2017年第9期60卷 132-148页

作者： Lingfeng BAO David lo Xin XIA Shanping LI College of Computer Science and Technology Zhejiang University School of Information Systems Singapore Management University Department of Computer Science University of British Columbia

The number of Android applications has increased rapidly as Android is becoming the dominant platform in the smartphone market. Security and privacy are key factors for an Android application to be successful. Android provides a permission mechanism to ensure security and privacy. This permission mechanism requires that developers declare the sensitive resources required by their applications. On installation or during runtime, users are required to agree with the permission request. However, in practice, there are numerous popular permission misuses, despite Android introducing official documents stating how to use these permissions properly. Some data mining techniques(e.g., association rule mining) have been proposed to help better recommend permissions required by an API. In this paper, based on popular techniques used to build recommendation systems, we propose two novel approaches to improve the effectiveness of the prior work. The first approach utilizes a collaborative filtering technique, which is inspired by the intuition that apps that have similar features — inferred from their APIs — usually share similar permissions. The second approach recommends permissions based on a text mining technique that uses a naive Bayes multinomial classification algorithm to build a prediction model by analyzing descriptions of apps. To evaluate these two approaches, we use 936 Android apps from F-Droid, which is a repository of free and open source Android applications. We find that our proposed approaches yield a significant improvement in terms of precision, recall, F1-score, and MAP of the top-k results over the baseline approach.

关键词： Android permission recommendation association rule collaborative filtering text mining

The existence spectrum of Meta(K_4^((3))>K_4^((3))-e)

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Science China Mathematics 2010年第11期53卷 2865-2876页

作者： lo FARO Giovanni TRIPODI Antoinette Department of Mathematics University of Messina

Let H and J1 be both t-uniform hypergraphs. Let J2 be a sub-hypergraph of J1. In this paper, the metamorphosis of a hypergraph decomposition is introduced, denoted by (H, J1 > J2)-design, which is a generalization of the concept of metamorphosis of a graph decomposition. Let Meta(J1>J2) denote the set of all integers v such that there exists a (Kv((3)), J1>J2)-design. We completely determine the set Meta(K4((3))>K4((3))-e).

关键词： hypergraph decomposition metamorphosis t-GDD group divisible (Γ t)-design candelabra (Γ t)-system

Endothelial DLC1 is dispensable for liver and kidney function in mice

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Genes & Diseases 2022年第3期9卷 814-819页

作者： Ying Tan Su Hao lo Department of Biochemistry and Molecular Medicine University of California-DavisSacramentoCA 95817USA

DLC1 is a focal adhesion molecule that regulates cell polarity,proliferation,migration,and ***1 functions as a tumor suppressor and its expression is often down-regulated *** malignant neoplasms of epithelial *** studies have suggested that lack of DLC1 in endothelial cells may contribute to the development of angiosarcoma,and that DLC1 mutations have been identified in patients with nephrotic syndrome,a disease mainly due to leaky glomerular filtration *** demonstrate whether lack of endothelial DLC1 induces angiosarcoma and/or damages glomerular capillaries leading to nephrotic syndrome,we have extended our analyses on endothelial cell-specific DLC1 knockout mice with focuses on their liver and kidney *** were monitored up to 24 months of ***,no histological or clinical difference was found between DLC1 knockout and wild type mice,indicating that lack of endothelial DLC1 alone does not compromise kidney and liver function in mice.

关键词： Angiosarcoma DLC1 Focal adhesion Nephrotic syndrome Tumor suppressor

An investigation into the correlations among GNSS observations and their impact on height and zenith wet delay estimation for medium and long baselines

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Geo-Spatial Information Science 2012年第4期15卷 219-228页

作者： Johnny lo Ahmed EL-MOWAFY Mathematics Discipline Group School of EngineeringEdith Cowan University270 Joondalup DriveWestern Australia 6027Australia Faculty of Science and Engineering Department of Spatial SciencesCurtin University of TechnologyKent StreetWestern Australia 6102Australia

Most stochastic modelling techniques neglect the correlations among the raw un-differenced observations when forming the variance-covariance matrix of the Global Navigation Satellite System(GNSS)*** methods were developed to model these *** such method is the Minimum Norm Quadratic Unbiased Estimator(MINQUE).Studies have shown that MINQUE improves ambiguity resolution,and ultimately,the positioning solution in short ***,its effect in cases of processing with longer baselines and on the estimation of zenith wet delay(ZWD)is somewhat *** this paper,a comparison between the impact of neglecting the correlations among the observations using an elevation-angle-dependent model(EADM)and modelling the correlations using MINQUE on height determination and ZWD for medium and long baselines is carried *** initial testing was carried out across two Australian GNSS stations with a medium-length baseline throughout a three-week *** results showed that using MINQUE did not resolve the coordinate,height and wet delay components as accurately as the *** results were further verified with two long-baseline campaigns whereby EADM was also able to provide better wet delay *** coordinate results were,however,***,the study concluded that the inclusion of the correlations among the observations,in general,do not improve the resolution of the coordinate and wet delay estimates.

关键词： stochastic models MINQUE ZWD heights

Frequency notched wide slot antenna for UWB/2.4 GHz WLAN applications

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The Journal of China Universities of Posts and Telecommunications 2007年第4期14卷 122-125页

作者： lo Wen-jun ZHU Hong-bo Laboratory of Wireless communications and EMC Nanjing University ofPosts and Telecommunications Nanjing 210003 China

Abstract A compact frequency notched microstrip slot antenna for ultra-wideband （UWB）/2.4 GHz-band wireless local area network（WLAN） applications is proposed. The antenna is similar to a conventional microstrip slot antenna; however, by introducing a cross wide slot and a meandered-slotted stub, both compact size and frequency notched function can be achieved. It has been studied both numerically and experimentally for its impedance bandwidth, surface current distribution, radiation patterns, and gain. As will be seen, an operation bandwidth of over 4.6：1 ranging fi＇om 2.39 to 11.25 GHz for return loss lower than -10 dB having a frequency notched band ranging from 4.75 to 5.85 GHz has been achieved, and good radiation performance over the entire frequency range has also been achieved.

关键词： printed slot antenna frequency notched ultrawideband 2.4 GHz-band WLAN

Ileocolonic mucormycosis in adult immunocompromised patients:A surgeon's perspective

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World Journal of Gastroenterology 2010年第9期16卷 1165-1170页

作者： Oswens Siu-Hung lo Wai-Lun Law Division of Colorectal Surgery Department of SurgeryUniversity of Hong Kong Medical CentreQueen Mary Hospital

We report three cases of ileocolic mucormycosis in adult immunocompromised patients presenting as acute *** patients underwent laparotomy but two of them died from multiorgan failure before the diagnoses were *** diagnosis of gastrointestinal mucormycosis is rarely suspected,and antemortem diagnosis is made in only 25%-50% of *** cases illustrate the difficulty encountered by surgeons in managing acute abdomen in neutropenic patients with hematological *** management of colonic mucormycosis in the published literature is also reviewed.

关键词： Gastrointestinal mucormycosis Colon Immunocompromised Surgery

Withdrawal Intention of Farmers from Vacant Rural Homesteads and Its Influencing Mechanism in Northeast China: A Case Study of Jilin Province

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Chinese Geographical Science 2023年第4期33卷 634-648页

作者： YU Jiaping LI Jing lo Kevin HUANG Shanlin Northeast Institute of Geography and Agroecology Chinese Academy of SciencesChangchun 130102China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China Department of Geography Hong Kong Baptist UniversityHong Kong 999077China School of Public Administration and Law Northeast Agricultural UniversityHarbin 150030China

The effective use of land in Northeast China is of great significance for ensuring national food security and regional rural *** this study,based on the survey data collected from Jilin Province,Northeast China,we analyzed the vacancy rates of rural homesteads in suburban,outer suburban,and remote villages,as well as the withdrawal intention of rural-settled farmers,urbansettled farmers,and farmers with urban and rural dual residency from vacant *** the perspective of farmers’perceptions,this study constructed a theoretical framework of the influence mechanism of their withdrawal intention and analyzed such mechanism by constructing a structural equation *** results indicated that:1)rural homestead vacancy rates increased with distance from the village to the city.2)rural-settled farmers showed a low withdrawal intention for vacant rural homesteads,followed by urban and rural dual-residence farmers,and urban-settled farmers showed the highest withdrawal intention.3)the relative importance of the factors influencing withdrawal intention is in the following order:policy awareness>interest perception>living environment perception>family ***,this study discussed the reformation of the homestead system and rural homestead transition in Northeast China,which can provide policy support to increase the potential of cultivated land and promote sustainable rural development and urban-rural coordination.

关键词： village hollowing vacant rural homesteads withdrawal intention influence mechanism Northeast China

TEMPERATURE RESPONSIVE METHACRYLAMIDE POLYMERS WITH ANTIBACTERIAL ACTIVITY

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Chinese Journal of Polymer Science 2010年第4期28卷 607-613页

作者：陈伯宽 Shuen-Hung lo Shu-Feng Lee Department of Polymer Materials Kun Shan University

A new methacrylamide monomer, hexylamine methacrylamide （MAHA）, was synthesized and used in polymerizations. The homopolymer of MAHA and its copolymers were synthesized by free radical polymerization techniques with N-isopropyl acrylamide （NIPAAm） in two different compositions. The quatemization of the homopolymer and copolymers were carried out using 1-bromopropane. The copolymers with NIPAAm and a low MAHA content showed temperature-responsive behavior in an aqueous environment. The lower critical solution temperatures （LCSTs） of these polymers varied between 32℃ and 44℃. The LCSTs of quatemized copolymers were higher than those of neutral copolymers because they were more hydrophilic. The obtained homopolymers and copolymers were tested for antibacterial activities against S. aureus and E. coli. The quatemized water-soluble copolymers showed antibacterial activities against S. aureus. The quaternization resulted in the synthesis of both antibacterial and temperature-responsive copolymers.

关键词： Methacrvlamide: NIPAAm: Antibacterial: Temperature-rest)onsive