• The KIPS Transactions:PartB
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• v.14B no.2
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• pp.135-140
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• 2007

Feature selection is a preprocessing technique commonly used on high dimensional data. Feature selection studies how to select a subset or list of attributes that are used to construct models describing data. Feature selection methods attempt to explore data's intrinsic properties by employing statistics or information theory. The recent developments have involved approaches like correlation method, dimensionality reduction and mutual information technique. This feature selection have become the focus of much research in areas of applications with massive and complex data sets. In this paper, we provide a feature selection method considering data characteristics and generalization capability. It provides a computational approach for feature selection based on fuzzy cluster analysis of its attribute values and its performance measures. And we apply it to the system for classifying computer virus and compared with heuristic method using the contrast concept. Experimental result shows the proposed approach can give a feature ranking, select the features, and improve the system performance.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.2
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• pp.156-165
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• 2014

This paper is the first investigation on the effect of flow control methods on the part load performance in a spark ignition engine. For comparison of the methods, two control devices, port throttling and masking, were applied to a conventional engine without any design change of the intake port. Steady flow evaluation shows that steady flow rates per unit opening area and swirl ratio are very low compared with the port throttling and saturated from mid-stage valve lift, however, swirl increases slightly as the lift is higher in case of 1/4 masking control. In the part load performance, the effect of simple port throttling on lean misfire limit expansion is limited and insufficient; on the other hand a masking improves the limit considerably without any port modification for increasing swirl. Also the results show that the intake flow control improves the combustion with following two mechanisms: stratification induced by the combination of the flow pattern and the fuel injection timing attribute to ignition ability and the intensified flow ensure fast burn. In addition fuel consumption reduces under the flow controls and the reduction rate is different according to the operation conditions and control methods. At the Stoichiometric and/or low speed and low load the throttling method is more advantageous; however vice versa at lean and high load condition. Finally, the throttling is more efficient for HC reduction than masking, on the other side the NOx emissions increase under the masking and decrease under the port throttling compared with conventional port scheme.

• Journal of Internet Computing and Services
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• v.9 no.6
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• pp.27-35
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• 2008

With the proliferation of wireless devices, mobile ad-hoc networking (MANETS) has become a very exciting and important technology. However, MANET is more vulnerable than wired networking. Existing security mechanisms designed for wired networks have to be redesigned in this new environment. In this paper, we discuss the problem of anomaly detection in MANET. The focus of our research is on techniques for automatically constructing anomaly detection models that are capable of detecting new or unseen attacks. We propose a new anomaly detection method for MANETs. The proposed method performs cross-feature analysis on the basis of Rough sets to capture the inter-feature correlation patterns in normal traffic. The performance of the proposed method is evaluated through a simulation. The results show that the performance of the proposed method is superior to the performance of Huang method that uses cross-feature based on the probability of feature attribute value. Accordingly, we know that the proposed method effectively detects anomalies.

• Korean Journal of Poultry Science
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• v.42 no.4
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• pp.275-283
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• 2015

A consumer survey was conducted for the subject of a total of 503 housewives in Korea, with the questionnaires on the quality attributes for Korean native chicken. The responding results collected were used for the importance-performance analysis of the quality attributes involved in production, processing, distribution, and consumption of Korean native chicken. The quality attributes with both relatively high importance and performance ("keep up the good work") were chicken origin, shelf life, freshness, and safety issues, while those with high importance but low performance ("concentrate here") were chicken breed certification and refrigerated/ frozen state. Respondents were also interested in lean meat and protein content of the chicken meat. In the aspect of eating quality attributes, chewiness was the most important one. The survey shows tenderer, chewier, and more flavorful chicken meat will be preferred and a new chicken breed with those eating quality attributes needs to be developed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.10A
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• pp.1532-1538
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• 1999

In general, because error rate of wireless link is higher than that of wired link, DLC layer protocol for wired network with low error rate is not proper for wireless environments. In addition, the conventional DLC layer protocol for wireless network is optimized for the low-speed data service, so it is difficult to use conventional DLC protocol in the current mobile communication environments handing high-speed and multimedia services. Therefore, a DLC layer protocol that is suitable to current wireless communication environments is required. In this paper, we propose a novel error control scheme that supports a variety of traffic attribute and is applicable to high-speed and multimedia data service in WATM. The proposed scheme provides enhanced throughput performance for real-time traffic by using modified ASR ARQ without ACK and reduces loss rate by using FEC in the case of high error condition. Also, for non real-time traffic, the use of ASR ARQ without ACK enhances throughput performance and delay time is decreased by using FEC in the case of high error rate channel. As a result of simulation, the proposed scheme has better performance than conventional ASR ARQ protocol in view of delay and throughput.

• Journal of KIISE:Software and Applications
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• v.33 no.7
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• pp.615-623
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• 2006

A non-functional requirement is a property or quality that the proposed systems have to support the functional requirements. A non-functional requirement is reflected by quality attribute These non-functional requirements playa crucial role during system development, serving as selection criteria for choosing among decisions. It should be continuously considered through the software development process. In spite of the importance of the non-functional requirements, it received little attention because of ambiguousness and invisibility of non-functional requirements. Therefore non-functional model which is a process to analyze the non-functional requirement is proposed for improving the management efficiency of non-functional requirements. Also, this paper presents the trace among the UML diagrams to the conceptual model. According to the non-functional requirement development process, this paper achieved performance-based case study. After then, non-functional requirement should be traced using the UML diagrams.

• Journal of KIISE
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• v.43 no.7
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• pp.744-750
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• 2016

Recent cloud infrastructures provide competitive performances and operation costs for many internet services through pay-per-use model. Particularly, object storages are highlighted, as they have unlimited file holding capacity and allow users to access the stored files anytime and anywhere. Several lines of research are based on cloud-backed file systems, which support traditional POSIX interface rather than RESTful APIs via HTTP. However, these existing file systems handle all files with uniform size backing objects. Consequently, the accesses to cloud object storages are likely to be inefficient. In our research, files are profiled according to characteristics, and appropriate backing unit sizes are determined. We experimentally verify that different backing unit sizes for the object storage improve the performance of cloud-backed file systems. In our comparative experiments with S3QL, our prototype cloud-backed file system shows faster performance by 18.6% on average.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.3
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• pp.307-318
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• 2021

The objective of this study is to analyze the performance of Islamic banks with the Maqashid Shariah approach. The analysis technique used is the Simple Additive Weighting Method (SAW) to solve multi-attribute decision problems. The sampling technique used was purposive sampling while the data came from the annual report of each bank. The results showed that the BTPN Shariah (BTPNS) and Bank Muamalat Indonesia (BMI) are ranked first and second respectively on the Maqashid Shariah Index (MSI) with values of 0.265429 and 0.237110 respectively. Panin Dubai Shariah Bank (PDSB) ranked third with an MSI value of 0.180733, followed by BCA Shariah which ranked fourth with an MSI value of 0.151299. BRI Shariah ranked fifth with an MSI value of 0.128606, followed by BNI Shariah which ranked sixth with an MSI value of 0.124661. Bank Mega Shariah ranked last with an MSI value of 0.087068. Furthermore, there is a relationship (correlation) between ROE, ROA, and OEOI and MSI since each data has a value of 0.000, 0.000, 0.050, and 0.001 respectively, which is smaller than the significance value of 0.05. On the other hand, NPF, TPF, and Asset Growth Rates do not correlate with the MSI since each data has a value of 0.051, 0.252, and 0.215 respectively which is greater than the significance value of 0.05.

• Journal of The Korean Society of Integrative Medicine
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• v.9 no.1
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• pp.69-90
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• 2021

Purpose : This study explores unmet medical services within a region for patients admitted to a single medical institution in one region and was to analyze the importance and satisfaction of hospital selection attributes. Through this, we tried to solve the unmet medical needs of patients and provide useful basic data in terms of hospital management in the region. Methods : It were collected to a total of 250 questionnaires for patients admitted to the regional integrative medical hospital. However, 232 samples were used for the final analysis, excluding 18 copies not reported in good faith. For the analysis, first, demographic frequency analysis of inpatients and inpatients was performed, and second, characteristics of patients, including frequent disease receiving treatment, were analyzed. Next, descriptive statistics analysis was conducted on unmet medical service intentions. In terms of hospital selection attribute, the items of continuity maintenance (I quadrant), priority visibility (II quadrant), low priority (III quadrant), and excessive effort (IV quadrant) were derived using the IPA (importance-performance analysis) matrix technique. Results : The derived results were classified by item and area. In the priority administration area, it was the reputation and recognition of medical institutions and the service area of medical institutions. In the case of items, there were 6 items including the importance of surgery and medical expenses, and diet at hospitalization. 1) Conclusion : Thus a result of this study, resources are efficiently allocated to priority correction areas with high importance but low satisfaction and circulatory medical treatment is performed in the departments required by patients who use medical care and, various methods, such as preparing a policy to support medical expenses, should be sought.

• Journal of Korea Society of Industrial Information Systems
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• v.27 no.6
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• pp.115-126
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• 2022

The purpose of this study is to try to IPA(Importance-Performance Analysis) by applying text mining approaches to user review data for korea mobile banking applications, and to derive priorities for improvement. User review data on mobile banking applications of korea commercial banks (Kookmin Bank, Shinhan Bank, Woori Bank, Hana Bank), local banks (Gyeongnam Bank, Busan Bank), and Internet banks (Kakao Bank, K-Bank, Toss) that gained from Google playstore were used. And LDA topic modeling, frequency analysis, and sentiment analysis were used to derive key attributes and measure the importance and satisfaction of each attribute. Result, although 'Authorizing service', 'Improvement of Function', 'Login', 'Speed/Connectivity', 'System/Update' and 'Banking Service' are relatively important attributes when users use mobile banking applications, their satisfaction is not at the average level, indicating that improvement is urgent.