• Journal of Korean Society of Transportation
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• v.30 no.2
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• pp.43-52
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• 2012

A lane departure warning system (LDWS) is an effective technology-based countermeasure for preventing traffic crashes as it provides warning information to drivers. Understanding the characteristics of perception and satisfaction levels on LDWS is fundamental for deriving better performance and functionality enhancements of the system. The purpose of this study is to evaluate the user satisfaction of LDWS. A survey to collect user perception and user preference data was conducted. Both cross-tabulation analysis and binary logistic regression technique were adopted to identify the factors affecting user satisfaction for LDWS. The results revealed that the accuracy and timeliness of warning information was significant for evaluating the effectiveness of LDWS. In particular, the warning accuracy at a curve segment on the road was the most dominant factor affecting user satisfaction. The outcome of this study would be valuable in evaluating and designing LDWS functionalities.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.9
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• pp.880-886
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• 2014

Many railway signalling functions have increasingly depended on computer software with recent development in computing technology, leading to evolution into more flexible and intelligent railway signalling system. Meanwhile, software programs are likely to have many errors and the cost incurred by such errors has increased. Especially, if fatal software error occurs during railway operation, it may result in loss of lives. So the software verification and validation have become more important. It is needed for software functional safety tool to support these, but most commercial tools depend on direct access to the system's memory, resulting in many difficulties in application. Owing to such difficulties and complexity, they are rarely used in railway signalling system software validation. In this study, a new testing tool for software functional testing through an external interface that can be easily used in functional testing of software was developed. Such testing tool allows development and analysis of test cases for black-box testing through analysis of actually used interface protocols, leading to increased user convenience.

• Journal of Korean Society for Quality Management
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• v.17 no.2
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• pp.17-26
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• 1989

This paper is concerned with forecasting the existing number of errors in the computer software and optimizing the stopping time of the software test based upon the forecasted number of errors. The most commonly used models have assessed software reliability under the assumption that the software failure late is proportional to the current fault content of the software but invariant to time since software faults are independents of others and equally likely to cause a failure during testing. In practice, it has been observed that in many situations, the failure rate decrease. Hence, this paper proposes a mathematical model to describe testing situations where the failure rate of software limearly decreases proportional to testing time. The least square method is used to estimate parameters of the mathematical model. A cost model to optimize the software testing time is also proposed. In this cost mode two cost factors are considered. The first cost is to test execution cost directly proportional to test time and the second cost is the failure cost incurred after delivery of the software to user. The failure cost is assumed to be proportional to the number of errors remained in the software at the test stopping time. The optimal stopping time is determined to minimize the total cost, which is the sum of test execution cast and the failure cost. A numerical example is solved to illustrate the proposed procedure.

• Journal of IKEEE
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• v.23 no.2
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• pp.448-453
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• 2019

Under the conflicting objectives of maximum user satisfaction and fast launching, there exist great needs for automated mobile app testing. In automated app testing, detection of usage-state changes is one of the most important issues for minimizing human intervention and testing of various usage scenarios. Because conventional approaches utilizing pre-collected training examples can not handle the rapid evolution of apps, we propose a novel method detecting changes in usage-state through graph-entropy. In the proposed method, widgets in a screen shot are recognized through DNNs and 'onverted graphs. We compared the performance of the proposed method with a SIFT (Scale-Invariant Feature Transform) based method on 20 real-world apps. In most cases, our method achieved superior results, but we found some situations where further improvements are required.

• Journal of Fashion Business
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• v.27 no.3
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• pp.50-62
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• 2023

The e-commerce fashion market has experienced a remarkable growth, leading to an overwhelming availability of shared information and numerous choices for users. In light of this, chatbots have emerged as a promising technological solution to enhance personalized services in this context. This study aimed to develop user-product attributes for a chatbot-based personalized fashion recommendation service using big data text mining techniques. To accomplish this, over one million consumer reviews from Coupang, an e-commerce platform, were collected and analyzed using frequency analyses to identify the upper-level attributes of users and products. Attribute terms were then assigned to each user-product attribute, including user body shape (body proportion, BMI), user needs (functional, expressive, aesthetic), user TPO (time, place, occasion), product design elements (fit, color, material, detail), product size (label, measurement), and product care (laundry, maintenance). The classification of user-product attributes was found to be applicable to the knowledge graph of the Conversational Path Reasoning model. A testing environment was established to evaluate the usefulness of attributes based on real e-commerce users and purchased product information. This study is significant in proposing a new research methodology in the field of Fashion Informatics for constructing the knowledge base of a chatbot based on text mining analysis. The proposed research methodology is expected to enhance fashion technology and improve personalized fashion recommendation service and user experience with a chatbot in the e-commerce market.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.12 no.1
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• pp.71-81
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• 1987

To fuly utilize the availability of the ISDN, it is very important to develop the ISDN user terminals which can provide various user services. In this paper, the basic concept of the ISDN user terminal is briefly studied and, based on this study, a stimulus type digital telephone which can be connected directly to the ISDN is designed. This digital telephone can provide the basic voice service and has general functions such as voice encoding / decoding(PCM is used), user-network signalling, digital tone supply, channel selection, key pad and atatus display. Echo cancellation method is adopted for the digital subscirber loop transmission and user-network signalling is implemented according to the LAPD(Link Access Procedure on D-channel) protocol recommended by the CCITT's recommendations I.440-I.441. The validity of designed S/W and H/W functions are verified by testing them with ISDN circuit switching emulator described in the first part of this paper.

• The Journal of Korean Association of Computer Education
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• v.22 no.1
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• pp.63-78
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• 2019

This study aims to improve User eXperience (UX) of the diagnostic-supplement learning system for Basic academic skills which has been utilized by teachers nationwide since 2015 in order to provide a consistent and systematic support on students' basic academic skills in K-12 school contexts. To achieve the research objective, usability evaluations such as basic questionnaire about UX/UI of the system according to user types, user testing, in-depth interview, expert heuristics were conducted. In addition, user-centered system was suggested through developing and iteratively evaluating the prototypes based on the user requirements drawn from the findings of such quantitative and qualitative usability evaluations. This study has an implication in suggesting the user-friendly design through the UX/UI improvements of the diagnostic-supplement learning system for Basic academic skills.

• Journal of KIISE:Computing Practices and Letters
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• v.13 no.2
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• pp.86-99
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• 2007

Packet filtering is to filter out potentially malicious network packets. In order to test a packet filtering function we should verify whether security policies are performed correctly as intended. However there are few existing tools to test the function. Besides, they need user participation when generating test cases or deciding test results. Many security administrators have a burden to test systematically new security policies when they establish new policies or modify the existing ones. To mitigate the burdens we suggest a new test method with minimal user articipation. Our tool automates generation steps of the test cases and the test oracles, respectively. By using the test oracles generated automatically, deciding test results is possible without user intervention. Our method realizes an automatic testing in three phases; test preparation phase, test execution, and test evaluation. As a result it may enhance confidence of test activities more highly. This paper describes the design and implementation of our test method and tool.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.10
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• pp.1216-1227
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• 2019

We propose TITAN (Tool for IoT ApplicatioN testing), a developer support tool that enables efficient testing of IoT applications. TITAN is designed to allow IoT application developers to run their applications under the development environment without being restricted by physical environments and users' behaviors required to test application logic being developed. Using TITAN, IoT application developers can save the time and effort needed to repeatedly perform the testing of application logic while they develop their applications. In this paper, we present the system architecture of TITAN and its current prototype implementation. We evaluate the usefulness and usability of TITAN through a small user study with two example IoT applications. The study participants show their positive perception about the usefulness of TITAN. We further discuss the limitations of the current study and future research directions.

• Journal of Korean Academy of Nursing
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• v.37 no.1
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• pp.14-25
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• 2007

Purpose: A user centered web-based mental health management system may be particularly useful in Korea where there is widespread diffusion of personal computers and internet connectivity. The purpose of this paper was to describe the development of a web-based system for mental health management in adolescents using principals of a user centered design. Method: Our design process includes five distinct phases: needs assessment, analysis, design, development/testing/revision, and application release. Results: Web content includes an introduction, information about mental health management in adolescents, self-assessment and guidance, interventions for improving mental health, directory of self-help groups, and counseling and additional community resources. The web site was released using the URL: http://www.baejy.com/youth. Conclusion: The end result was a web based mental health management system for adolescents with a high degree of usability. The author believes that web-based mental health interventions in the future have true potential in helping Koreans who are suffering, or at risk, for mental health problems, particularly because of the stigma related to psychiatric therapy in Korea.