• KIPS Transactions on Software and Data Engineering
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• v.2 no.9
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• pp.629-642
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• 2013

Recently, with the advent of smart phones, it brought many changes in lives of modern people. Especially, application utilizing the sensor information of smart phone, which provides the service adapted by user situations, has been emerged. Sensor data of smart phone can be used for recognizing the user situation, Because it is closely related to the behavior and habits of the user. currently, GPS sensor one of mobile sensor has been utilized a lot to recognize basic user activity. But, depending on the user situation, activity recognition system cannot receive GPS signal, and also not collect received data. So utilization is reduced. In this paper, for solving this problem, we suggest a method of user activity recognition that focused on the accelerometer sensor data using smart phone. Accelerometer sensor is stable to collect the data and it's sensitive to user behavior. Finally this paper suggests a noble approach to use state transition diagrams which represent the natural flow of user activity changes for enhancing the accuracy of user activity recognition.

• Journal of the Korea Society of Computer and Information
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• v.26 no.7
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• pp.57-64
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• 2021

In this paper, we propose and test the efficacy of an easy-to-use user location certification system for public places that relies on frequencies outside the audible range for humans. The inaudible frequencies come in signal frequency between 18-20 kHz and are generated by general audio speaker. After an individual's smart device detects the signal frequency, it sends the frequency value, user's personal ID, and user's location to a system server that certifies the user's visit location currently. The system server then saves a user visit record and categorizes it by individual. To show the usefulness of this proposed system, we developed a user visit certification application for smart devices linked to a system server. We then conducted a user visit certification experiment using the proposed system, with the result showing 99.6% accuracy. For a comparison, we then held a user visit certification experiment using a QR code, which confirmed that our proposed system performs better than QR code location certification. This proposed system can thus provide restaurants and other facilities reliable user contact tracing and electronic visitor access lists in the age of COVID-19.

• The KIPS Transactions:PartD
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• v.15D no.3
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• pp.327-336
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• 2008

Many XML-compliant UIDLs(User Interface Description Languages) have been developed to specify user interfaces. Although previous UIDLs are helpful to describe user interfaces of web and desktop applications, they are not available of developing UI of mobile applications. In this paper, in order to effectively specify user interfaces of MIDlet which is application model on J2ME(Java Platform, Micro Edition), we propose MIML(Midlet Interface Markup Language) and present transformation rules to generate source codes from MIML. Further, we enhance the usability of MIML through J2MERenderer which is a tool using presented rules. The proposed method can specify user interfaces of mobile applications and allow developers to keep productivity and consistency in development phase.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.23 no.5
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• pp.83-88
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• 2023

In this paper, we developed a workout and diet assistance application to meet the growing demand for workout and dietary support services due to the increase in the home training population. The application analyzes the user's workout posture in real-time through the camera and guides the correct posture using guiding lines and voice feedback. It also classifies the foods included in the captured photos, estimates the amount of each food, and calculates and provides nutritional information such as calories. Nutritional information calculations are executed on the server, which then transmits the results back to the application. Once received, this data is presented visually to the user. Additionally, workout results and nutritional information are saved and organized by date for users to review.

• Journal of Information Technology Application
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• v.2 no.1
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• pp.25-53
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• 2000

As Information Technology has developed, The structure of information system used in organizations is changing from centralized computing structure to distributed computing structure. The roles of information department have expanded, which is not only develope and maintain system but also provide usage-support service to end-user. If organization support end-user properly, they get many benefits. if they don't do it properly, they waste many resource. Therefore, the purpose of this study is the search for quality determinant factors and type of information that provide user effective service under web-based information system. The result of this study is as follow First, when SERVQUAL is used, the quality determinant factors of usage-support service are categorized three, which is responsibility and assurance, empathy and tangable, and reliability. When SERVPERF is used, the determinant factors consist of five, but the use of assurance as a factor is cautious. Second, reliability and tangability among determinant factors affect general service quality, and tangibility is most important factors. third, When the locations of user are distributed the degree of general service quality is not different whether formal or informal information center provide usage-support service. This study may suggest practical implication as follows; First, as user are good at to use information system the degree of importance for tangibility are decreased. when user are individualized and improve their ability to use information system, empathy will not be important factors any more, therfore it assume that reliability will be most important factors. Second, if organizations promote not only formal informaton center but also informal inforamtion center they may support end-user more effectively. However, this study has the following limitations: First, it is difficult to generalize the result of this study Second, service quality determinant factors used in this study don't explain the influence to general service quality fully. Third, this study analyze a simple relation between service quality determinant factor and general service quality. Finally, this study don't distinguish between information system service and information support service.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.943-945
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• 2003

This paper firstly focused on introducing the current status of ITS activities in Korea. Then, possibility of RS application within the surface transportation was studied. ITS in Korea was first introduced in early ninties, since then, Korean government puts lots of efforts for flourishing it. Topics for the paper are composed of the Korean ITS Strategic Plan, ITS R&D, Metropolitan Model Deployment Initiative Projects, and RS application in ITS. One of the main findings in the process of revision of the national strategic plan for the 21$^{st}$ century was that ITS should thoroughly reflect end users’ needs in establishing its goals and objectives. For ITS R&D, Korean Government took initiatives, and drove it since 1997. In conclusion, authors suggest future application of RS within ITS in developing country.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.4
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• pp.1779-1798
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• 2018

Heterogeneous wireless sensor networks (HEWSN) is a kind of wireless sensor networks (WSN), each sensor may has different attributes, HEWSN has been widely used in many aspects. Due to sensors are deployed in unattended environments and its resource constrained feature, the design of security and efficiency balanced authentication scheme for HEWSN becomes a vital challenge. In this paper, we propose a secure and lightweight user authentication and key agreement scheme based on biometric for HEWSN. Firstly, fuzzy extractor is adopted to handle the user's biometric information. Secondly, we achieve mutual authentication and key agreement among three entities, which are user, gateway and cluster head in the four phases. Finally, formal security analysis shows that the proposed scheme defends against various security pitfalls. Additionally, comparison results with other surviving relevant schemes show that our scheme is more efficient in term of computational cost, communication cost and estimated time. Therefore, the proposed scheme is well suitable for practical application in HEWSN.

• ETRI Journal
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• v.43 no.1
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• pp.95-108
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• 2021

Application (app) ratings are feedback provided voluntarily by users and serve as important evaluation criteria for apps. However, these ratings can often be biased owing to insufficient or missing votes. Additionally, significant differences have been observed between numeric ratings and user reviews. This study aims to predict the numeric ratings of Google apps using machine learning classifiers. It exploits numeric app ratings provided by users as training data and returns authentic mobile app ratings by analyzing user reviews. An ensemble learning model is proposed for this purpose that considers term frequency/inverse document frequency (TF/IDF) features. Three TF/IDF features, including unigrams, bigrams, and trigrams, were used. The dataset was scraped from the Google Play store, extracting data from 14 different app categories. Biased and unbiased user ratings were discriminated using TextBlob analysis to formulate the ground truth, from which the classifier prediction accuracy was then evaluated. The results demonstrate the high potential for machine learning-based classifiers to predict authentic numeric ratings based on actual user reviews.

• Proceedings of the Korean Information Science Society Conference
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• 2012.06a
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• pp.161-163
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• 2012

전통적으로 단순 그래픽 연산에만 사용되던 GPU는 연산 속도의 증가와 고수준의 언어 지원을 통해서 일반적인 용도로도 사용 가능한 GPGPU기술로 발전했다. GPGPU는 병렬 처리 능력과 속도 개선을 목적으로 다방면에 걸쳐 사용되고 있는데, 기본적으로 Linux user mode에서의 사용만 가능하며 kernel mode에서의 사용은 지원되지 않는다. Linux kernel 내부에서도 GPGPU 사용이 가능해진다면, User application 뿐만 아니라 Linux kernel의 성능 개선에도 GPGPU를 사용할 수 있을 것이다. 우리는 Linux kernel의 system call과 user mode의 mediator process를 사용한 Linux kernel mode에서의 GPGPU 사용법을 제시하고, 향후 성능 개선을 위한 기준점을 제공한다.

• ETRI Journal
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• v.29 no.2
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• pp.169-178
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• 2007

With the advent of ubiquitous computing environments, it has become increasingly important for applications to take full advantage of contextual information, such as the user's location, to offer greater services to the user without any explicit requests. In this paper, we propose context-aware active services based on context-aware middleware for URC systems (CAMUS). The CAMUS is a middleware that provides context-aware applications with a development and execution methodology. Accordingly, the applications based on CAMUS respond in a timely fashion to contextual information. This paper presents the system architecture of CAMUS and illustrates the content recommendation and control service agents with the properties, operations, and tasks for context-aware active services. To evaluate CAMUS, we apply the proposed active services to a TV application domain. We implement and experiment with a TV content recommendation service agent, a control service agent, and TV tasks based on CAMUS. The implemented content recommendation service agent divides the user's preferences into common and specific models to apply other recommendations and applications easily, including the TV content recommendations.