• Journal of KIISE:Information Networking
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• v.30 no.4
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• pp.559-571
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• 2003

ENUM(tElephon NUmbering Mapping) is protocol that brings convergence between PSTN Networks and IP Networks using a unique worldwide E.164 telephone number as an identifier between different communication infrastructure. The mechanism provides a bridge between two completely different environments with E.164 number; IP based application services used in PSTN networks, and PSTN based application services used in IP networks. We propose a new way to organize and handle ENUM Tier 2 name servers to improve performance at the name resolution process in ENUM based application service. We build an ENUM based network model when NAPTR(Naming Authority PoinTeR) resource record is registered and managed by area code at the initial registration step. ENUM promises convenience and flexibility to both PSTN and IP users, yet there is no evidence how much patience is required when users decide to use ENUM instead of non-ENUM based applications. We have estimated ENUM response time, and proved how to improve performance up to 3 times when resources are managed by the proposed mechanism. The proposition of this thesis favorably influences users and helps to establish the policy for Tier 2 name server management.

• Journal of Korean Society of Archives and Records Management
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• v.19 no.3
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• pp.155-178
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• 2019

The study aims to analyze the characteristics and problems of raw image file formats, evaluate its suitability for the management of digital photographic records, and suggest the introduction method to utilize such format in public institutions. Raw image file formats feature reversibility and flexibility. However, most of them are proprietary file formats that depend on the digital camera manufacturer. The DNG format, which was developed to standardize raw image file formats, has received positive reviews from overseas public agencies. However, the DNG format is not fully recognized as a standard; hence, it is appropriate to use it tentatively until the standard raw format appears. On the other hand, the converted digital photo file format is not recognized as an original with legal authenticity. Therefore, in the short term, DNG files created by format conversion and original raw files should be encapsulated and preserved. Furthermore, it is necessary to redefine the baseline of the hash value and file size to recognize the legal authenticity only with DNG files in the long term.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.67 no.4
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• pp.274-284
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• 2022

To use kenaf (Hibiscus cannabinus L.) as a fiber and livestock feed, a high-yielding variety needs to be identified. For this, accurate phenotyping of plant height is required for this breeding purpose due to the strong relationship between plant height and yield. Plant height can be estimated using RGB images from unmanned aerial vehicles (UAV-RGB) and photogrammetry based on Structure from Motion (SfM) algorithms. In kenaf, accurate measurement of height is limited because kenaf stems have high flexibility and its height is easily affected by wind, growing up to 3 ~ 4 m. Therefore, we aimed to identify a method suitable for the accurate estimation of plant height of kenaf and investigate the feasibility of using the UAV-RGB-derived plant height map. Height estimation derived from UAV-RGB was improved using multi-point calibration against the five different wooden structures with known heights (30, 60, 90, 120, and 150 cm). Using the proposed method, we analyzed the variation in temporal height of 23 kenaf cultivars. Our results demontrated that the actual and estimated heights were reliably comparable with the coefficient of determination (R²) of 0.80 and a slope of 0.94. This method enabled the effective identification of cultivars with significantly different heights at each growth stages.

• Journal of the Korean Society for Library and Information Science
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• v.57 no.2
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• pp.379-408
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• 2023

This case study reports on the redevelopment of a course, Local Culture Information Theory offered by the Department of Library and Information Science at C University, into a capstone design course using a project-based learning approach. In collaboration with a local community youth organization, the redesigned course provided an opportunity for LIS students to develop and implement a digital literacy program that enabled high school students to use a variety of digital multimedia technologies to complete a project of digital Human Library featuring video, audio, and digital are such as webtoons. Through semi-structured interviews with 5 students and 3 staff from partner organizations, this study reports on course development process, the establishment of local partnerships, project outcome, as well as suggestions for improvements. In addition, a qualitative analysis of the participating students' interview responses using the Framework for 21st Century Learning (P21) found they developed and improved 11 skills across three core areas: life and career skills including self-direction, project management, collaboration with diverse teams, flexibility, responsibility, leadership; learning and innovation skills including communication and collaboration, problem-solving, creativity, and critical thinking; and information, media, and technology skills through media creation. Lessons learned and recommendations from this case study may be useful for other LIS programs and faculty interested in implementing project-based learning or developing capstone design courses.

• Journal of Service Research and Studies
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• v.14 no.3
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• pp.188-205
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• 2024

The food truck business, which involves selling various types of food from mobile vehicles, has gained significant popularity in urban centers and at events. These food trucks have rapidly expanded due to their relatively low initial investment and high flexibility, attracting customers with unique menus and personalized services. However, as competition increases, the need to manage service quality to boost customer satisfaction and encourage repeat visits has become more critical. Despite this growing importance, there has been limited empirical research on the topic. This study aims to analyze customer experiences with food truck services to gain strategic insights for improving service quality. By applying structural topic modeling to customer review data, the study identified 50 key topics. The process included a comprehensive evaluation of model diagnostics and interpretability to determine the optimal number of topics, ultimately selecting the most relevant ones related to service experiences. The impact of these identified topics on overall customer satisfaction was empirically tested using regression analysis. The results showed that aspects such as "Food Taste," "Friendly Staff," and "Positive Emotion" had a positive influence on customer satisfaction, whereas "Delayed Service," "Negative Emotion," and "Beverage Service" had a negative impact. Based on this analysis, the study proposes concrete methods for food truck operators to systematically analyze customer feedback and use it to drive service improvements and innovation. This research highlights the importance of data-driven decision-making in small business environments like food trucks and contributes to expanding the application of topic modeling in the service industry.

• Journal of Energy Engineering
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• v.20 no.1
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• pp.13-20
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• 2011

The high fuel flexibility of Micro Gas Turbine(MGT) has boosted their use in a wide variety of applications. Recently, the demand for biogas generated from the digestion of organic wastes and landfill as a fuel for gas turbines has increased. We researched the influence of firing landfill gas(LFG) on the performance and operating characteristics of a micro gas turbine combined heat and power system. $CH_4$ and $CO_2$ simultaneous recovery process has been developed for field plant scale to provide an isothermal, low operating cost method for carrying out the contaminants removal in Land Fill Gas(LFG) by liquid phase catalyst for introduce into the green house for the purpose of $CO_2$ rich cultivation of the plants. Methane purification and carbon dioxide stripping by muti panel autocirculation bubble lift column reactor utilizing Fe-EDTA was conducted for evaluate optimum conditions for land fill gas. Based on inflow rate of LFG as 0.207 $m^3$/min, 5.5 kg/$cm^2$, we designed reactor system for 70% $CH_4$ and 27% $CO_2$ gas introduce into MGT system with $H_2S$ 99% removal efficiency. A green house designed for four different carbon dioxide concentration from ambient air to 1500 ppm by utilizing the exhaust gas and hot water from MGT system.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.5
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• pp.12-28
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• 2017

The core of the transportation service, so-called Mobility 4.0 is the flexibility of the entire mobility and its implementation. By doing so, the most essential element is to build a platform to link a supply and a demand simultaneously. In other word, a comprehensive analytical framework is to be set with a data repository which can be periodically updated. With such circumstances, the entire trip chain including pedestrian movements is required to be thoroughly investigated and constructed at the viewpoint of the intermodal transit station. A few studies, however, have been attempted. In this study, the comprehensive analytical framework with the integrated mobility at intermodal transit station was proposed, which consisted of the three modules; 1) Data Repository Extracting from Smart Card DB, 2) Framework of Analyzing Integrated Mobility, and 3) Interpretation of the Integrated Mobility with GIS information and the other factors. A case study with the seven railway stations (Sadang, Sindorom, Samseong, Gwanghwanoon, Gangnam, Jamsil, Seoul Nat'l Univ. of Education) was conducted. The stations of the case study were clustered by the three groups with the statistical ground, and it is most likely to understand the effect of a variety of factors and a comprehensive data-driven analyses with the entire trip stages.

• Information Systems Review
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• v.17 no.1
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• pp.117-140
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• 2015

Cloud Computing has drawn attention as one of 10 IT strategic technology trends and has various advantages such as cost reduction and enhancing business flexibility. However, corporations hesitate to adopt the service because of unexpected risks. Especially compared to large firm, medium and small ones use public cloud that security risk is high. Meanwhile, real option strategy has drawn attention as the method to hedge uncertainty in IT projects. Therefore, in this study causal relationships among technical, security, relational, and economic risks of cloud service will be investigated. Eventually, this study investigates how those risks influence the intention to choose the real option about the cloud service. For this study, five hypotheses is drawn, and a survey is conducted about the medium and small firms which are currently using cloud service to examine hypotheses. Since the study is at organizational level, 287 questionnaire replies are recalculated to 120 firms. For statistical analysis, Smart PLS and SPSS Statistics18 are used. As a result, technical risk of cloud service has significantly positive influence on security risk. Second, security risk and relational risk of cloud service has significantly positive influence on economic risk. Third, economic risk of cloud service has significantly positive influence on the intention to purchase the delay option or abandon option. Based on this result, this research discussed practical and academic implications and the limitations.

• Journal of Korean Society of Transportation
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• v.27 no.4
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• pp.155-166
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• 2009

Road design safety assessment by existing tools and methods have normally been examined by expert judgements using design documents and on-site inspections. The existing methods, however, have two main problems such as insufficiency of objectiveness and inability to measure effects of accident countermeasures. This paper studies ways to develop a road safety assessment system through reviewing the IHSDM developed in USA. The crash prediction module of IHSDM calculate accident frequency and rate of roadway segments using accident prediction models and accident modification factors for safety evaluation. The methodology of evaluation and development of accident modification factors somewhat overcome the problems of the existing methods. In spite of these advantages, IHSDM could not relevantly reflect characteristics of domestic rural roadways since it overestimate the number of accidents and rate of korean rural roadways. Especially, IHSDM may not evaluate or consider land use patterns of Korean roadways, and futhermore, original environment on base conditions used to develop IHSDM may not be different from ours. The user requirements being developed for a road safety assessment system for Korean roadways include enhanced flexibility and diversity of data input-output processes.

• Journal of KIISE:Computing Practices and Letters
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• v.5 no.4
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• pp.426-439
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• 1999

본 논문에서는 웹(World Wide Web)에서 사용자가 손쉽고 편리하게 이용할 수 있는 멀티미디어 대중교통 안내시스템 개발 경험을 소개한다. 개발된 시스템은 클라이언트와 서버 시스템, 경로탐색 시스템, 교통정보 저장 시스템, 노선 및 정류장 관리 시스템으로 구성되어 있다. 클라이언트에서 작동되는 사용자 인터페이스는 직관적으로 이해가 쉽고, 사용이 편리하며 인터액티브한 멀티미디어 대중 교통안내 서비스를 제공한다. 서버 시스템은 교통정보 수집 시스템으로부터 입력되는 데이타와, 경로탐색 시스템, 교통정보 저장 시스템과 연동되어 클라이언트의 요구사항을 처리하고 그 결과를 사용자에게 돌려준다. 수정된 A* 알고리즘을 이용하는 경로탐색 시스템은 최적경로를 탐색하며, 교통정보 저장 시스템은 현재 교통상황, 정류장, 노선, 지도 등의 정보를 저장한다. 노선 및 정류장 관리시스템은 시스템 관리자가 노선 또는 정류장 관리를 서버 화면의 지도상에서 효율적으로 수행할 수 있는 도구이다. 본 논문에서 다루는 대중교통 안내시스템은 Java로 구현하였기 때문에 확장과 이식이 용이하며, 시스템 유지보수 비용이 적게 드는 장점을 가지고 있다. 그리고, 웹 브라우저가 동작되는 환경에서는 어디서나 쉽게 접근이 가능하며 향후 구축될 Intelligent Transportation Systems(ITS)의 한 모듈로써 바로 작동될 수 있을 뿐만 아니라, 현재 인터넷상에서 제공되는 다양한 서비스와도 연동이 가능하다.Abstract This paper introduces our experience for developing a public transportation guidance system, which facilitates the World-Wide Web(WWW) to provide users with easier access and use. The proposed system is composed of four subsystems: client/server system, path search system, traffic data storage system, and traffic raw-data management system. The user interface in clients utilizes Java to furnish users with multimedia data accessibility and interactivity. The server processes clients' requests based on the traffic data coming from remote sensing devices and interacts with the path search system and traffic data storage system to provide users with the results. The path search system, which uses a modified A* algorithm, produces optimal solutions based on dynamic traffic data. The traffic data storage system stores the current traffic information together with the geographical information about the b$us_way routes. The traffic raw-data management system is a graphical user interface which enables the system manager to handle the traffic information easily on the map in the terminal screen. The system has considerable benefits such as portability, scalability, and flexibility since it is implemented using Java. Also, it can be extended to an integrated Intelligent Transportation Systems(ITS) which includes a variety of information on the Internet as well as traffic information.n.