• Educational Technology International
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• 제16권1호
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• pp.31-57
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• 2015

This study aims to understand the overall experiences of students who use notebook computers in class by using a qualitative approach. Interview data were collected from 23 Korean college students at a Korean university, who use notebook computers in their classes; the data were analyzed through the constant comparison method. The results from this study can be categorized into two themes: the positive and negative effects of using a notebook computer in class, and different perspectives on the effects of using a notebook computer in class. The positive effects of notebook computer usage were specified as production of lecture notes, performing searches for information, management of learning materials, and effective time management. However, behaviors such as perusing other works not associated with the class were indicated as negative effects. The participants had different perceptions about the effect of notebook computer usage in increasing academic performance, although they were satisfied in their experience with notebook computers in general. These results imply that appropriate methods of technology usage are needed and that the support of an instructor is essential to achieve fully beneficial use of notebook computers in class.

• 산업경영시스템학회지
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• 제42권4호
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• pp.153-164
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• 2019

Since the appearance of smartphones, the smartphone market has been in fierce completion by new technologies and marketing trends. The smartphone market is now somewhat saturated, and the manufacturers are trying to improve their position in the market through the repurchase of existing customers and the influx of competitors. At the same time, customers have their own purchasing criteria for smartphones. Therefore, manufacturers need to determine new technology and marketing trends based on customer purchasing trends and usage characteristics. The aim of this study is to analyze the quality attributes of smartphones. We conducted a survey on 220 respondents, and divided the respondents into several groups by purchasing trends and usage characteristic through cluster analysis. The groups are analyzed and compared based on the Kano model for the quality attributes of smartphone. The analysis result are as follows. Firstly, purchasing trends divide responders into groups that prefers high-end premium smartphones and those that take into account practicality in terms of purchasing trends. Secondly, usage characteristic divide responders into three groups: those with clear usage pattern, those who prefer ease of use, and the rest, and we find out that those with clear usage pattern are important customer in viral marketing. Lastly, Kano analysis is revealed the 'Slow/hi-speed camera', 'Private mode', 'Widget', 'Health care' are attractive quality attributes.

• 상하수도학회지
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• 제31권2호
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• pp.177-186
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• 2017

This study concerned the analysis on the efficiency of the conversion of water tank type supply system to direct water supply system to examine the feasibility of the conversion, as well as the calculation of optimal conversion range that enables the supply of safe, high-quality water at stable pressure in accordance with the standards of water supply facility. The results of this research showed that when converting water supply system from water tank type supply system to direct water supply system, more nodal points could be properly converted and more reduction of electricity usage was expected in case water pressure rather than residence time was fixed. This means that higher efficacy can be obtained by fixing water pressure when converting water supply system. However, since the number of the locations that received on-spot inspection was small and the electricity usage measured was not exclusively by water supply facility, it is difficult to judge that such reduction of electricity usage accurately represents reduced electricity usage by water supply facility alone. therefore, after having secured on-spot information about a larger number of locations in apartment complexes that have converted water supply system, and utilizing information about electricity usage exclusively by water supply facility, the proposed method of this research could be applied to accurately deducing expected reduction of electricity usage by water supply facilities of various other apartment complexes. It is also considered possible to deduce an effective operation method of water supply system by finding out an area that shows low pressure or low residual chlorine concentration in the optimal conversion range of water supply, followed by estimating the proper location of pumping station or the proper chlorine dosage at the power purification plant that supply water to the target area.

• 전자공학회논문지CI
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• 제46권2호
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• pp.10-18
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• 2009

본 논문에서는 휴대용 보안 저장매체를 이용한 방송프로그램의 사적 이용 인증을 통해, 도메인에 등록된 휴대용 사적 이용 인증기기를 보유한 사용자가 물리적인 장소에 구애 받지 않고 자신이 녹화한 방송프로그램을 자유롭게 사용할 수 있도록 함으로써 사용자의 사적이용을 보장할 수 있는 방법을 제안한다. 본 논문에서 제안하는 사적이용 인증과정은 휴대용 사적이용 인증기기, 휴대용 사적이용 인증기기 접근제어 모듈, 휴대용 사적이용 인증기기 연동 재생 툴에 의해 이루어진다. 휴대용 사적이용 인증기기는 도메인 인증정보를 보호된 상태로 안전하게 저장할 수 있는 저장매체 역할을 수행하며, 휴대용 사적이용 인증기기 접근제어 모듈은 휴대용 사적이용 인증기기에 저장된 도메인 인증정보와 방송프로그램의 인증정보를 이용하여 방송프로그램 재생 정보를 추출하는 역할을 수행한다. 휴대용 사적이용 인증기기 연동 재생 툴은 휴대용 사적이용 인증기기 접근제어 모듈을 통해 획득한 방송프로그램 재생 정보를 이용하여 사용자의 명령에 따라 보호된 방송프로그램을 복호화 재생하는 기능을 제공한다. 본 논문에서는 제안 모델의 구성과 동작 절차를 기술하고 구현을 통해 제안한 인증방법에 대한 유효성 검증을 수행한다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2005년도 추계종합학술대회
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• pp.436-439
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• 2005

최근 모바일 컴퓨터 및 임베디드 시스템이 대중화 되면서 전력, 공간, CPU 클럭, 메모리 등과 같은 자원을 효율적으로 사용하기 위한 연구가 많이 진행되고 있다. 기존의 임베디드 시스템 개발에서는 하드웨어 측면의 자원 사용에 대한 연구가 주를 이루어 졌으나 최근 임베디드 시스템에서 소프트웨어의 비중이 커짐에 따라 소프트웨어 측면에서의 자원 사용에 대한 연구가 필요하게 되었다. 본 연구에서는 임베디드 시스템의 자원 사용을 분석하는 새로운 방법인 '명령어 기반의 자원 사용 분석 방법(Instruction Level Resource Usage Analysis Method'을 제안하고 이를 'I-Debugger'라는 도구로 구현하였다. I-Debugger는 프로그램을 명령어 단위의 수행으로 제어하는 디버깅 층(Debugging Layer), 실시간으로 수행되는 명령어에 대한 데이터를 활용 가능한 정보를 변환하는 통계 층(Statistics Layer) 및 분석하고자 하는 응용에 적합하게 정보를 분석하는 분석 층(Analysis Layer)으로 구성된다. 본 연구에서 개발된 I-Debugger를 간단한 문제에 적용한 결과 자원 효율적인 임베디드 시스템 개발에 매우 유용하게 사용될 수 있음을 알 수 있었다.

• 한국항해학회지
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• 제4권2호
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• pp.7-38
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• 1980

Nowadays researchers attach a great importance to the problems concerned with scientific information in the field of science and engineering. There are some reasons for it, that is, ⅰ) the amount of scientific information increases in proportion to the activities of scientists and engineers, so it is difficult to pick up a real valuable information ⅱ) it becomes more important to use a variety of information in proportion to the spread ofthe branch of science ⅲ) since the medium of scientific information is mostly technical papers, it is very difficult to mechanically transact these papers and to keep all documents and scientific informations for a long time. To cope with these difficult situations, many technical skills have been developed, for example, data-base, automatic information retrieval, micro-film and so on. But there are comparatively few investigation on the matter how the researchers who are users and producers think about the systematization of scientific information usage, so this paper investigates the thought and information needs of researchers, and proposes a basis of a method for systematization of scientific information usage. The author inspects the actual conditions of scientific information, reconsider the method which has been used and investigates the matter of how researchers whose interest is closely related to the study of marine affairs think about problems of scientific information usage by thequestionarie of Fuzzy-DEMATEL method. Also, FSM which is method for structuring hierarchy for the several complex problems on the basis of fuzzy sets theory is adopted as a tool of analysis. We can understand the key problems and make a story to solve the systematization of scientific information usage from the results of the analysis and those results will be directly applicable to construct a new system for scientific information usage.

• Industrial Engineering and Management Systems
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• 제11권1호
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• pp.82-86
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• 2012

In For the past few years, query log data has been collected to find user's behavior in using the site. Many researches have studied on the usage of query logs to extract user's preference, recommend personalization, improve caching and pre-fetching of Web objects, build better adaptive user interfaces, and also to improve Web search for a search engine application. A query log contain data such as the client's IP address, time and date of request, the resources or page requested, status of request HTTP method used and the type of browser and operating system. A query log can offer valuable insight into web site usage. A proper compilation and interpretation of query log can provide a baseline of statistics that indicate the usage levels of website and can be used as tool to assist decision making in management activities. In this paper we want to discuss on the tasks performed of query logs in pre-processing of web usage mining. We will use query logs from an online newspaper company. The query logs will undergo pre-processing stage, in which the clickstream data is cleaned and partitioned into a set of user interactions which will represent the activities of each user during their visits to the site. The query logs will undergo essential task in pre-processing which are data cleaning and user identification.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 추계학술대회 초록집
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• pp.87.2-87.2
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• 2011

Many type of fuel cell stacks have been developed to improve the efficiency of reactants usage. The cascade type fuel cell stack using dead end operation is able to attain above 99% usage of hydrogen and oxygen. It is sectionalized to several parts and the residual reactants which are used previous parts would be supplied again to next parts which have less number of cells in dead end operation stack. The oversupply of reactants which is usually 120%~150% of the theoretical amount to generate current for preventing the flooding effect could be provided to each part except the last one. The final section which is called monitoring cells is supposed to be supplied insufficient the fuel or oxidant that would have some accumulated inert gas from former parts. It makes some voltage drop in the part and the fresh reactants must be supplied to the part for recovering it by venting the residual gas. So the usage of fuel and oxidant is depend on the time and frequency of opening valves for venting of residual gas and it is important to optimize the vent logic for achieving higher usage of hydrogen and oxygen. In this research, many experiments are performed to find optimal condition by evaluating the effect of time and frequency under several power conditions using over 100kW class fuel cell module. And the characteristics of the monitoring cells are studied to know the proper cell voltage which decide the condition of opening the vent valve for stable performance of the cascade type fuel cell module.

• Healthcare Informatics Research
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• 제24권4호
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• pp.283-291
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• 2018

Objectives: To identify the current status of smartphone usage and to describe the needs for smartphone-based cardiac telerehabilitation of cardiac patients. Methods: In 2016, a questionnaire survey was conducted in a supervised ambulatory cardiac rehabilitation (CR) program in a university affiliated hospital with the participation of heart failure or heart transplantation patients who were smartphone users. The questionnaire included questions regarding smartphone usage, demands for smartphone-based disease education, and home health monitoring systems. Results were described and analyzed according to principal diagnosis. Results: Ninety-six patients (66% male; mean age, $5{\pm}11$ years), including 56 heart failure and 40 heart transplantation patients, completed the survey (completion rate, 95%). The median daily smartphone usage time was 120 minutes (interquartile range, 60-300), and the most frequently used smartphone function was text messaging (61.5%). Of the patients, 26% stated that they searched for health-related information using their smartphones more than 1 time per week. The major source of health-related information was Internet browsing (50.0%), and the least sought source was the hospital's website (3.1%). Patients with heart failure expressed significantly higher needs for disease education on treatment plan, home health monitoring of blood pressure, and body weight (${\chi}^2=5.79$, 6.27, 4.50, p < 0.05). Heart transplantation patients expressed a significant need for home health monitoring of body temperature (${\chi}^2=5.25$, p < 0.05). Conclusions: Heart failure and heart transplantation patients show high usage of and interest in mobile health technology. A smartphone-based cardiac telerehabilitation program should be developed based on high demand areas and modified to suit to each principal diagnosis.

• 수산해양교육연구
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• 제27권2호
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• pp.576-588
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• 2015

This study analyzed the influences of elementary students' usage of smartphone, computer and TV on academic attitude. Of the subjects residing in the U city to target of 10 elementary schools from the fourth grade to sixth grade, 865 students were sampled. This research made a frequency analysis and reliability analysis of the obtained date using SPSS 21.0 program were used. Research results are as follows. First, in the smartphone, computer and TV usage status of elementary school, smartphone, computer and TV were used the high frequency with which almost every commonly used, was found to be necessary to take advantage of the time to less than one hour a day, mostly alone, it has been found that a lot of online games, videos and SNS. Second, the use of smartphone, computer and TV were showed a significant effect on all sub-variables of open, self-concept, initiative, responsibility, learning enthusiasm, future orientation, creativity, self-assessment.