• Journal of The Korean Association of Information Education
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• v.17 no.1
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• pp.1-8
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• 2013

SNS is a social networking service that removes the barrier between cyber spaces and the real world and helps people who have common interests to have a two-way communication, manage their interpersonal relationships and share information. The domestic and international SNS markets have attained a steady growth, and their growth is being more accelerated in recent days. However, studies on SNS have just examined adults, and it's required to research the use of SNS and cyber behaviors via SNS among elementary and middle school students. This study attempted to analyze the relationship of the use of SNS, motivation of using SNS, the use of active SNS functions, SNS-dependent tendency and SNS awareness to cyber behaviors via SNS among elementary and middle school students. As a result, regardless of gender and grade, stealing private information was the most frequent activity and the frequency of 'contacting strangers' activity increased most rapidly with the usage time and grade. SNS dependency turned out to be the most highly correlated with the negative cyber behavior. Moreover, the difference of gender was not significant to the overall negative cyber behavior, whereas that of grade was.

• The KIPS Transactions:PartC
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• v.17C no.1
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• pp.89-98
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• 2010

In current digital broadcasting systems, GEM(Globally Executable MHP)-based middlewares such as MHP(Multimedia Home Platform), OCAP(OpenCable Application Platform), ACAP(Advanced Common Application Platform) are the norm. Despite much of the common characteristics shared, such as MPEG-2 and DSM-CC(Digital Storage Media-Command and Control) protocols, the information and data structures they need are slightly different, which results in incompatibility issues. In this paper, in line with an effort to develop an integrated DTV middleware, we propose a general-purpose, reconfigurable DSM-CC architecture for supporting various standard GEM-based middlewares without code modifications. First, we identify DSM-CC components that are common and thus can be shared by all GEM-based middlewares. Next, the system is provided with middleware-specific information and data structures in the form of XML. Since the XML information can be parsed dynamically at run time, it can be interchanged either statically or dynamically for a specific target middleware. As for the performance issues, the response time and usage frequency of DSM-CC module highly contribute to the performance of STB(Set-Top-Box). In this paper, we also propose an efficient application cache management strategy and evaluate its performance. The performance result has shown that the cache strategy reflecting user preferences greatly helps to reduce response time for executing application.

• Journal of Distribution Science
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• v.11 no.10
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• pp.47-53
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• 2013

Purpose - Six months have passed since the amendment of the SSM regulation law; however, as yet, there is no confirmed research or report on the effects of this amendment, which are indefinite. Further, there have been no attempts to study the effects of the SSM regulation law from the consumers' viewpoint, which is important because consumers are the main agents that are greatly influenced by the amendment law. Therefore, this study aims to investigate the consumers' attitude toward the SSM regulation law as well as the effects of the SSM regulation law on the changes in purchase behavior. Research design, data, and methodology - This study was initiated from four research problems that are linked to consumer reaction to the SSM regulation law. Research problem 1: What is the consumers' reaction (perception, attitude, and perceived fairness) to the SSM regulation law? Research problem 2: How do the consumers' reactions to the SSM regulation law differ by consumers' characteristics? Research problem 3: Could the SSM regulation law change a consumer's purchase behavior? Research problem 4: Is it necessary to amend the SSM regulation law? This study collected the data through the interview and survey of housewives for the purpose of solving the research problems. The interview was conducted as a pilot study for the field survey. We interviewed three housewives, who were: an employed housewife, a full-time homemaker, and a manager of a housewife club, respectively. We then conducted a field survey of 232 housewives who were housewife club members or elementary school parents in Chunghcheong-do. Results - We verified the reliability and validity of the data, and analyzed it to solve the research problems. The main findings of this study were as follows. First, consumers still have a positive attitude toward large discount chains and SSM, which has been the case since the law was introduced. Second, perceived risk of consumers associated with traditional markets and small neighborhood shops was low. Third, consumers think that amendments of the SSM regulation law are important, and they positively assess the satisfaction, necessity, and propriety of the law. Fourth, although the SSM regulation law caused inconvenience to consumers, this law did not have any influence on the usage frequency and the use-behavior of large discount chains. Finally, consumers reacted very negatively to the toughening up of the SSM regulation law. Conclusions - In short, consumers still have a positive attitude toward the SSM regulation law. However, this act did not have any influence on the use-behavior of large discount chains (General Super Market). Thus, policy making authorities require active communication and promotions to enhance the effect of the SSM regulation law. This study was of the nature of exploratory research, which did not focus on hypothesis testing, but on finding solutions to the research problems. Therefore, this study is no more than a simple data analysis. Future studies should attempt to investigate the actual effects of the SSM regulation law, on the basis of sufficient literature review and real sales data.

• The Journal of Korean Academy of Prosthodontics
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• v.35 no.4
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• pp.647-661
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• 1997

The resin modified glass ionomer cements(RMGICs) have been used for years since 1989. Recently it has been developed for luting of fixed restorations. To evaluate the bond strength and marginal leakage of RMGICs for luting usage, the 80 extracted human molars which had uniform area of exposed dentin were cemented with 3 types of RMGICs(Fuji Duet, Advance, Vitremer), a conventional Glass Ionomer Cement(GIC-Fuji I), and a resin cement (Panavia 21) to base metal alloy(Ni-Cr-Be). After thermocycling the specimens were immersed in basic fuschin dye for measuring marginal leakage. The shear bond strength was measured with Instron and the maximum dye penetration was measured to 0.1mm. The types of fractured patterns were determined with stereoscope(${\times}7.5$). The results are as follows. 1. The difference between 3 RMGICs and a conventional GIC in shear bond strength was not statistically significant. It seemed that RMGICs had lower shear bond strength than resin cement. (p<0.01) 2. The mean scores of marginal leakage had no significant difference between the resin cement and 3 RMGICs but it was much higher in conventional GIC than the RMGICs (p<0.05) 3. It was determined that the manufacturer and the methods of dentin pretreatment determined the pattern of fracture surfaces and the frequency of adhesive failure between teeth and 3 RMGICs standed as in following order - Vitremer, Advance, Fuji Duet. (p<0. 01) When the fracture pattern was analyzed, it could be said that the materials and the method of dentin pretreatment have much effect on bonding states. This means that the dentin bonding agents should be improved. But the limited products in this experiment can not evaluate the physical properties of the entire RMGICs. Therefore a further study which can evaluate various RMGICs should be in progress to develope better cements.

• Journal of Internet Computing and Services
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• v.10 no.5
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• pp.65-78
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• 2009

The most commonly adopted approach to find valuable information from tree data is to extract frequently occurring subtree patterns from them. Because mining frequent tree patterns has a wide range of applications such as xml mining, web usage mining, bioinformatics, and network multicast routing, many algorithms have been recently proposed to find the patterns. However, existing tree mining algorithms suffer from several serious pitfalls in finding frequent tree patterns from massive tree datasets. Some of the major problems are due to (1) modeling data as hierarchical tree structure, (2) the computationally high cost of the candidate maintenance, (3) the repetitious input dataset scans, and (4) the high memory dependency. These problems stem from that most of these algorithms are based on the well-known apriori algorithm and have used anti-monotone property for candidate generation and frequency counting in their algorithms. To solve the problems, we base a pattern-growth approach rather than the apriori approach, and choose to extract maximal frequent subtree patterns instead of frequent subtree patterns. The proposed method not only gets rid of the process for infrequent subtrees pruning, but also totally eliminates the problem of generating candidate subtrees. Hence, it significantly improves the whole mining process.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06c
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• pp.274-276
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• 2006

e-seal은 RFID(Radio Frequency IDentification) 기술을 사용하여 원격에서 자동으로 봉인상태를 확인할 수 있는 컨테이너 봉인 장치를 말한다. RFID의 특징상 반도체 칩에 기록된 정보를 제 삼자가 쉽게 판독 및 변조할 수 있다는 취약점으로 인하여 활성화되지 못하고 있는 실정이다. ISO에서는 RFID의 취약점을 보안하기 위한 표준작업(ISO 18185)을 진행 중이다. 이 중, ISO 18185-4는 e-seal에 저장되는 자료나 리더와의 RF통신에서 데이터 보호를 위한 표준이다. 이와 관련된 연구로는 인증 프로토콜과 ISO 18185-4를 위한 보고서로 제출된 보안 프로토콜이 있다. 제안된 e-seal 보안 프로토콜을 적용하기 위해서는 e-seal과 리더 간의 데이터를 암/복호화할 키가 필요하지만, 키 서버를 통해 전달받은 마스터 키를 데이터 암/복호화 키로 바로 사용하는 것은 보안 상의 문제점을 야기할 수 있기 때문에 PRF(Pseudo Random Function)을 이용하여 마스터 키로부터 MTK(Mutual Transient Key)를 유도하고, MTK를 암/복호화 키로 사용해야 한다. 기존의 PRF는 일방향 해시 함수(MD5, SHA 등)를 기반으로 하는 HMAC[2. 3]을 일반적으로 사용하였다. 그러나 일방향 해시 함수는 e-seal과 같은 제한된 자원을 갖는 환경에 적합하지 않다. 따라서, 본 논문에서는 e-seal 보안 프로토콜을 위한 효율적인 PRF을 제안한다. 기존의 일방향 해시 함수 기반이 아닌 블록 암호화 알고리즘을 기반으로 하는 MAC을 이용하여 PRF을 보다 효율적으로 구현하였고, 블록 암호화 알고리즘은 AES를 선택 합성체 $GF((2^4)^2)$을 통해 하드웨어 모듈을 최적화 하였다. AES를 기반으로 하는 MAC은 HMAC에 비해 면적 및 처리율에서 뛰어난 결과를 보여주었다.<0.01).이상의 연구 결과, cook-chill생산 시 녹차 추출물의 첨가가 미생물적 품질유지에 효과가 있다고 사료되는 바 본 연구결과를 기초로 급식소에서 음식 생산 시 녹차 추출물 및 천연 항균성 물질 첨가에 따른 미생물적 품질 및 관능적 품질검사를 통한 레시피 개발에 관한 지속적인 연구가 수행되어야 하겠다.다.다리다보니 점심시간을 활용할 수 없게 되는 문제점에 대한 재검토가 필요하다. 따라서 차후 학교급식의 안전성 확보를 위한 급식환경 개선의 일환으로 식당공간 확보 시 신속한 시간 내에 급식이 가능하도록 넓은 공간과 쾌적한 환경의 식당 조성에 대해 관심을 기울여야 할 것으로 사료된다. 이상 여부를 반영하는 임상증상의 빈도가 높은 청소년기 남녀 중학생의 경우 아침과 저녁의 결식빈도 및 외식과 간식의 빈도가 높았고, 아침식사의 질과 체형만족도가 낮은 것으로 나타나 청소년의 건강과 식습관 및 체형만족도가 상호 관련성이 높은 것으로 나타났다. 따라서 본 연구 결과는 성장기 청소년의 건강 유지를 위하여 바람직한 식습관의 중요성을 재인식할 수 있었으며, 올바른 식습관 확립을 위한 영양교육의 중요성이 재확인되었다.경제적일 것으로 판단된다.er 90 % of good relative dynamic modulus of elasticity due to fineness of formation caused by the increase of the unit powder content and the improvement of flowability, without regard to the replacement of crushed stone fines. Therefore, it can be said that the usage of crushed stone fines can control the strength of super flowing concrete by replacement and re

• The Journal of the Korea Contents Association
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• v.12 no.9
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• pp.500-511
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• 2012

Recently, use frequency for traffic information which provides shortest paths and traffic condition is increasing. Specially, in the survey, it is shown that users prefer internet portal sites which can be used the most easily among traffic information media. But, there are not many verification systems for traffic information contents of internet portal sites which collect and provide information than traffic information contents which are provided by public service. The purpose of this study is to investigate real accuracy and accuracy felt by users about information provided by portal sites. Therefore, in this research we verified accuracy of information by portal site with real field data and investigate real usage about contents and experienced accuracy by users through survey. Also, users' expectation and satisfaction were surveyed and the contents to be improved were selected by using IPA technique. By the result of accuracy verification by field data using portable DSRC(Dedicated Short Range Communication) devices, it is shown that average error was 14~32% and sometimes very high rate. Also, it is shown that 28.3 % of total respondents prefers the information by portal sites and 50 % of total respondents felt that contents of traffic information by portal sites are not accurate. Real-time traffic condition was selected as the most inaccurate one among all contents of traffic information and it was analyzed that intensive efforts for improving information about real-time traffic condition are needed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.7
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• pp.1132-1137
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• 2014

The purpose of this study was to assess the need for nutritional education in male workers living in Busan, Korea. This study surveyed 310 industrial workers at five companies in Busan using a questionnaire. According to the results, need for nutritional education scored 3.60/5.00 points. The usage rate of mass media as a means of acquiring nutritional information was significantly higher (P<0.001) in subjects in their 50s compared to other age groups. Regarding scores on need for nutritional education according to theme, 'balanced eating habits' showed the highest score, followed by 'food safety', 'diet therapy related to a disease', and 'food hygiene and food poisoning prevention'. In terms of frequency of nutritional education, 29.0% of subjects considered 'biannually' to be desirable, whereas 25.8% and 21.0% considered 'annually' and 'quarterly' to be desirable, respectively. The results of this study suggest that nutritional education for industrial workers should be implemented in various ways in accordance with their characteristics. Furthermore, considering workers' low awareness levels of the need for nutritional education, employees are required to take the education in order to encouraged to improve their nutritional status and commit to a desirable diet.

• Journal of Digital Convergence
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• v.14 no.11
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• pp.275-281
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• 2016

In modern society, which boomed it became easier to obtain the necessary information to the emergence of a variety of smart devices. Due to this, the frequency of using the content based on the Web is growing rapidly. In addition, companies are turning into a production and modify the content using the CMS under the web-based. It can be a very important part to provide users with the content. Currently web services are designing a UI to the device and provided. To improve the ease of use, they are enhancing services only by survey and analysis of the patterns of all users. Most are designed without considering the UX only in the technical aspects. In this paper, to break the limits that apply to all users of the Web service pattern analysis, we propose a visualization system via the animation based on the individual user's movement patterns and usage patterns. Through this convergence is expected to be able to transform the web from the central manager to the user UX and the planning aspects researchers.

• Journal of the East Asian Society of Dietary Life
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• v.18 no.6
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• pp.873-883
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• 2008

In this study, we assessed consumers' recognition of frozen foods via a survey study, and monitored the contamination levels of total aerobic bacteria and Escherichia coli in imported and domestic frozen seafoods obtained from five whole sale markets in Seoul. A questionnaire used to assess the perception of frozen food safety and the attitude towards frozen food usage was developed and distributed to 350 adults. A total of 324 questionnaires were subjected to frequency analysis and a chi-square test, using SPSS for Windows. The results of our survey study demonstrated that 44.6% of the respondent consumed frozen processed foods two to three times per month, with dumplings being the most frequently purchased. 70.5% of the respondents selected "convenient cooking" as the principal reason for their frozen food purchases. 58% of the respondents believed that frozen processed food is not safe to eat as the result of food additives and changes in quality during the shelf life period. Consumers most profoundly preferred frozen seafood originating from America, and preferred that from China least profoundly (81.2%). Microbiological analyses demonstrated that the aerobic plate counts of frozen seafood, regardless of origin, fulfill the standard requirements except for one frozen clam (6.6 Log CFU/g), which was a heated-frozen domestic product. In addition, E. coli was isolated from frozen cooked mussels, frozen raw clams and squids, thus indicating that more strict hygienic regulation for frozen seafoods will be necessary to protect the consumer in both domestic and foreign markets.