• Journal of Korea Game Society
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• v.4 no.4
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• pp.11-18
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• 2004

The on-line games in the past were played by only two persons exchanging data based on one-to-one connections, whereas recent ones (e.g. MMORPG: Massively Multi-player Online Role-playings Game) enable tens of thousands of people to be connected simultaneously. Specifically, Korea has established an excellent network infrastructure that can't be found anywhere in the world. Almost every household has a high-speed Internet access. What made this possible was, in part, high density of population that has accelerated the formation of good Internet infrastructure. However, this rapid increase in the use of on-line games may lead to surging traffics exceeding the limited Internet communication capacity so that the connection to the games is unstable or the server fails. expanding the servers though this measure is very costly could solve this problem. To deal with this problem, the present study proposes the load distribution technology that connects in the form of local clustering the game servers divided by their contents used in each on-line game reduces the loads of specific servers using the load balancer, and enhances performance of sewer for their efficient operation. In this paper, a cluster system is proposed where each Game server in the system has different contents service and loads are distributed efficiently using the game server resource information such as CPU utilization. Game sewers having different contents are mutually connected and managed with a network file system to maintain information consistency required to support resource information updates, deletions, and additions. Simulation studies show that our method performs better than other traditional methods. In terms of response time, our method shows shorter latency than RR (Round Robin) and LC (Least Connection) by about 12%, 10% respectively.

• Journal of Environmental Policy
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• v.8 no.2
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• pp.83-118
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• 2009

Clean Development Mechanism(CDM) projects under the Kyoto Protocol have two objectives. One is to assist the Parties included in Annex I in achieving compliance with their quantified emission limitation and reduction commitments in cost-effective ways by allowing them to implement emission reduction projects in Non-Annex I countries and receive CERs, which will offset their reduction commitments. The other is to assist Parties not included in Annex I in achieving sustainable development and technology transfers through investments by Annex I countries. However, in reality, it is said that the former objective is achievable but the latter is not. In this light, this article suggests sustainability appraisal criteria applicable for Korea. Among various methodologies, we used the 'multi-attributes utility theory(MAUT)'; one of the 'multi-criteria analysis (MCA)' methodologies judged to be the most practical and relevant. Based on the guidelines of the MAUT methodology, we identified sustainability criteria that meet the guidelines. We took two tracks, the first to find the preferences of Korean experts, and the other to check foreign cases. In all, 37 preliminary criteria were suggested to Korean experts and each criterion was scored, from between 1 and 3, in terms of relevance, possibility of real improvement, easiness of data collection, and preferences. We combined foreign cases and the results of a survey conducted in Korea and selected 12 core criteria and 10 additional criteria. After that, all the criteria were converted into indicators. The indicators were applied to a CDM project for case study. We chose the "Sihwa Tidal Power Project", which is currently the biggest tidal power plant in the world. Twelve core indicators and 3 additional indicators were applied. In order to weight each indicator, the 'analytical hierarchy process (AHP)' was used. A total of 30 experts were asked to suggest weights and 21 answered. Among them, only 14 respondents were proven to meet the consistency ratio. We analyzed the 14 responses through Expert Choice and the CDM project was scored (+)53.082. In addition, sensitivity analysis was undertaken with the result of (+)44.667 to (+)65.522. As a result of this study, it was proven that this project would contribute to the sustainable development of Korea.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.1
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• pp.141-152
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• 2015

The objective of this study is to estimate shear wave velocity of rockfill materials by making practical use of the micro-earthquake records which are ordinarily obtained at a domestic rockfill dam and to verify its applicability. Micro-earthquake records were obtained at the site of Heongseong dam and Soyanggang dam, which are the existing multi-purpose dams in Korea. In the previous study, the fundamental periods of each dam were already evaluated by analyzing the response spectrum of the observed records. In this study, numerical analyses varying shear moduli of rockfill zone were carried out using the acceleration histories measured at the abutment as input ground motions. From comparison between the fundamental periods calculated by numerical analyses and measured records, the shear wave velocities with depth were estimated. It is found that the effect of different earthquake events on shear wave velocity estimation for the target dam materials is negligible and the shear wave velocity can be consistently evaluated. Furthermore, comparing the shear wave velocity with the previous researchers' empirical relationships and field test results, applicability of suggested method is verified. Therefore, in case that it is impossible to conduct field tests and estimation is preliminary, the suggested method can be practically used.

• The Journal of the Korea Contents Association
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• v.12 no.7
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• pp.394-405
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• 2012

This study is aimed at developing a tool to measuring school police's job performance, and verifying its credibility and validity. This study collected the sample to 250 subjects using a significance collection method to parents of elementary schools school police work. But excluding dishonestly responding data, this used total 210 people for the final analysis. This study executed experts' meeting, exploratory and confirmatory factor analysis, and item analysis to verify reliability, and verification of internal consistency and reliability. This study extracted and confirmed 7 factors for specialization, attitude, program, prevention activity of school violence, effect, basic duty, teaching for school time and home time, and correlation with related people. Through the above research approach and procedure, this study arrived at the following conclusion. First, validity to school police's job performance and measurement tool to job performance is very high. That is, school police's job performance was explored and confirmed through correlation with specialization, attitude, program, prevention activity of school violence, effect, basic job, teaching for school time and home time, and related people, and of them, explanation of attitude is the highest. Second, reliability to the measurement scale for school police's job performance is very high. That is, school police's job performance has high correlation between items, sub-factors, and total scores, and reliability of internal consistency, Cronbach's ${\alpha}$ value, is over .708. Putting them together, measurement scale for school police's job performance is a questionnaire sheet with very high level of validity and reliability.

• The KIPS Transactions:PartD
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• v.8D no.5
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• pp.523-532
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• 2001

An atomic commitment protocol ensures that distributed transcations terminate consistently at participating sites. An atomic commitment protocol is said to be non-blocking if it permits transaction termination to proceed at correct participants despite of failure in the coordinator site and communication. It is well known that the famous two phase commit(2PC) is a blocking protocol, whereas the three phase commit(3PC) protocol is a non-blocking. In this paper, we propose a non-blocking two phase commit(NB-2PC) protocol reducing the blocking problem than propose non-blocking protocols. The NB-2PC protocol can be obtained through modifications of the 2PC protocol. After receiving Prepare message from coordinator in the NB-2PC protocol, participants respond to the coordinator and several participants in voting phase. While participants wait for decision message from the coordinator, the blocking occurs due to the failure of the coordinator site, participants elect new coordinator among several participants receive response message. Despite of the coordinator site failures, participants consult new coordinator and follow termination protocols and achieve non-blocking property. We propose a basic structure of NB-2PC protocol and termination protocol and new coordinator election protocol. The NB-2PC protocol has non-blocking property and reduces processing time of commit protocol than the 3PC protocol. Also, through simulation experiments, we propose the NB-2PC protocol exhibits better performance of processing time of commit protocol than 3PC protocol.

• Korean Journal of Culture and Social Issue
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• v.17 no.4
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• pp.435-459
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• 2011

The present study explored Korean parents' perceptions of and behavior toward game use among teenagers in Korea. A total of 600 Korean mothers of teenagers residing in Seoul and five other metropolitan areas participated in the survey. The survey was constructed based on five categories of variables, including the overall perception of games and game use, specific attitudes toward game use, cognitions about and attitudes toward game addiction, factors predicting parental monitoring of children's game use, and views and opinions about what needs to be done to promote healthy game cultures as well as to prevent problematic game use among teenagers in Korea. Results indicate that the respondents' overall perceptions of and attitudes toward games and game use are negative. In contrast, attitudes toward game use of the respondent's own child are contingent upon various comparison standards. Results also indicate that the respondents tend to overestimate the possibility that their own child is addicted to games, and their perceptions of game addiction are based on a narrow range of behavioral symptoms. Additional analyses indicate that parental monitoring of teenagers' game use can be predicted by the theoretical model driven from Ajzen(1991)'s theory of planned behavior. Finally, results also indicate that, in order to deal with the problems associated with teenagers' game use, proactive approaches to promote healthy game cultures as well as various initiatives to prevent problematic game use are necessary. Implications of the findings and future direction were discussed.

• Journal of the Korean Society of Earth Science Education
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• v.9 no.2
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• pp.199-216
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• 2016

The purpose of this study is to figure out how much gifted science education teachers in charge of the class realize the necessity of individualized curriculum and program for scientifically gifted, to find out the problems of the gifted science educational institutions from exploring them in depth in the light of the reality in the gifted science educational institutions, and to draw implications about the applicable direction of more aggressive individualized curriculum and program for scientifically gifted. I chose 15 people with the incumbent teachers who have ever taught scientifically gifted and have a degree in the gifted education or science subject education as study participants and had a depth interview with them. According to result of the study, 14 of 15 study participants recognized the necessity of individualized education in science should understand the personal requirements according to the tendency of the gifted students and should be a study led by students themselves. Of the problems in gifted science education, teachers regarded the reduction in the financial support as the biggest problem and the vocation and professionalism of teachers were referred as a very important factor. With constraints of time and space, there were plenty of opinions that can't ignore the influence of educational environment associated with the university entrance examination. There were many opinions that there is excessive expansion of the agencies and the target for gifted students, no standardized measurement tools and programs and the lack of the system for the coherent observation as a teacher. Also, the unified curriculum of gifted science education institutions were pointed out as the problem and the individualized programs which were already under way have a lot of weakness and being offered marginally. Thus, from now on, to apply for individualized education of gifted science, teachers demanded optimized education conditions and consistent policy support, and expressed the opinion that there needs of a possible continuous observation system. Besides, the curriculum and programs matched the needs of the students should be taken priority the most, and there were another answers that fellow learning within the cooperative learning can be an alternative of the individualized. Along with that, there were lots of opinions that the treatment to overcome an inferiority complex according to the individualized should be followed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.6
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• pp.527-536
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• 2016

This study aims to generate baseline data for vitalizing the sales of functional cosmetics through an Importance-Performance Analysis (IPA) of the selection attributes of functional cosmetics. From the analysis of consumers' selection criteria, the study will assist functional cosmetics companies in reflecting consumer demands and therefore securing competitiveness. For this, general consumers aged over 20 years were surveyed for 5 weeks from Feb 23 through Mar 30, 2015, and 447 empirical data (response rate 88.9%) were processed through SPSS WIN 21.0 program for analysis. To conduct gender difference analysis on the IPA of the selection attributes of functional cosmetics, 17 selection attributes were categorized into 4 factors: functionality, labeling, popularity, and product. Cronbach's alpha for all factors was 0.5, proving the internal consistency and reliability of the survey. The survey results showed that while the entire average came out significantly higher for females (5.89/7points) than for males (5.66/7points) (p<0.001), the selection attributes 'anti-wrinkling', 'whitening function', 'functionality', 'expiration date', 'full ingredient labeling system' and 'various promotional events' showed significant gender differences. IPA results pertaining to gender showed 'price', 'functionality', 'spreadability' and 'full ingredient labeling system' as 2nd quadrant attributes, whereas female consumers selected 'price', 'whitening function', 'anti-wrinkling', 'functionality' and 'full ingredient labeling system' as attributes. Results show that businesses in the field of cosmetics and related areas need to prioritize improving the following factors that received low satisfaction from all consumers: 'price', 'functionality', and 'total labeling.' In particular, the 'price' aspects are considered to require reasonable and affordable pricing.

• Journal of Korean Home Economics Education Association
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• v.27 no.1
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• pp.111-126
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• 2015

The purpose of this study was to investigate the moderating effects of perceived father's rearing attitudes on the relationship between self-efficacy and smartphone addiction in adolescents. A survey was conducted using a convenient sample drawn from 570 students from eleven junior high school in Seoul. Data were analyzed using SPSS 20.0 program. The results show that 22.4% of students was in the risk of smatphone addiction. High risk of smartphone addiction group use smartphone longer for communication and had more trouble with their parents because of smartphone use. Smartphone addiction showed negative relationship with self-efficacy and affection-rational explanation of perceived father's rearing attitude but had positive relationship with inconsistency-intrusiveness of perceived father's rearing attitude. Furthermore, the result showed the moderating effects of perceived father's rearing attitude on the relationship between self-efficacy and smartphone addiction. Therefore, to prevent smartphone addiction in adolescent, we should try to increase self-efficacy in adolescent as well as to develop educational program to assist parent to understand their children.

• Journal of the Korean earth science society
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• v.41 no.3
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• pp.273-290
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• 2020

This study aims to investigate tenth graders' understanding of the nature of scientific inquiry (NOSI). A total of 100 public school students participated. A questionnaire of Views about Scientific Inquiry was used to assess their understanding of the NOSI, and data were collected using qualitative research methods such as open-ended questionnaires and, when necessary, semi-structured interviews. By employing a constant comparison method to analyze their responses, five students were consistently categorized as the group with informed views regarding all the eight aspects of the NOSI. The rest of the students showed different levels of understanding regarding each aspect. A large portion of the students represented a group with mixed views about four aspects and informed views about three aspects, whereas naive views about one aspect prevailed among them. The results showed that many students comparatively lacked understanding of the aspect related to the scientists' process of constructing explanations and formulating theories. This study discusses the relationship between its results and the current science curriculum and presents implications for the overall enhancement of students' understanding of the NOSI. Finally, it encourages the acquisition of scientific inquiry ability and makes suggestions to promote further studies.