• Journal of the Korea Institute of Information Security & Cryptology
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• v.23 no.6
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• pp.1199-1206
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• 2013

SNS is relationship based service and its users are increasing rapidly because it can be used in variety forms as penetration rate of Smartphone increased. Accordingly personal information can be exposed easily and spread rapidly in SNS so self-control on information management, right to control open and distribution of own personal information is necessary. This research suggest way of measuring personal information leaking risk factor through personal information leaking possible territory's, based on property value and relationship of personal information in SNS, personal information exposure frequency and access rate. Suggested method expects to used in strengthening self-control on information management right by arousing attention of personal information exposure to SNS users.

• The Journal of Korean Association of Computer Education
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• v.7 no.1
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• pp.55-66
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• 2004

The Internet today provides group communication model, multicast service. It is important to keep security for multicast communication. Member leaving is associated with scalability problem for group key management. If one member of the group is removed, new group key has to be changed and communicated to all remaining members of group. Modification and distribution of new group keys for rekeying is an expensive operation. Minimizing the number of messages and operation cost for generation of the composite keys are important evaluating criteria of multicast key management scheme. Periodic rekey helps reducing these important parameters rather than removing members sequentially in fashion one after another. In this paper, Hamming distance is calculated between every members to be removed. The members with Hamming distance less than threshold are selected for rekeying procedure. With running the round assignment algorithm, our model has advantages of reducing the number of message and operation cost for generation of the composite keys for rekeying.

• The KIPS Transactions:PartC
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• v.9C no.3
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• pp.439-444
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• 2002

In this paper, we present both the link budget analysis according to system parameters and the cell coverage according to transmitter power and modulation scheme of digital MMDS among the wireless CATV system methods which is bated on the wireless internet service. Also, in this paper, we present C/I and number of subscriber according to splitting cell. In this paper, the cell coverage of which obtain the results according to both transmitter power from 0dBW to -9dBW and modulation scheme of QPSK, 16QAM and 64QAM based on link budget was analysis for system parameter of digital MMDS was able to provide from maximum 134km to minimum 4.3km. Also, in this paper, the number of subscriber of which obtain the results according to polarization wave, frequency of frequency reuse and C/I in 4. 6 and 8 sectors was able to provide from maximum 5,200DSI to minimum 1,300DSI.

• Journal of IKEEE
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• v.23 no.4
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• pp.1175-1181
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• 2019

In this paper, we have studied the chemical mechanical polishing(CMP) characteristics of mixed abrasive silica slurry(MAS) retreated by adding of manganese oxide(MnO₂) abrasives within 1:10 diluted silica slurry. A slurry designed for optimal performance should produce high removal rates, acceptable polishing selectivity with respect to the underlying layer, low surface defects after polishing, and good slurry stability. The polishing performances of MnO₂ abrasive-added MAS are evaluated with respect to their particle size distribution, surface morphology, and CMP performances such as removal rate and non-uniformity. As an experimental result, we obtained the comparable slurry characteristics compared to original silica slurry in the view-point of high removal rate and low non-uniformity. Therefore, our proposed MnO₂-MAS can be useful to save on the high cost of slurry consumption since we used a 1:10 diluted silica slurry.

• Journal of the Korea Fashion and Costume Design Association
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• v.5 no.3
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• pp.111-123
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• 2003

This study is designed to understand evaluation criteria for garment depending on demographic factors among college students in Yanbian, China. Questionnaire was used for measurement tools to study the subject of the thesis. The main study was conducted against 450 college students from May 17 to June 5, 2001. The data for the study were analyzed using SAS PC program for frequency distribution, percentage, t-test, and one way ANOVA. The evaluation criteria for garment are affected by demographic factors such as gender, average monthly household income, monthly expense for clothing. The result was showed as follows: The evaluation criteria for garment based on gender showed almost no meaningful different between male and female college students. Means on factors considered highly in selecting clothes was studied. The result shows that 'fit to the body, 'quality', 'color' and 'pattern' are considered most highly and 'harmony with other clothes', 'after service', design' 'easy to manage' and 'price' are considered relatively highly, but 'brand' and 'trendy fashion' were not considered highly. A meaningful difference was showed only in one area-trendy fashion-among three different income level groups. Those with an average monthly household income between 500 and 2,000yuan showed a highest tendency compared to those with above 2,000yuan and those with 500yuan. In terms of evaluation criteria for garment based on monthly expense for clothing, 'brand' is the only area which showed a meaningful difference. Respondents with monthly clothing expense of above 100yuan showed a higher means than those with below 100yuan.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.4
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• pp.25-34
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• 2004

UMTS network, evolved from GSM, includes packet core network that consists of SGSNS and GGSNs. Service providers should consider subscriber mobility, location registration, and subscriber distribution when designing packet core networks and network elements. Since one of the major traffic sources for IMT-2000 will be data which has bursty characteristics, new design guidelines for dimensioning of SGSN and GGSN should be proposed under various constraints of system parameters. In this paper, we first evaluate the performance of signaling traffic for packet call subscribers. After that, we also obtain the impact of bursty data traffic on the SGSN and GGSN by simulation, and suggest new dimensioning guidelines for packet core network of UMTS under various environments.

• Korean journal of applied entomology
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• v.17 no.2 s.35
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• pp.81-87
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• 1978

Late blight incited by Phytophthora infestans (Mont.) de Bary, is an important problem for seed potato prodcution in Korea. At the alpine Daekwanryeong area, unprotected potatoes are often defoliated within 14 days after late blight is first observed in the field. Since regular spraying can control late blight, the forecasting service is needed for timely initiation of the spraying program. Climatological data and notes on late blight incidence were recorded during 1970-1977 at the Alpine Experiment Station. The moving graph method using 7-day average mean temperature and 7-day total rainfall did not give highly accurate forecasts. Adding data on relative humidity and 7-day average minimum temperature increased the usefulness of the moving graph. Yields of late blight susceptible varietieties in sprayed plots were related to late blight occurrence and to the rainfall distribution pattern.

• The Journal of the Korea Contents Association
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• v.11 no.1
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• pp.26-33
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• 2011

In ubiquitous environments that numerous mobile objects exist, the location-based services have risen as an important application field. For efficient location-based services, various techniques with broadcast schemes have been studied. However, they were mainly concerned with the implementation of a broadcast index and did not consider techniques for reducing the size of the entire broadcast data. Therefore, this paper proposes a data distribution broadcast scheme based on sensor networks that considers the mobile patterns of an object in road network environments. In this paper we also propose a road network based sensor clustering technique for the efficiency of the proposed distributed broadcast scheme. In order to show the superiority of the proposed scheme, we compare it with the existing broadcast scheme in various environments.

• The Korean Journal of Food And Nutrition
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• v.19 no.4
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• pp.502-514
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• 2006

This Study was carried out to find out regional differences about dietary life and factors associated with meal of school children and adolescents between urban and rural area. Forty students from each of the nationwide 51 schools of three different levels(elementary, middle and high school) were surveyed by self-developed questionnaires. Total of 1,886 questionnaires (1,243 from urban and 681 from rural) were collected and distribution of subjects was 544 from elementary school, 661 from middle school, and 681 from high school. The results were summarized as follows. BMI and degree of satisfaction on body weight of elementary and middle school subjects were not significantly different between urban and rural area. But there were significant regional differences in $BMI(urban\;21.2{\pm}3.0,\;rural\;20.5{\pm}2.8,\;p<0.05)$ and degree of satisfaction on body weight of high school subjects(p<0.001). Elementary(p<0.01) and middle school(p<0.05) subjects in urban area had exercised more frequently than those in rural area. Regularity of having breakfast was not significantly different between urban and rural area at each of three different levels of school. Most subjects(urban 92.2%, rural 92.1%) had lunch regularly by virtue of school lunch service. Regularity of having dinner of elementary(p<0.01) and high school subjects (p<0.01) was significantly different between urban and rural area. Reason for skipping dinner of high school subjects was significantly different between urban and rural area (p<0.05). The most delicious meal was dinner for 51.8% of the urban high school subjects and lunch for 51.7% of the rural subjects. Only one third had intention of participating in school breakfast program regardless of region and levels of school. The findings suggested that nutrition education programs for school children and adolescents include different strategy according to region and levels of schools.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.2
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• pp.217-223
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• 2013

Population aging is a shift in the distribution of a country's population towards older ages. This is usually reflected in an increase in the population's mean and median ages, a decline in the proportion of the population composed of children, and a rise in the proportion of the population that is elderly. Population ageing is widespread across the world. Barrier-free or Design for All concept consists of modifying buildings or facilities so that they can be used by people who are disabled or have physical impairments. Design for All criteria are aimed at ensuring that everyone can participate in the Information society. Safety-related products being easy to adapt according to different needs, or using standardized interfaces that can be accessed simply by using assistive technology. To this end, policy makers and service providers, especially in the ubiquitous technologies, produce new technologies, products, services and applications for pedestrians.