• Journal of Astronomy and Space Sciences
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• v.24 no.4
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• pp.327-338
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• 2007

We estimate the momentum fluxes of short-period gravity waves which are observed in the OI 557.7 nm nightglow emission with all-sky camera at Mt. Bohyun ($36.2^{\circ}\;N,\;128.9^{\circ}\;E$) in Korea. The intrinsic phase speed ($C_{int}$), the intrinsic period (${\tau}_{int}$), and vertical wavelength (${\lambda}_z$) are also deduced from the horizontal wavelength (${\lambda}_h$), observed period (${\tau}_{ob}$), propagation direction (${\phi}_{ob}$), observe phase speed (${\upsilon}_{ob}$) of the gravity wave on the all-sky images. The neutral winds to deduce intrinsic wave parameters are measured with Fabry-Perot interferometer on Shigaraki ($34.8^{\circ}\;N,\;13.1^{\circ}\;E$) in Japan. We selected 5-nights of observations during the period between July 2002 and December 2006 considering of the weather and instrument conditions in two observation sites. The mean values of intrinsic parameter of gravity waves are $({\tau}_{int})\;=\;12.9\;{\pm}\;6.1\;m/s,\;({\lambda}_z)\;=\;12.9\;{\pm}\;6.5,\;and\;(C_{int})\;=\;40.6\;{\pm}\;11.6\;min$. The mean value of calculated momentum fluxes for four nights besides of ${\lambda}_z\;<\;6\;km$ is $12.0\;{\pm}\;15.2\;m^2/s^2$. It is needed the long-term coherent observation to obtain typical values of momentum fluxes of the mesospheric gravity waves using all-sky camera and the neutral wind measurements.

• The Transactions of the Korea Information Processing Society
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• v.5 no.5
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• pp.1274-1284
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• 1998

Multicasting plays an important role in providing multimedia services like audio and video conferencing and has been actively studied for many years. The study of multicasting has been mainly focused on finding a low-cost tree on the assumption that every edge of the tree has enough link capacity to be allocated to the amound of bandwidth required by a service. In some cases, however, a multicasting tree whose some edges do not have enough bandwidth to be allocated may exist. A typical example of this case is to multicast among the group users located in the different sub-networks in the interconnected networks composed of the high bandwidth networks such as B-ISDN and the low bandwidth networks such as PSTN and PSDN. This paper proposes a novel multicasting protocol for providing multimedia services in a wide area network interconnected by multiple heterogeneous networks. First, the paper discusses the inherent limitation of present multicasting protocols for the case. Second, se introduce a new concept, multiple QoS's for a service, which extends the implicit assumption that only one QoS is assigned to a service in order to overcome this limitation. Third, our multicasting protocol is designed based on the current Internet protocol stacks. Last, we perform simulations for possible scenarios to provide multimedia services in the network and analyze their pros and cons.

• Journal of forensic and investigative science
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• v.1 no.2
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• pp.5-19
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• 2006

Data mining is an information extraction activity to discover hidden facts contained in databases. Using a combination of machine learning, statistical analysis, modeling techniques and database technology, data mining finds patterns and subtle relationships in data and infers rules that allow the prediction of future results. Typical applications include market segmentation, customer profiling, fraud detection, evaluation of retail promotions, and credit risk analysis. Law enforcement agencies deal with mass data to investigate the crime and its amount is increasing due to the development of processing the data by using computer. Now new challenge to discover knowledge in that data is confronted to us. It can be applied in criminal investigation to find offenders by analysis of complex and relational data structures and free texts using their criminal records or statement texts. This study was aimed to evaluate possibile application of data mining and its limitation in practical criminal investigation. Clustering of the criminal cases will be possible in habitual crimes such as fraud and burglary when using data mining to identify the crime pattern. Neural network modelling, one of tools in data mining, can be applied to differentiating suspect's photograph or handwriting with that of convict or criminal profiling. A case study of in practical insurance fraud showed that data mining was useful in organized crimes such as gang, terrorism and money laundering. But the products of data mining in criminal investigation should be cautious for evaluating because data mining just offer a clue instead of conclusion. The legal regulation is needed to control the abuse of law enforcement agencies and to protect personal privacy or human rights.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.1
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• pp.288-293
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• 2011

This study was conducted to investigate the elementary school students' consciousness of safety, activities to prevent their accidents and factors causing such accidents. For this aim, a research was conducted from Nov. 19 through Dec. 22, 2007 by means of questionnaires distributed to 800 students enrolled in the 5th and 6th grades of 4 elementary schools in a urban-rural combined city. Out of the questionnaires distributed, 785 were collected and put to analysis by using SPSS 13.0 program to determine t-test, ANOVA, logistic regression, etc. 1. The maximum scores of safety consciousness revealing relatively high level of safety consciousness. There was, however, statistically significant difference by grade, type of residence, school life and academic achievements. In detail, 5th graders featured higher level of safety consciousness and those who live in apartments, lead a pleasant life at school and get better academic scores tended to keep higher level of safety consciousness. 2. The subjects of the high scored of activities to prevent accidents, with a statistically significant difference by gender, grade and individual personality. Females, 5th graders and active students were found to be more conscious of preventive activities for accidents. 3. In general, 6th graders and active students turned out to have experienced more accidents. 4. The main factors exerting influence on occurrence of accidents on the part of elementary school students are known to be preventive actions and consciousness of traffic safety in the category of safety consciousness. The significant variable in preventive actions was preventive actions of traffic accidents, burns and intoxication by category of accidents, but individual personality by category of general characters. Sixth graders and male students experienced more accidents, without significantly significant difference, though. As a result, From the above findings, prevention of safety accidents is found to be very important for elementary school students. It is therefore suggested that schools as well as homes should continue to conduct practical education to prevent accidents with priority placed on familiarizing students with preventive activities in daily life in consideration of their personal characters.

• Korean Journal of Heritage: History & Science
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• v.52 no.1
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• pp.120-147
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• 2019

In this study, we divided the portraits in the reign of King Seonjo into those which were created before and after the Japanese invasion. We then examined various aspect of costumes expressed in the portraits of meritorious vassals. To analyze official uniforms (Heuk-Danryeung), we examined the Samo height; the side wings' type and pattern; the Danryeung pattern; the Mu style; the processing method of lateral lines in Danryeung the rank badge and rank belt, the color of Dabho and Cheolrik, which were undergarment of Danryeung and Heuk-wa. The meritorious vassals' portraits, prior to Imran, were analyzed with a portrait of Han Eung-in, a Gwang-kuk Pyeong-nan meritorious vassals. The Samo was the highest of the Choson dynasties, and the cloud and treasure pattern was identified on the side wings. The Heuk-Danryeung was a dark blue(acheongsaeg) Danryeung of manja-shaped cloud patterns with a large outward wrinkled Mu, and it had a wild goose badge (second rank) and a Sabgeumdae. It did not coincide with the Pumgye(Jaheondaebu) recorded in Gugjo-inmulgo. Reddish Dabho for Dangsang-kwan, green Cheolrik which was undergarment of Danryeung, and Heuk-wa. were identified. After the invasion of Japan, portraits of Hoseong, Seonmu, and Cheong-nan meritorious vassals were analyzed through eighteen portraits, including Lee Hyeon-bok. After the invasion of the Japanese, the height of the Samo's top was much lower and the width of the side wings was wider than before the invasion of Japanese. The Heuk-Danryeung was a dark blue (acheongsaeg) Danryeung of manja-shaped cloud patterns with a stretching backward Mu. Rank badge and rank belts were almost identical with the record, but there were two exceptions (Sin-jab and Kim, Sae-sin). Therefore, it was reaffirmed that the meritorious vassals' portraits were drawn by the Pumgye at the time of appointment. Among the undergarments of Heuk-Danryeung, green Dabho(11), blue Dabho(4), reddish Dabho(3), and blue Cheolrik(10), green Cheolrik(6), reddish Cheolrik(1), and yucheongsaeg Cheolrik(1) were identified, However, it is suggested that the Dabho of Hoseong, Seonmu, and Cheong-nan meritorious vassals should be the reddish Dabho of Dangsang-kwan, which is the same as the previous Imran, and a green Cheolrik.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.5
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• pp.695-706
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• 1998

SST (Sea Surface. Temperature) fronts which were found in the South-West Sea of Korea and the northern area of the East China Sea were examined in order to clarify their positions, shapes, seasonal changes and the formation mechanism, For this study used SST data rearranged from the SST IR image during 1991 to 1996 and oceanographical data obtained by National Fisheries Research and Development Institute. Temperature front in the Cheju Strait was analyzed by the data obtained from a fisheries guidance ship of Cheju Provincial Government, The coastal frontal zone in the South-West Sea of Korea and the offshore frontal zone in the northern area of the East China Sea can be divided into several types (Type of Winter, Summer, Spring, Autumn and late Autumn), Short term variations of SST fronts have a tendency not to move to any Bleat extent for several days. The location of the frontal zone in the southwestern sea of Cheju Island changes on a much large scale than that of the one in the southern coast of Korea, The frontal Tone, formed every year in the southern sea of Korea approaches closer to the coastal area in winter, and moves closer to the south in spring and autumn. The frontal zone of the southwestern sea of Cheju Island moves in a westerly direction from the east, and reaches its most westerly point in the winter and its most easterly point in the summer related to the seasonal change of the Tsushima Current. Additionally, the frontal zone of the southwestern sea of Korea becomes extremely weak in March, April and November. SST fronts are formed every year around the line connecting Cheju Island to Yeoseo Island or to Chungsan Island in the Cheju Strait. A Ring-shaped tidal mixing front appears along the coastal area of Cheju Island throughout the year except during the months from November to January. Especially, in May and October fronts are formed between the coastal waters of Cheju Island and the Tsushima currents connecting the frontal zone of the coastal region in the southern sea of Korea with that of the southwestern sea of Cheju Island.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.10
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• pp.1594-1606
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• 2014

The purpose of this study was to examine safety accidents related to school foodservice, working and operating environments of school foodservice, status and awareness of safety education, educational needs, and information on qualitative improvement of school foodservice. The subjects in this study were 234 cooks in charge of cooking at elementary and secondary schools in Chungbuk. A survey was conducted from July 30 to August 8, 2012, and among 202 questionnaires gathered, 194 completed questionnaires were analyzed. Statistical analyses were performed on data utilizing the SPSS version 19.0. The main results of this study were as follows: 44.3% of workers experienced safety accidents. The most frequent safety accident was 'once' (60.5%), and most safety accidents took place between June and August (31.4%). The time at which most safety accidents happened was between 8 and 11 am. Most safety accidents happened during cooking (52.3%) and while using a soup pot or frying pot (52.4%). The most common accidents were 'burns', 'wrist and arm pain', and 'slips and falls'. Respondents who experienced safety accidents replied that 57.6% of employees dealt with injuries at their own expense, and only 35.3% utilized industrial accident insurance. In terms of the operating environment, the score for 'offering information and application' was highest (3.76 points), whereas that for 'security of budget' was lowest (1.77 points). As for accident education, employees received safety education approximately 3.45 times and 5.10 hours per year. Improving the working environment of school foodservice cooks requires administrative and financial support. Furthermore, educational materials and guidelines based on the working environment and safety accident status of school foodservice cooks are required in order to minimize potential risk factors and control safety accidents in school foodservice.