• Journal of the Korean Society of Safety
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• v.35 no.5
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• pp.15-21
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• 2020

Quantitative risk assessment (QRA) is used as a legal or voluntary safety management tool for the hazardous material industry and the utilization of the method is gradually increasing. Therefore, a leak frequency analysis based on reliable generic data is a critical element in the evolution of QRA and safety technologies. The aim of this paper is to derive the leak frequency function that can be applied more flexibly in QRA based on OGP report with high reliability and global utilization. For the purpose, we first reviewed the data on the 16 equipments included in the OGP report and selected the predictors. And then we found good equations to fit the OGP data using non-linear regression analysis. The various expectation functions were applied to search for suitable parameter to serve as a meaningful reference in the future. The results of this analysis show that the best fitting parameter is found in the form of DNV function and connection function in natural logarithm. In conclusion, the average percentage error between the fitted and the original value is very small as 3 %, so the derived prediction function can be applicable in the quantitative frequency analysis. This study is to contribute to expand the applicability of QRA and advance safety engineering as providing the generic equations for practical leak frequency analysis.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.8B
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• pp.677-686
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• 2012

In the presence of a high power cellular network, picocells are added to a Macro-cell layout aiming to enhance total system throughput from cell-splitting. While because of the different transmission power between macrocell and picocell, and co-channel interference challenges between the existing macrocell and the new low power node-picocell, these problems result in no substantive improvement to total system effective throughput. Some works have investigated on these problems. Pico Cell Range Expansion (CRE) technique tries to employ some methods (such as adding a bias for Pico cell RSRP) to drive to offload some UEs to camp on picocells. In this work, we propose two solution schemes (including cell selection method, channel allocation and serving process) and combine new adaptive frequency partitioning reuse scheme to improve the total system throughput. In the simulation, we evaluate the performances of heterogeneous networks for downlink transmission in terms of channel utilization per cell (pico and macro), call blocking probability, outage probability and effective throughput. The simulation results show that the call blocking probability and outage probability are reduced remarkably and the throughput is increased effectively.

• Journal of the Korean Society of Food Culture
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• v.14 no.4
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• pp.271-287
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• 1999

A change in distribution structure affect a consumption structure which may result in considerable changes in lifestyle including food purchase. The purpose of this study was to investigate the effect of change of distribution structure on the indigenous fermented food purchase. The informations of this study were obtained from 407 housewives residing in Seoul and the capital area by using questionnaire during May to June, 1997 Their data were statistically analyzed based on frequency, mean, and $X^2-test$. The results were as follows; 1) The percentages of subjects buying ready made fermented food were 69.8% for Jotkals(salt-fermented fish products), 22.3% for Kochujang(fermented red pepper soybean paste), 21.6% for Janachis(pickled basic side dishes), 21% for Kanjang(Korean style soybean sauce), 17.1% for Toenjang(Korean style soybean paste), and 3% for Kimchi(seasoned and fermented vegetables). 2) With decreasing age, preparation ability of Kanjang, Janachis, and Kimchi. The subjects living close to the new distribution channel were higher in ready made fermented food than the others. 3) Compared to the subject living far from the new distribution channel, the subject living close to the new distribution channel was high in frequency of new distribution channel utilization for indigenous fermented food purchase but low in frequency of conventional market utilization. The younger in age, higher in educational level, and nuclear family, the higher the utilization of new distribution channel for indigenous fermented food purchase.

• Journal of KIISE:Information Networking
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• v.37 no.3
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• pp.249-253
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• 2010

Resource of wireless frequency bandwidth is gradually going to be deficient due to explosive increase of traffic and saturated non-licensed frequency band such as ISM. In the contrary, many licensed frequency bands are revealed to be low in utilization by several measurement based researches. To alleviate this inefficiency, a concept of cognitive radio is suggested. Cognitive radio lets non-licensed user exploit the licensed frequency band as long as non-licensed user does not interfere licensed user and as a result, it is possible to harness wireless frequency more efficiently. IEEE 802.22 is the first standard network with cognitive radio technology and it employs Two-Stage channel sensing mechanism to accomplish both enough licensed user protection and efficient channel utilization. In this paper, we analyze the overhead of Two-Stage channel sensing mechanism and identify the influence of channel sensing time to the overhead.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.1
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• pp.186-205
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• 2019

Intercell interference coordination (ICIC) is considered as a promising technique to increase the spectral efficiency of OFDMA cellular systems. The soft frequency reuse (SFR) and fractional frequency reuse (FFR) are representative and efficient management techniques for ICIC. Herein, to enhance the performance of the SFR scheme, we propose a call admission (CAC) scheme. In this CAC scheme, called Spectrum handoff-SFR(S-SFR), the spectrum handoff technique is applied to the user equipment (UE) located near the cell center. We derive the traffic analysis model to describe the S-SFR. In addition, a two-dimensional (2-D) Markov chain and an outage analysis are used in our analytical model. From the traffic analysis, the significant performance measures are the outage probability, call blocking probability, system throughput and resource utilization. Based on those, the outage probability and system throughput are obtained using resource utilization as an interference pattern. The analytical results are verified with computer simulation results. Finally, we compare our proposed scheme with other ICI schemes.

• Journal of the Korean Data and Information Science Society
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• v.27 no.2
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• pp.419-427
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• 2016

To examine whether the effect on utilization of ambulatory dental care are associated with oral disease according to pack-years of smoking in Korean population. Using data from Korea Health Panel between 2008 and 2012, we analyzed 3,866 participants who were male and more than 20 years. Pack-years of smoking were significantly associated with utilization in ambulatory dental care after adjustment for age, marital status, family income, and chronic disease. Ambulatory dental visitation frequency has been estimated to increase by 6% when 10.0 pack-years of smoking increased. Especially, the smokers who had 20.0~29.9 and 30.0 or more pack-years of smoking in forties and fifties males were 25% and 52% respectively more than non-smokers in utilization of ambulatory dental care.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.526-529
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• 2015

as the smartphone industry developed, the smartphone's internal hardware devices have become high-end devices and it requires more power consumption than the previous one. therefore a battery of high capacity needed, but there is a limit in order to equip a large battery on account of smartphone minimization. The Linux Kernel provides the DVFS Mechanism to compensate for these limitations by software techniques. DVFS is dynamically adjust the frequency of the CPU to reduce the power consumption of the CPU. ondemand governor, the default policy in DVFS, apply the maximum frequency of the CPU whenever exceeding the up_threshold. so it result in a waste of CPU resources. by paying attention to this point, this paper propose the mechanism that maintain a high CPU utilization in proportion to the current frequency of the cpu to prevent the waste of CPU resources and conserve energy.

• Journal of Families and Better Life
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• v.9 no.1 s.17
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• pp.113-130
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• 1991

The purpose of the present study was to describe the expectation and the performance on the housework socialization of the age homemakers and to ivestigate their relationships to the demographic characteristics and the influences of other related factors. 344 homemakers who were older than 45 years and were living in Chunlabuk-do, 1990 were sampled for this study. The data were collected by questionnaire designed by the researcher and analyzed by using frequency, one-way ANOVA analysis of variance, t-test, and multiple regression analysis. The major findings were as follows ; 1) The aged homemakers' housework socialization score was higher than the average, The score of the expectation was higher than one of the present performance. Scores for the utilization of the household equipments and the utilization of employes's services were higer comparing to those for other variables of the performance and the expectation respectively. 2) There was the significant differences in the each of the present performance varibles related to th housework socialization among the following demographic varables ; Age of homemakers, years of marriage, education, residence area, types of housing, monthly income, and level of housework equipment possession. 3) There was the significant differences in the expectation on the housework socialazation among the following variables ; age of homemakers, years of marriage, education, monthly income, and types of housing. The significant differences were found in the utilization of grouped, the utilization of the commodity, the utilization of the household equipments as subvariables of housework socialization, among age of homemakers, years of marriage, and level of education, The significant differences were found in the utilization of employee's services among age of homemakers, types of family, and level of health. 4) The level of education and monthly income significantly influenced on the present performance of the house work socialization. Years of marriage, significantly influenced on the utilization of grouped, education on the utilization of the commodity.(the utilization of the producted materials) and the utilization of employee's services and monthly income on the utilization of the household equipments (the utilization of the household appliances, and equipments). The years of marriage and education significantly influenced on the expectation on the housework socialization in the order, Age of homemakers and years of marriage significantly influenced on the utilization of grouped, the utilization of the commodity, the utilization of employee's services and age of homemakers and monthly income on the utilization of the household equipments.

• Korea Journal of Hospital Management
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• v.14 no.1
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• pp.36-61
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• 2009

This study focused on finding the variation of medical service utilization, paths of medical service utilization and medical payments of the patients died by cerebrovascular diseases. For this study, data of the one-year episodes of the health insurance subscribers died in 2004 were selected. The frequency of medical visits, the lengths of stays, the days of outpatient visits, the total period of medical services and the total medical payments were compared by the characteristics of the suppliers and utilizers. This study is useful in reviewing the equity of medical service utilization because it analyzed variance in utilization by episodes. In oder to collect accurate data of the patients died by cerebrovascular diseases in 2004 the 2004 reimbursement data of all medical institutions were matched to the data of funeral fee payment by the National Health Insurance Corporation from January 2004 to May 2005. The major results of the study are as follows. The variation of medical service utilization of cerebrovascular diseases was influenced by supplier factors suppliers, such as types and locations of medical institutions and user factors such as sex and age. It was suspected that the reimbursement by fee-for-service contributed to the variation quite a lot, but we could not compare the variation between the different reimbursement systems in Korea. On the basis of analyzing results this study suggests that the factors of suppliers and utilizers should be reviewed to reduce the under use and over use expressed by variations of medical service. The processes of care, effective communication and management system should be investigated for the equity of medical service utilization and also. alternative medical services would be recommended to reduce the high medical payment. Additionally to find other causes of variation further in depth study controling the severity of diseases, socio-economic status of the users and the system factors is required.

• Journal of Preventive Medicine and Public Health
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• v.37 no.2
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• pp.150-156
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• 2004

Objectives : To investigate the utilization patterns of non-steroidal anti-inflammatory drugs (NSAIDs) among the elderly with osteoarthritis (OA) undergoing primary ambulatory care in Busan metropolitan city, Korea. Methods : OA patients, aged 65 years and over, were identified from the Korean National Health Insurance Review Agency drug prescription database. The subjects had at least one episode of claim for OA (ICD-10-CM: M15-M19) between August 1, 2000 and February 28, 2002. Trends in the determinations of NSAIDs utilization were identified using chi-squared tests for trend. Results : There were 47,711 osteoarthritic patients. The total number of visits by these patients was 177,443, with a total frequency for NSAID prescriptions of 214,952. Seventy-nine percent of the OA patients were female. NSAIDs were prescribed on 133,284 visits (75.1%) and the proportion of prescriptions was significantly increased with age. Only the proportion of visit when NSAIDs were prescribed decreased, from 65.1 to 43.5%, during the study period (p<0.001). However, the proportion of combined treatments with anti-ulcer drugs was increased. The use of NSAIDs injections was decreased. Of the individual NSAIDs, diclofenac (28.7% of total frequency of NSAID prescriptions), piroxicam (15.0%) and talniflumate (8.7%), were the most frequently prescribed. Among the NSAIDs prescribed OA visits, 45.7% used two or more NSAIDs. Conclusion : The total proportion of NSAIDs prescribed to the osteoarthritic patients was higher than in other studies. The decline in the use of NSAIDs during the study period, and the frequent selection of safer medications, such as combination therapy with anti-ulcer drug, may reflect the risk awareness of the use of NSAIDs.