• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.4 no.2
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• pp.10-14
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• 1990

• Health Policy and Management
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• v.30 no.3
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• pp.326-334
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• 2020

Background: Korea has gradually expanded the coverage of medical care services in its national health insurance system. On April 1, 2018, it implemented a policy that expanded the coverage for an ultrasonography in the upper abdomen. In this study, we aimed to investigate the effect of the policy on the utilization of the ultrasonography in the upper abdomen in tertiary care hospitals. Methods: Using the dataset of the Health Insurance Review and Assessment Service, we explored changes in the utilization of the ultrasonography in the upper abdomen in tertiary care hospitals from July 1, 2017 to November 30, 2018 through the difference-in-difference (DID) mixed-effects-model method. Facility factor, equipment factor and personnel factors, type of hospital, the total amount of medical care expenses, and geographic region were considered as control variables. Results: On average, the utilization of the ultrasonography in the upper abdomen increased by 228% after the coverage expansion policy. However, the results of DID mixed-effects-model method analysis showed that the utilization increased by 73%. As for the number of beds, the utilization was higher with a group of 844-930, 931-1,217, and 1,218 or greater compared with a group of 843 or fewer, while the utilization of the number of ultrasonic devices was lower with a group of 45-49 compared with a group of 44 or fewer. The utilization decreased with the number of interns and the number of nurse assistants. Besides, relative to Seoul, the utilization was lower in the other metro-cities and provinces. Conclusion: The coverage expansion policy in the national health insurance system increased service utilization among people. Future research needs to investigate the degree to which such coverage expansion policy reduces the unmet medical care needs among the deprived in Korea.

• Journal of Korean Society of Transportation
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• v.31 no.5
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• pp.71-78
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• 2013

This paper investigated the influences of ramp traffic flow on the lane utilization for signalized intersection approaches which are adjacent to an off-ramp-street junction. The statistical test showed a correlation between lane utilization and the ramp traffic flow. As the ramp traffic flow increases, the left lanes are less utilized and the right lanes are more utilized. The lane utilization factors are calculated by applying traffic data collected from the Seoul Metropolitan area. The utilization factors are 1.113 for 2 lanes, 1.124 for 3 lanes, and 1.131 for 4 lanes. The lane utilization factors proposed in the paper show higher values than those in current Korea Highway Capacity Manual (KHCM) under the conditions that the number of lanes is 2 or 3. However, the lane utilization factor for 4 lanes in the paper shows lower value than in KHCM. The ramp traffic flow causes more utilization of the right lanes than at normal signalized intersections and the extent gets larger as the number of lanes decreases. Based on the results of the paper, the lane utilization factors at signalized intersection approaches should be revised and reasonable capacity should be recalculated if the signalized intersection is adjacent to an off-ramp-street junction.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.6
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• pp.704-709
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• 2014

Plate heat exchanger is being applied in the field of marine plants and chemical industry, such as OTEC and SWAC equipment. The study aims to interpret the heat transfer and pressure drop characteristics of plate heat exchangers to determine the geometric design parameters such as the channel space. In this study, heat transfer performance was numerically studied with respect to the variation of channel spaces. The results from numerical analysis indicated that the j factor was linearly decreased with the flowrate of seawater over every cases. As the flowrate of water increased with respect to channel spaces, the j factor decreased linearly. And the f factor decreased linearly with the increase of flowrate. When the channel space is 2.8~3.2 mm and 3.2~3.2 mm, respectively, the area goodness factor of plate heat exchanger showed the highest performance.

• Journal of Korean Society of Transportation
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• v.27 no.6
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• pp.7-18
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• 2009

In 2008, there are 135 service areas, which provide for drivers to convenience on expressways. But there are some problems on parking capacity, because it is failed to calculate the appropriate parking lots of the service area. The fundamental problem is that the size of parking lots is calculated by simple value; despite there are various factors of utilization, congestion, and turnover. This paper describes a study on proper coefficient for calculating the appropriate service area, considering the characteristics of drivers' behavior. We conducted statistical analysis with the surveyed data in "Status of the expressway facilities in 2004." Analysis results show there are some difference by day and night, and vehicle type with the factor of utilization, congestion, and turnover, and there are different usages according to expressway route. The results indicate that the usage of a service area have different characteristics by time and space, and vehicle type.

• Resources Recycling
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• v.14 no.2
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• pp.33-42
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• 2005

Solvent extraction experiments have been performed to separate Nd and Sm from chloride solution with PC88A. The effect of the saponification of PC88A on the extraction and separation of the two metals were studied. In the experimental ranges conducted in this study, the distribution coefficients of Sm were higher than those of Nd and separation factor between them increased with the equilibrium pH of aqueous solution. Saponification of PC88A enhanced the distribution coefficients of Sm and Nd and the separation factor. A chemical model was developed to predict the distribution coefficients of metals and separation factor from the initial extraction conditions. The measured distribution coefficients of Nd and Sm with PC88A and saponified PC88A agreed well with those calculated in this study.

• Korean Journal of Social Welfare
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• v.56 no.4
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• pp.123-147
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• 2004

The purposes of this study are, 1) to explore the factors related to the family caregivers' preferences for service utilization both of the community-based welfare and health-care services, and 2) to examine the reasons why not want to use services analyzing a survey data obtained from family caregivers(n=1,000). Anderson and Newman's Behavior model was employed to examine the factors related to the preferences for service utilization. The main results are as follows. 1) Logistic regression analyses demonstrated that predisposing factor(such as age and relations with frail elderly) and enabling factor(such as economic status, secondary caregiver, informal informational support provider, etc) were significant predictor for caregivers' preference for service utilization. Contrary to an expectation, needs factor was negatively related to the preference for service. More specifically, the more they have service needs, the less they show their willingness to use community-based service both in welfare and health-care services except for care education program. 2) Caregiver identified 'family caregiving consciousness'(family should take care of frail elderly, elderly dislike be taken care of) as an important reason not want to use community services next to financial factor. These findings have several implications for policy making especially for 'public long-term care insurance' which was planned to start in 2007.

• Journal of Information Processing Systems
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• v.11 no.4
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• pp.583-600
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• 2015

Generally, the wireless network provides priority to handover calls instead of new calls to maintain its quality of service (QoS). Because of this QoS provisioning, a call admission control (CAC) scheme is essential for the suitable management of limited radio resources of wireless networks to uphold different factors, such as new call blocking probability, handover call dropping probability, channel utilization, etc. Designing an optimal CAC scheme is still a challenging task due to having a number of considerable factors, such as new call blocking probability, handover call dropping probability, channel utilization, traffic rate, etc. Among existing CAC schemes such as, fixed guard band (FGB), fractional guard channel (FGC), limited fractional channel (LFC), and Uniform Fractional Channel (UFC), the LFC scheme is optimal considering the new call blocking and handover call dropping probability. However, this scheme does not consider channel utilization. In this paper, a CAC scheme, which is termed by a uniform fractional band (UFB) to overcome the limitations of existing schemes, is proposed. This scheme is oriented by priority and non-priority guard channels with a set of fractional channels instead of fractionizing the total channels like FGC and UFC schemes. These fractional channels in the UFB scheme accept new calls with a predefined uniform acceptance factor and assist the network in utilizing more channels. The mathematical models, operational benefits, and the limitations of existing CAC schemes are also discussed. Subsequently, we prepared a comparative study between the existing and proposed scheme in terms of the aforementioned QoS related factors. The numerical results we have obtained so far show that the proposed UFB scheme is an optimal CAC scheme in terms of QoS and resource utilization as compared to the existing schemes.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.5
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• pp.1005-1010
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• 2011

The accidents caused by dielectric instability have been increasing in power grid. It is important to enhance the dielectric reliability of a high voltage apparatus to reduce the damage from electrical hazards. To develop an electrically reliable high voltage apparatus, the experimental study on the electrical breakdown field strength is indispensable, as well as theoretical approach. In this paper, the lightning impulse breakdown characteristics considering utilization factors are studied for the establishment of insulation design criteria of an high voltage apparatus. The utilization factors are represented as the ratio of mean electric field to maximum electric field. Dielectric experiments are performed by using several kinds of sphere-plane electrode systems made of stainless steel. As a result, it is found that dielectric characteristics are affected by not only maximum electric field intensity but also utilization factors of electrode systems. The results are expected to be applicable to designing the air-insulated high voltage apparatuses.

• The Journal of Korean Medicine
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• v.32 no.1
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• pp.97-108
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• 2011

Objective: This study aimed to analyze the utilization of Oriental medical services and its determinants among the elderly. Method: Data from a Korean longitudinal study of aging was used. Regression analysis was used to find the determinants of the utilization of medical care. Results: People with low education and low income were more likely to use Oriental medical services. Determinants of using Oriental health service were sex, marriage, income, subjective health condition, activity restriction due to pain, and chronic disease. Among them, only subjective health condition and activity restriction due to pain were significant determinants of frequency of and expenditure on Oriental medical services. Especially, activity restriction due to pain was a significant factor in the use of Oriental medical services, but not in the use of Western medical services. Conclusion: Treatment related to pain was closely associated with Oriental medical services. These treatments need to be developed with scientific and clinical evidence.