• KDI Journal of Economic Policy
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• v.12 no.2
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• pp.51-79
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• 1990

Research on technical efficiency, an important dimension of market performance, had received little attention until recently by most industrial organization empiricists, the reason being that traditional microeconomic theory simply assumed away any form of inefficiency in production. Recently, however, an increasing number of research efforts have been conducted to answer questions such as: To what extent do technical ineffciencies exist in the production activities of firms and plants? What are the factors accounting for the level of inefficiency found and those explaining the interindustry difference in technical inefficiency? Are there any significant international differences in the levels of technical efficiency and, if so, how can we reconcile these results with the observed pattern of international trade, etc? As the first in a series of studies on the technical efficiency of Korea's manufacturing industries, this paper attempts to answer some of these questions. Since the estimation of technical efficiency requires the use of plant-level data for each of the five-digit KSIC industries available from the Census of Manufactures, one may consture the findings of this paper as empirical evidence of technical efficiency in Korea's manufacturing industries at the most disaggregated level. We start by clarifying the relationship among the various concepts of efficiency-allocative effciency, factor-price efficiency, technical efficiency, Leibenstein's X-efficiency, and scale efficiency. It then becomes clear that unless certain ceteris paribus assumptions are satisfied, our estimates of technical inefficiency are in fact related to factor price inefficiency as well. The empirical model employed is, what is called, a stochastic frontier production function which divides the stochastic term into two different components-one with a symmetric distribution for pure white noise and the other for technical inefficiency with an asymmetric distribution. A translog production function is assumed for the functional relationship between inputs and output, and was estimated by the corrected ordinary least squares method. The second and third sample moments of the regression residuals are then used to yield estimates of four different types of measures for technical (in) efficiency. The entire range of manufacturing industries can be divided into two groups, depending on whether or not the distribution of estimated regression residuals allows a successful estimation of technical efficiency. The regression equation employing value added as the dependent variable gives a greater number of "successful" industries than the one using gross output. The correlation among estimates of the different measures of efficiency appears to be high, while the estimates of efficiency based on different regression equations seem almost uncorrelated. Thus, in the subsequent analysis of the determinants of interindustry variations in technical efficiency, the choice of the regression equation in the previous stage will affect the outcome significantly.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.36 no.3
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• pp.1-15
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• 2018

This study aims to investigate an aspect of physical palace by reviewing the emergences of tigers and leopards in the palace in Hanyang from the environmental historical perspective. To do so, three topics in environmental history were reviewed including 'environment,' 'impact of human-beings on the environment,' and 'sense and attitude of human-beings on the environment' based on the historical records such as "'Wangjoshilok(王朝實錄)". The results of this study are as follows. First, It was confirmed that leopards and tigers were emerged not only in the palace but also near the City Wall of Hanyang from time to time in Joseon Dynasty. Moreover, tigers lived and propagated in the backyard. Second, This situation may be caused by the natural factors of palace in Hanyang including location, philosophy and technique of building, and so on. That means 'good location' placed by palace worked favorably not only for human-beings but also for the activities of tigers and leopards. Third, In addition to the locational environment, forest policies on the palace and capital may facilitate the emergences of leopards and tigers. With the managements of pine trees, prohibition of burials, prohibition of climbing, prohibition of mountain entrance, and so on, forests were developed in the mountainous territories, which might play a role of shelters or passages for the tigers and leopards. Fourth, It was confirmed that countermeasures on the emergences of tigers in the palace as well as the capital city were different by the kings. Out of these, Jeong-jo was highlighted to seek the realistic countermeasures with actual understanding on the emergences of tigers and leopards. Fifth, In summary, frequent emergences of tigers and leopards in the palace and capital city could be a practical evidence to show 'pro-naturalism' or 'eco-friendliness' of the palace in Joseon which was mentioned superficially, paradoxically speaking. Further studies with the related disciplines are required on the cultural or ecological history of the palace. In addition, it is considered to conduct more detailed scientific studies related to the trend of ecological changes in Joseon.

• Journal of radiological science and technology
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• v.29 no.2
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• pp.83-92
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• 2006

Based on the data of cervical cancer patients who were treated by the radiotherapy with concurrent chemotherapy at the radiation oncology department of National Cancer Center from January 2002 to February 2003, we have studied the method recommended by ICRU 38 to maximize the prescription dose to the planing target volume (PTV) with minimizing the dose to surrounding normal organs. Clinical stage of the patients are 1 patient for stage IB, 3 patients for IIA, 19 patients for IIB, 3 patients for IIIA, 3 patients for IIIB and 1 patient for IV. All patients took the MRI before treatment and the maximum size of the gross tumor volume were under 4cm for 17 patients and from 4 cm to 6 cm for 12 patients and above 6 cm for 1 patient. The results show that while the irradiated volume can be reduced with optimized dose distribution using PTV treatment planning (p<0.0001) when the remained tumor size is small, the surrounding normal organs will receive unnecessarily large dose when the irradiated tumor volume is relatively large. This is because there is some limitation in controling the intensity of radiation in Fletcher Williamson Applicator. To overcome the limit of applicator and to achieve the optimal dose distribution, we have virtually applied 4 needles with Fletcher Williamson Applicator for 10 patients who have relatively large tumor and studied the change in dose distribution before and after application. The results show that this new virtual treatment plan reduces the volume covered by 100 % isodose (p=0.0608, p=0.0607) and reduces the dose of normal organs (p=0.0162, p=0.008). This evidence suggest that this method is superior than the currently used method such as PTV treatment and ICRU treatment.

• Korea journal of population studies
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• v.10 no.1
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• pp.28-38
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• 1987

This paper was set out to study the structure of the career occupational mobility in the early and rapid phase of industrialization in Korea. By analyzing the individual life histories regarding occupational mobility and achievement, I propose a model of yearly career mobility of Korean men and Women during the period of 30 years between 1954 and 1983. With the occupational classification scheme of 5 groups - Upper Nonmanual, Lower Nonmanual, Self Employed, Manual, Farm - the mobility pattern in the person-year mobility table analyzed can be characterized primarily by the strong influence of immobility. The degree of immobility, however, is different by the occupational groups. The absolute amount of immobility can be summarized as being U-shaped. Overall, the pattern of mobility can be explained best by the concept of occupational distance. I then propose a model of relative career occupational mobility pattern that combines the conceptual and theoretical basis and the methodological rigor. The model is based on the notion of the reproduction of inequality, the labor market context, and the life history perspective. The model encompasses the 6 conceptual explanatory factors such as persistence effect, ceiling effect, traditional sector effect, nonmanual occupation effect, alternative mobility channel effect, and occupational distance effect, as well as the effects of both origin and destination occupations. The relative pattern of career mobiliity in Korea can be characterized by the following six findings. First, the persistence effect on the diagonal cells of the mobility table is dominant. Second, a clear evidence of the negative effect of occupational distance between nonmanual occupations and manual and farm occupations is found. Third, the out-mobility from farming took place regardless of the destination occupations. Fourth, the internal mobility within the nonmanual occupation block is high and bi-directional, and is exclusive against other occupations. Fifth, the 'self employed' occupation is serving a peculiar function in both inflow and outflow pattern. Last, the relative pattern of career occupation mobility is asymmetrical in terms of the upward and downward mobility.

• Journal of Korean Society of Transportation
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• v.24 no.5 s.91
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• pp.89-108
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• 2006

Korea has been entering the ageing society as the population of age over 65 shared over 7% since the year 2000. The ageing society needs to have transportation facility considering elderly people's travel behavior. This study aims to understand the elderly people's travel behavior using recent data in Korea. The activity schedule approach begins with travel outcomes are part of an activitv scheduling decision. For tho?e approach. used discrete choice models (especially. Nested Logit Model) to address the basic modeling problem capturing decision interaction among the many choice dimensions of the immense activity schedule choice set The day activity schedule is viewed as a sot of tours and at-home activity episodes tied togather with overarching day activity pattern using the Seoul Metropolitan Area Transportation Survey data, which was conducted in June, 2002. Decisions about a specific tour in the schedule are conditioned by the choice of day activity pattern. The day activity scheduling model estimated in this study consists of tours interrelated in a day activity pattern. The day activity pattern model represents the basic decision of activity participation and priorities and places each activity in a configuration of tours and at-home episodes. Each pattern alternative is defined by the primary activity of the day, whether the primary activity occurs at home or away, and the type of tour for the primary activity. In travel mode choice of the elderly and non-workers, especially, travel cost was found to be important in understanding interpersonal variations in mode choice behavior though, travel time was found to be less important factor in choosing travel mode. In addition, although, generally, the elderly was likely to choose transit mode, private mode was preferred for the elderly over 75 years old owing to weakened physical health for such things as going up and down of stairs. Therefore. as entering the ageing society, transit mode should be invested heavily in transportation facility Planning tor improving elderly transportation service. Although the model has not yet been validated in before-and-after prediction studies. this study gives strong evidence of its behavioral soundness, current practicality. and potential for improving reliability of transportation Projects superior to those of the best existing systems in Korea.

• The Korean Society of Law and Medicine
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• v.16 no.2
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• pp.55-84
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• 2015

The tuberculosis is the infectious disease. Generally, the active tuberculosis patient can infect the 10 persons for one year within the daily activities like casual conversation and singing together. The infectivity of tuberculosis can continue for a life time, and infected persons can remain at risk for developing active tuberculosis. To control this contagious disease, along with the active tuberculosis patients, non-infectious but non-compliant patients who can be infectious if their immune systems become impaired have to be managed. To control the non-complaint patients, medical treatment order should be combined with the public order. Because tuberculosis is the risk of community health, the human rights like liberty and freedom of movement can be restricted for public welfare under the article 37(2) of constitution. Even when such restriction is imposed, no essential aspect of the freedom or right shall be violated. The degree of restriction on the rights of citizens is different what methods are chosen to non-complaint patients. For example, under the directly observed therapy program, the patients and medical staffs make an appointment and meet to confirm the drug intakes according to the schedule, which is the medical treatment combined with the mildest public order. If the patients break the appointments or have the history of disobedient, the involuntary detention can obtain the legitimate cause. The Tuberculosis Prevention Act has the two step programs on this involuntary detention, The admission order (Article 15) is issued when the patients are infectious. The quarantine order (Artle 15-2) is issued when the patients are infectious and non-complaint. The legal criteria for involuntary detention are discussed and published through the international conventions and covenants. For example, World Health Organization had made guidance on human rights and involuntary detention for tuberculosis control. The restrictions should be carried out in accordance with the our law and in the legitimate objective of public interest. And the restriction should be based on scientific evidence and not imposed in an unreasonable or discriminatory manner. We define and adopt these international criteria under our constitution and legal system. Least restrictive alternative principle, proportionality principle and the individual evaluation methods are explained through the reviews of United States court decisions. Habeas Corpus Act is reviewed and adopted as the procedural due process to protect the patient rights as a citizen. Along with that, what conditions and facilities which are needed to performed quarantine order are discussed.

• Horticultural Science & Technology
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• v.31 no.5
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• pp.607-616
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• 2013

Light with two faces, beneficial and harmful effects is an important signal for every living cell. Optimal adaptation to light environment enhances the fitness of an organism and survival in nature. Understandings of light quality and plant growth provide with the economical guides for artificial light sources like LEDs. Compared with those under white light, the 1 week seedlings of Chinese cabbage (Brassica rapa) under monochromic red and blue light showed normal development and growth. In contrast to extremely long and etiolated hypocotyls of the seedlings under dark, those under far-red etiolated were extremely short. Based on the microarray analysis, blue light induced the vigorous development and growth and two fold changes of transcripts than red light condition. To have insight of gene products under different light qualities conditions, GO term enrichments were calculated and each gene according to their GO terms were categorized. The blue and red lights affected the expressions of genes related to biological process. Especially, the genes related to metabolic process and developmental process and plastid and chloroplast in the cellular component category were induced under blue light. This study provided the molecular biological evidence for various light qualities on the growing process of B. rapa.

• Journal of Food Hygiene and Safety
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• v.33 no.2
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• pp.124-130
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• 2018

The Ministry of Food and Drug Safety (MFDS) is amending its test methods for the use of health functional foods (dietary food supplement), in order to establish regulatory standards and specifications in Korea. In this regard, we continue to pursue and perform our research on the analytical method development for the items being researched and reviewed. In this study, we have developed a sensitive and selective test method that could simultaneously separate and determinate six major bioactive flavonolignans in silymarin, which are based on the use of a liquid chromatographic-tandem mass spectrometry (LC-MS/MS). The standard calibration curves presented a linearity effect with the correlation coefficient ($r^2$) > 0.999. The limits of detection (LODs) and limits of quantitation (LOQs) were in the range of $0.3{\sim}9.0{\mu}g/L$ and $0.8{\sim}27.3{\mu}g/L$, respectively. The recovery results ranged between 96.2~98.6% at 3 different concentration levels, and its relative standard deviations (RSDs) were less than 5% as noted in this study. The proposed analytical method was characterized with a noted high resolution of the individual silymarin constituents, and the assay was fully validated as well. Our research can provide a significant scientific evidence that can be useful to amend the silymarin test method for the Health Functional Food Code.

• Journal of Oral Medicine and Pain
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• v.34 no.2
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• pp.207-216
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• 2009

Trigeminal neuralgia is defined "a sudden, usually unilateral, severe, brief, stabbing, recurrent pain in the distribution of one or more branches of the fifth cranial nerve". The initial treatment of choice for trigeminal neuralgia is medical therapy. In patients with medically intractable pain or intolerable medication side effects, invasive therapeutic approaches are often necessary. Based on the amount of evidence and estimated efficacy, carbamazepine is the drug of choice in the management of trigeminal neuralgia. In case of insufficient or no response to carbamazepine, second-line drugs can be added. In this study, the author tried to review and analyzed the cases of 90 patients whom had visited for treatment of trigeminal neuralgia at the Department of Oral Medicine, Kyungpook National University Hospital from 2003 to 2008. The results were as follows: 1. Trigeminal neuralgia was significantly more common with advancing age, and nearly twice as common in women than men (ratio of 2.1:1) 2. The maxillary branch of the trigeminal nerve involved most often (51.1%), and the right side of the face is affected more commonly than the left (ratio of 2.9:1). 3. 85(94.4%) patients had experiences visiting medical or dental specialties before being referred to the Department of Oral Medicine. 4. 40(44.4%) patients with trigeminal neuralgia had systemic diseases. 5. Treatment with carbamazepine monotherapy was satisfactory initially in 69(76.7%) the patients, and the mean daily dose of carbamazepine was 402.9mg. On the other hand, 16(17.8%) patients expressed effectiveness after combination therapy of carbamazepine and other drugs. 6. Of the 69 patients who had a good initial response to carbamazepine monotherapy, 18 patients became resistant, so that combination therapy of carbamazepine and other drugs were necessary. 7. 54(60%) patients developed side effects such as dizziness, drowsiness, nausea, vomiting, blood dyscrasias, skin rash and constipation, and 11 of the patients decided to stop tmedicaion due to side effects.

• Korean Journal of Social Welfare Studies
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• v.44 no.3
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• pp.421-450
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• 2013

One of the challenging tasks of the National Health Insurance Corporation(NHIC). the only public insurance institution administrating the Korea's compulsory national health insurance(NHI) system, is to make those NHI beneficiaries who fail to make a scheduled monthly premium payment to pay. For this purpose, the NHIC has been using a measure known as 'Benefit Limit Measure(BLM)' in which those who miss premium payment for six or more month's in total are classified as 'late payer' and are sent warnings and late payer status notices. If the late payers fail to make a full payment of missed premiums even after receiving the written notices, the NHIC can order a temporary seizure of the late payer's property until all missed premiums plus interest are paid. Recently, the BLM has been criticized by the public of its cruel nature, and its effectiveness has been questioned because no empirical evidence has been collected. In this study, the authors using the NHIC data set attempted to analyze the effectiveness of the BLM. Those late payers for whom the BLM was administered were compared to those not in terms of the likelihood of paying missed premium payments with a series of logistic regression analyses models. Data analyses results showed that the likelihood of paying one or more month's unpaid premium of the former group was 14 to 46 times higher than the latter. It, however, was also found that the BLM was only effective to make no more than 12% of the late payers to pay at all. Based on the study findings, the authors made a few recommendations regarding the BLM.