• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.109-110
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• 2007

Most transmission lines pass through mountainous terrain and deep valleys, to avoid populated areas. Accordingly, the impact of climate changes, environmental conditions and system expansion have caused an increase in transmission line system fault rates. KEPCO has developed and applied phase-spacers to reduce contact faults between phases. Contact between phases represented 9% of total line faults before the devices were installed. Phase-spacers have reduced faults by up to 3.4% since the phase-spacers were installed in 2005. Also, recently developed devices provide additional economic benefits as they cost about a third of the price as similar devices introduced in foreign countries. Phase-spacers are an effective way to prevent phase contact accidents by maintaining physical space between phases. These spacers will be implemented in areas where contacts are likely to occur. They are expected to reduce accident rates and improve power quality.

• Nuclear Engineering and Technology
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• 제40권1호
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• pp.9-20
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• 2008

Since plutonium accounts for 40-50% of the power produced by uranium fuels, spent fuel contains only residual plutonium. Management of this plutonium is one of the aspects influencing the choice of a fuel cycle back-end option: reprocessing, direct disposal or wait-and-see. Different grades and qualities of plutonium exist depending from their specific generation conditions; all are valuable fissile material. Safeguard authorities watch the inventories of civil plutonium, but access to those data is restricted. Independent evaluations have led to an estimated current inventory of 220t plutonium in total (spent fuel, separated civil plutonium and military plutonium). If used as MOX fuel, it would be sufficient to feed all the PWRs and BWRs worldwide during 7 years or to deploy a FBR park corresponding to 150% of today' s installed nuclear capacity worldwide, which could then be exploited for centuries with the current stockpile of depleted and spent uranium. The energy potential of plutonium deteriorates with storage time of spent fuel and of separated plutonium, due to the decay of $^{241}Pu$, the best fissile isotope, into americium, a neutron absorber. The loss of fissile value of plutonium is more pronounced for usage in LWRs than in FBR. However, keeping the current plutonium inventory for an expected future deployment of FBRs is counterproductive. Recycling plutonium reduce the required volume for final disposal in an underground repository and the cost of final disposal. However, the benefits of utilizing an energy resource and of reducing final disposal liabilities are not the only aspects that determine the choice of a back-end policy.

• The Journal of Asian Finance, Economics and Business
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• 제8권4호
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• pp.239-247
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• 2021

Conventional banks are often considered more efficient than Islamic banks because they have been operating for decades, but Islamic banks have shown rapid development recently. Therefore, this study mainly aims to compare the level of efficiency of conventional banks and Islamic banks and which ones have the best level of efficiency. This study employs panel data using Stochastic Frontier Analysis (SFA) as the data analysis technique. The data used is annual data from 13 conventional banks and 13 Islamic banks in Indonesia during the 2014-2019 period. The result shows no significant difference in the efficiency of conventional banks and Islamic banks. This result is presumably influenced by the small size of the bank and the total number of banks used in the study. The data used in the study is limited to the period from 2014 to 2019. The variables utilized are also limited to the availability of financial report data which is publicly published. This study provides additional empirical evidence regarding conventional banks' and Islamic banks' efficiency in Indonesian banking by using the latest data. While theoretically, Islamic banks are expected to be more efficient than conventional banks, this study did not find any strong support for the case in Indonesia during the observation period.

• Geomechanics and Engineering
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• 제34권6호
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• pp.597-609
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• 2023

One of the applicable methods for the stabilization of soil walls is the nailing system which consists of tensile struts. The stability and safety of soil nail wall systems are influenced by the geometrical parameters of the nailing system. Generally, the determination of nailing parameters in order to achieve optimal performance of the nailing system for the safety of soil walls is defined in the framework of optimization problems. Also, according to the various uncertainty in the mechanical parameters of soil structures, it is necessary to evaluate the reliability of the system as a probabilistic problem. In this paper, the optimal design of the nailing system is carried out in deterministic and probabilistic cases using meta-heuristic and reliability-based design optimization methods. The colliding body optimization algorithm and first-order reliability method are used for optimization and reliability analysis problems, respectively. The objective function is defined based on the total cost of nails and safety factors and reliability index are selected as constraints. The mechanical properties of the nailing system are selected as design variables and the mechanical properties of the soil are selected as random variables. The results show that the reliability of the optimally designed soil nail system is very sensitive to uncertainty in soil mechanical parameters. Also, the design results are affected by uncertainties in soil mechanical parameters due to the values of safety factors. Reliability-based design optimization results show that a nailing system can be designed for the expected level of reliability and failure probability.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 가을 학술논문 발표대회
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• pp.219-220
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• 2021

It is considered that the construction industry is one of the pivotal players in the national economy in terms of Gross Domestic Production (GDP) and employment. Behind the positive role of this industrial sector to the national economy, the construction industry generates approximately 50 % of the total waste generation from all the industrial sectors. There are several measures to mitigate the adverse impacts of the construction waste such as reduce, reuse and recycle. Recycling would be one of the effective strategies for waste minimisation, which would be able to reduce the demand upon new resources as well as enhance reusing the construction materials on sites. The automated construction waste classification system would make it possible not only to reduce the amount of labour input but also mitigate the possibility of errors during the manual classification process. In this study, we proposed an automated waste segmentation and classification system for recycling the construction and demolition waste in the real construction site context. Since the practical application to the real-world construction sites was one of the significant factors to develop the system, a YOLACT (You Only Look At CoefficienTs) algorithm was chosen to conduct the study. In this study, it is expected that the proposed system would make it possible to enhance the productivity as well as the cost efficiency by reducing the manpower for the construction and demolition waste management at the construction site.

• Nuclear Engineering and Technology
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• 제55권7호
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• pp.2373-2379
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• 2023

In sodium systems, leakage is one of the safety concerns; it can cause chemical reactions, which may result in fires. There are contact and non-contact types of leak detectors, and the conventional method of non-contact type detection is by gas sampling. Because of the complexity of this method, there has always been a need for a simple gas sensor, and the resistive-type nanostructure ZnO sensor is a promising option with various advantages. In this study, a ZnO sensor was fabricated, and the concept was tested as a leak detector using a dedicated experiment facility. The experiment results showed distinctive changes in resistance with the presence of sodium aerosol under various conditions. Replacing the conventional gas sampling with the ZnO sensors is expected to enable identification of the leakage location if used as a point-wise instrumentation and to greatly reduce the total cost, making the system simple, light, and effective. For further study, more tests will be performed to evaluate the sensitivity of key parameters under various conditions.

• KDI Journal of Economic Policy
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• 제14권2호
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• pp.29-54
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• 1992

무역자유화(貿易自由化)나 지역경제통합(地域經濟統合)의 경제적(經濟的) 효과(效果)를 논의할 때 시장구조(市場構造)와 규모(規模)의 경제(經濟)와 관련된 개방효과(開放效果)를 분석(分析)하는 것이 중요하다. 잠재시장(潛在市場)의 크기가 확대되는 데에 따르는 제품차별화(製品差別化)의 심화(深化)나 규모(規模)의 경제실현(經濟實現)은 '무역(貿易)의 이익(利益)'의 차원(次元)을 확장시킨다. 개방(開放)에 따르는 해외로부터의 경쟁강화(競爭强化)는 국내기업(國內企業)의 경쟁환경(競爭環境)을 심화(深化)시켜 시장진입(市場進入) 퇴출(退出)과 산업합리화(産業合理化)에 영향을 미치기 때문이다. 본고(本稿)는 무역장벽완화(貿易障壁緩和)가 유발하는 자원배분효과(資源配分效果) 및 후생효과(厚生效果)뿐만 아니라, 시장구조(市場構造)가 불완전경쟁적(不完全競爭的)이고 생산과정(生産過程)에 규모(規模)의 경제(經濟)가 존재(存在)하기 때문에 나타나는 '개방(開放)의 이익(利益)'을 가상적(假想的)인 한국(韓國) 일본(日本)의 쌍무적(雙務的) 관세인하효과분석(關稅引下效果分析)을 중심으로 검토하고 있다. 이를 위하여 전산업을 완전경쟁적(完全競爭的) 산업(産業), 불완전경쟁적(不完全競爭的) 산업(産業), 비교역산업(非交易産業)으로 구성되는 30개 산업으로 분류하였으며, 가상적(假想的)인 관세인하(關稅引下)(한국(韓國)의 경우 법정관세 인하, 일본(日本)의 경우 실적관세율 50%인하)를 상정(想定)하여 이것이 양국의 산업에 미치는 영향을 검토하였다. 관세인하는 산업내(産業內) 무역(貿易)을 증가(增加)시킬 것이나, 산업합리화(産業合理化) 효과(效果)나 규모(規模)의 경제(經濟) 실현(實現)에 미치는 영향은 크지 않을 것으로 추정된다. 또한 관세인하(關稅引下)로 한국(韓國)과 일본(日本)의 총수출(總輸出)과 총수입(總輸入)이 모두 증가하나, 한국(韓國)의 경우 수출증가보다 수입증가가 큰 반면 일본(日本)의 경우 수입증가보다 수출증가가 큰 것으로 나타났다. 한편 관세인하로 한국(韓國)과 일본(日本)의 총산출증가(總産出增加)가 예상되는데, 증가폭은 각각 0.5~0.6%에 이를 것으로 예상된다.

• 대한간호학회지
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• 제24권4호
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• pp.545-556
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• 1994

Medical insurance and health care delivery system enabled Korean people to get the necessary medical service, but it caused increased needs for medical service, and resulted in the occurence of some problems such as a lack of manpower and medical facilities. In order to solve these problems, many countries, which already had medical insurance system had developed home care system and it has been regarded effective both in reducing costs and in increasing the rates of turnover of bed. Recently, Korea has included home nursing care in its health care delivery system, and some models of the hospital based home nursing care had been tried and its effects had been evaluated. So, author tried to run a home nursing care for the Cesarean section mothers and evaluate Its effects both in the mother's health and costs. This study was designed as a Quasi-experimental study. Subjects were thirty mothers who got Cesarean section operation in hospital in Seoul. Experimental group consisted of 15 volunteers, and control group were selected by means of matching technique. Data were gathered from February 1st to March 26th by two assistants who were trained by author. Experimental group were discharged on the 4th day after their operation, and got nursing care and assessment about their home three times on the 5th, 6th, and 7th day. Control group stayed in the hospital until 7th day as usual and were checked on the same day as above mentioned To evaluate the state of physiological recovery, vital signs, H.O.F, presence of edema in the legs, bathing, appetite, sleep, presence of pain or discomfort in the breasts, amount of lochia, color of lochia, defecation urination. To compare incidence of complication in experimental group with that in control group, specific assessment was done such variables as smell of lochia, presence of inflammation of operation wound, dizziness, and presence of immobilization in the extremities. The activities of daily living were checked Satisfaction of nursing were checked To calculate costs, author asked subjects to specify expenditure including hospital charge, traffic enpenses, and food expenses. The results were as fellows. 1. On effectiveness of home nursing careThere were n significant differences between experimental and control group in incidence of abnormal symptoms and any complication. The number of taking a bath [POD #5 P=0.001, #6 P=0.0003, #7 P=0.001] and the degree of appetite [POD #5 P=0.03, #6 P=0.02, #7 P=0.013] were significantly higher in experimental group than in control group. Contrary to author's expectation, the degree of the activities of daily living in experimental group was not higher than that of control group. All of the experimental group said they were satisfied with the home nursing care. 2. Cost analysis 1) Hospital charge of experimental group was lower than that of control group. ［P=0.009］ By taking home nursing care, average period of hospitalization was shortened to 3.1 days, and family members could save 22.8 hours. Total amount of money saved by early discharge was 3,443,093 Won. It is estimated that total amount of money saved by early discharge in a year will be 40,398,956 Won. 2) Home nursing care charge of 15 mothers was 1,781,633 Won. It is estimated that total amount of money Saved by it in a year Will be 20,904,493 Won. It was lower altogether than hospital charge of the three days which is 5th, 6th, 7th day of operation. The average cost of single home visit was calculated 10,940 Won. It took 87 minutes per round and it costed 1,017.3 Won. The average hour of home care was 39.0 minutes. 3) It is expected that early discharge can bring forth the increase of hospital income. On the condition that the rate of running bed is 100%, the expected increase of hospital income will be 202,374, 026 Won in a year. Suggestions for further study and nursing practice are as follows : 1. For the welfare of patients and the increased rates of running bed, home nursing care system should be included in the hospital nursing care system. 2. Studies to test effect of home nursing care on the patients with other diseases are needed. 3. Establishment of law on the practice of home nursing care is strongly recommended.

• 대한교통학회지
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• 제25권4호
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• pp.123-133
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• 2007

본 연구에서는 위계구조를 갖는 대중교통 노선망이 효율적인지, 효율적이라면 과연 어떤 조건 하에서 효율적인지에 대한 해석적 검토를 수행하였다. 대중교통 노선망을 구성하는 총 비용을 모형화하고 구축된 모형을 통해 위계구조를 갖는 대중교통 노선망과 단일 위계로 구성된 노선망의 총 비용을 비교하여 위계구조를 갖는 대중교통 노선망의 효율적 조건을 제시하였다. 위계구조 노선망의 효율성 조건은 상위 노선이 도입됨에 따라 절감되는 통행비용 절감이 상위 노선이 도입됨에 따라 추가적으로 발생하는 접근비용, 대기비용, 그리고 운영비용의 합인 비통행비용의 증가보다 클 경우에 해당한다. 이는 일반적인 상식과 부합하며 경제성평가의 비용/편익 분석의 개념과도 일치하는 결과이다. 상위 노선으로 구분된 단위 공간 내부의 통행은 하위 노선만을 이용하여 통행하고 단위 공간 외부의 통행은 하위 노선과 상위 노선을 모두 이용하여 통행하는 것으로 수요조건을 가정하였을 경우에는 상위 노선을 이용하는 통행수요가 노선간격 감소에 제곱하여 증가하게 되는데 이는 상위 노선의 간격이 줄어들어 상위 노선망이 연계체계를 이룰수록 적은양의 수요증가로도 상위 노선망의 효율성이 보장됨을 의미한다. 이는 대중교통 노선망에 있어서 규모의 경제를 의미하는 것으로, 대도시의 대중교통 노선망이 확장되어 효율적인 연계체계가 구축될수록 대중교통 통행수요가 급격하게 증가하는 현상과 일맥상통하는 결과로 해석된다. 본 연구는 대중교통 노선망에서의 위계구조를 해석적으로 풀이한 최초의 연구이며 대중교통 노선설계에 관한 수리적 연구의 기반이 될 것이다. 그러나 본 연구는 해석적 연구로써 현실적인 네트워크를 고려하는데 있어서 한계를 갖기 때문에 수리적 연구의 보완이 필요하다.시 인접교차로와의 관계를 고려하여 유출연결로의 위치를 결정하는 설계기준에 반영할 수 있을 것이고, 이로 인해 향후 인터체인지 주변의 교차로 운영과 고속도로 본선 교통류의 효율적 관리에 기여할 것으로 기대된다.22.97 %로 quercetin의 함량이 가장 큰 것으로 나타났다. 루이보스 추출물의 ethylacetate 분획의 TLC 크로마토그램은 7개의 띠로 분리되었고, HPLE 크로마토그램은 9개의 피이크를 보여주었다. TLC와 HPLC의 띠와 피이크를 확인한 결과, HPLC의 9개의 피이크는 용리순서로 peak 1 (조성비 14.71 %)은 isoorientin, peak 2 (28.84 %)는 orientin peak 3 (5.63 %)은 vitexin, peak 4 (12.73 %)는 rutin과 isovitexin, peak 5 (9.24 %)는 hyperoside, peak 6 (5.40%)은 isoquercitrin, peak 7 (1.48 %)은 luteolin, peak 8 (17.61 %)은 quercetin 및 peak 9 (4.59 %)는 kaempferol로 확인되었다. Aglycone 분획은 elastase 저해활성($IC_{50}$)이 $9.08\;{\mu}g/mL$로 매우 큰 활성을 나타내었다. 이상의 결과들은 루이보스 추출물이 $^1O_2$ 혹은 다른 ROS를 소광시키거나 소거함으로써 그리고 ROS에 대항하여 세포막을 보호함으로써 생체계, 특히 태양 자외선에 노출된 피부에서 항산화제로서 작용할 수 있음을 가리키며, 루이보스 성분에 대한 분석과 ethylacetate 분획의 당 제거 실험 후 얻어진 aglycone 분획의

• 보건행정학회지
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• 제17권2호
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• pp.1-17
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• 2007

Limited coverage for health care services of National Health Insurance(NHI) in Korea has been ongoing policy issue but additional NHI financing through raising contribution or taxes in order to improve coverage faces substantial obstacles. Private health insurance(PHI) is often considered as an alternative financing source to improve coverage. Recent reform that attempted to stretch the role of PHI allowed life insurance companies to provide complementary PHI, indemnity plan which will pay for uncovered services by NHI and out-of-pocket spending for covered services. Although complementary PHI may relieve financial burden of patients, it may significantly raise NHI spending as well as total health expenditure since little out-of-pocket spending may increase utilization of health care. So far, there has not been enough discussion about concerns of potential adverse effect resulting from extended role of PHI. This study investigated potential increase of NHI spending followed by extension of complementary PHI through sensitivity analysis. The amount of NHI spending for services that would be covered by complementary PHI was calculated using 2005 NHI statistics and expected complementary PHI enrollment rate by age and sex. Expected utilization increases were obtained based on price elasticities$(-0.2{\sim}-0.5)$ from previous studies and expected coverage rate$(50{\sim}80%)$ of complementary PHI and then converted to monetary figures. Because coverage rate of complementary PHI has not been determined yet, we employed the sensitivity analysis using coverage rate of $50{\sim}80%$. Findings demonstrate that additional spending for health care services is expected to be $426{\sim}1,702$ billion won, corresponding amount payed by NHI $298{\sim}1,192$ billion won. In conclusion, since complementary PHI may raise NHI spending significantly, there should be an agreement whether this additional cost would be accountable and acceptable in our society. Potential inefficiency resulting from extended role of complementary PHI should be considered since public and private financing do not operate in isolation and there should be more discussion on proper role of PHI in Korea.