• 지역연구
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• 제12권2호
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• pp.21-36
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• 1996

This thesis focused on the extent of the area-by-area gap of the unit production cost that should be taken into account without exception in supply of the local public goods production cost. With the advent of the local autonomy era, what should be considered in the local governmen's production of the local public goods are the government's fiscal capacity and the environmental difference that shows up in accordance with the area's characteristics. Though with the same level of the fiscal capacity, an occurrence of environmental difference will lead inevitably to the different level of actual supply of the local public goods. The method of analysis used in this thesis was first to bring out implicit price, to combine this with induced expenditure function, to separate demand function parameter and cost function parameter, and then to analyzed the impact of environmental variables on the production cost. The environmental variables were set on the basis of the ones that affected expenditure per person of the public goods. The analysis was conducted in distinction of city areas and county areas. The results showed that, in cases of cities, more production cost of the public goods was in presence in urban areas and in areas where there was sluggish development. In other words, distinction could be drawn between areas where there was a large consumption of production cost resulting from poor environmental sparked by slow development and those where additional costs were required due to population concentration caused by a certain level of accomplished development. In the meantime, in cases of county areas, the results were around the same. However, a comparison between city areas and county ones told that overall difference between city areas was not that big in the production cost while that in county areas was large enough. In times ahead, in implementation of grant-in-aid scheme, production cost index for local public goods could be used as it was written in consideration of environmental characteristics of areas concerned.

• 한국작물학회:학술대회논문집
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• 한국작물학회 1999년도 추계 학술대회지
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• pp.145-167
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• 1999

Our self-sufficiency of food has become less than $30{\%}$ and our nation is highly dependant on world's grain market for food. which is unstable in long term due to the world population growth faster than food production. Therefore, it is a great possibility that food might become a political weapon by way of its global shortage. its purchasing difficulty in international free trade market. and the resultant price rising. Our maximal capability of food production has become the most outstanding problem in the dimension of future food security. It would be the utmost scheme for maximal production of food to realize the maximal utilization of arable land through the enlargement of sufficient farming land and the conversion of rotation system for the more grain production. Extensional enlargement of arable land can be positively executed through the development of farming land in domestic and abroad countries. The readjustment of arable land and the installation or irrigation and drainage system can enforce the farming basement for maximal utilization of arable land through the improved rotation between paddy and upland. The prevention policy against farming land encroachment should be strictly executed through grain production encouragement on resting or marginal lands and regulation of utilization conversion for the other than food production on high grade farming lands. It is also required urgently to develope high yielding and high quality varieties through advanced genetic technology for the improvement of unit area yield, especially of wheat, corn. and soybean we import in large quantity The maximal utilization of arable land for the highest production of food can be realized through rational rotation system, the most adaptable crop cultivation on the suitable land, and the most optimal fertilization through the GIS analysis of agricultural environment information on the basis of the computerized soil resource data on super detailed soil maps(1:5000) surveyed plot by plot of whole nation.

• 한국정보컨버전스학회:학술대회논문집
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• 한국정보컨버전스학회 2008년도 International conference on information convergence
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• pp.47-52
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• 2008

A radio-frequency identification(RFID) tag is a small, inexpensive microchip that emits an identifier in response to a query from a nearby reader. The price of these tags promises to drop to the range of $0.05 per unit in the next several years, offering a viable and powerful replacement for barcodes. The challenge in providing security for low-cost RFID tags is that they are computationally weak devices, unable to perform even basic symmetric-key cryptographic operations. Security researchers often therefore assume that good privacy protection in RFID tags is unattainable. In this paper, we explore a notion of minimalist cryptography suitable for RFID tags. We consider the type of security obtainable in RFID devices with a small amount of rewritable memory, but very limited computing capability. Our aim is to show that standard cryptography is not necessary as a starting point for improving security of very weak RFID devices. Our contribution is threefold: 1. We propose a new formal security model for authentication and privacy in RFID tags. This model takes into account the natural computational limitations and the likely attack scenarios for RFID tags in real-world settings. It represents a useful divergence from standard cryptographic security modeling, and thus a new view of practical formalization of minimal security requirements for low-cost RFID-tag security. 2. We describe protocol that provably achieves the properties of authentication and privacy in RFID tags in our proposed model, and in a good practical sense. Our proposed protocol involves no computationally intensive cryptographic operations, and relatively little storage. 3. Of particular practical interest, we describe some reduced-functionality variants of our protocol. We show, for instance, how static pseudonyms may considerably enhance security against eavesdropping in low-cost RFID tags. Our most basic static-pseudonym proposals require virtually no increase in existing RFID tag resources.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2011년도 춘계학술발표대회 논문집
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• pp.80-85
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• 2011

As the instability of oil prices rose because of the situation in Libya, oil prices worldwide recorded the highest level due to the interference in supply. And so, in the 21st century, increasing efforts are being made to use clean new renewable energy centered on solar energy in accommodation of the cycle of nature instead of being reliant on the oil exporting nations. In order to reduce city energy internationally, the implementation of a low carbon city under the combined cooperation of industrial. construction, new renewable energy and transportation sectors with continuous development centered on low carbon green urban planning is now becoming established as the paradigm of the times. Recently, the government has begun carrying out the One Million Green Home Project, which is a project where the government with the goal of providing one million renewable energy homes by 2020 gives renewable energy subsidization for a partial amount of the standard unit price of installation when solar ray, solar heat, geothermal heat, small wind power or fuel cell energy is used. Thus, through this thesis which studies the state of and surveys the green village at Shingok-ri Songhak-myun Jaecheon-shi, it is the desire that the One Million Green Homes Project will be more efficiently developed and plans for improvement formed so that a high level of satisfaction in the product will be provided.

• KEPCO Journal on Electric Power and Energy
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• 제2권2호
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• pp.299-305
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• 2016

초전도 전력 케이블의 상용화 노력에 따라 점차 장선화 되면서, 단위 냉각 시스템당 냉각용량이 큰 대용량 냉동기의 필요성이 증가하고 있다. 국내에서는 극저온 냉동기에 대한 기술 부족으로 인해 현재 극저온 냉동기는 해외 선진사로부터 고가의 비용으로 수입되고 있다. 초전도 전력 케이블의 상용화를 위해서는 대용량 브레이튼 냉동기의 국내 개발이 시급하다. 대용량 브레이튼 냉동기의 구성은 복열식 열교환기, 압축기, 극저온 터보 팽창기로 구성되어 있으며, 냉동기 효율과 가장 직접적인 연관이 있는 것은 극저온 터보 팽창기이다. 극저온 터보 팽창기는 극저온에서 고속으로 회전하면서 고압의 헬륨 혹은 네온 가스를 팽창시켜 온도를 낮추는 역할을 한다. 본 논문에서는 역브레이튼 냉동 사이클을 설계하고, 이에 적합한 극저온 터보 팽창기를 설계하였다.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2008년도 정기학술발표대회 논문집
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• pp.885-890
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• 2008

최근 몇 년 사이 공동주택 리모델링을 둘러싼 여건의 변화는 리모델링의 활성화라는 입장에서 볼 때 매우 고무적이라 할 수 있다. 리모델링의 추진에 대한 단지 내 다른 주민들의 반발을 어떻게 조정할 것인가가 주요한 과제로 대두되었고, 리모델링을 위한 재원 조달과 리모델링 이후의 자산가치 변화가 핵심적인 쟁점으로 부각되었다. 특히 많은 언론의 보도에도 불구하고 리모델링에 의한 자산가치 즉 부동산 가격의 상승효과가 뚜렷하게 입증되지 못하고 있으며, 금융기관 역시 리모델링 이후의 자산가치 상승에 대해 상당히 보수적인 평가를 하고 있기 때문에, 입주자들은 리모델링을 위한 재원의 조달에 상당한 어려움을 겪고 있을 뿐만 아니라 리모델링 사업의 성공여부도 확신하지 못하고 있다. 제도개선은 동 단위 리모델링을 보다 효율적이면서도 도시와 단지 전체의 관리 방향과 조화되는 방향으로 추진되어야 하며, 또한 공공지출을 최소화하면서도 리모델링을 실질적으로 지원할 수 있는 제도적 방안이 강구되어야 한다.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2002년도 춘계공동학술대회
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• pp.449-455
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• 2002

This paper considers that advanced planning and scheduling (APS) in manufacturing and the efficient purchasing where each customer order has its due date and multi-suppliers exit We present a Make-To­Order Supply Chan (MTOSC) model of efficient purchasing process from multi-suppliers and APS with outsourcing in a supply chain, which requires the absolute due date and minimized total cost. Our research has included two states. One is for efficient purchasing from suppliers: (a) selection of suppliers for required parts; (b) optimum part lead­time of selected suppliers. Supplier selection process has received considerable attention in the business­management literature. Determining suitable suppliers in the supply chain has become a key strategic consideration. However, the nature of these decisions usually is complex and unstructured. These influence factors can be divided into quantitative and qualitative factors. In the first level, linguistic values are used to assess the ratings for the qualitative factors such as profitability, relationship closeness and quality. In the second level a MTOSC model determines the solutions (supplier selection and order quantity) by considering quantitative factors such as part unit price, supplier's lead-time, and storage cost, etc. The other is for APS: (a) selection of the best machine for each operation; (b) deciding sequence of operations; (c) picking out the operations to be outsourcing; and (d) minimizing makespan under the due date of each customer's order. To solve the model, a genetic algorithm (GA)-based heuristic approach is developed. From the numerical experiments, GA­based approach could efficiently solve the proposed model, and show the best process plan and schedule for all customers' orders.

• 약학회지
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• 제49권6호
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• pp.449-458
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• 2005

There have been rapid changes in the pharmaceutical environment after the separation of Dispensing and Prescribing practice. In the early stage of this system, outpatients had few options to choose their pharmacies due to various obstacles. Under these circumstances, this study on the defection tendency of long-term care patients was performed through the analysis of outpatients who quit visiting a pharmacy nearby general hospital. PowerBuilder ver 9.0 program was used to extract significant data, and SPSS package was employed for statistic analysis. 3,308 outpatients who visited a pharmacy nearby hospital for a month (in January, 2004) were studied. Patients' sex, age and location of residence, the class of medical insurance, the characteristic type of medication (powder, split form, medication for external use/injection), waiting time, disease (department) were considered as variable factors. It turned out that the patient revisit ratio was 80.8$\%$ and the patient defection ratio was 32.4$\%$. As was expected, those factors mentioned above influenced on the revisit and defection ratio considerably. In terms of patient factors, it proved that there was no relationship among sex, location of residence, the class of medical insurance and revisit (defection) ratio. Only age factor influenced the ratio; the older, the higher revisit ratio and the less defection ratio. In respect of dispensing factors, there were obvious relationships among the factors and the ratio: bill (money they had to pay individually), waiting time, number of medications, splitting of tablets, unit price of drug and revisit (defection) ratio showed significant relationship. The result of this study revealed an aspect of outpatients' behavior and it could be used as a reference for better patient service and customer relationship management.

• 한국임상약학회지
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• 제24권2호
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• pp.126-134
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• 2014

Purpose: This study was aimed to examine the financial effect of 2-tiered copayment system on annual expenditure of pharmacy benefit in the National Health Insurance (NHI) of Korea, focusing on oral antidiabetic medications. Methods: 284 oral antidiabetic products with 14 different active single ingredients listed in the National Formulary of NHI (August 2009) were assigned to tier 1 or tier 2 according to the selected criteria. 10 different combinations of coinsurance rates were selected to estimate the changes in drug expenditure cost of NHI. Results: The annual drug cost was estimated based on the drug price per unit listed in the National Formulary and the used amount of products in 2009 from the IMS Health data of Korea. In the combinations of coinsurance rate of 20% for tier 1 and 40% for tier 2, the total annual drug cost was estimated to be reduced by 1.3% in the case of no change of generic and original drug consumptions, and to be reduced by 4.3% in the case of 10% increased generic drug consumptions. Conclusion: The tiered copayment system with optimal coinsurance rates appears to be a potential strategy to reduce the financial burden of NHI in Korea by promoting the use of generic products.

• Current Optics and Photonics
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• 제1권5호
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• pp.474-490
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• 2017

Since the recent slowdown in the smartphone market, studies for wearable devices are briskly being carried out to find new markets, such as virtual reality devices. In this paper, a head-mounted display (HMD) which provides expanded virtual images before human eyes by enlarging images of a small display was designed, and the tolerance analysis method for a focus-adjustable HMD based on afocal optical systems was studied. There are two types of HMDs: a see-through type that allows the user to view the surroundings, and a see-close type where the user can only view the display screen; the former is used in this study. While designing the system, we allowed a lens within the system to be shifted to adjust its focus from +1 to -4 D (diopters). The yield of the designed systems was calculated by taking the worst-case scenario of a uniform distribution into account. Additionally, a longitudinal aberration was used rather than MTF for the tolerance analysis with respect to system performance. The sensitivity of the designed system was calculated by assigning a certain tolerance, and the focus lens shift was calculated to adjust the image surface variations resulting from the tolerance. The smaller the tolerance, the more expensive the unit price of the products. Very small tolerances may even be impossible to fabricate. Considering this, the appropriate tolerance was assigned; the maximum shift of the focus lens in which the image surface can be adjusted was obtained to find the changes in aberration and a good yield.