• 한국통신학회논문지
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• 제34권3A호
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• pp.229-234
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• 2009

본 논문에서는 자원 재사용이 가능한 무선 멀티홉 시스템에서 RS (Relay Station)간 적응적으로 무선자원을 재사용하기 위한 요구 자원량 결정 기법을 제안한다. 멀티홉 시스템에서 BS (Base Station)는 RS 각각의 요구 자원량을 고려하여 RS에게 자원을 동적으로 할당할 수 있다. 이 때 RS간에 무선자원을 재사용하면 시스템의 사용 가능한 자원량이 증가하는 효과를 얻을 수 있다. BS는 같은 자원을 재사용하는 RS에게 일반적으로 동일한 자원을 할당하며, 이를 위해 RS들의 서로 다른 요구 자원량을 대표하는 하나의 값을 결정해 줄 필요가 있다. 본 논문에서는 각 RS의 요구 자원량과 buffer 사용비율을 바탕으로 재사용 RS들의 요구 자원량의 대표값을 적응적으로 결정하는 기법을 제시한다. 모의실험을 통해 제안한 기법이 멀티홉 시스템의 성능을 증대시킬 수 있음을 보였다. 재사용 RS들의 대표 요구 자원량 값을 고정적으로 적용하는 경우에 비해 제안된 적응적 기법을 적용했을 때 시스템 용량이 약 두 배까지 증대됨을 확인하였다.

• Journal of Electrical Engineering and Technology
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• 제9권2호
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• pp.433-440
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• 2014

In this study, a method for the low-carbon active distribution system (ADS) planning is proposed. It takes into account the impacts of both network capacity and demand correlation to the renewable energy accommodation, and incorporates demand response (DR) as an available resource in the ADS planning. The problem is formulated as a mixed integer nonlinear programming model, whereby the optimal allocation of renewable energy sources and the design of DR contract (i.e. payment incentives and default penalties) are determined simultaneously, in order to achieve the minimization of total cost and $CO_2$ emissions subjected to the system constraints. The uncertainties that involved are also considered by using the scenario synthesis method with the improved Taguchi's orthogonal array testing for reducing information redundancy. A novel cuckoo search (CS) is applied for the planning optimization. The case study results confirm the effectiveness and superiority of the proposed method.

• Korean Journal of Hydrosciences
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• 제7권
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• pp.37-49
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• 1996

This study aims at suggesting an alternative to improve flood controling capacity according to the cument design criteria for the existing Soyanggang Multi-purpose Dam which was constructed 20 years ago as the largest dam in Korea. The peak inflow of the adopted probable maximum flood (PMF) at the time of construction was 13,500 $m^3$/s. However, the newly estimated peak inflow of the PMF is 18,000 $m^3$/s which is 1.34 times bigger than the original one. This is considered to be due to the accumulation of the reliable flood and storm event records after construction, and due to the increasing tendency of the local flood peaks according to the influence of world-wide weather change. The new estimation of the probable maximum precipitation (PMP) was based on the hydro-meteorological method suggested by the guideline of the World Meteorological Organization (WMO). The unit hydrograph which was applied for the estimation of PMF was derived through linear programming algorithm by minimizing the sum of absolute deviations of the calculated and recorded flood hydrographs. In order to adopt the newly estimated PMF as a design flood, following four alternatives were compared : (1) allocation of more flood control space by lowering the normal high water level, (2) construction of a new spillway in addition to the existing spillway, (3) construction of a new dam which has relevant flood control storage at the upstream of the Soyanggang dam, (4) raising the existing dam crest. The preliminary evaluation of these alternatives resulted in that the second alternative is most economic and feasible. So as to stably cope with the newly estimated PMF by meeting all the current functions of the multipurpose dam, a detailed study of an additional spillway tunnel has to be followed.

• 보건행정학회지
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• 제25권3호
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• pp.149-151
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• 2015

United Nations (UN) adopted 17 global sustainable development agenda to the year 2030 in the 68th general assembly on september, 2015. The global agendas and goals are important for 3 reasons: (1) to adopt the international standard for determining the health status; (2) to identify areas in need of attention; and (3) to advance international cooperation regarding health issues. In the area of infectious diseases, our goals include the eradication of human immunodeficiency virus infection and acquired immune deficiency syndrome, tuberculosis, and malaria as well as a substantial reduction of hepatitis by the year 2030. In the area of non-communicable diseases, our goal is to reduce premature mortality (${\leq}70years$) at least 30% by the year 2030. Preventive activities such as smoking cessation, alcohol abstinence, nutritional measures, and physical activities, should also be promoted intensively nationwide. It is also necessary to establish stringent policies for control hypertension, diabetes, obesity, and hypercholesterolemia. Additionally, environmental health, injury by traffic accident, mental health, and drug and alcohol abuse are important health policies. Furthermore, in the area of international health and cooperation, maternal and child health remain important areas of support for underdeveloped countries. Education and training towards the empowerment of health professionals in underdeveloped countries is also an important issue. The global agenda prioritize resources(manpower and budget) allocation of international organizations such as UN, World Health Organization, United Nations Development Programme, and World Bank. The global agenda also sets the contribution levels of Official Developmental Assistance donor countries. Health professionals such as professors and researchers will have to turn their attention to areas of vital international importance, and play an important role in implementation strategies and futhermore guiding global agenda.

• Journal of Korea Trade
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• 제25권5호
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• pp.58-73
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• 2021

Purpose - In the context of economic globalization and the continuous development of international trade, as countries around the sea peninsula, port construction is particularly important. Based on the research on the influencing factors of port logistics development based on the allocation analysis, QCA (Qualitative Comparative Analysis) provides the basis for the planning and policy of port logistics development and has important theoretical value and practical significance for improving the level of port logistics management, reducing logistics operating costs and increasing economic benefits. In the tide of global integration for the development of port logistics, promote the growth of foreign trade economy of the city. It is also of great significance to the development and progress of commerce and trade. Design/methodology - Based on the relevant data samples of various ports in South Korea, this paper uses fsQCA (fuzzy set Qualitative Comparative Analysis) to integrate and analyze the influence mechanism of port logistics development and extracts five influencing factors of port logistics development, including the port's scale and infrastructure in the hard environment, port-neighboring enterprises in the soft environment, hinterland economy and government support. Findings - The five factors are unable to separately constitute the necessary and sufficient conditions of port logistics development, only a combined model can influence lake port logistics development. The scale and infrastructure of the port itself and port-neighboring ring enterprises are the main core conditions, which work together on the port, affect the throughput capacity of the port, and promote the development of port logistics. When the port-neighboring enterprises are not complete and the scale is low, the growth of port throughput will be restrained and the development of port logistics will be affected, whether the hinterland economic benefits are general, the development of port-neighboring enterprises is insufficient, or the government supports are limited. Originality/value - Through the research on the development of port logistics in South Korea from the perspective of configuration, this paper finds the configuration influence of hard environment and soft environment on the development of port logistics, which has important theoretical and practical significance for better promoting the development of port logistics in South Korea.

• 인터넷정보학회논문지
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• 제24권6호
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• pp.57-64
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• 2023

본 연구에서는 초·중등 학생들의 기본소양을 갖추기 위한 SW·AI 교육의 중요성과 담당 교과에서 SW·AI 융합 또는 활용 교육의 필요성에 대한 초·중등 교사들의 인식을 분석하기 위하여 판단표집 표본추출 방법으로 전국의 초·중등 교사 830명을 연구대상으로 선정하여 설문 자료를 수집, 분석하였다. 분석 결과, 초·중등 교사 모두 SW·AI 교육의 중요성과 필요성을 학교 특성, 지역, 교육 경력, SW·AI 교육 운영 경험 여부와 상관없이 매우 높게 인식하고 있었다. 그럼에도 불구하고 SW·AI 교육을 운영하지 못하는 사유로는 업무부담과 본인의 교육 역량 부족이 높게 나타났다. SW·AI 교육 운영을 위한 필요 여건에 대한 의견을 분석한 결과에서도 업무량 경감과 예산 지원, 교사 역량 강화를 위한 교사연수, 콘텐츠 보급, 교과 연계 수업 확대, 시수 확보 등이 중요한 영향 요인으로 제시되어 다각적 수업 지원과 교사 역량 강화 프로그램에 대한 높은 수요를 확인할 수 있었다.

• 한국농공학회논문집
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• 제62권3호
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• pp.1-13
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• 2020

The management of agricultural water can be divided into management of agricultural infrastructure and operation to determine the timing and quantity of water supply. The target of water management is classified as water-supply facilities, such as reservoirs, irrigation water supply, sluice gate control, and farmland. In the case of agricultural drought, there is a need for water supply capacity in reservoirs and for drought assessment in paddy fields that receive water from reservoirs. Therefore, it is necessary to analyze the water supply amount from intake capacity to irrigation canal network. The analysis of the irrigation canal network should be considered for efficient operation and planning concerning optimized irrigation and water allocation. In this study, we applied a hydraulic analysis model for agricultural irrigation networks by adding the functions of irrigation canal network analysis using the SWMM (Storm Water Management Model) module and actual irrigation water supply log data from May to August during 2015-2019 years in Sinsong reservoir. The irrigation satisfaction of ponding depth in paddy fields was analyzed through the ratio of the number of days the target ponding depth was reached for each fields. This hydraulic model can assist with accurate irrigation scheduling based on its simulation results. The results of evaluating the irrigation efficiency of water supply can be used for efficient water distribution and management during the drought events.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1993년도 Proceedings of International Conference for Agricultural Machinery and Process Engineering
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• pp.109-118
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• 1993

Development process of agricultural technology has been studied with a case study of Korean agriculture. Technological is considered as a transformer of inputs into outputs and hence technological appropriateness, an important aspect of agricultural development strategies, is considered as a dynamic concepts. Considering the concept of agricultural system as a delivery system for providing essential materials and services to producers and consumers, it has been divided into two major groups of dimensions vis. external challenge dimensions and internal response dimensions. Market, investment and agro-ecosystem constitute the external challenge dimensions : whereas trade , technology as well as production and resources allocation constitute internal response dimensions. The system manager is responsible for maintaining equilibrium in the mentioned six sub-systems. Two kinds of alternatives paths of technological development viz. land saving technology and labour saving technolog have been studied. Technology is considered as a combination of four basic components viz. facilities, abilities, facts and frameworks. Adoption of innovation in agriculture depends on profitability, awareness, risk aversion, financial capacity, institutional infrastructure, availability of physical inputs and adaptability to the local conditions. For a cast study of Korea, changes in the agricultural system through external challenge dimensions are investigated. The impacts of industrialization on agro-ecosystem reported are shift of labour from the agricultural sector to non-agricultural sectors and continuously increasing demand of farm the agricultural sector to non-agricultural sectors accompanied by increase in land prices. The impacts on the commodity market discussed are shift in demand from rice, barley and other cereals to meat , dairy products and vegetables : and increasing in supply capacity of agricultural inputs. The process of agricultural development from 1962 to 19 1 9 (i.e. from start of the first to the end of the sixth five year plan) are also discussed in details with several policy measures taken. The trend of agricultural income and productivity are also analyzed. The main cause of increase in the agricultural income is considered as increase in labour productivity. The study revealed that during the span of 1965-88, holding size has not changed significantly, but both the land and labour productivity increased and so did the agricultural income. R&D activities in Korea have changed over time in three stages vix. import of improved technology, localization by adaptive research and technological mastery. For the new technology to be made affordable to farmers, policy measures like fertilizer and food grain exchange system, dual price system in rice and barely and loan for machinery were strengthened.

• 한국산학기술학회논문지
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• 제20권12호
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• pp.167-175
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• 2019

최근 건강검진센터는 병원의 보조시설에서 핵심적이고 독립적인 의료시설로 위상이 높아지고 있다. 그러나 검진센터를 비롯한 의료시설들은 공간 및 인간간의 관계가 주체가 되는 가변적 특성으로 인하여 개선이 쉽지 않다. 이에 검진센터의 문제점과 및 개선방법을 발견하기 위하여 보행자 기반 이산사건시뮬레이션 분석프로그램을 개발하고자 하였다. 프로그램은 5가지 평가지표와 수검자 밀도를 분석할 수 있도록 구축하였으며, 시뮬레이션을 통해 소요시간, 수용능력, 검사항목별 대기열 규모를 분석하여 문제점을 도출하였다. 제안된 평가방법을 통해 검사시간이 길어지는 가장 큰 원인은 대기열의 증가와 집중에 의한 장시간 대기자의 발생으로 밝혀졌다. 적정한 서비스 재배분으로 대기열을 분산시켜 검사시간을 크게 단축시킬 수 있었으며 조정안의 검증 결과, 수검인원 18% 증가, 1인당 수검시간 15% 단축, 이동거리 5.5% 단축의 효과를 정량적으로 계산해 낼 수 있었다. 또한 히트맵 분석과 병행한 공간 재배치 계획으로 복도의 교차부에 집중되었던 과밀현상을 해소할 수 있었으며, 이는 통행자와 대기자간의 혼잡을 줄이는 긍정적 효과를 가져올 것이다. 본 연구는 분석프로그램을 구축하기 위한 기초적 성격을 가진 알고리즘 중심의 검토연구이지만, 이러한 복잡계 시뮬레이션 분석방법론은 운영 중인 시스템을 중단시키지 않으면서도 저비용의 최적 대안을 도출하는 도구로서 충분한 활용가치를 가질 수 있을 것으로 기대하고 있다.

• 한국통신학회논문지
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• 제23권7호
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• pp.1797-1806
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• 1998

멀티미디어 서비스를 위한 미래 위성통신용 Ka 대역(20/30 GHz)은 지상의 간섭으로부터 자유롭고 상대적으로 넓은 주파수 대역을 장점으로한다. 그러나, Ka 대역의 큰 단점은 강우 조건에서 매우 큰 대기중감쇄가 존재한다는 점이다. 통기화 CDMA는 유연한 주파수 재사용과 연성 통화인계(soft-handover), 간섭에 덜 민감한 점등의 이동통신을 위한 CDMA의 주요 특징뿐만아니라, 자기간섭을 상당히 줄일 수 있다는 특징도 가진다. 본 논문에서는 Ka 대역에서 운용되는 동기화 CDMA 정지위성 시스템 리턴링크의 성능을 고찰하였다. 기후 조건에 영향을 받는 특성을 가지는 정지위성 채널에 대해 신호의 포락선과 위상을 가우시안으로 모델링 하였다. 강우 조건에서의 비트 오율과 outage 확률 그리고 불완전한 칩동기화로 인한 검출손실을 해석적으로 계산하고, 기후 조건에 의한 시스템 수용용량 감소를 추정하였다. 강우에 의해 모든 사용자가 영향을 받는 일반적인 경우와, 기준 사용자만 영향을 받는 최악의 경우 두가지 경우에 대한 분석이 수행되었는데, 그 결과 동기화 CDMA는 전력제어 요구의 부담을 덜어주고, 불완전한 전력제어에 덜 민감함을 보였다.