• 대한지리학회지
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• 제41권3호
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• pp.301-318
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• 2006

본 논문은 한국 경제가 식민지 경제 체제로 이행되는 과정에서 식민지 도시 경성의 상업공간이 도시 내부에서 어떻게 식민지 근대성을 표출시키고 있었는가를 상업회사를 중심으로 분석하고자 하였다. 경성의 상업회사에 대한 1920년대와 1930년대의 시계열적 분석을 보면, 상업회사의 수와 규모 면에서 본정2정목의 성장이 활발하였다. 민족별로 보면 일본인 상업회사 수는 본정1정목에서 가장 많이 증가하였고, 규모 면에서는 황금정2정목의 상업회사가 크게 성장하였다. 조선인 상업회사의 변화를 보면, 종로2정목이 회사 수나 규모 면에서도 가장 많이 성장하였다. 일제강점기 경성에서 일본인의 상업활동이 활발하고 규모가 켰지만 조선 상인들은 이에 대해 대처하려고 노력하였다. 조선 상인들의 근대적 경영 방식의 회사 설립과 운영 등을 시도하였고 종로2정목의 화신연쇄점을 비롯한 여러 상업회사가 비교적 규모가 큰 상업회사를 유지하면서 근대성을 담지하고 있었다. 그러나 상업회사의 규모에서 조선인 회사는 일본인 회사에 비해 영세하였고 상업회사를 중심으로 분석한 식민지 도시 경성 상업공간의 식민지 근대성은 상업활동과 상업공간의 민족별 격리와 조선인 상업자본의 영세성이라는 이중구조를 보였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권7호
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• pp.2389-2413
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• 2015

High data rates in long-term evolution (LTE) networks can affect the mobility of networks and their performance. The speed and motion of user equipment (UE) can compromise seamless connectivity. However, a proper handover (HO) decision can maintain quality of service (QoS) and increase system throughput. While this may lead to an increase in complexity and operational costs, self-optimization can enhance network performance by improving resource utilization and user experience and by reducing operational and capital expenditure. In this study, we propose the self-optimization of HO parameters based on fuzzy logic control (FLC) and multiple preparation (MP), which we name FuzAMP. Fuzzy logic control can be used to control self-optimized HO parameters, such as the HO margin and time-to-trigger (TTT) based on multiple criteria, viz HO ping pong (HOPP), HO failure (HOF) and UE speeds. A MP approach is adopted to overcome the hard HO (HHO) drawbacks, such as the large delay and unreliable procedures caused by the break-before-make process. The results of this study show that the proposed method significantly reduces HOF, HOPP, and packet loss ratio (PLR) at various UE speeds compared to the HHO and the enhanced weighted performance HO parameter optimization (EWPHPO) algorithms.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권3호
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• pp.921-940
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• 2015

In this paper, we investigate the multi-resource allocation problem, a unique feature of which is that the multiple resources can compensate each other while achieving the desired system performance. In particular, power and time allocations are jointly optimized with the target of energy efficiency under the resource-limited constraints. Different from previous studies on the power-time tradeoff, we consider a multi-server case where the concurrent serving users are quantitatively restricted. Therefore user selection is investigated accompanying the resource allocation, making the power-time tradeoff occur not only between the users in the same server but also in different servers. The complex multivariate optimization problem can be modeled as a variant of 2-Dimension Bin Packing Problem (V2D-BPP), which is a joint non-linear and integer programming problem. Though we use state decomposition model to transform it into a convex optimization problem, the variables are still coupled. Therefore, we propose an Iterative Dual Optimization (IDO) algorithm to obtain its optimal solution. Simulations show that the joint multi-resource allocation algorithm outperforms two existing non-joint algorithms from the perspective of energy efficiency.

• Journal of Biosystems Engineering
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• 제11권1호
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• pp.64-75
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• 1986

The objective of this study was to develop a mathematical model for optimum design of diversified farming systems which have the regional characteristics. For this purpose, the farming surveys were conducted for mainly 1984 agriculture. They were carried out on January and July 1985 for three villages of central region of Korea. The surveyed data were analyzed by systems analysis and the diversified farming systems were modeled. They consist of four and six croping patterns for paddy and upland, two and three kinds of fruit crop and livestock, and seven kinds of farm machinery for each work system. Then a mathematical model was developed by the multiple objective decision making (MODM) method in order to design optimum systems of diversified farming. It consists of 23 decision variables, two objective functions and nine constraint functions. The goals of objective function are maximization of agricultural incomes and power inputs of farm machinery, and the modeled factors for constraint function are arable land, available capital, labor, and land utilization.

• Journal of Electrical Engineering and Technology
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• 제12권4호
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• pp.1511-1518
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• 2017

Renewable energy hybrid systems look into the process of choosing the finest arrangement of components and their sizing with suitable operation approach to deliver effective, consistent and cost effective energy source. This paper presents hybrid renewable energy system (HRES) solar photovoltaic, downdraft biomass gasifier, and fuel cell based generation system. HRES electrical power to supply the electrical load demand of academic research building sited in $23^{\circ}12^{\prime}N$ latitude and $77^{\circ}24^{\prime}E$ longitude, India. Fuzzy logic programming discover the most effective capital and replacement value on components of HRES. The cause regarding fuzzy logic rule usage on HOMER pro (Hybrid optimization model for multiple energy resources) software program finds the optimum performance of HRES. HRES is designed as well as simulated to average energy demand 56.52 kWh/day with a peak energy demand 4.4 kW. The results shows the fuel cell and battery bank are the most significant modules of the HRES to meet load demand at late night and early morning hours. The total power generation of HRES is 23,794 kWh/year to the supply of the load demand is 20,631 kWh/year with 0% capacity shortage.

• KDI Journal of Economic Policy
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• 제32권4호
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• pp.153-195
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• 2010

세계금융위기의 근본적인 원인은 시장과 제도의 괴리에서 나오는 '제도의 실패'라고 할 수 있다. 특히 현재의 국제통화제도는 무제도(non-system)나 다름없다고 할 수 있다. 현재 당면하고 있는 국제통화제도의 문제점들을 볼 때 개편 방향의 핵심은 (1) 수요 측면에서는 과대한 외환보유고를 축적하려는 인센티브를 어떻게 줄일 수 있을 것인가 하는 것이며, (2) 공급 측면에서는 현재 미국 달러화에 주로 의존하고 있는 제도를 탈피, 보다 다양한 국제통화 혹은 대체적 외화준비자산(SDR을 포함하여)으로 전환해 나가거나 혹은 보다 근본적인 개혁방안으로서 새로운 세계통화(global reserve currency)를 창출하는 것이다. 그리고 (3) 이러한 변화를 뒷받침 하기 위해 필요한 기구적 개편, 특히 IMF의 개혁을 추진하는 것이다. 이러한 개편은 현실적 국제역학관계로 볼 때 오직 점진적으로 일어날 수 있는 것이다. 따라서 현재 세계경제의 안정적 성장을 위해 중요한 것은 이러한 개편을 점진적으로 추진함과 동시에 주요국 간의 거시경제정책공조를 이뤄 나가는 것이다. 이러한 과정을 원활히 해나가기 위해서는 효율적인 세계경제 지배구조를 갖추는 것이 필수적이다. 세계금융위기 이후 출범한 G20 정상회의가 효율적인 협의체가 되기 위해서는 의사결정이 원활히 이루어질 수 있는 방안과 장치를 세워나갈 필요가 있다. 사무국(secretariat) 혹은 그와 유사한 기능을 행사할 수 있는 조직의 설립과 위원회제도 같은 것을 활용할 필요가 있을 것으로 보인다.

• Journal of Trauma and Injury
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• 제34권1호
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• pp.50-56
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• 2021

Purpose: Fractures are common in the military population, but limited studies have investigated the incidence of fractures among Korean military personnel. Hence, this study aimed to clarify this issue. Methods: Eligible subjects were patients who had sustained a fracture and were registered in the N-DEMIS (the medical records system of participating hospitals) from June 2017 to May 2019. Fractures were categorized according to the fracture site, patients' age, sex, and type of duty. Results: In total, 23,687 patients with 23,981 fractures were included. There were 216 patients with multiple fractures, of whom 156 had fractures at two sites, 42 had fractures at three sites, and 18 had fractures at four sites. Of the 23,687 patients, 23,340 were men and 347 were women. The incidence of fractures in men and women was 12.96 per 1,000 person-years and 0.19 per 1,000 person-years, respectively. In terms of the broad location of fractures, the percentage of fractures was the highest in the hand, followed by the foot and lower leg. When the location of fractures was analyzed more specifically, the percentage of fractures was the highest in the phalanx (thumb and fingers), followed by the ankle and metacarpal bones. Conclusions: Hand, foot, ankle, and wrist fractures were the most commonly encountered fractures in the Korean military population. To prevent the loss of combat power due to non-battle-related injuries, thorough preparation is necessary, including protective equipment and preliminary training for areas with a high frequency of fracture occurrence.

• 한국콘텐츠학회논문지
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• 제22권7호
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• pp.318-331
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• 2022

세계적으로 높은 우리나라 노인자살률을 해결하기 위하여 정부는 2004년 제1차 자살예방기본계획을 시점으로 하여 자살예방정책을 추진하여왔지만, 여전히 노인자살률은 개선되지 못하고 있다. 본 연구는 자살문제 해결에 있어 지방 정부의 역할에 주목하고, 지역 단위의 자살예방정책과 노인자살률의 관계를 규명하기 위하여 2015~2017년까지의 3개년 자료를 시군구 단위에서 분석하였다. 노인자살률에 영향을 줄 수 있는 사회자 본 요인, 인구사회학적 요인, 의료이용접근성 요인 등을 통제하고자 다중회귀분석과 로지스틱회귀분석을 실시하였다. 분석결과, 자살률이 높은 지역에 자살조례 제정과 기초 자살예방센터·정신건강복지센터의 설치 등이 이뤄지고 있음을 확인할 수 있었고, 자살률이 높은 지역에서는 센터설립 후 경과기간이 길면 자살률이 감소하는 것을 확인할 수 있었다. 자살률은 지역의 복지정책에 영향을 받는 것으로 분석되어 자살예방정책은 복지정책 강화와 연계하여 추진되어야 한다는 점을 확인할 수 있었다.

• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.831-838
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• 2022

Machine Learning is a process of using computer algorithms to extract information from raw data to solve complex problems in a data-rich environment. It has been used in the construction industry by both academics and practitioners for multiple applications to improve the construction process. The Construction Industry Institute, a leading construction research organization has twenty-five years of experience in benchmarking capital projects in the industry. The organization is at an advantage to develop useful machine learning applications because it possesses enormous real construction data. Its benchmarking programs have been actively used by owner and contractor companies today to assess their capital projects' performance. A credible benchmarking program requires statistically valid data without subjective interference in the program administration. In developing the next-generation benchmarking program, the Data Warehouse, the organization aims to use machine learning algorithms to minimize human effort and to enable rapid data ingestion from diverse sources with data validity and reliability. This research effort uses a focus group comprised of practitioners from the construction industry and data scientists from a variety of disciplines. The group collaborated to identify the machine learning requirements and potential applications in the program. Technical and domain experts worked to select appropriate algorithms to support the business objectives. This paper presents initial steps in a chain of what is expected to be numerous learning algorithms to support high-performance computing, a fully automated performance benchmarking system.

• 산업경영시스템학회지
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• 제39권3호
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• pp.30-38
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• 2016

Shuttle-Based Storage/Retrieval System (SBS/RS) is relatively new to industry. The system is in the category of Automated Storage/Retrieval System (AS/RS), but it is different in that the SBS/RS uses shuttles as Storage/Retrieval (SR) machine instead using a stacker crane. The shuttles are assigned to each tier on multi-tier system and operated for pick-up or drop-off order. Since the system can handle multiple orders simultaneously, it can provide much higher throughput than that of general AS/RS with single stocker crane. Thus, this new system is well fit to recent tendency of increasing small quantity batch production and orders. One of the drawback of this system is that it needs a lot of investment to set up. The efficient operation of the system would be one of the critical matters to increase economic efficiency of capital investment. In this study, we focused on the dwell point policy for shuttles to find efficient way of operating the system. There are four basic policies for the dwell point and we had simulation-based experiment for two different scenarios based on the speed of the shuttle and inter-arrival time of the loads coming to the system combined with four different policies. As it was mentioned above, this SBS/RS relatively new to the field and there is no such experiment shown on previous research and the study of dwell point policy for this SBS/RS could provide the direct comparison of each policy with different hardware specification; the capability of the system. The policy that achieves most efficient operation among the given environment is proposed and the usability of the system is discussed.