• Journal of the Korea Society for Simulation
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• v.16 no.3
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• pp.19-28
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• 2007

We considered the authoritative representations of torpedo systems that was the engagement level model to develop system specifications and to analyze operational requirements on concept design phase. The Work Breakdown Structure(WBS) of models was defined about authoritative representations of the torpedo systems. The communication of information among each subsystems and input/output parameters were defined. In the heavy weight and light weight torpedo model, presetter, underwater maneuver, war head, sonar, guidance and control, propulsion subsystem modeling were developed for heavy-weight and the light-weight torpedo systems. The authoritative representations of torpedo systems have similar structures with those of the engineering level models and could be verified via engagement level simulations according to the V&V process in the future.

• Korea journal of population studies
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• v.9 no.2
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• pp.107-128
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• 1986

본 연구의 목적은 노동력의 사회적 특성적인 면에 있어서 각기 다른 산업에 종사하는 노동력의 "누가" "어떻게" 변화해 가는가에 중점을 두면서 한국의 산업 각 부분간의 변천과정을 조사하는 데 있다. 이 연구에는 1960, 1970, 1980년에 실시된 한국 센서스 자료가 주로 사용되었다. 본 연구의 결과에 따르면 1960년과 1980년 사이의 한국의 산업 구조적인 면에 있어서의 급속한 변화를 보여주고 있다. 그러한 변화들은 주로 경제발전 정책과 더불어 농촌지역에서 도시지역으로의 인구이동에 기인된다고 하겠다. 예를 들면 1960년에 65%의 노동력이 1차 산업에 종사한 반면에 1980년에는 38.5%로 감소했고 이와는 대조적으로 1960년에 오직 8.7%의 노동력이 2차산업에 종사하던 것이 1980년에는 27.6%로 증가하였다. 3차 산업 역시 1960년에 23.8%에서 1980년에 33.9%로 10%의 증가를 보였다. 경제.발전이 이루어지는 과정에서 실업자들이나 잠재 실업자들이 경제활동에 참여할 수 있었기 때문에 경제구조 자체가 예전에 비해 더 안정이 되고 생활수준도 향상이 되었다고 하겠다. 이러한 결과는 부분적으로는 계속된 5개년 경제개발 계획에 기인된다고 할 수 있다. 경제발전 과정에서의 대도시로의 인구집중, 특히나 2차 산업과 3차 산업이 집중되어 있는 서울로의 인구집중은 주택, 교통, 범죄등 많은 문제를 낳고 있다. 동시에 도시지역에의 과잉 노동력의 존재와 농촌지역에는 특히나 농번기에 노동력 부족현상을 야기시키고 있다. 시간의 흐름에 따라 여성노동력의 비율, 전문직과 사무직 종사자, 그리고 서비스분야 종사자들의 비율이 증가하였는 데 비해 대부분의 다른 국가에서 처럼 한국에 있어서도 자영인의 비율은 경제발전 과정에서 감소하였다. 경제발전과 더불어 보다 전문화되고 조직화된 시장중심의 생산체제가 가구와 지역사회 중심의 생산기능을 흡수하므로서 많은 노동력이 임금 노동자가 되었다. 특히나 단순노동을 통한 많은 젊은 여성들을 고용하는 제조산업 분야에서 여성들이 낮은 임금과 과로 그리고 나쁜 작업환경으로 인하여 그들의 건강을 해치고 직업병을 유발할 가능성이 많다고 하겠다. 지난 20년에 걸친 급속한 정부 주도형의 경제발전은 노동력의 제 산업 간의 급속한 변천과 더불어 긍정적인 측면과 부정적인 측면을 모두 낳았다고 할 수 있겠다.측면을 모두 낳았다고 할 수 있겠다.

• Journal of the Korea Convergence Society
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• v.10 no.9
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• pp.161-166
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• 2019

This study examines the flows near the different side mirrors by analyzing the flow due to air resistance at A, B and C models of automotive side mirrors. Model A is a square-shaped side-mirror. Model B is a triangular side-mirror and model C is an oval-shaped side-mirror. The air resistance of the side-mirror while driving is reduced and the automotive power can be reduced by changing the design of automotive side-mirror. As analysis result, as the pressure of air resistance against side mirror becomes larger, it can be seen that the air flow rate becomes great. Therefore, it can be estimated that the smaller the pressure of air resistance, the smaller the flow rate and the better the air flow. Therefore, it can be acknowledged that model B is the best model. As the design data of the automotive side mirror obtained on the basis of this study result are utilized, the esthetic sense can be shown while driving a car at real life.

• Ecology and Resilient Infrastructure
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• v.9 no.3
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• pp.141-153
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• 2022

In this study, a numerical model of debris flow considering driftwood and entrainment erosion is developed. Subsequently, numerical simulations based on the observation data of the 2011 Mt. Umyeon are performed. To develop the debris flow model, the Nays2DFlood model, which is a flooding model based on the shallow water equation, is coupled with the transport diffusion of mixed sediment concentration, debris flow bottom shear stress, and entrainment erosion modules. The simulation closely reproduced the depth, flow velocity, and debris flow volume of Mt. Umyeon. In addition, the reproducibility of the simulation result with driftwood is more accurate than that without driftwood. The results of this study can facilitate in establishing measures to reduce debris disasters, thus alleviating the current increase in debris damage due to climate change.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.4
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• pp.425-437
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• 2007

Flow distribution of water and sedimentation rate were investigated to understand the hydrodynamics and settling characteristics of particulate materials in a constructed wetland for treatment of non-point sources pollutants, the Sihwa constructed wetland, Korea. The Sihwa constructed wetland is divided into three sub-wetlands(the Banwol, the Donghwa and the Samhwa wetlands) to treat the polluted water from three streams, the Banwol stream, the Donghwa stream and the Samhwa stream. From the results of water flow experiment using dye(Rhodamine 50WT Red), it was found that the water flow in the wetland was prevailing at the waterway and open water. Dye was spread slowly in the closed water area planted by plants. The mean hydraulic retention time(HRT) at the upper area of high wetland and lower wetland of Banwol, was found to be 34.1 hr at the upper area and 74.6 hr at the lower area respectively, totaling approximately 108.7 hr(4.5 days). The sedimentation rate was higher at lower area(sites of B, C and D) of the wetland than upper area(site of A which is settling zone). Based on the forecast for 20 years as to the amount of sediment that can be deposited in the open water in the future, the sediment depth of each area would be like this: A: 6.3 cm, B: 8.3 cm, C: 7.0 cm, D: 9.5 cm. The contents of organic materials in the sediment deposited within the sediment trap were found to be higher overly in the first investigation period which had much rainfall, and B, C and D areas were found to have an increased COD accumulation than A area. Also, nitrogen and phosphorus were found to increase in the down-stream of the wetland. The results of this study suggest that a sustainable research and management for the characteristics of water flow pattern and sedimentation changeable as time passes is needs to maintain or improve the efficiency of water treatment in the constructed wetland.

• Journal of Korea Society of Industrial Information Systems
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• v.23 no.5
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• pp.119-134
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• 2018

Today, many firms face the environment of high uncertainty and severe competition due to the rapid technology development and the diverse needs of customers. In the business environment, one of the most important ways to gain sustainable competitive advantage and future growth engine is related to NPD (New Product Development), which is a very important issue for practice and academia. Thus, this study intends to provide new values to practitioners and researchers related to NPD by analyzing current research trends and future trends in NPD field. For this, we bibliometrically analyzed keyword networks which consist of keywords that were already published in the eminent journals from Scopus database to generate insights that have not been captured in the previous reviews on the topic. As a result, we could understand the extant research streams in NPD field, and suggest the changes of specific research topics based on the connected relationships among keywords over the time. In addition, we also foresaw the general future research trends in NPD field based on the keywords according to preferential attachment processes. Through this study, it was confirmed that NPD keyword network is a small world network that follows the distribution of power law and the growth of network is formed by link formation by keyword preferential attachment. In addition, through component analysis and centrality analysis, keywords such as Innovation, New product innovation, Risk management, Concurrent engineering, Research and development, and Product life cycle management are highly centralized in NPD keyword network. On the other hand, as a result of examining the change of preferential attachment of keywords over the time, we suggested the required new research direction including i) NPD collaboration with suppliers, ii) NPD considering market uncertainty, iii) NPD considering convergence with the other academic areas like technology management and knowledge management, iv) NPD from SME(Small and medium enterprises) perspective. The results of this study can be used to determine the research trends of NPD and the new research themes for interdisciplinary studies with other disciplines.

• The Korean Journal of Applied Statistics
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• v.30 no.3
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• pp.363-376
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• 2017

The insurance market is saturated and its growth engine is exhausted; consequently, the insurance industry is now in a low growth period with insurance companies that face a fierce competitive environment. In such a situation, it will be an important issue to find the probability distributions that can explain the flow of insurance claims, which are the basis of the actuarial calculation of the insurance product. Insurance claims are generally known to be well fitted by lognormal distributions or Pareto distributions biased to the left with a thick tail. In recent years, skew normal distributions or skew t distributions have been considered reasonable distributions for describing insurance claims. Cooray and Ananda (2005) proposed a composite lognormal-Pareto distribution that has the advantages of both lognormal and Pareto distributions and they also showed the composite distribution has a higher fitness than single distributions. In this paper, we introduce new composite distributions based on skew normal distributions or skew t distributions and apply them to Danish fire insurance claim data and US indemnity loss data to compare their performance with the other composite distributions and single distributions.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.12 no.6
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• pp.89-98
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• 2017

The dynamic entrepreneurial activities of small businesses or individual entrepreneurs seeking to enter the global market based on innovative ideas and challenging spirit in the modern society, which is trending in entrepreneurial capitalism according to the times, Leading to new growth engines. In order to promote the establishment of universities in Korea, the government has been working on 'Five-Year Plan for University Entrepreneurship Education(2013-2017)', 'Efficiency of Government Start-up Support in 2015', and 'Five-Year Basic Plan for Activation of Industry-University Cooperation(2016-2020)'. However, there are still practical limitations in spite of the efforts made by universities and research institutes to revitalize start-ups. As a way to overcome these limitations, this study aims to systematize the entrepreneurship education of the university, and examines the role of changing universities and theory of clusters and the entrepreneurship education. In addition, we will look at the factors of creative university culture centering on the representative cases of the Innovation University in US, and present a conceptual framework for cluster-based entrepreneurship education for the purpose of 'successful entrepreneurship' which is different from 'start-up success'. The conceptual framework of cluster-based entrepreneurship education is based on the establishment of 'Integrated Entrepreneurship Education Platform' to revitalize start-ups centered on university technology. At the same time, this framework focuses on the three factors of talent, technology, and culture based on the relevant theories and examples, and emphasizes the clustering of entrepreneurial resources, entrepreneurial policies and leadership that should be involved in entrepreneurship education.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.454-454
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• 2011

녹색성장은 최근 세계적인 이슈가 되고 있다. 세계물위원회(World Water Council, WWC)의 경우 2012년 마르세유에서 개최되는 제6차 세계물포럼(World Water Forum, WWF)에서 물문제 해결을 위한 신개념 패러다임으로서 '녹색성장(Green Growth)'을 채택하기 위한 협력방안의 필요성을 제안하고 있다. 우리나라에서는 이미 녹색성장을 국가 슬로건으로 선정하고 글로벌 녹색성장연구소(Global Green Growth, GGGI)를 설립하는 등 녹색성장을 선도하고 있다. 이는 물의 중요성에 비추어볼 때 녹색성장을 물 분야에 확산시킬 수 있는 적절한 기회로 보인다. 녹색성장은 물 관련 환경서비스가 환경오염 없는 경제성장을 이룩하는 데 주요한 역할을 수행할 수 있다는 가능성과 당위성에서 파생된 최근에 만들어진 개념으로서, 물 분야의 경우 녹색경제에 있어서 중요한 역할을 수행해왔으며 이후 지속적인 인구증가, 물 소비패턴의 변화, 에너지비용 증가, 기후 변화 등으로 물 분야의 중요성은 더욱 커질 것으로 기대된다. 이처럼 물 관리는 경제발전, 재해로부터 보호, 인간의 건강 및 생태계와 삶의 질을 위하여 필수적이기에 녹색성장에 있어 중요한 역할을 수행하고 있다. 하지만 올바른 물 관리가 녹색성장에 기여할 수 있는 방법에 대해서는 아직 명확화 구체화되지 못하고 있는 실정이다. 이에 따라 녹색성장을 새로운 국가 성장 동력의 패러다임으로 구축하기 위해 수자원분야에서의 녹색성장방법론을 정립하고, 선진국과 개도국 정부들의 균형 있는 참여를 통한 글로벌 파트너십 구축이 요구되고 있으며, 이를 세계물위원회 등 국제기구와 공동으로 연계시킨다면 상당한 시너지 효과가 기대된다. 물관리는 국가의 경제발전, 재해로부터 생명과 재산의 보호, 인간의 건강 및 생태계 다양성 및 건전성 유지와 삶의 질을 향상을 위하여 매우 중요하며, 환경보존과 경제성장을 동시에 추구하는 녹색성장을 실현하는 데 있어서도 가장 핵심적인 사항이라고 할 수 있다. 그러나 올바른 물 관리가 녹색성장에 기여할 수 있는 방법에 대해서는 아직 명확하고 구체화 되지 못하고 있는 실정이다. 따라서 본 연구에서는 '물과 녹색성장'의 이론적 배경, 필요성, 개념정립, 벤치마킹 사례, 국제사회에서의 녹색성장과 관련한 논의 기구 및 흐름 등의 이해를 기초로 녹색성장을 통한 경제성장의 상호작용과 선순환구조를 체계화시키기 위한 균형방안을 제시하고자 한다. 또한 수자원 및 하천관리 분야에서의 WGG구현을 위한 정책제안 및 실행방안이 담긴 중장기 로드맵을 구축하여 물을 통한 성장의 발판을 마련하고자 한다.

• Solar Energy
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• v.13 no.1
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• pp.22-30
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• 1993

This Paper deals with the experimental study of the axisymmetric air jet impinging vertically on the flat heating surface with and without swirl. The purpose of this study is to investigate the characteristics of flow, augmentation of heat transfer rate, turbulent intensity, and the comparison of heat transfer rate, the optimal swirling condition about the swirl and nonswirl axisymmetric air jet. In order to augment the heat transfer on the flat heating surface without introducing any additional power, the technique used in the present work was placement of twisted tape inserted pipe in front of the nozzle exit in order to make a swirl. The effect of swirl degree is investigated in case of S=0., 0.056, 0.111, 0.222 and the velocity of the jet was 14, 20, 26, 32, 38, 44m/s. The distance between the nozle exit and the stagnation point on the impinging plate was the H/D=$1{\sim}14$. In order to analyze of the flow structure which increase heat transfer, the velocity and the turbulent intensity of the axisymmetric jet was measured by a hot wire anemometer according to the swirl number and H/D.