• Title/Summary/Keyword: Expansion Method

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Intimate Understanding for Growth Mode of Graphene on Copper

  • Song, U-Seok;Jeon, Cheol-Ho;Kim, Su-Yeon;Kim, Yu-Seok;Kim, Seong-Hwan;Lee, Su-Il;Jeong, Dae-Seong;Park, Jong-Yun
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.08a
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    • pp.181-181
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    • 2012
  • Direct synthesis of graphene using a chemical vapor deposition (CVD) has been considered a facile way to produce large-area and uniform graphene film, which is an accessible method from an application standpoint. Hence, their fundamental understanding is highly required. Unfortunately, the CVD growth mechanism of graphene on Cu remains elusive and controversial. Here, we present the evidences for two different growth modes of graphene on Cu investigated by varying carbon feedstock (C2H2 and CH4) and working pressure. The number of uniform graphene layer grown by C2H2 increased with increasing its injection time. A combined secondary ion mass spectrometry (SIMS) and X-ray diffraction (XRD) study revealed a carbon-diffused Cu layer created below surface region of Cu substrate with the expansion of Cu lattice. The graphene on Cu was grown by the diffusion and precipitation mode not by the surface adsorption mode, because similar results were observed in graphene/Ni system. The carbon-diffused Cu layer was also observed after graphene growth under high CH4 pressure. Based on various previous results and ours, we have successfully found that there are two selective growth modes for graphene on Cu substrate, and a desired mode can be chosen by tuning working pressure corresponding to the kind of carbon feedstock. We believe that this finding will shed light on high quality graphene growth and its multifaceted applications.

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Assessing the Unemployment Problem Using A Grey MCDM Model under COVID-19 Impacts: A Case Analysis from Vietnam

  • NGUYEN, Phi-Hung;TSAI, Jung-Fa;NGUYEN, Hong-Phuc;NGUYEN, Viet-Trang;DAO, Trong-Khoi
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.12
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    • pp.53-62
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    • 2020
  • The COVID 19 pandemic has led to a new global recession and is still causing a lot of issues because of the delays in the employment of people. This scenario has severe consequences for many countries' labor markets in the world. This problem's complexity and importance requires an integrated method of subjective and objective evaluation rather than intuitive decisions. This research aims to investigate sustainable indexes for assessing the unemployment problem by using a Multi-Criteria Decision-Making Model (MCDM). Grey theory and Decision Making Trial and Evaluation Laboratory (GDEMATEL) are deployed to transform the experts' opinions into quantitative data. The analysis based on 20 crucial criteria is employed to determine the weights of sustainability of unemployment problems. The results revealed that the top ten of determinants are Economic growth, Industrialization, Foreign direct investment, Real GDP per capita, Education level, Trade Openness, Capacity Utilization Rate, Urbanization, Employability skills, Education system expansion, which have the most significant effects on the unemployment rate under COVID 19 impacts. Furthermore, GDEMATEL could effectively assess the sustainable indicators for unemployment problems in "deep and wide" aspects. The study proposes the Grey MCDM model, contributes to the literature, provides future research directions, and helps policymakers and researchers achieve the best solutions to the unemployment problems under "economic shocks."

Thermo-Mechanical Analysis of Continuous-Adjustment Thruster using Explosion Pressure (폭압을 사용하는 연속조정 추진구조체의 열-구조해석)

  • Kim, Kyung-Sik;Kwon, Young-Doo;Kwon, Soon-Bum;Gil, Hyuck-Moon
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.24 no.6
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    • pp.699-705
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    • 2011
  • High-maneuver missile is a projectile which demands a strong momentum at short time. To produce a necessary thrust for the flight, the gas of high temperature and pressure is generated through explosive combustion of solid propellant, and a great thrust can be obtained by expanding this high temperature and pressure gas. Although the operating time of a rocket motor is less than a few seconds, a failure of part or ablation near the throat of nozzle may take place during the expansion of high temperature and pressure gas for great thrust. In other words, for the precise control of a missile an exact stress analysis considering both, the thermal stress caused by the heat transfer between combustion gas and wall, and the mechanical stress caused by the pressure change in the flow, should be considered first. In this connection, this study investigated the safety, as a point of view of stress and melting point of the material, of the pre-designed thrust generating structure which is subjected to high temperature and pressure as a function of motor operating time.

Mechanism Method for Smart Work and the Creation of IT Job (스마트워크와 IT의 일자리창출을 위한 메커니즘 방안)

  • Kim, Man-Ki
    • Journal of Digital Convergence
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    • v.10 no.2
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    • pp.55-61
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    • 2012
  • This space is for the abstract of your study in English. Recently, we began to face a significant change in our daily lives due to the expansion of the use of smartphones. In this regard, this study aims at examining the mechanism of Smart Work, necessary for the creation of job, led by the use of smart devices, and ways of its development. Accordingly, this study defined concepts of Smart Work clearly and analyzed the convergence of information through IT, the exploitation of new markets, derived from information industry, along with foreign cases of job creation through ICT. Furthermore, change in people's cultural recognition is required for the place of smart Work. For example, cluster development based on the public-private cooperation will promote the creation of job. In addition, the cooperation of the academic world and the service industry will play a leading role in developing local economy. To attain this end, the policy support of government for Smart Work and the public-private cooperation are needed.

Activating Strategy of Free Trade Zone in Pyeongtaek Port (평택항 자유무역지역의 활성화 방안 연구)

  • Jung, Hyun-Jae;Lee, Dong-Hyon
    • Journal of Digital Convergence
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    • v.16 no.9
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    • pp.115-123
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    • 2018
  • This study aims to analyze the importance of activating factors in the companies operating in the free trade zone of Pyeongtaek Port by using hierarchical analytical decision making method and suggest implications according to the analysis results. As a result of analyzing the importance of the five factors, it was found that most of the companies in the free trade zone of Pyeongtaek Port were aware of the infrastructure factor (0.330), finance and budget (0.223), organization and operation (0.188), manpower (0.119) in order of importance. In detail, the expansion of the route was recognized as the most important improvement. and Manufacturing companies were judged to be a more important factor in improving the entry conditions of manufacturers and strengthening the distribution of value added. In logistics companies, the importance of manpower is higher than manufacturing companies. The implications for the results of the analysis are diversification of route in Pyeongtaek Port, improvement of the infrastructure near the free trade zone, and The need for institutional improvements. Also, in the future, we suggest the necessity of activation research for non - residents.

Fundamental Studies on Sinyewon Clays (新禮院粘土에 관한 基礎的 硏究)

  • Park, Soon-Za;Ann, Nam-Soon;Kim, Yoon-Ho
    • Journal of the Korean Chemical Society
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    • v.10 no.2
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    • pp.67-75
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    • 1966
  • Four kinds of clays from Sinyewon mine which is located in Chungchoungnam-Do district and two kinds of Japanese clays (Gairome, Kibushi) were selected and studied on the fundamental properties of these clays and those which are refined by the elutriation method. Chemical analysis, grading analysis such as refractoriness, specific gravity, color, fired color and plasticity, particle size distribution, various thermal tests, X-ray diffraction analysis and electron microscopic survey were carried out on these clays. The comparison of domestic clays with Japanese clays was made. 1. In chemical composition and physical properties, these four kinds of Sinyewon clays are almost similar to each other and also to Gairome and Kibushi clays. In refractoriness, Gairome and Kibushi clays have relatively high value such as SK 34 and 35, while Sinyewon clays have the value of about SK 32. Especially Sinyewon clay B has the low refractoriness (SK 18) and plasticity. Refined clays have the tendency of somewhat higher value than crude ones in refractoriness. 2. When burnt up to $900^{\circ}C$, the coefficients of contraction of Sinyewon clays were under 1.5%, Gairome under 1.3%, Kibushi under 3.0%. Only Sinyewon clay B showed expansion (1.0%) instead of contraction. 3. X-ray diffraction analysis and electron micrography showed that all of four Sinyewon clays and two Japanese clays are mainly composed of poorly crystallized kaolin, containing small amount of halloysite, sericite and considerable amount of quartz and feldspar. Sinyewon clay B contains especially large amount of quartz and feldspar. In general, it has been found out that the refined clays were free from large amount of iron oxide, quartz and feldspar.

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A change of rigging method for purse seine gear of Korea tuna purse seine fishery in the Western and Central Pacific Ocean (중서부태평양 한국 다랑어 선망어업에서의 어구 구성의 변화)

  • Ryu, Kyung-Jin;Lee, Yoo-Won;Kim, Hyung-Seok
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.51 no.1
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    • pp.50-60
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    • 2015
  • This paper conducted research on identifying the process of change in fishing gear and organizing the function of periodically-used fishing gear types through net plan and computer simulation by selecting the design of the four types of fishing gear used for the Korea tuna purse seiner in the Western and Central Pacific Ocean, which 1,000 G/T class and whose length over all 60 m class. In the late 1980s, the length of the tuna purse gear was 1,939 m and the design depth was 160 m, but currently, the length and the design depth are 2,515 m and 230 m, respectively. As a result of the simulation, the expansion of the fishing gear increased buoyance, sinking force, sinking depth, surrounded area, and purse wire continuously. Recently, the maximum tension of the currently used purse wire of tuna purse seiner is 23.5 tons and is close to 25.4 tons which is the maximum lift capacity of WS454 winch. The way to improve fishing gear should be proceeded to increase sinking speed rather than expand the size of fishing gear.

A Study on the Direction for Customized Home modification Through the Process for a case of Visually Impaired Person in Rural Area (농촌거주 시각장애인의 주택개조사례 과정을 통해 본 맞춤형 개조 방향도출연구)

  • Lee, Yeun-Sook;An, So-Mi;Kim, Min-Ju;Hyun, Ji-won
    • Korean Institute of Interior Design Journal
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    • v.27 no.2
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    • pp.55-67
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    • 2018
  • There is a growing interest on and expansion of rights of people with disabilities. Among them, people with visual impairment show high adaptation to environments in comparison to people with other types of disabilities, thus a large percentage of them live in their own houses rather than residing in a care facility. According to the housing status of people with visual impairment, the ratio of their residence in rural areas is high. In rural areas people who have disabilities often live in poor residential environments, requiring much improvement. However, such improvement is too costly for them to pay, and home modification that does not fully consider the user, may cause less efficiency and another dangerous situation to people with disabilities. The purpose of this study is to delineate empirical lessons for direction of customized home modification for people with disabilities through analysis of process of home modification including the execution as a intervention. This study used qualitative method to examine and analyzed the entire customized home modification process. The conclusion of this study is as follows. First, home modification measures should be derived considering the suitability of the target building for the specific condition of residents. Second, discussions with various stakeholders from the early stage during which proper home modification measure is searched are essential for realizing appropriate customized home modification. This study has significance in that it provides the direction for customized home modification for people with disabilities as well as empirical data that could reduce trials and errors in the future.

A Study of the Possibility of Building Energy Saving through the Building Data : A Case Study of Macro to Micro Building Energy Analysis (건물데이터를 통한 건물에너지 절감 가능성에 대한 연구 : 도시단위의 거시적 분석부터 미시적 건물에너지 분석사례)

  • Cho, Soo Youn;Leigh, Seung-Bok
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.29 no.11
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    • pp.580-591
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    • 2017
  • In accordance with 2015 Paris agreement, each individual country around the world should voluntarily propose not only its (individual) reduction target, but also actively develop and present expansion targets of its scope and concrete reduction goals exceeding the previous ones. Accordingly, it is necessary to prepare a macroscopic, long-range strategy for reducing energy consumption and greenhouse gas emissions, which can cover a single building, town, city and eventually even a province. The purpose of this research is to gather and compile government-acquired data from various sources and (in accordance with contents and specificity), combine building data by stages by using multi-variable matrix and then analyze the significance of combined data for each stage. The first order data presents the probability and the cost effectiveness of energy saving on the scale of a city or a province, based only upon general information, size and power consumption of buildings. The second order data can identify a pattern of energy consumption for a building of a specific purpose and which tends to consume a larger amount of energy during one particular season (than others). Finally, the third order data can derive influential factors (base load, humidity) from the energy consumption pattern of a building, and thus propose an informed and practical energy-saving method to be applied in real time.

A Case study of "Branded Contents" applied Gamification concepts (게이미피케이션 개념을 적용한 브랜디드 콘텐츠 사례 연구)

  • Na, Ji Young;Park, Young Il;Kim, Hye Bin
    • Journal of Korea Game Society
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    • v.16 no.5
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    • pp.45-56
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    • 2016
  • This paper researches on the cases wherein the concept of gamification is applied to branded content. Gamification is the application of game elements to non-game fields, and it is being actively utilized in the areas of education, marketing, medical, sports, and shopping. Especially, the concept of gamification is applied to branded content and wherein marketing (advertisements) are expanded into entertainment content. This paper studies the methods on how the concept of gamification affects marketing, and application in the expansion of branded content into entertainment content. To achieve this, this paper looked into the concepts and characteristics of gamification and branded content, and analyzed the methods on how the elements of game (goal, competition, feedback, reward) were applied to five kinds of real cases. Finally, this paper verified that gamification is an efficient method of extending branded content into entertainment content.