• Title/Summary/Keyword: Research and development

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Structure and Evolution of a Numerically Simulated Thunderstorm Outflow (수치 모사된 뇌우 유출의 구조와 진화)

  • Kim, Yeon-Hee;Baik, Jong-Jin
    • Journal of the Korean earth science society
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    • v.28 no.7
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    • pp.857-870
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    • 2007
  • The structure and evolution of a thunderstorm outflow in two dimensions with no environmental wind are investigated using a cloud-resolving model with explicit liquid-ice phase microphysical processes (ARPS: Advanced Regional Prediction System). The turbulence structure of the outflow is explicitly resolved with a high-resolution grid size of 50m. The simulated single-cell storm and its associated Kelvin-Helmholtz (KH) billows are found to have the lift stages of development maturity, and decay. The secondary pulsation and splitting of convective cells resulted from interactions between cloud dynamics and microphysics are observed. The cooled downdrafts caused by the evaporation of rain and hail in the relatively dry lower atmosphere result in thunderstorm cold-air outflow. The outflow head propagates with almost constant speed. The KH billows formed by the KH instability cause turbulence mixing from the top of the outflow and control the structure of the outflow. Ihe KH billows are initiated at the outflow head, and pow and decay as moving rearward relative to the gust front. The numerical simulation results of the ratio of the horizontal wavelength of the fastest growing perturbation to the critical shear-layer depth and the ratio of the horizontal wavelength of the billow to its maximum amplitude are matched well with the results of other studies.

A Study on Competitiveness and Effect Analysis for Developing a Port Specialized in Northern Sea Route (경쟁력분석에 따른 국내 북극항로 전진기지 구축방안에 관한 연구)

  • Park, Jin-Hee;Lee, Min-Gyu
    • Journal of Navigation and Port Research
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    • v.39 no.3
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    • pp.241-251
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    • 2015
  • Recently, It became possible to transport freights and energy resources via Northern Sea Route(NSR) as global warming has been accelerated. As a result, all countries of the world and Korean local governments have had a struggle to take the advantageous position first in NSR development. However, this extreme competitions might have a negative effect on the national port industry and cause unnecessary social costs and economic losses. Therefore, the main target of this study is to find the most suitable port for NSR using AHP analysis. Most of the data was gained from previous literatures and public statistics and the weight of each factor was calculated by the result of expert survey. As a result, Busan port has the biggest competitiveness, followed by Yeosu Gwangyang, Ulsan and Incheon. From the result, this study suggested 3 possible scenarios. The first scenario specializing Busan port in NSR focuses more on developing the related businesses such as repair of ships, refueling, ship stores trade than attracting the more cargoes. the second is a strategy to make Ulsan port as a hub for energy resources, especially liquid cargo on NSR. the last is a mixed one to assign suitable roles to the ports according to their competitive capabilities.

Development of a 4S Multiple Media Switching Server and an Information Exchange System (4S 다중매체 스위칭 서버와 육해상 정보교환 시스템 개발)

  • Mun, Seong-Mi;Jang, Won-Seok;Son, Joo Yong;Yang, Gyu-Sik
    • Journal of Navigation and Port Research
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    • v.37 no.3
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    • pp.275-281
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    • 2013
  • Ship Standard Network was submitted as a common subject of e-navigation by 81th IMO MSC 2005. This agenda was given an official status with strategy planning of e-navigation for Ship Standard Network after approval of WG program of 81th MSC 2006. Nowadays approximately 400 heterogeneous navigation and communication equipments are working on ships at sea. Standardization of ship network is to support exchanging various data efficiently. Among them, 4S network is defined as a wireless communication network between ship to ship and ship to shore which provides unceasing communication channel ship to shore. It has been expected to trigger various services and applications based on 4S network. However, no technologies and products has been appeared at fields yet. but now there's not specific technologies and developing products. In this paper, We developed a 4S multiple media switching server and a ship-land information exchange system to overcome the heterogeneity and provide efficient communication environments.. The performance of the implemented system was verified by TTA(Telecommunications Technology Association) V&V(Verification and Validation).

The Plans for Core Personnel Management to Prevent Industrial Technology Leakage (산업기술 유출방지를 위한 핵심인력 관리방안에 관한 연구)

  • Kim, Soon-Seok;Shin, Jae-Chul
    • Korean Security Journal
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    • no.25
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    • pp.109-130
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    • 2010
  • As many countries in the world including the Republic of Korea have used all their national resources in the accelerating economic information warfare, illegal leakage of industrial technologies and information has increased rapidly. The costs required for damage prevention from 2007 to 2008 are estimated at approximately KRW 180 trillion which is expected to increase gradually in future. Because the tricks of leaking key technologies are also getting increasingly systematized, sophisticated and bigger, e.g., simple theft at the individual level or the conspiracy of all the staff taking part in the research activities, we should pay special attention to technology security in addition to technology development. While there are several factors affecting such the brain drain, they usually include personal, social, political and cultural factors, for instance, very heavy educational expenditure of children compared to relatively low pay, the speedy labor market circulation for experienced personnel, or political restrictions on researches. In this context, as part of efforts made to prevent the outflow of core personnel, individual companies and research institutes should establish systematically appropriate core personnel management systems for their own organizational or business goals and principles which are intented to ensure to give better treatment and benefit to core personnel and to exercise closer supervision over them. Furthermore, the conventional personnel management system should be radically and flexibly improved in the manner of encouraging the core personnel returning to the organization to combine their external experiences with practices, instead of penalizing them. At the same time, it is necessary to train and educate core personnel through mutual collaboration and in-house training facilities as well as external academic programs operated jointly at the level of the industry. Finally, as the issues concerning the outflow of core personnel are not just problems of relevant companies and other advanced countries have devoted their best efforts to secure their own key technologies at the national level, it is urgent for the industry and the competent authorities to cooperate closely.

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Characterization of Brugmansia mosaic virus Isolated from Brugmansia spp. in Korea (국내 브루그만시아에서 분리한 Brugmansia mosaic virus의 특성)

  • Park, Chung Youl;Kim, Bong-Sub;Nam, Moon;Lee, Min-A;Baek, Da-Som;Bae, Yang Su;Park, Eun-Hye;Kim, Jeong-Sun;Choi, Jong-Yoon;Lim, Seungmo;Moon, Jae Sun;Lee, Su-Heon
    • Research in Plant Disease
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    • v.20 no.4
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    • pp.307-313
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    • 2014
  • In May 2013, an angel's trumpet leaves showing mosaic and malformation symptoms were collected from Suwon city, Gyeonggi-do. An analysis of the collected sample by transmission electron microscopy observation showed filamentous rod particles of 720-800 nm in length. On the basis of the these observations, we performed PCR against three reported Potyviruses (Brugmansia mosaic virus, Colombian datura virus and Brugmansia suaveolens mottle virus), and the sample was positive for BruMV. Pathogenicity and host range test of BruMV was determined by mechanical inoculation. Solanaceae (tobacco, tomato and eggplant) and Amaranthaceae (ground cherry) appeared typical virus symptoms. To determine coat protein of this virus, we designed specific primer pairs, and performed PCR amplification, cloning, and sequencing. Phylogenetic analysis showed that BruMV-SW was most closely related to BruMV isolate SK. Comparison of the BruMV-SW coat protein nucleotide sequences showed 92% to 99% identities to the other BruMV isolates.

Aluminum Powder Metallurgy Current Status, Recent Research and Future Directions

  • Schaffer, Graham
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2001.11a
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    • pp.7-7
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    • 2001
  • The increasing interest in light weight materials coupled to the need for cost -effective processing have combined to create a significant opportunity for aluminum P/M. particularly in the automotive industry in order to reduce fuel emissions and improve fuel economy at affordable prices. Additional potential markets for Al PIM parts include hand tools. Where moving parts against gravity represents a challenge; and office machinery, where reciprocating forces are important. Aluminum PIM adds light weight, high compressibility. low sintering temperatures. easy machinability and good corrosion resistance to all advantages of conventional iron bm;ed P/rv1. Current commercial alloys are pre-mixed of either the AI-Si-Mg or AL-Cu-Mg-Si type and contain 1.5% ethylene bis-stearamide as an internal lubricant. The powder is compacted in closed dies at pressure of 200-500Mpa and sintered in nitrogen at temperatures between $580~630^{\circ}C$ in continuous muffle furnace. For some applications no further processing is required. although most applications require one or more secondary operations such as sizing and finishing. These sccondary operations improve the dimension. properties or appearance of the finished part. Aluminum is often considered difficult to sinter because of the presence of a stable surface oxide film. Removal of the oxide in iron and copper based is usually achieved through the use of reducing atmospheres. such as hydrogen or dissociated ammonia. In aluminum. this occurs in the solid st,lte through the partial reduction of the aluminum by magncsium to form spinel. This exposcs the underlying metal and facilitates sintering. It has recently been shown that < 0.2% Mg is all that is required. It is noteworthy that most aluminum pre-mixes contain at least 0.5% Mg. The sintering of aluminum alloys can be further enhanced by selective microalloying. Just 100ppm pf tin chnnges the liquid phase sintering kinetics of the 2xxx alloys to produce a tensile strength of 375Mpa. an increilse of nearly 20% over the unmodified alloy. The ductility is unnffected. A similar but different effect occurs by the addition of 100 ppm of Pb to 7xxx alloys. The lend changes the wetting characteristics of the sintering liquid which serves to increase the tensile strength to 440 Mpa. a 40% increase over unmodified aIloys. Current research is predominantly aimed at the development of metal matrix composites. which have a high specific modulus. good wear resistance and a tailorable coefficient of thermal expnnsion. By controlling particle clustering and by engineering the ceramic/matrix interface in order to enhance sintering. very attractive properties can be achicved in the ns-sintered state. I\t an ils-sintered density ilpproaching 99%. these new experimental alloys hnve a modulus of 130 Gpa and an ultimate tensile strength of 212 Mpa in the T4 temper. In contest. unreinforcecl aluminum has a modulus of just 70 Gpa.

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A Study on the Development and Adaption of Open Innovation Analysis Model (특허기반 개방형 혁신 분석 모델 개발 및 적용 연구)

  • Yun, Jin-Hyo Joseph;Kwon, Oh-Jin;Park, Jin-Seo;Jeong, Eui-Seob
    • Journal of Korea Technology Innovation Society
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    • v.13 no.1
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    • pp.99-123
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    • 2010
  • We develop Open Innovation Analysis Method in the Patent analysis field and applies it to analyze Deagu-Gyung-buk Cases. After Chesbrough researches the open innovation situation about U. S. company Cases, many researchers began to study about Open Innovation of Companies. And Hippel participated in User Innovation research about Medical equipments and extreme sporting equipments. He pointed out that user innovation occurred new products. I call it User based Open Innovation. But the methods for Open Innovation are limited such as Case study, Survey analysis, and Quality study. So, we need to develop objective analysis method for open innovation of any firm. In this study, we want to develop new objective analysis method for open innovation and apply it to analyze rocal cases and global comparative studies. We will develop the Chesbrough's patent analysis method about open innovation.We apply this new open innovation analysis method to analyze medical equipment and fuel cell industries in Daegu and Gyung-buk Province. faembedded structure of the cooperative research network of innovation We also will apply this method to analyze Samsung and Nokia Mobile industry, and Hyundae and Toyota automobile industry.

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Comparative Analysis of TTAK.KO-06.0288-Part3 and Development of an Open-source Communication Library for Greenhouse Control System

  • Kim, Joon Yong;Kim, Sangcheol;Lee, Jaesu
    • Journal of Biosystems Engineering
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    • v.43 no.1
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    • pp.72-80
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    • 2018
  • Purpose: A modern greenhouse consists of various Information and Communications Technology (ICT) components e.g., sensor nodes, actuator nodes, gateways, controllers, and operating softwarethat communicate with each other. The interoperability between these components is an essential characteristic for any greenhouse control system. A greenhouse control system could not work unless the components communicate via common interfaces. The TTAK.KO-06.0288 is an interface standard consisting of four parts. Notably, TTAK.KO-06.0288-Part3, which describes the interface between a greenhouse operating system (GOS) and a greenhouse control gateway (GCG), is the core standard of TTAK.KO-06.0288. The objectives of this study were to analyze the TTAK.KO-06.0288-Part3 standard, to suggest alternative solutions for identified issues, and to develop a library as a proof of the alternative solutions. Methods: The "data field" was analyzed using a comparative analysis method, since it is a data transmission unit of TTAK.KO-06.0288-Part3. It was compared with other parts of TTAK.KO-06.0288 in terms of definition, format, size, and possible values. Although TTAK.KO-06.0288-Part1 and TTAK.KO-06.0288-Part2 do not use a "data field," they have a similar data structure. That structure was compared with the "data field" of TTAK.KO-06.0288-Part3. Results: Twenty-one issues were identified across four categories: inter-standard issues, intra-standard issues, operational issues, and misprint issues. Since some of the issues can raise interoperability problems, 16 alternative solutions were suggested. In order to prove the alternative solutions, an open-source communication library called libtp3 was developed. The library passed 14 unit tests and was adapted to two research. Conclusions: Although TTAK.KO-06.0288-Part3 is an interface standard for communication between a GOS and a GCG, it might not communicate between different implementations because of the identified issues in the standard. These issues could be solved by the alternative solutions, which could be used to revise TTAK.KO-06.0288. In addition, a relevant organization should develop a program for compatibility testing and should pursue test products for smart greenhouses.

A study on the efficient supporting methods for small and medium businesses of mobile sector (모바일 분야 중소기업에 대한 효율적 지원 방안 연구)

  • Ahn, Jong-Chang;Lee, Dong-Han;Jung, Gag-Jin
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.2
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    • pp.192-201
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    • 2018
  • This study intends to find efficient support methods for small and medium-sized businesses (SMBs) especially in the increasingly important mobile sector. We investigated regarding perceptions of mobile sector-specific support programs and their current state of usage, and perceptions of the new mobile market and the present conditions of each stage of production based on analysis of a survey that included 204 respondents in each SMB to achieve this goal. Concretely, detections through this research were the reasons for non-selection of support businesses, the future prospective mobile business area, the company's own first-preference item and the reason for the preference, plus new mobile areas of willingness to apply the company's own product and its own first-preference item, and the reason for the preference. In addition, we found out covering costs and revenue size of the maximum-revenue product for each stage (from the first to the fourth stage), the kind of a product's execution method connected to the product (e.g. self-production, outsourcing to another company to produce a product), and the execution method for pre-products. We can suggest a policy regarding efficient support alternatives for SMBs related to the mobile sector thanks to these findings.

Lipase-Catalyzed Reactions for Fats and Oils in Non-Polar Solvent (유기용매 내에서의 유지의 리파제 촉매반응)

  • Daeseok Han;Kwon, Dae-Young;Rhee, Joon-Shick
    • Microbiology and Biotechnology Letters
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    • v.16 no.3
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    • pp.250-258
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    • 1988
  • Lipases are well known as the enzymes which catalyze the hydrolysis of ester bonds combining aliphatic chains and glycerol on mono-, di- and triglycerides. Their reactions are characterized by be-ing heterogeneous and catalyzing the water-insoluble substrates. This property has been one of the Hurdles which delayed the application of lipases in fats and oils industry, However, with the development of biological reaction system of which organic solvent is introduced in part or whole as the reaction media, enzymatic manipulation of fats and oils is attracting increasing attention from the academic and industrial sectors. Trials in two-phase system and reversed micellar system to produce fatty acids through enzymatic hydrolysis of triglycerides preyed to be efficient in respect to volumetric productivity, fat hydrolysis rate, product separation, etc. In organic solvent system lipases have been found to have the ability to catalyze aminolysis, transesterification, esterification, thiotransesterification and oximolysis that are virtually impossible to catalyze in water. The organic solvent system is being extensively used in interesterifying glycerides to produce a fat with the modified physical and chemical nature.

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