• Journal of the Korean Chemical Society
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• v.48 no.3
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• pp.273-282
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• 2004

The synthetic technology of improved polyaluminiumchloride (IPAC) similar to characteristics of PACS was established with minimum expense for modifying existing production line. The conditions for activating silicate was studied before the synthesis of IPAC, and the IPAC was synthesised with raw materials such as aluminumhydroxide and concentrated hydrochloric acid, followed by adding activated silicate and alginate. The specification of product, chemical structure, and coagulating properties were tested by using specification testing method, instrumental analytical method, and Jar tester, respectively. As a result, the product, IPAC, contained aluminium oxide content more than 17%, and no precipitation was shown at all while the IPAC solution was preserved, and the larger floc and faster coagulation were represented compared to existing PAC under the same conditions. It was suggested that these synthetic technology could be applied to the existing production line for producing PAC without approximately cost raising factor because of adding sulfuric acid-activated silicate instead of sodium sulfate.

• Information and Communications Magazine
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• v.25 no.1
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• pp.5-11
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• 2008

우리 경제의 성장잠재력 저하에 대한 우려가 심화되는 상황에서 국민소득 2만불 시대 견인을 위해 2004년 수립한 IT 산업 발전전략이 IT839이다. 신성장동력 핵심기술 개발 등 IT839전략에 힘입어 세계 최초로 WiBro, DMB 기술개발과 국제표준화에 성공하는 등 IT분야 기술개발을 주도하여, 선진국과의 기술격차가 1년 이상 단축되었으며, 특히, 이동통신 DIV 분야는 미국, 일본 등 선진국 수준으로 경쟁력이 향상되는 성과를 보았다. 한편, 최근 IT를 둘러싸고 있는 환경은 IT를 기반으로한 융복합화 진전, 글로벌화 심화, 인터넷 확산과 웹의 진전이다. 2008년에는 이런 환경변화 속에서 IT산업의 지속적인 성장을 위한 전략을 수립.추진할 계획이다. 무선 융합환경에서 신시장 창출 및 선점, 고부가가치 IT산업의 집중 육성, IT중소기업, 핵심인력 양성 등 경쟁력 향상을 위한 기반 구축도 강화한다. IT R&D 정책은 기초 원천기술분야 R&D 투자비중을 확대하고, IT와 비IT융합 등 융합분야 기술개발 투자도 확대할 것이다. 혁신형 IT 중소기업 육성을 위해 민간 정책협력 네트워크인 IT전문협의회 운영을 개선하고, 중소기업의 원가절감을 위한 공통서비스 확대, 대 중소 기업의 상생협력을 제도화는 등 IT정책 인프라도 고도화한다. 또한, 반도체, 디스플레이 이후의 글로벌 주력품목군으로 IT SoC, u-센서, IT-BT-NT 융합분야 등 3대 핵심분야를 선정하여 집중 육성하고, 부품기업간 협업 활성화를 적극 유도할 것이다. 시장이 원하는 글로벌 수준의 인재양성을 목표로 공학교육인증 확산, IT 융합분야를 중심으로 대학의 R&D 지원도 강화하며, 전공역략을 갖춘 IT 전문인력, 석박사급 핵심 연구개발 인력, IT재직자 교육 등 시장이 원하는 맞춤형 인력양성도 병행 추진한다. 마지막으로 SW산업의 글로벌 경쟁력을 제고하고 신시장 창출을 위해 노력도 강화한다. 조선, 자동차 등 비 IT분야의 SW활용을 확산하기 위한 선도프로젝트를 추진하고, 틈새분야 중 세계적 시장점유율을 갖춘 중소기업 제품에 임베디드SW를 탑재하여 첨단기능을 구현하는 시범사업도 적극 추진할 계획이다.

• The Transactions of the Korean Institute of Power Electronics
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• v.14 no.1
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• pp.23-30
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• 2009

A new high performance and low cost unified power system is proposed through investigating conventional Power-Integrated Drive(PID) system and Power-Separated Drive(PSD) system applied to LCD TV. Since the proposed system consists of two stage, namely power and inverter stage it features high efficiency and cost effectiveness. To satisfy the safety standard of the High voltage transformer, 1:1 transformer is employed between inverter and high voltage transformer. Moreover, to ensure the Zero Voltage Switching(ZVS) of all power switches and the Pulse Count Modulation(PCM) method is employed, which controls the number of pulse at the fixed frequency and fixed duty cycle. Therefore, it features high efficiency, improved heat generation, cost effectiveness and good EMI performance including no additional current balancing coil. To confirm the validity of proposed system, comparison of conventional system, verification of experimental results are presented.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.12
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• pp.2906-2913
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• 2013

Only small numbers of medium-sized manufacturers have adopted a production management system. They have difficulty maintaining production cost and progress management, because they have used the ways that win a contract, not mass production system like a big company. Also a small company has to change standard features of products whenever customers want, by means of non-standardization and small quantity production method. As a result, it has been very difficult for a small company to establish a proper production management system. So, this paper tried to make a study about increasing production management system, using QR codes in a small-sized manufacturer with the ways that win a contract, based on real application case.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.269-269
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• 2010

현재 화석연료의 부족으로 인한 에너지 수급의 불균형, 자연환경의 파괴로 인해 대체에너지 개발이 절실히 요구되고 있다. 이러한 문제점을 극복하기 위한 방안으로 태양전지에 대한 관심이 높아지고 있다. 기존 결정형 실리콘 태양전지와 비교해 화합물 반도체를 기반으로 한 박막형 태양전지는 친환경적인 제품이면서 제조원가를 절감시킬 수 있고, 반영구적인 수명 및 값싼 기판을 활용할 수 있는 장점으로 인해 활발한 연구가 진행되고 있다. 본 실험에서는 Co-sputtering법으로 제작된 $CuInSe_2$(CIS)를 광활성층으로 한 박막형 태양전지에서 실온 ${\sim}550^{\circ}C$의 다양한 온도에서 후열 처리된 CIS 박막들의 전기적, 구조적, 광학적인 특성들을 분석하였다. 제작된 박막들 가운데 Hall Effect 측정결과 $550^{\circ}C$에서 후열 처리된 박막이 가장 높은 1.227E+22(/$cm^3$)의 캐리어 농도와 1.581(cm/$V{\cdot}s$)의 홀 이동도를 가지며, 3.092E-4(${\Omega}{\cdot}cm$)의 가장 낮은 비저항 값을 갖는 것으로 나타났다. EFM 측정결과 열처리 하지 않은 박막에 비해 후열처리된 CIS 박막의 전도성이 전체적으로 높아졌다. 특히, $550^{\circ}C$에서 후열 처리된 박막의 표면은 전체적으로 전기 전도성이 높은 결정립들이 골고루 분포하며 가장 높은 표면 포텐셜 에너지 값을 갖는 것으로 나타났다. 박막들의 구조적 특성을 분석하기 위해 SEM과 XRD를 측정한 결과, $350^{\circ}C$에서 후열 처리된 박막들은 열처리 되지 않은 박막과 비교해 표면형상 변화가 일어났으며, $550^{\circ}C$에서 후열 처리된 CIS 박막들은 $CuInSe_2$(112) 방향이 향상된 chalcopyrite-like 구조를 가지면서 박막 밀도가 높고 결정립의 크기가 증가된 것을 확인하였다. 이는 박막 성장시 기판온도의 상승으로 CIS 박막 내에서 셀레늄의 확산과 상호작용으로 3원 화합물이 재결정화되어 구조적인 특성향상에 기여하였기 때문이다. 결론적으로 본 연구는 CIS 광활성층에서 후열 처리의 효과들 뿐만아니라 박막 증착시 co-sputtering법을 이용함으로써 증착시간의 감소 및 대면적화와 대량생산으로도 적용 가능함을 제시하고자 한다.

• Korean Journal of Labor Studies
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• v.23 no.1
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• pp.221-253
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• 2017

This study aims at analyzing the management strategy and performance of companies that have been pursuing Generational Diversity. The management strategies were examined in terms of production, organizational structure and skill development. Performance was then evaluated using Balanced Scorecard (BSC). We selected four Japanese companies that practice Generational Diversity between the younger(age less then 34) and older generation(age older then 65). Our findings suggest the following. The common management strategies of the four companies include 1) creating generation-diverse teams 2) ensuring flexible work arrangements and 3) providing skill training programs. These strategies have yield positive outcomes such as sales increase, cost reduction (financial perspective) and expansion of the market share (customer perspective). Non-financial performance includes improvement of product and service quality (internal business perspective) and skill improvement of both the young and the old workers (learning and growth perspective). This study provides practical implications to domestic companies for their successful management of generational diversity in workplace.

• Journal of Digital Convergence
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• v.19 no.6
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• pp.285-292
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• 2021

Due to the recent Corona 19 outbreak, camping culture is rapidly drawing attention from many people. Convective heating devices, which many campers use during winter, have the temperature stratification problem. To solve this problem, various power circulators are being used. Several non-powered circulators are also on sale, but the direction of the circulator is designed to be at the right angle relative to the convection heating mechanism and the circulator does not properly play the role of air circulation. To solve this problem, a 3D printer is used to design a non-powered circulator in the same direction as the convection heating mechanism. Electricity is generated without power using Peltier element and ceramic paper and the circulator is produced to withstand heat using HTPLA-CF filament. This study presents a method to solve the temperature stratification problem through efficient convective circulation. In addition, the purpose of this study is to manufacture products at a lower cost by using a 3D printer.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.1
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• pp.58-65
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• 2021

In this study, as a method to increase the recycling of circulating fluidized bed combustion ash(CFBCA), CFBCA was utilized to produce autoclave aerated concrete product since CFBCA contains quicklime and calcium sulfate components that are required for the manufacture of autoclave aerated concrete. Successful achievement of such objective will bring cost reduction with high value addition, saving of natural resources, and the reduction of environmental load. Various mixing designs were designed to evaluate the properties of autoclave aerated concrete made of CFBCA. Based on series of experimental program, prototypes mix design for factory manufacturing was obtained. According to the experimental results, it was confirmed that gypsum can be replaced with CFBCA through the method of pre-treating the CFBCA as a slurry. It was possible to produce competitive autoclave aerated concrete products using CFBCA.

• Journal of Food Hygiene and Safety
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• v.38 no.5
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• pp.338-346
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• 2023

The demand for probiotic products has been steadily increasing, and Lactobacillus strains are widely used and are currently the most popular probiotics. Optimizing culture conditions for Lactobacillus production for use as probiotics will enhance their profitability by reducing production costs and time. Statistical analysis using response surface methodology revealed the following optimal sets of independent variables: 22.55 h (cultivation time), 25℃ (cultivation temperature), and 3.41% (w/w, prebiotics concentration) for Lactobacillus acidophilus; 24 h, 30.86℃, and 2% (w/w) for Lactiplantibacillus plantarum; 66.67 h, 35℃, and 3.41% (w/w) for Lacticaseibacillus rhamnosus. Actual outcomes using predicted optimal conditions for Lactobacillus strains have been confirmed to closely match predicted results. This study will provide valuable guidelines for high yield Lactobacillus production.

• Journal of Distribution Research
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• v.6 no.2
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• pp.1-17
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• 2002

The recent dot-com craze has been one of the main causes that accelerated the growth of internet-related companies in diversity as well as in size. Meanwhile, the domestic market of supplies and equipment for internet businesses has been dominated by major foreign companies. To regain their market positions, the domestic manufacturers had to find the way to build up their competitive advantages, such as meeting their customers needs and reducing overall costs. In this study, one domestic PC server manufacturer, which competes fiercely with foreign manufacturers for the top place, has been chosen as a model to evaluate its current supply chain and to find an area that can be improved for a better performance. System Dynamics is used throughout the study. The central concept to system dynamics is understanding how all the objects in a system interact with one another. It focuses on feedback and secondary effects to think through how a strategy might or might not work, depending on how organizational changes are received, and what kinds of consequences emerge. Then, computerized models were built for simulations, each with different conditions, and, finally, the results were evaluated based on some criteria which are considered to be important and meaningful. The inefficiency that exists in the supply chain was proved to be a thirty-day long purchasing order leadtime, and it was expected that more effective supply chain could be formed if the leadtme were reduced to 14 days or 7 days. The results of simulations showed that the overall expected costs in supply chain was the least with the purchasing leadtime being 7 days. The lower average number of parts held as inventory, along with the reduced lost sales, acted as the factor reducing the expected overall costs. Although there was a slight increase in the average number of final products held as inventory and the total ordering cost, the benefits from lower parts inventory and reduced lost sales were large enough to justify the overall cost reduction.