• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.3
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• pp.185-194
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• 2022

Coffee is one of the most consumed beverages in the world and is the second largest traded commodity after petroleum. Due to the great demand of this product, large amounts of waste is generated in the coffee industry, which are toxic and represent serious environmental problems. This study aims to study the possibility of recycling spent coffee grounds (SCG) as a mineral admixture by replacing the cement in the manufacturing of concrete. To recycle the coffee g rounds, the SCG was dried to remove moisture and fired in a kiln at 850 ℃ for 8 hours. Carbonized coffee grounds are produced as coffee grounds ash (CGA) through ball mill grinding. The chemical composition of the prepared coffee grounds ash was investigated using X-ray fluorescence (XFR). According to the chemical composition analysis, the major elements of coffee grounds ash are K₂O(51.74 %), CaO(15.92 %), P₂O₅(14.39 %), MgO(7.74 %) and SO₃(6.89 %), with small amounts of F₂O₃(0.66 %), SiO₂(0.59 %) and Al₂O₃(0.31 %) content. To evaluate quality and mechanical properties, substitutions of 5, 10, and 15 wt.% of coffee grounds ash (CGA) were tested. From the quality test results, the 28-day activity index of CGA5 reached 80 %, and the flow value ratio reached 96 %, which is comparable to the minimum requirement for second-grade FA. From the test results of the mortar, the optimal results have been found in specimens with 5 wt-% coffee grounds ash, showing good mechanical and physical properties.

• Journal of the Korean Recycled Construction Resources Institute
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• v.12 no.3
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• pp.281-289
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• 2024

In this study, CO₂-immobilized desulfurized gypsum(CFDG) was applied to ground granulated blast furnace slag to examine the basic properties of mortar and concrete, and to evaluate its responsiveness through field demonstration test. CFDG had a relatively circular composition compared to desulfurized gypsum(DG), and its main components were CaO 47.6 % and SO₃ 22.1 %. As a result of mortar and concrete tests, the flow tended to increase and the compressive strength was at the same level. In addition, the target properties of concrete for application to farm roads, which were a slump of 120±25 mm and a compressive strength of 24 MPa, were satisfied with a slump of 135 mm and a compressive strength of 42.1 MPa at 28 days. In February 2024, an on-site demonstration of a farm road was conducted in Seongmun-myeon, Dangjin-si, and as a result of reviewing the compressive strength according to curing conditions, the physical properties and durability of unhardened concrete, the target results were satisfied, expanding the use of CFDG by applying fine powder of blast furnace slag and carbon reduction can be expected.

• Journal of the Korean Recycled Construction Resources Institute
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• v.12 no.3
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• pp.306-313
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• 2024

In this study, the status of fuel substitution in Korea cement industry and the chloride contents of cement products were investigated to consider the revision of KS F 4009. The annual average chloride contents of cement products were 130~485 ppm, and the chloride in cement products was calculated to be 1,033 ppm with increasing the use of waste plastic. As a result from the increase of chloride in cement, the chloride contents in concrete will exceed 0.3 kg/m³, if more than 250 kg/m³ of cement is used. In many countries, the limit of chloride in concrete is decided by the environment where concrete is used and the quantity of cement used in concrete. Considering the inevitable increase in the chloride in cement and concrete due to the increased use of waste plastic and the trends in overseas standards for chloride of concrete, it is thought that the revision of KS F 4009 should be reviewed.

• Journal of Technology Innovation
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• v.17 no.1
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• pp.119-148
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• 2009

The paper presents and empirically tests a model of the digital contents(DC) innovation systems that enables us to study interactions between users, service providers, contents developers and network providers, and to examine the relationship between manufacturing innovation and service innovation as well as patterns of innovation in the DC industry. The framework of Gallouj and Weinstein(1997) and Gallouj(2002) is modified into the DC innovation model according to characteristics of the DC industry, that is, user involvement and network externalities. The model is applied to a case analysis that traces the growth of the online game industry in Korea since its introduction. The model offers several advantages over other approaches in understanding the dynamics in the DC industry. Most importantly, it provides a single unified basis within which both service innovation resulting from users and service providers and manufacturing innovation induced by contents developers, platform holders and network providers are analyzed. The distinction between service and manufacturing innovation is important in many ways, for instance in selecting proper government policy tools for promotion or regulation of the DC industry. Second, the Korean online game industry has experienced both radical innovation during the beginning period and non-radical innovation throughout the maturation period. The model developed herein helps to illustrate several types of non-radical innovations such as recombinative innovation that are crucial to sustainable development of the DC industry. Third, the model clarifies impacts of network externalities that are characteristics of the DC industry.

• Cartoon and Animation Studies
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• s.39
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• pp.27-58
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• 2015

The crisis in profit and funding for animation is in evidence around the world. The change in media environment has forced broadcasting advertising revenue down and animation viewers spread out. Now, animation players in the strongest position are either the US major studios, or producers benefiting from domestic support schemes. Government support is available in many countries because many governments believe that support for domestic animation carries both economic and cultural benefits. This paper is designed to suggest new policy schemes for Korean animation industry. The new paradigm of animation policy needs a new perspective on content industry as a whole, not centered on the animation itself. The researchers on public policy for culture, audiovisual and content industry argued that the government should, (i) play the role of facilitator for virtuous cycle of industry value chain, (ii) provide fiscal support through automatic and selective schemes, (iii) provide tax benefit to strengthen the competitiveness of industry, and (iv) enforce the broadcasters to contribute to domestic programming and financing. Comparative analysis on French and Canadian audiovisual policy supports such arguments, and animation industry of two countries are enjoying the high audience ratings and sustainable production volume. From the analysis, this paper suggests the new government schemes for Korean animation industry, which are, (i) securing the public funding for fiscal support, (ii) introduction of automatic production support, (iii) modification of broadcasting quota, (iv) broadcaster's performance envelope and production quota, and (v) tax benefit as indirect support.

• Proceedings of the Technology Innovation Conference
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• 2009.02a
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• pp.355-389
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• 2009

절충교역은 국방과학기술의 다양한 획득방법 중의 하나로써 국외로부터 무기체계를 구매할 경우 반대급부로 핵심기술, 방산물자 및 부품 수출 등을 획득하는 국제무역거래의 한 특수형태이다. 우리나라는 방위산업의 발전과 국방과학기술력 향상을 위해 1983년부터 절충교역을 추진하여 오고 있다. 절충교역은 일반적인 상업 무역거래와는 달리 절충교역 추진국가가 기술 수혜국으로서 소기의 목적을 달성하여 성공적인 기술이전을 완수하기 위해서는 절충교역 추진과장상의 운영의 묘미가 절실히 요구된다. 따라서 우리나라는 그동안 절충교역 추진 효율성을 강화하고 실패사례를 줄이기 위해 절충교역 추진 목적과 정책을 전략적으로 개선하여 절차화 표준화해오고 있다. 최근 방위사업청 개청 이후 절충교역 추진 정책의 방향을 목표지향 성과지향적으로 설정하고 다시 한번 제도를 개선하여 적용하고 있으나 아직까지 정책적 방향성에 부합하는 실무적 절충교역 추진 모델은 미흡하여 여전히 개선의 여지가 존재한다. 따라서 본 연구에서는 절충교역 제도의 완성도를 높여 우리나라의 국방과학기술력 향상과 방위산업 육성을 위해 필요한 기술을 최대한 확보할 수 있도록 하는 선순환 구조의 한국형 절충교역 추진 모델을 개발 제안한다. 제안하는 한국형 절충교역 추진 모델은 현행 제도에 대한 심층적인 분석을 통해 도출된 개선 필요사항을 보완할 수 있도록 전체 절충교역 추진절차를 식별(Detecting), 확보(Securing), 이전(Transfer), 활용(Applying), 확산(Diffusion)이라는 다섯 단계로 나누고 각 단계의 성공적인 목적 달성을 위한 제도적 개선 방안을 제시한다.

• Journal of the Korea Computer Industry Society
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• v.2 no.6
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• pp.791-802
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• 2001

In this paper, DARC(Data Radio Channel) error correction decoder for the U Subcarrier Broadcasting System is designed of using (272,190)$\times$(272,190) product code based on (272,190) shortened difference set cyclic code. This decoder has error flag of column and row direction that can store the result of the error correction of column and row direction in the block and frame structure, is designed to be of no benefit the output with majority logic determination to cancel the corrected and determined bit, and can improve by using the error correction method that no error correction of the row direction is performed, if error correction of the column direction is completely performed by error flag.

• Journal of Wetlands Research
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• v.14 no.4
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• pp.675-685
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• 2012

The purpose of this study was to propose a measure for eco-cultural regeneration by a detailed examination of closed down schools, old defective residences, deteriorated industrial facilities and space no long in use located throughout Ijak-do. The reserch method utilized a selection of the major elements from the eco-cultural regeneration element of island regions and a measure for application and regeneration on the deteriorated facilities of Ijak-do was proposed.

• Journal of Industrial Technology
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• v.25 no.A
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• pp.191-201
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• 2005

A numerical analysis was done for a tunnel fire in a 1000m road tunnel. A cartesian coordinate was adopted to make a computational grid sytem which has 448,000 computational cells. A transient flow phenomena in the tunnel was simulated by the commercial code of PHEONICS from the ignition of fire to 600 seconds by the interval of 100 seconds. Total computational time of about 44 hours was required to get a convered solution in each time step. The purpose of this research is to analyze of the backlayering pheonomena and recirculation flow in a tunnel. The compuational results say that the backlayering does not happens near the fire of vehicle in this case because the vehicle fire is located at the outside of recirculation zone of flow ocuured near the jet fan. In this research, onset of backlayering pheonomena could be escaped if jet fan is set 95m in front of the the fire of vehicle.

• Journal of Korea Society of Industrial Information Systems
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• v.4 no.2
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• pp.73-80
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• 1999

A major concern in Concurrent Engineering is the control and management of workload As a general rule, leveling the peak of workload in a period is difficult because concurrent processing is comprised of various processed, including overlapping, paralleling and looping and so on. Therefore workload management with resource constraints is so beneficial that effective methods to analyze design process are momentous. This paper presents a procedure to transform the IDEF3 process model into the precedence network model for more useful assessment of the process. This procedure is expected to facilitate resolving resource constrained scheduling problems more systematically in Concurrent Engineering environment.