• 제목/요약/키워드: Diffusion of Issues

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Forecasting the consumption of dairy products in Korea using growth models

  • Jaesung, Cho;Jae Bong, Chang
    • 농업과학연구
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    • 제48권4호
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    • pp.987-1001
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    • 2021
  • One of the most critical issues in the dairy industry, alongside the low birth rate and the aging population, is the decrease in demand for milk. In this study, the consumption trends of 12 major dairy products distributed in Korea were predicted using a logistic model, the Gompertz model, and the Bass diffusion model, which are representative S-shaped growth models. The 12 dairy products are fermented milk (liquid type, cream type), butter, milk powder (modified, whole, skim), liquid milk (market, flavored), condensed milk, cheese (natural, processed), and cream. As a result of the analysis, the growth potential of butter, condensed milk, natural cheese, processed cheese, and cream consumption among the 12 dairy products is relatively high, whereas the growth of the remaining dairy product consumption is expected to stagnate or decrease. However, butter and cream are by-products of the skim milk powder manufacturing process. Therefore, even if the consumption of butter and cream grows, it is difficult to increase the demand of domestic milk unless the production of skim milk powder produced from domestic milk is also increased. Therefore, in order to support the domestic dairy industry, policy support should be focused on increasing domestic milk usage for the production of condensed milk, natural cheese, and processed cheese.

Multi-path Routing Protocol with Optimum Routes Finding Scheme in Wireless Sensor Networks

  • Keuma, Tae-Hoon;Bu, Ki-Dong;Kim, Hyun-Sung;Lee, Sung-Woon
    • 한국산업정보학회:학술대회논문집
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    • 한국산업정보학회 2008년도 추계 공동 국제학술대회
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    • pp.449-454
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    • 2008
  • Finding an energy efficient route is one of the very important issues in the wireless sensor networks. The route scheme should consider both of the energy level of sensor nodes and the number of hops at the same time. First of all, this paper proposes an optimum routes finding scheme (ORFS), which could be used in the sensor network routing protocols. The scheme uses an optimum value for the path with the considerations of both the minimum energy level of a path and the number of hops at the same time. After that, this paper proposes a routing protocol based on the ORFS for how it could be used for the multipath directed diffusion with data aggregation (MDD-A), to get the better energy efficiency. The analysis result shows that the proposed routing protocol could lengthen the network life cycle about 18.7% compared to the previous MDD-A related protocols.

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마이크로파가 인가된 화염에서의 화염안정성 및 오염물질 배출특성 (Characteristics of the Microwave Induced Flames on the Stability and Pollutant Emissions)

  • 전영훈;이의주
    • 한국안전학회지
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    • 제29권4호
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    • pp.23-27
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    • 2014
  • The use of electromagnetic energy and non-equilibrium plasma for enhancing ignition and combustion stability is receiving increased attention recently. The conventional technologies have adapted the electrical devices to make the electromagnetic field, which resulted in various safety issues such as high-maintenance, additional high-cost system, electric shock and explosion. Therefore, an electrodeless microwave technology has an advantage for economic and reliability compared with conventional one because of no oxidation. However, the application of microwave has been still limited because of lack of interaction mechanism between flame and microwave. In this study, an experiment was performed with jet diffusion flames induced by microwaves to clarify the effect of microwave on the combustion stability and pollutant emissions. The results show that microwave induced flames enhanced the flame stability and blowout limit because of abundance of radical pool. However, NOx emission was increased monotonically with microwave intensity except 0.2 kW, and soot emission was reduced at the post flame region.

CALS의 추진현황 및 발전방안에 관한 연구 (A Study on the Advancing Status and Suggestions for the Development of CALS)

  • 신호균;강해중
    • 한국정보시스템학회지:정보시스템연구
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    • 제9권1호
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    • pp.61-86
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    • 2000
  • CALS(Commerce At Light Speed) which originated in the early 1980's in the military sector is now an integral component in our global strategy to further heighten competitiveness. Through integration and streamlining of production, distribution, technical information and management, CALS will certainly lead the world out of these economically challenging times and into new global prosperity. However, not much effort have been focused on the development and diffusion issues of component technologies such as ERP/SCM(Enterprise Resourses Planning/supply Chain Management), PDM(Product Data Management), and BPR(Business Process Reengineering) related with the CALS in electronic industry. Therefore, the purpose of this study is to analyze the advancing status and to present suggestions for the development of the CALS in electronic industry. In order to achieve the purpose, the case study has been conducted using the questionaries on the end-users and the interviews on the managers in the CALS area. The case study cover 57 users of the CALS for the three outstanding electronics(L, S, and D Electronics) in Korea. The questionaries include five success measures and eleven diffusion factors for the component technologies such as ERP/SCM, PDM, and BPR. In summary, the CALS will serve as the bases for exciting corporated innovations and the common business framework which facilitates the realization of Virtual Enterprise and Electronic Commerce in the 21st century.

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해안인접지역 기초 구조물콘크리트의 내염해 성능 평가 -건축구조기준과의 성능비교- (An Evaluation on the Chloride Resistance of Concrete Footing at Coastal Area -Comparision of Performance in Korea Building Code(KBC)-)

  • 박용규;윤기원;김현우;김용로;송영찬
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2016년도 추계 학술논문 발표대회
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    • pp.148-149
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    • 2016
  • In this paper, the increase in chloride resistance of footing concrete at coastal area was evaluated by replacement of Mineral Admixture. In KBC 2009, the footing concrete's minimum specific concrete strength at coastal area is determined to 35MPa. However, this is criteria only based on the strength aspect. Thus, it is not considered to increase the chloride resistance by replacement of Mineral Admixture. According to the test results of chloride ions penetration resistance, 35MPa class concrete with OPC 100% shown inaccessible state. Low-strength (24~30MPa class) concretes with Mineral Admixture, however, presented better performances. In addition, chloride diffusion coefficient tests showed identical appearance. Therefore, the current KBC's chloride resistance criteria based on only concrete strength has to review for the reason it can cause many problems (ex. cost increases by growing concrete strength and the environmental issues by a lot of cement use).

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Predicting Health Communication Patterns in Follower-Influencer Networks: The Case of Taiwan Amid COVID-19

  • Chang, Angela;Jiao, Wen
    • Asian Journal for Public Opinion Research
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    • 제8권3호
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    • pp.246-264
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    • 2020
  • As netizens increasingly utilize social media to obtain and engage with information, this study aims to determine the extent to which the follower-influencer interaction is manifested and strengthened. To analyze information related to the novel coronavirus disease (COVID-19), a total of 62,119 online posts from 11 Internet forums were examined to find a relationship between followers and influencers in Taiwan. These forums are PTT, SOGO, Ck101, Plurk, Mobile01, TalkFetnet, Gamez, PlaySport, Dcard, Eyny, and PCDVD. The variables that were the best predictors of influencer classification were strong influences, engagements, and hot values across 11 Internet forums. Learning the response to the COVID-19 pandemic is vital because public actions could have been fueled by stigmatizing terms that may harm public health and well-being. The results questioned the conventional diffusion of traditional news sources because the influencers brought widespread attention to the health threat issues in the early outbreak stages. This study enhances the understanding of forum types, follower engagement, and influencers' impact maximization in social networks. The conclusion provides insight into the relationships and information diffusion mechanisms to ensure accurate health information dissemination.

HC저감용 최적 연료분사 시스템에 관한 연구 (A Study on the Fuel Injection System for Optimizing Reduction of HC Emission)

  • 이기형;이창식
    • 한국자동차공학회논문집
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    • 제3권2호
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    • pp.146-156
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    • 1995
  • Growing international concern about environmental issues in recent years has led to new proposals for strengthening exhaust emission standards and fuel economy requirements throughout the world. The low emission vehicle(LEV) standards drawn up by the California Air Resources Board(CARB) in the U.S.A are noticeably stringent To cope with this regulation, a reduction of HC emission is the most important challenge for the automotive industry because HC emission levels are severer than any other components emission levels. In this paper, the apparatus for visulalizing the wall film flow in a intake manifold and the spark plug with optical fiber for detecting the signal from diffusion flame are developed to mal,e the HC formation mechanism clear. High speed camera system is also used to elucidate the correlation wall film flow and the diffusion flame. Using these methods, the effect of fuel injection systems such as injection direction, spray angle, atomised injection on HC emission levels is investigated. Consequently, the optimal fuel injection conditions for minimizing the wall film flow and reducing the HC emission are found through this research.

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기체확산층의 미세다공층 침투 깊이에 따른 고분자 전해질형 연료전지의 내구성능 저하 분석에 관한 연구 (Study on the Durability Characteristics of the PEM Fuel Cells having Gas Diffusion Layer with Different Micro Porous Layer Penetration Thicknesses)

  • 박재만;오환영;조준현;민경덕;이은숙;정지영
    • 한국수소및신에너지학회논문집
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    • 제24권3호
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    • pp.216-222
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    • 2013
  • Durability characteristics of Gas Diffusion Layer(GDL) is one of the important issues for accomplishing commercialization of Proton Exchange Membrane Fuel Cell(PEMFC). It is strongly related to the performances of PEMFC because one of the main functions of GDL is to work as a path of fuel, air and water. When the GDL does not work on their proposed functions due to the degradation of durability, mass transfer in PEMFC is disturbed and it might cause the flooding phenomenon. Thus, investigating the durability of GDL is important and understanding the GDL degradation process is needed. In this study, electrochemical degradation with carbon corrosion is introduced. The carbon corrosion experiment is carried out with GDLs which have different MPL penetration thicknesses. After the experiment, the amount of degradation of GDL is measured with various properties of GDL such as weight, thickness and performance of the PEMFC. The degraded GDL shows loss of their properties.

아연-이온 배터리의 에너지 저장 성능 향상을 위한 망간산화물이 코팅된 흑연시트의 제조 (Synthesis of Manganese Oxide Coated Graphite Sheet for Zinc-Ion Batteries with Improved Energy Storage Performance)

  • 이영근;안건형
    • 한국재료학회지
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    • 제31권2호
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    • pp.68-74
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    • 2021
  • Zinc-ion Batteris (ZIBs) are recently being considered as energy storage devices due to their high specific capacity and high safety, and the abundance of zinc sources. Especially, ZIBs can overcome the drawbacks of conventional lithium ion batteris (LIBs), such as cost and safety issues. However, in spite of their advantages, the cathode materials under development are required to improve performance of ZIBs, because the capacity and cycling stability of ZIBs are mainly influenced by the cathode materials. To design optimized cathode materials for high performance ZIBs, a novel manganese oxide (MnO2) coated graphite sheet is suggested herein with improved zinc-ion diffusion capability thanks to the uniformly decorated MnO2 on the graphite sheet surface. Especially, to optimize MnO2 on the graphite sheet surface, amounts of percursors are regulated. The optimized MnO2 coated graphite sheet shows a superior zinc-ion diffusion ability and good electrochemical performance, including high specific capacity of 330.8 mAh g-1 at current density of 0.1 A g-1, high-rate performance with 109.4 mAh g-1 at a current density of 2.0 A g-1, and remarkable cycling stability (82.2 % after 200 cycles at a current density of 1.0 A g-1). The excellent electrochemical performance is due to the uniformly decorated MnO2 on the graphite sheet surface, which leads to excellent zinc-ion diffusion ability. Thus, our study can provide a promising strategy for high performance next-generation ZIBs in the near future.

첨단 반도체 패키징을 위한 미세 피치 Cu Pillar Bump 연구 동향 (Recent Advances in Fine Pitch Cu Pillar Bumps for Advanced Semiconductor Packaging)

  • 노은채;이효원;윤정원
    • 마이크로전자및패키징학회지
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    • 제30권3호
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    • pp.1-10
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    • 2023
  • 최근, 고사양 컴퓨터, 모바일 제품의 수요가 증가하면서 반도체 패키지의 고집적화, 고밀도화가 요구된다. 따라서 많은 양의 데이터를 한 번에 전송하기 위해 범프 크기 및 피치 (Pitch)를 줄이고 I/O 밀도를 증가시킬 수 있는 플립 칩 (flip-chip), 구리 필러 (Cu pillar)와 같은 마이크로 범프 (Micro-bump)가 사용된다. 하지만 범프의 직경이 70 ㎛ 이하일 경우 솔더 (Solder) 내 금속간화합물 (Intermetallic compound, IMC)이 차지하는 부피 분율의 급격한 증가로 인해 취성이 증가하고, 전기적 특성이 감소하여 접합부 신뢰성을 악화시킨다. 따라서 이러한 점을 개선하기 위해 UBM (Under Bump Metallization) 또는 Cu pillar와 솔더 캡 사이에 diffusion barrier 역할을 하는 층을 삽입시키기도 한다. 본 review 논문에서는 추가적인 층 삽입을 통해 마이크로 범프의 과도한 IMC의 성장을 억제하여 접합부 특성을 향상시키기 위한 다양한 연구를 비교 분석하였다.