• 제목/요약/키워드: useful components

검색결과 1,474건 처리시간 0.031초

업무지식의 획득 프레임워크 및 적용사례 (A Framework for the Acquisition of Task Knowledge and a Case)

  • 서우종;정재우
    • 지식경영연구
    • /
    • 제4권1호
    • /
    • pp.67-79
    • /
    • 2003
  • Today, corporate knowledge plays a critical role in obtaining competitive advantage. It is often pointed out that corporate knowledge is expected to be able to support various efforts for process innovation. Accordingly, it is important to establish a systematic infrastructure for the acquisition of knowledge which can support business-critical tasks effectively. From this motivation, this paper proposes a framework to guide a series of acquisition procedures for task knowledge and shows how to intemperate with activities for an innovation purpose. Moreover, the useful components of task knowledge are proposed; the schema of the components is ultimately implemented as a repository in a system for the management of task knowledge. To demonstrate the practical usefulness of the framework and the schema components, a real-life case is illustrated.

  • PDF

Surface Texturing에 의한 유압부품의 마찰저감 (Surface Texturing in Hydraulic Machine Components for Friction Reduction)

  • 박태조;김민규
    • 드라이브 ㆍ 컨트롤
    • /
    • 제13권1호
    • /
    • pp.27-33
    • /
    • 2016
  • In hydraulic machinery, the hydraulic fluid acts primarily as working fluid and secondarily as a lubricant. Hence, the viscous friction force acting on the sliding components should be reduced to improve the mechanical efficiency. It is now well known that the surface texturing is a useful method for friction reduction. In this study, using a commercial computational fluid dynamics (CFD) code, FLUENT, the lubrication characteristics of a surface textured slider bearing under high boundary pressure difference is studied. The streamlines, velocity profiles, pressure distributions, load capacity, friction force and leakage flowrate are highly affected by the film thickness ratio and the textured region. Partial texturing at the inlet region of the inclined slider bearing can reduce both friction force and leakage flowrate than in the untextured case. The present results can be used to improve the lubrication characteristics of hydraulic machinery.

Chemometric A spects of Sugar Profiles in Fruit Juices Using HPLC and GC

  • 윤정현;김건;이동선
    • Bulletin of the Korean Chemical Society
    • /
    • 제18권7호
    • /
    • pp.695-702
    • /
    • 1997
  • The objective of this work is to determine the sugar profiles in commercial fruit juices, and to obtain chemometric characteristics. Sugar compositions of fruit juices were determined by HPLC-RID and GC-FID via methoxymation and trimethylsilylation with BSTFA. The appearance of multiple peaks in GC analysis for carbohydrates was disadvantageous as described in earlier literatures. Fructose, glucose, and sucrose were major carbohydrates in most fruit juices. Glucose/fructose ratios obtained by GC were lower than those by HPLC. Orange juices are similar to pineapple juices in the sugar profiles. However, grape juices are characterized by its lower or no detectable sucrose content. In addition, it was also found that unsweeten juices contained considerable level of sucrose. Chemometric technique such as principal components analysis was applied to provide an overview of the distinguishability of fruit juices based on HPLC or GC data. Principal components plot showed that different fruit juices grouped into distinct cluster. Principal components analysis was very useful in fruit juices industry for many aspects such as pattern recognition, detection of adulterants, and quality evaluation.

모터팬 방진고무부품의 노화수명 예측 (Prediction of Useful Life by Heat Aging of Motor Fan Isolating Rubber)

  • 김완수;우창수;조상준;김완두
    • Elastomers and Composites
    • /
    • 제37권2호
    • /
    • pp.107-114
    • /
    • 2002
  • 청정실(Clean room)에 사용되는 환기팬용 모터의 방진고무부품의 수명을 예측하기 위해서 가속 열 노화 시험을 수행하였다. 방진고무부품은 EPDM으로 만들었다. 노화 수명을 판단하기 위한 한계점을 20%의 압축 영구 줄음률로 하여 절대 온도의 역수 값으로 아레니우스 선도를 유도하였다. 아레니우스 관계식으로부터 방진고무부품의 다양한 온도에서의 수명과 활성화에너지를 구하였다. 그리고 수명을 판단하는데 있어 상당한 시간을 대체할 수 있는 가속 시험법을 설계하였다. 또한 방진고무부품에 첨가되는 노화 방지제가 수명에 미치는 영향을 알아보았다.

High Spatial Resolution Optical Characterization of LCDs and their Components

  • Boher, P.;Bignon, T.;Leroux, Thierry
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 한국정보디스플레이학회 2008년도 International Meeting on Information Display
    • /
    • pp.859-862
    • /
    • 2008
  • We present a new tool to measure precisely the emissive properties of displays at the pixel level with submicrometric spatial resolution. It is useful to check the technological defects and their impact on the emissive properties of the displays. Backlight films and transflective and reflective displays are measured.

  • PDF

JACOBIAN VARIETIES OF HYPERELLIPTIC CURVES OVER FINITE FIELDS WITH THE FORMAL STRUCTURE OF THE MIXED TYPE

  • Sohn, Gyoyong
    • East Asian mathematical journal
    • /
    • 제37권5호
    • /
    • pp.585-590
    • /
    • 2021
  • This paper consider the Jacobian variety of a hyperelliptic curve over a finite field with the formal structure of the mixed type. We present the Newton polygon of the characteristic polynomial of the Frobenius endomorphism of the Jacobian variety. It gives an useful tool for finding the local decomposition of the Jacobian variety into isotypic components.

JACOBIAN VARIETIES OF HYPERELLIPTIC CURVES WITH MIXED SYMMETRIC FORMAL TYPE

  • Sohn, Gyoyong
    • East Asian mathematical journal
    • /
    • 제38권5호
    • /
    • pp.611-616
    • /
    • 2022
  • This paper considers the Jacobian variety of a hyperelliptic curve over a finite field with mixed symmetric formal type. We present the Newton polygon of the characteristic polynomial of the Frobenius endomorphism of the Jacobian variety. It gives a useful tool for finding the local decomposition of the Jacobian variety into isotypic components.

Exploring Students Competencies to be Creative Problem Solvers With Computational Thinking Practices

  • Park, Young-Shin;Park, Miso
    • 한국지구과학회지
    • /
    • 제39권4호
    • /
    • pp.388-400
    • /
    • 2018
  • The purpose of this study was to explore the nine components of computational thinking (CT) practices and their operational definitions from the view of science education and to develop a CT practice framework that is going to be used as a planning and assessing tool for CT practice, as it is required for students to equip with in order to become creative problem solvers in $21^{st}$ century. We employed this framework into the earlier developed STEAM programs to see how it was valid and reliable. We first reviewed theoretical articles about CT from computer science and technology education field. We then proposed 9 components of CT as defined in technology education but modified operational definitions in each component from the perspective of science education. This preliminary CTPF (computational thinking practice framework) from the viewpoint of science education consisting of 9 components including data collection, data analysis, data representation, decomposing, abstraction, algorithm and procedures, automation, simulation, and parallelization. We discussed each component with operational definition to check if those components were useful in and applicable for science programs. We employed this CTPF into two different topics of STEAM programs to see if those components were observable with operational definitions. The profile of CT components within the selected STEAM programs for this study showed one sequential spectrum covering from data collection to simulation as the grade level went higher. The first three data related CT components were dominating at elementary level, all components of CT except parallelization were found at middle school level, and finally more frequencies in every component of CT except parallelization were also found at high school level than middle school level. On the basis of the result of CT usage in STEAM programs, we included 'generalization' in CTPF of science education instead of 'parallelization' which was not found. The implication about teacher education was made based on the CTPF in terms of science education.

A Review on Studies of Marijuana for Alzheimer's Disease - Focusing on CBD, THC

  • Kim, Seok Hee;Yang, Jin Won;Kim, Kyung Han;Kim, Jong Uk;Yook, Tae Han
    • 대한약침학회지
    • /
    • 제22권4호
    • /
    • pp.225-230
    • /
    • 2019
  • Objectives: This study was to discuss the research trend of dementia treatment using cannabis for the purpose of providing the basis of cannabis use for medical purposes in the future. Methods: This study searched publications, which were registered to databases or published by Aug 22, 2019, and targeted the full-text or abstracts of these publications. We selected the final nine studies met all selection criteria. Results: These results implied that the CBD components of cannabis might be useful to treat and prevent AD because CBD components could suppress the main causal factors of AD. Moreover, it was suggested that using CBD and THC together could be more useful than using CBD or THC alone. Conclusion: We hope that there will be a solid foundation to use cannabis for medical use by continuously evaluating the possibility of using cannabis for clinical purposes as a dementia treatment substance and cannabis can be used as a positive tool.

표면복제기법을 이용한 고온 설비의 수명평가 현황과 적용사례 (State of the Art in Life Assessment for High Temperature Components Using Replication Method)

  • 김덕희;최현선
    • 비파괴검사학회지
    • /
    • 제30권5호
    • /
    • pp.489-496
    • /
    • 2010
  • 발전 및 화학플랜트의 많은 고온 설비는 장시간 운전으로 인해 재질열화 현상이 필연적으로 발생된다. 이러한 고온설비의 건전성 확보와 신뢰성 있는 수명평가를 위해서는 비파괴평가기법인 표면복제시험을 통한 미세조직분석 평가법이 현재까지 유용한 것으로 인식되어왔다. 이러한 표변복제기법은 기존의 평가법과 함께 탄화물평가를 통한 재질열화도 평가 등 새로운 정량적 접근법이 필요하며 다양하게 시도되고 있다. 본 논문에서는 표면복제기법과 관련한 기술개발 현황과 현장 적용사례들을 소개하고, 합리적인 평가결과 여부에 대해 기술하였으며, 현장설비에 대해 표면복제시험 후 미세조직을 분석한 결과 탄화물 평가방법이 정량적으로 유용함을 입증하였다.