• Title/Summary/Keyword: Technical aspect

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Study of Morphology and Physical Properties of Indian Mallow(Abutilon avicennae Gaertner) Fibers by Image Analyzer (화상분석기를 이용한 어저귀 섬유의 형태학적 특성과 물성연구)

  • 정선화;조남석
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.35 no.4
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    • pp.17-22
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    • 2003
  • A kind of image analysis system is used to investigate the structural features of the papers made from Indian mallow. The screen mark on the paper was identified and analyzed. The dusts, shives and fiber bundles were manifested and calculated. In the aspect of Indian mallow hanji's surface characteristics analyzed by an Image analyzer, the average of gray level and its standard deviation hanji from the woody core were rather lower than of bast fiber pulp because of better sheet formation of the formers. Hower. high brightness hanji showed high value of gray level. The sheet formation and paper opacity were increased with the decrease of standard deviation of gray level. From these results, gray level measurement could be used to predict the paper opacity as well as sheet formation.

Physical Properties of Paper Depending on Two-Step Refining (2단고해에 의한 종이의 물성 변화)

  • 장현성;박종문
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.36 no.2
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    • pp.1-9
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    • 2004
  • Structure and strengths of paper have been studied by analyzing fibers characteristics depending on refining methods. In those studies stock preparation aspect of softwood and hardwood fibers mixing and fibers characteristics was focused for paper quality improvement. In this study drainage of fibers were analyzed to improve the production efficiency and paper product's quality. Fiber properties by one and two-step refining processes were compared. By applying two-step refining processes($2.8kg_f$ and $5.6kg_f$ of refining load), refining efficiency, drainage, and strengths could be improved at specific extent of refining.

Dynamic behaviour of orthotropic elliptic paraboloid shells with openings

  • Darilmaz, Kutlu
    • Structural Engineering and Mechanics
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    • v.63 no.2
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    • pp.225-235
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    • 2017
  • In this paper a vibration study on orthotropic elliptic paraboloid shells with openings is carried out by using a hybrid stress finite element. The formulation of the element is based on Hellinger-Reissner variational principle. The element is developed by combining a hybrid plane stress element and a hybrid plate element. Natural frequencies of orthotropic elliptic paraboloid shells with and without openings are presented. The influence of aspect ratio, height ratio, opening ratio and material angle on the frequencies and mode shapes are investigated.

Frequency optimization for laminated composite plates using extended layerwise approach

  • Topal, Umut
    • Steel and Composite Structures
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    • v.12 no.6
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    • pp.541-548
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    • 2012
  • This paper deals with the applicability of extended layerwise optimization method (ELOM) for frequency optimization of laminated composite plates. The design objective is the maximization of the fundamental frequency of the laminated plates. The fibre orientations in the layers are considered as design variables. The first order shear deformation theory (FSDT) is used for the finite element solution of the laminates. Finally, the numerical analysis is carried out to show the applicability of extended layerwise optimization algorithm of laminated plates for different parameters such as plate aspect ratios and boundary conditions.

The World Wind Energy Conference in Berlin (1) (베를린 제1회 세계풍력회의를 다녀와서(1))

  • 기우봉
    • Journal of the Korean Professional Engineers Association
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    • v.35 no.4
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    • pp.52-55
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    • 2002
  • The development of environment-friendly Energy Resources (New Renewable Energy Resources) is one of the global topics these days, considering CO2 Reduction Agreement by Kyoto Protect and the limit of Conventional Energy Resources in near future. Among the New Renewable Energy, Wind Energy is the most feasible Renewable Energy in view of economical and technical aspect at this moment. Last 10 years the Wind Energy Development was really dramatical in Europe. especially in Germany, Denmark and Spain. In this circumstance World Wind Energy Conference was held in Berlin Germany, in order to review the present status and future development of the Wind Energy. This report is a brief report of the Conference .

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Vibration analysis of functionally graded material (FGM) grid systems

  • Darilmaz, Kutlu
    • Steel and Composite Structures
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    • v.18 no.2
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    • pp.395-408
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    • 2015
  • The paper considers the free vibration analysis of FGM grid systems. Up to now, very little work has been done on this type of system and the paper aspires to fill this gap. Based on the hybrid-stress finite element formulation free vibration solutions for FGM grid systems of various aspect ratios, different types of gradations functions, and support conditions are determined. The tabulation of these results, not available thus far, should be useful to designers and researchers who may use them.

Applicability Comparison of Transmission Line Parameter Extraction Methods for Busbar Distribution Systems

  • Hasirci, Zeynep;Cavdar, Ismail Hakki;Ozturk, Mehmet
    • Journal of Electrical Engineering and Technology
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    • v.12 no.2
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    • pp.586-593
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    • 2017
  • Modeling busbar distribution system as a transmission line is an important subject of power line communication in the smart grid concept. This requires extraction of busbar RLGC parameters, accurately. In this study, a comparison is made between conventional and modified method for the aspect of optimum RLGC parameters extraction in the 1 MHz to 50 MHz frequency band. The usefulness of these methods is shown both in time and frequency-domain analysis. The frequency-domain analyzes show that the inherent power of modified method can eliminate the errors especially due to the discontinuities arise in conventional method. This makes the modeling approach of modified method more advantageous for the busbars due to its robustness against disturbances in the S-parameters measurements which cannot be eliminated with the calibration procedure. On the other hand, time-domain simulations show that the transmission line representation of the modified method is closer to physical reality by handling causality issues.

A Study on Quality-incorporating Models in Evaluation of Hospital Efficiency with Data Envelopment Analysis - An Analysis on National University Hospitals in Korea - (DEA에 의한 병원 효율성 평가에서 질적 측면 통합 모형에 관한 연구 - 국립대학교병원에 대한 분석을 중심으로 -)

  • Shin, Dong-Wook;Shin, Chong-Gak;Jung, Kee-Taig
    • Korea Journal of Hospital Management
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    • v.13 no.3
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    • pp.69-93
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    • 2008
  • Rising healthcare cost is a global phenomenon that justifies governments' introduction of 'incentive regulation' plan for the improvement of hospital efficiency. A number of previous studies tried to evaluate the efficiency of healthcare organization by using Data Envelopment Analysis(DEA), a common efficiency benchmarking method. However, there is a concern that this kind of efficiency evaluation could induce "quantity-quality trade-off". Moreover, as quality aspect is especially important in terms of 'effectiveness' of health care, it should be considered in efficiency evaluation of healthcare organization. A number of different models were tried so far to incorporate quality aspect into DEA, however, none is universally recognized as a standard. Thus, in this study, previous quality-incorporating DEA models were categorized into 6 types according to the way of incorporating quality aspect, and strengths and limitations of each type were reviewed with a set of artificial data as an example. Based on this review, a new quality-incorporating efficiency evaluation model, named Quality-adjusted output DEA(QAO-DEA), was suggested. As an exploratory empirical analysis, technical efficiency of human resource were measured with different quality-incorporating DEA models, using 2004 data from National University Hospitals. In conclusion, Quality-adjusted output DEA(QAO-DEA) model seems to be one of the most desirable alternatives to incorporate quality aspect in efficiency evaluation of hospital, and deserves the consideration as a policy tool to induce simultaneous improvement of both efficiency and quality.

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A Study on the Cases of Fun Elements Designing and the Application to Furniture (Fun 요소의 디자인 사례와 가구 적용에 관한 연구)

  • Yoo, Do-Hyun;Yoon, Yeoh-Hang
    • Journal of the Korea Furniture Society
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    • v.20 no.2
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    • pp.105-114
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    • 2009
  • Recently, as living of people becomes economically liberal, people's interests are being directed to enjoying leisure and finding fun. The design area is not exceptional from this change and thus fun elements are working as important purchase factors when people are purchasing goods in addition to intrinsic uses of the goods. Along with the development of cutting-edge technologies, other manufacturing industries like electronics, automobiles etc are swiftly responding to this trend, but the furniture industry that has been perceived as a relatively low technical industry is not at all prepared for this trend. Here, this thesis is to suggest a direction for our furniture industry to go by proposing many potentials to apply fun elements to furniture through surveys of design cases addressing fun in other areas. The surveys made in this study are largely divided into the fun in the aspect of perception and the fun in the aspect of awareness. First, the fun in the aspect of perception of furniture can be experienced through the assembling of D. I. Y. furniture and this requires studies and efforts of developers in order to enable people to enjoy the processes of assembling as a sort of 'play' without feeling a burden in the processes of assembling. Second, the fun in the aspect of awareness of furniture can be created by boldly introducing new technologies and materials from other industrials and this includes adding other functions than the intrinsic use of furniture such as containing things.

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An Empirical Study on the Effect of Technical and Social Anonymity on the Self-control Behavior (온라인 커뮤니티에서 기술적, 사회적 익명성이 자기통제에 미치는 영향에 관한 연구)

  • Choi, Hee-Jai;Lee, Zoon-Ky;Kim, Jung-Won
    • Journal of Internet Computing and Services
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    • v.10 no.1
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    • pp.63-74
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    • 2009
  • There have been many previous studies about an effect of anonymity on self control behavior. However the previous studies are on the aspect of results such as the usefulness, the problems of cyber crime or a lack of trust by anonymity. This study identifies the accurate definition of the objective technical anonymity and subjective social anonymity. And it reveals the relationship among technical anonymity, social anonymity, community tie, and self control as an effect of anonymity. The result of survey shows that technical anonymity affects self control through social anonymity and the relationship between technical and social anonymity is affected by community tie. This study presents how the anonymity affects individual behaviors. So it can be used as a reference to the policy on anonymity of the internet.

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