• Title/Summary/Keyword: Structural Efficiency

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Shaking Table Test of a Stainless Water Tank with Natural Rubber Bearing (천연고무받침이 설치된 스테인리스 물탱크의 진동대 실험)

  • Kim, Hu-Seung;Oh, Ju;Jung, Hie-Young
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.4
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    • pp.52-58
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    • 2016
  • Recently, interest in structural stability has increased due to earthquakes. Isolation systems can improve seismic ability without harming the functions and appearance of existing and new constructions, and they have established efficiency in foreign country that have experienced earthquakes. In this study, an isolation system is suggested using a natural rubber bearing (NRB) on a stainless water tank for stability assurance in an earthquake. A shaking table test was carried out to evaluate the seismic capacity of a non-isolated water tank and an isolated tank. Displacement meters in the water tank measured the behavior characteristics of the tanks, which were compared using artificial seismic waves of 0.154 g, 0.231 g, 0.341 g, and 0.348 g with water levels of 0.0 m, 1.5 m, and 2.5 m. At 2.5 m, a decrement effect was generally shown in the isolated water tank, and a bigger displacement occurred in the non-isolated water tank than in the isolated one at water levels of 0.0 m and 1.5 m. It is interpreted that the weight of different water levels affects the decrement effect. If seismic reinforcement is done, the isolated bearing should be designed while considering the fluid storage level.

The Factors Affecting on the Integration Intention among the Port Authority Members in Korea (우리나라 항만공사 조직구성원들의 통합의도 및 영향요인 연구)

  • Song, Yong-Soo;Ha, Myung-Shin;Choi, Sung-Kwang
    • Journal of Korea Port Economic Association
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    • v.28 no.1
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    • pp.25-52
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    • 2012
  • In order to solve the current problems and inefficiencies within the Port Authorities(PA) in Korea, this study introduces the concept of the integration of PA and analyses the intention of integration. This study is based on analysing the surveys participated by the members of PA. The surveys consist of six main factors which could influence the intention of integration of PA; contribution, autonomy, strategic factor, financial factor, marketing factor and environmental factor. The two main implications from this study can be categorised as follows. First, this study identifies the structural problems such as regional self-centredness of PA, obscurity of organisations' roles and their rights, limitations on diversification of business and restrictions within PA. Second, this study extensively discusses the option of improving the inefficiency whilst maintaining the current system or to switch to the integration of PA. In addition, it has been found that individual PA recognise the little need for integration. Since the results show that the strategic, financial, marketing and environmental factors would cause both significant and little significant impacts, it would be too haste to decide on a conclusion. However, it is possible to say that the rapid integration of PA can neither improve the efficiency nor improve the characteristics of each region. Therefore, the significance of integration of PA must be further discussed from many different perspectives. The results of this research will serve as a basic literature for further studies on the integration of PA in Korea. Moreover, the problems that have been identified and analysed in this study will contribute to establishing the strategy for further development of PA in Korea.

Performance Test of Wall to Wall Modular Structure Joint for Near-surface Transit (저심도 모듈식 구조체의 벽체간 연결 조인트 성능검증 실험)

  • Lee, Jong Soon;Kim, Hee Sung;Lee, Sung Hyung;Lee, Jun Kyoung
    • Journal of the Korean Society for Railway
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    • v.18 no.3
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    • pp.261-269
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    • 2015
  • To overcome the weaknesses of viaduct bridges and the non-economic efficiency of underground LRT, the study of near-surface railway systems is in progress. To apply a box structure to the low depth transit, a connection joint to precast modules are very important when applying precast modular structures to replace temporary structures. In this study, wall to wall connections were applied in diverse cases such as rebar connections, guiding structures that were used to fit the verticality of precast walls during construction, and non-reinforcement structures used only for waterstop. Experimental performance verification was carried out for the bending, shear and splitting of the wall to wall connection. Precision of construction joints between wall to wall was identified as a factor that influenced the structural performance of the precast wall. A structure that can serve as a guide during the vertical insertion of a wall is confirmed for the most suitable case, but it will be necessary to modify this structure for detailed cases.

Development and Prospect of Emulsion Technology in Cosmetics (화장품에서 유화기술의 발전 및 전망)

  • Kyong, Kee-Yeol;Lee, Cheon-Koo
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.32 no.4 s.59
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    • pp.209-217
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    • 2006
  • Emulsion is a dispersion system among liquids which are not miscible together. There are numerous cosmetic raw materials which have different physicochemical properties. Therefore, emulsion technology is very useful in cosmetics. With the development of emulsifier, several emulsification technologies have been developed. Since HLB method by Griffin in 1950's, PIT method, gel method, and D-phase methods, etc, have been developed. Recently, the application of natural emulsifier and polymeric emulsifier increases in cosmetics in order to achieve enhanced safety and biocompatibility. Besides nano-emulsion, multiple-emulsion, liquid crystal emulsion, and Pickering emulsion have been developed and applied as means of differentiating appearance and texture of products and achieving enhanced delivery of active ingredients. Meanwhile, the application studies of nano-dispersed structural system such as liposome or cubosome are on progress. Liposome is a bi- or multi-lamella layer dispersion system composed of amhiphilic molecules - phospholipids which are main components of plasma membrane. Cubosome also is a nano-sized dispersion system composed of a specific molecule like glyceryl monoloeate derived from natural products. And it has a cubic bicontinuous structure in water due to its unique molecular structure. Incorporating compounds (active materials) into such nano-particles can increase biocompatibility and delivery efficiency of target compounds. Manufacturing process and application of cosmetic emulsions and nano-particles are briefly introduced in this paper.

Color Filter Based on a Sub-wavelength Patterned Metal Grating (광파장 이하 주기를 갖는 금속 격자형 컬러필터)

  • Lee, Hong-Shik;Yoon, Yeo-Taek;Lee, Sang-Shin;Kim, Sang-Hoon;Lee, Ki-Dong
    • Korean Journal of Optics and Photonics
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    • v.18 no.6
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    • pp.383-388
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    • 2007
  • A color filter was demonstrated incorporating a patterned metal grating in a quartz substrate. The filter is created in a metal layer perforated with a symmetric two-dimensional array of circular holes, with the pitch smaller than the wavelength of the visible light. A finite-difference time-domain simulation was performed to analyze the device by investigating the effect of structural parameters like the grating height, the period, the hole size, and the refractive index of the hole-filling material on its performance. The device performance was especially optimized by controlling the refractive index of the material comprising the holes of the grating. And two different devices were fabricated by means of the e-beam direct writing with the following design parameters: the grating height of 50 nm, the two pitches of 340 nm for the red color and 260 nm for the green color. For the prepared device with the period of 340 nm, the center wavelength was 680 nm and the peak transmission 57%. And for the other device with the pitch of 260 nm, the center wavelength was 550 nm and the peak transmission was 50%. The filling of the hole with a material whose refractive index is matched to that of the substrate has led to an increase of ${\sim}15%$ in the transmission efficiency.

Functional Analysis of Fibroblastic Reticular Cells Derived from Mouse Lymph Node via Bidirectional Crosstalk with T Cells (T세포와 양방향 작용을 통한 마우스 림프절로부터 분리된 fibroblastic reticular cell의 기능적 분석)

  • Park, Sung Hee;Lee, Jong-Hwan
    • Journal of Life Science
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    • v.23 no.10
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    • pp.1199-1208
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    • 2013
  • Fibroblastic reticular cells (FRCs) form the structural backbone of the T zone provide a guidance path for immigrating T cells in the lymph node (LN). FRCs may contribute directly to developing T-cell biology in the LN and allow analyses of fundamental aspects of FRC biology related to T cells. FRCs inhibited T-cell apoptosis, and FRC culture supernatants strongly induced the expression of Bcl-xL in T cells against doxorubicin. Coculture of FRC and T cells resulted in rearrangements of the actin cytoskeleton, as well as global changes in the morphology of the FRCs. In addition, when cocultured, the T cells adhered to the FRC monolayer, and the membrane intercellular adhesion molecule (ICAM)-1 was slightly increased by day-dependent manner. In contrast, the expression of soluble ICAM-1 was dramatically increased in a day-dependent manner. Several chemokines, such as CCL5, CXCL1, CXCL5, CXCL16, CCL8, CXCL13, and ICAM-1, and MMPs were expressed in FRCs sensed by tumor necrosis factor (TNF) families. Nuclear factor kappa B ($NF{\kappa}B$)-RelA of the $NF{\kappa}B$ canonical pathway was translocated into FRC nuclear by $TNF{\alpha}$. In contrast, p52 proteolyzed from p100, a counterpart of RelB of the noncanonical $NF{\kappa}B$ pathway, accumulated in the peripheral FRC nucleus by agonistic anti-$LT{\beta}R$ antibody. In summary, we propose a model in which FRCs engage in bidirectional crosstalk to increase the efficiency of T-cell biology. This cooperative feedback loop may help to maintain tissue integrity and function during immune responses.

An Overview on the Physicochemical Properties and Photocatalytic Pollutant Removal Performances of TiO2-incorporated Cementitious Composites (TiO2 혼입 시멘트 복합체의 물리·화학적 특성 및 광촉매 반응을 이용한 오염물 제거 성능에 대한 개요)

  • Seo, J.H.;Yoon, H.N.;Kim, S.H.;Bae, S.J.;Jang, D.I.;Kil, T.G.;Park, S.M.;Lee, H.K.
    • Composites Research
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    • v.33 no.2
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    • pp.68-75
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    • 2020
  • Recently, the use of TiO2 as a phtocatalyst has been diversely investigated due to its excellent durability performance and high photocatalytic reaction efficiency. Active researches have particularly focused on the development of TiO2-incorporated cementitious composites in order to remove the atmospheric pollutants. Furthermore, the potential utilization of TiO2-incorporated cementitious composites as road accessories such as tunnels, road median separators and soundproof walls in the form of tiles, blocks and structural components has been widely examined. In this regard, a thorough understanding on the material characteristics of TiO2-incorporated cementitious composites should be preceded. The present overview article, therefore, revisits previous studies of TiO2-incorporated cementitious composites and summarizes their various physicochemical properties and atmospheric pollutants removal performance.

An Implementation of the Report View Generator using Program Performance Log Information (프로그램 성능 평가 로그 정보를 이용한 레포트 뷰 생성기 구현)

  • Cho Yong-Yoon;Yoo Chae-Woo
    • Journal of the Korea Society of Computer and Information
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    • v.10 no.3 s.35
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    • pp.35-44
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    • 2005
  • A software developer can use a performance evaluation tool to elevate development speed and improve qualify of softwares. But, evaluation results that most performance evaluation tools offer are complicated strings. Therefore, a developer cannot intuitively understand the meanings of the results and must make much times and efforts in analysing the result. In this paper, we propose a report view generator that can transform and provide the text-based performance evaluation results for softwares with various graphic-based views. Our proposed generator consists of a screen generator that creates a structural XML document about the text-based performance evaluation results and a log analyzer that makes various report view through the created XML evaluation document. Because the XML evaluation result document can express the result information structured according to performance evaluation items for resources of softwares, it can have flexibility in offering and integrating the result information for the items. Through the suggested report view generator, developers can intuitively understand and analysis performance evaluation results of embedded software. And they can easily and quickly improve software quality and improve development efficiency of softwares.

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Filter Media Specifications for Low Impact Development: A Review of Current Guidelines and Applications (LID 시설 여재에 관한 기술지침 및 적용에 관한 고찰)

  • Guerra, Heidi B.;Kim, Lee-Hyung;Kim, Youngchul
    • Journal of Wetlands Research
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    • v.21 no.4
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    • pp.321-333
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    • 2019
  • A primary aspect of low impact development (LID) design that affects performance efficiency, maintenance frequency, and lifespan of the facility is the type of filter media as well as the arrangement or media profile. Several LID guidelines providing media specifications are currently available and numerous studies have been published presenting the effectiveness of these systems. While some results are similar and consistent, some of them still varies and only a few focuses on the effect of filter media type and arrangement on system performance. This creates a certain level of uncertainty when it comes to filter media selection and design. In this review, a synthesis of filter media specifications from several LID design guidelines are presented and relevant results from different laboratory and field studies are highlighted. The LID systems are first classified as infiltration or non-infiltration structures, and vegetated or non-vegetated structures. Typical profiles of the media according to classification are shown including the different layers, materials, and depth. In addition, results from previous studies regarding the effect of filter media characteristics on hydraulic and hydrologic functions as well as pollutant removal are compared. Other considerations such as organic media leaching, clogging, media washing, and handling during construction were also briefly discussed. This review aims to provide a general guideline that can contribute to proper media selection and design for structural LIDs. In addition, it also identifies opportunities for future research.

Development of Evaluation Indicators of Greenhouse for Tomato Cultivation Using Delphi Survey Method (델파이 설문조사를 통한 토마토 재배시설 평가지표 개발)

  • Yu, In Ho;Cho, Myeong Whan;Lee, Eung Ho;Ryu, Hee Ryong;Kim, Young Chul
    • Journal of Bio-Environment Control
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    • v.21 no.4
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    • pp.466-477
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    • 2012
  • This study aimed to develop the comprehensive indicators which can be used for evaluating greenhouse for tomato cultivation. To achieve this aim, the study developed the evaluation indicators composed of evaluation items, grades and criteria by extracting preliminary evaluation items through analyzing the related papers and preceding studies, and conducting Delphi survey on an expert group. During the three surveys, the questions of closed-ended type were given to a panel of 100 experts - professors related to tomato cultivation and facilities, researchers and farmers (practical users). As a result, the finally established evaluation indicators consist of 4 categories and 39 specific evaluation items. The 4 categories are the structural factor of greenhouse, equipment factor of greenhouse, cultivation factor, and infrastructure factor. These factors consist of specific evaluation items of 9, 15, 7 and 8, respectively. In addition, on 39 specific evaluation items, weighted values were calculated and grades and criteria were established by collecting opinions of the experts. The newly developed evaluation indicators through this study will play an important role in developing new greenhouse models, considering things that should be complemented preferentially regarding in-use facilities, and improving the efficiency of projects supported by the government.