• Title/Summary/Keyword: R&D capacity

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Seismic Response Analysis of Reinforced Concrete Wall Structure Using Macro Model

  • Kim, Dong-Kwan
    • International Journal of Concrete Structures and Materials
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    • v.10 no.1
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    • pp.99-112
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    • 2016
  • During earthquake, reinforced concrete walls show complicated post-yield behavior varying with shear span-to-depth ratio, re-bar detail, and loading condition. In the present study, a macro-model for the nonlinear analysis of multi-story wall structures was developed. To conveniently describe the coupled flexure-compression and shear responses, a reinforced concrete wall was idealized with longitudinal and diagonal uniaxial elements. Simplified cyclic material models were used to describe the cyclic behavior of concrete and re-bars. For verification, the proposed method was applied to various existing test specimens of isolated and coupled walls. The results showed that the predictions agreed well with the test results including the load-carrying capacity, deformation capacity, and failure mode. Further the proposed model was applied to an existing wall structure tested on a shaking table. Three-dimensional nonlinear time history analyses using the proposed model were performed for the test specimen. The time history responses of the proposed method agreed with the test results including the lateral displacements and base shear.

Up/Downlink Hybrid Inter-Cell Coordination Patterns of the TDD/MC-CDMA System, TDD/MC-CDMA

  • Han, Sang-Jin;Lee, Sung-Jin;Lee, Sang-Hoon;Gil, Gye-Tae
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.34 no.5A
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    • pp.421-428
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    • 2009
  • Inter-cell coordination has been an emerging issue for mitigating inter-cell interference in broadband wireless access networks such as IEEE802.16 and 3GPP LTE (Long Term Evolution). This paper proposes uplink/downlink hybrid inter-cell coordination patterns for a TDD (Time Division Duplex)/MC-CDMA (Multi-Carrier Code Division Multiple Access) system. For the performance analysis, closed forms of inter-cell interferences are derived when uplink and downlink transmissions coexist over a multi-cell environment. In the analysis, we find an optimal ratio of downlink transmit powers of BSs (Base Stations) based on the target outage probability and the performance according to ratios of uplink/downlink transmit powers of MSs (Mobile Stations)/BSs is explored. Our numerical results show that interference mitigation utilizing the characteristics of the uplink and downlink power ratio is very effective in improving system performance in terms of QoS.

Shear Behavior of Wide Beam-Column Joints with Slab (슬래브가 있는 넓은 보-기둥 접합부의 전단거동)

  • 안종문;최종인;신성우;이범식;박성식;양지수
    • Proceedings of the Korea Concrete Institute Conference
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    • 2003.05a
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    • pp.157-162
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    • 2003
  • An experimental investigation was conducted to study the behavior of high-strength RC wide beam-column joints with slab subjected to reversed cyclic loads under constant axial load. Six half scale interior wide beam-column assemblies representing a portion of a frame subjected to simulated seismic loading were tested, including three specimens without slab and three specimens with slab. The primary variables were compressive strength of concrete($f_ck$=285, 460kgf/$cm^2$), the ratio of the column-to-beam flexural capacity($M_r$=$\Sigma M_c / \Sigma M_b$ ; 0.77 -2.26), extended length of the column concrete($l_d$ ; 0, 12.5, 30cm), ratio of the column-to-beam width(b/H ; 1.54, 1.67). Test results are shown that (1) the behavior of specimen using high-strength concrete satisfied for required minimum ductile capacity according to increase the compressive strength, (2) the current design code and practice for interior joints(type 2) are apply to the wide beam-high strength concrete column.

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Fixed Bed Study for a Detritiation Adsorber

  • Kim K. R.;Lee M. S.;Paek S.;Yim S. P,;Ahn D. H.;Chung H.;Shim M. H.
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • 2005.11b
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    • pp.119-125
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    • 2005
  • A method of predicting the tritium concentration in the air leaving an atmospheric detritiation dryer was modeled for designing a fixed bed dryer and preparing an advanced dryer control. In order to quantify the bed utilization and the dynamic capacity against an inlet humidity and a flow rate, a series of quantitative tests based on the break-through behavior were carried out in an isothermal fixed bed of synthetic zeolites such type as molecular sieve 4A, 5A, 13X and mordenite. The amount of water vapor breaking during the adsorption was estimated to give a breakthrough capacity at the various inlet flow rates and humidity conditions. The molecular sieve 13X exhibited a better adsorption performance at a given bed height.

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Performance of Expanded Graphite as Anode Materials for High Power Li-ion Secondary Batteries

  • Park, Do-Youn;Lim, Yun-Soo;Kim, Myung-Soo
    • Carbon letters
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    • v.11 no.4
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    • pp.343-346
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    • 2010
  • The various expanded graphites (EGs) was prepared and applied as anode material for high power Li-ion secondary battery (LIB). By changing the processing conditions of EG, a series of EG with different structure were produced, showing the changed electrochemical properties. The charge-discharge test showed that the initial reversible capacity of EG anodes prepared at the suitable conditions was over 400 mAh/g and the charge capacity at 5 C-rate was 83.2 mAh/g. These values demonstrated the much improved electrochemical properties as compared with those for the graphite anode of 360 mAh/g and 19.4 mAh/g, respectively, showing the possibility of EG anode materials for high power LIB.

The Apparent Mass Capacity Method for Transient Diffusion Problems with Change of Phase

  • Kim, Yongsoo;Wonmok Jae;D. R. Olander
    • Proceedings of the Korean Nuclear Society Conference
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    • 1995.05b
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    • pp.643-650
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    • 1995
  • A numerical method for treating transient diffusion Involving change of phase is presented. In other methods of dealing with this class of problems, the mass flux balance at the moving phase boundary requires explicit treatment of two distinct phases. The technique, originating from the apparent heat capacity method in transient heat conduction with the phase change, avoids the difficulty by transferring the concentration discontinuity at the boundary to smoothed physical property variations near the moving front. This technique accomodates the nonlinearities which preclude use of analytical solutions. It was tested against known analytical solutions for simple cases and turned out to be quite accurate.

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A Study on GUI based Subgraph Generation Tool for Similar Matching in Large Capacity Graphs (대용량 그래프에서의 유사 매칭을 위한 그래픽 사용자 인터페이스 기반 서브 그래프 생성 도구에 대한 연구)

  • Song, Je-O;Hong, Seung-Min;Lee, Sang-Moon
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2018.07a
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    • pp.349-350
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    • 2018
  • 최근 빅데이터를 비롯한 각종 실험 장비의 발전에 따라 첨단 분야에서의 과학데이터가 급격히 증가하고 있는 가운데, 그래프 매칭은 컴퓨터 네트워크 모니터링, 소셜 네트워크의 진화 분석, 생물학 네트워크에서 모티프(motif) 탐지 등 네트워크 분석 및 데이터 마이닝 분야에서 널리 활용되고 있다. 이와 같이, 폭발적으로 증가하는 데이터에 대한 네트워크 모델링 및 유사 그래프 매칭 분석을 수행하기 위한 연구 및 기반 기술 개발은 필수적인 실정이다. 본 논문에서는 이미 확보된 대용량 그래프에서 유사한 형태의 서브 그래프를 매칭할 수 있는 GUI(Graphic User Interface)기반의 생성 도구를 제안한다.

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Quality Characteristics of Sugar Snap-Cookie with Added Cornus fructus (산수유 분말을 첨가한 쿠키의 품질 특성에 관한 연구)

  • Ko, Hee-Chul
    • Journal of the East Asian Society of Dietary Life
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    • v.20 no.6
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    • pp.957-962
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    • 2010
  • This study examined the effects of Cornus fructus addition to suger snap cookies on WRC (water rentention capacity) and AWRC (alkaline water retention capacity). WRC and AWRC increased as more Cornus fructus powder was added, whereas the sedimentation value and Pelshenke value decreased. Regarding cookie color, L value decreased, whereas the a and b values increased. As the cookie diameter became smaller, thickness increased and spread factor decreased. Hardness of the cookies decreased, and preference was highest for cookies with 5% added Cornus fructus. The preferences for cookies were in the following order: 7% < 3% < 1% < 0% < 5% addition. In conclusion, addition of less than 5% Cornus fructus powder was the most desirable. To complement cookie appearance, it seems necessary to adjust the water content of Cornus fructus powder or add an emulsifier.

Changes in Hardness and Damping Capacity of Aged Mg-5%Sn Alloy (시효한 Mg-5%Sn 합금의 경도와 진동감쇠능 변화)

  • Jun, Joong-Hwan
    • Journal of the Korean Society for Heat Treatment
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    • v.35 no.5
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    • pp.255-261
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    • 2022
  • In this work, the strain-amplitude independent and strain-amplitude dependent damping capacities of Mg-5%Sn alloy have been investigated as a function of its age-hardening response. The hardness increased with an increase in aging time, reached a peak value after 48 h, and then it gradually decreased. The damping capacities of the Mg-5%Sn alloy exhibited a decreasing tendency in the order of solution-treated, under-aged, peakaged, and over-aged states in the strain-amplitude dependent region, whereas they increased continuously with aging time in the strain-amplitude independent region. The microstructural examination during aging revealed that the lower concentration of Sn solutes in the α-(Mg) matrix and the lower density of the Mg2Sn precipitate particles may well be the crucial factors for better damping values in the strain-amplitude independent and strain-amplitude dependent regions, respectively.

Hair Growth Promoting Effect of Black Soybean Extract In Vitro and In Vivo (In vitro 및 in vivo에서 검은콩 추출물의 육모 효과)

  • Jeon, Hee-Young;Kim, Seung-Hun;Kim, Chae-Wook;Shin, Hyun-Jeong;Seo, Dae-Bang;Lee, Sang-Jun
    • Korean Journal of Food Science and Technology
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    • v.43 no.6
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    • pp.747-753
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    • 2011
  • It is commonly believed that black soybean (Glycine max: BB) prevents and alleviates hair loss. However, few studies have directly assessed the effect of BB on hair growth. We presently evaluated the mitosis induction on dermal papillae cell and mitogenic effect on NIH3T3 cells in vitro. To elucidate the hair growth promoting effect in vivo, anagen induction and hair restoration were examined in a shaving model of C57BL/6 mice. We also conducted biochemical analysis of blood plasma. Significant stimulation of dermal papillae and NIH3T3 cell proliferation were observed by treatment of BB in a dose-dependent manner. BB markedly promoted hair growth and significantly improved blood total antioxidant capacity and reduced lipid peroxidation and triglyceride level. These results suggest that BB has hair growth promoting effect and it is a potent candidate for the prevention of hair loss.