• 제목/요약/키워드: High-capacity

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고력볼트의 변형능력을 향상시킨 강구조 보-기둥 접합부의 제안 (A Proposal of Steel Structure Beam-to-Column Connection Appling High Strength Bolt Improved in Deformation Capacity)

  • 김승구;이승재;오상훈;강창훈
    • 한국공간구조학회:학술대회논문집
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    • 한국공간구조학회 2006년도 춘계 학술발표회 논문집 제3권1호(통권3호)
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    • pp.182-188
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    • 2006
  • This study propose cutting body portion-high strength bolts to improve deformation capacity of High strength bolts, which are the mechanical fasteners used for End-plate connection. And, we report that loading test results of steel beam-to-column connection using high deformation capacity-high strength bolts in accordance with SAC2000 loading program. As a result, the initial stiffness and the maximum strength of the connection using high deformation capacity-high strength bolts, are approximately the same in comparison with those of the end-plate connection using the existing high strength bolts. But the deformation capacity of the connection is more than twice as much as those.

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수산기업의 부채수용력이 자본조달순서이론에 미치는 영향 (The Effect of Debt Capacity on the Pecking Order Theory of Fisheries Firms' Capital Structure)

  • 남수현;김성태
    • 수산경영론집
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    • 제45권3호
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    • pp.55-69
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    • 2014
  • We try to test the pecking order theory of Korean fisheries firm's capital structure using debt capacity. At first, we estimate the debt capacity as the probability of assigning corporate bond rating from credit-rating agencies. We use logit regression model to estimate this probability as a proxy of debt capacity. The major results of this study are as follows. Firstly, we can confirm the fisheries firm's financing behaviour which issues new debt securities for financial deficit. Empirical test of SSM model indicates that the higher probability of assigning corporate bond rating, the higher the coefficient of financial deficit. Especially, high probability group follows this result exactly. Therefore, the pecking order theory of fisheries firm's capital structure applies well for high probability group which means high debt capacity. It also applies for medium and low probability group, but their significances are not good. Secondly, the most of fisheries firms in high probability group issue new debt securities for their financial deficit. Low probability group's fisheries firms also issue new debt securities for their financial deficit within the limit of their debt capacity, but beyond debt capacity they use equity financing for financial deficit. Therefore, the pecking order theory on debt capacity come into existence well in high probability group.

신형상 메카니컬패스너를 사용한 엔드플레이트 형식 보-기둥 접합부의 변형성능 (Deformation Capacity of Endplate-type Beam-to-Column Connection with New Type Mechanical Fasteners)

  • 이승재
    • 한국공간구조학회논문집
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    • 제6권3호
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    • pp.123-130
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    • 2006
  • 본 연구에서는 기존의 고력볼트의 축부절삭 가공방법을 이용한 신형상 메카니컬패스너를 개발하였다. 개발된 신형상 메카니컬패스너를 엔드플레이트 형식의 보-기둥 접합부에 적용하여 변형능력 및 강도특성에 대한 재하실험 및 유한요소법에 의한 수치해석을 수행하였다.

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조직구성원의 자기주도학습능력이 흡수능력과 정서적 몰입 및 직무몰입에 미치는 영향 (Enhancing organizational commitment and job involvement through self-directed learning and absorptive capacity)

  • 장태원;홍아정
    • 지식경영연구
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    • 제12권2호
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    • pp.17-34
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    • 2011
  • As organization's success depends on how much employees are active in recognizing new knowledge and transform into organization's value, this study is to examine the influence of employees' self-directed learning capacity on organizational absorptive capacity, organizational commitment and job involvement. The study has shown that managerial level employees have high level of self-directed learning capacity, and employees who have such high level capacity also shown to have high level of absorptive capacity and organizational affective commitment and job involvement. There were static correlations between all the variables, and absorptive capacity has a complete meditated effect on each variables. Hence, in order to enhance absorptive capacity, organizations should put their effort to develop employees' self-directed learning capacity, which will not only improve individual competency but also lead to organization's success in this competitive global market.

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초고용량 양방향 말뚝재하시험(BDH PLT) 수행사례 분석 (A Case Study of High Capacity Bi-Directional High Pressure Pile Load Test)

  • 김상일;이민희;정성민;정은택;최용규
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2010년도 춘계 학술발표회
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    • pp.1156-1163
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    • 2010
  • The bi-directional high pile load test(BDH PLT) does not have weaknesses found in the existing bi-directional low pile load test(BDL PLT); it has strong economics, is unbound by load capacity limit and secures quality stability of working piles. In this study, Verification the field found a very high capacity level of stability and reliability of the BDH PLT, as well as outstanding field applicability. Field verifications reaffirmed the advantage of the BDH PLT device, which was capable of loading 90 MN capacities as maximum. It was also found to be durable enough to load high capacity with ease.

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고출력 리튬이온 이차전지 음극재용 피치/코크스/천연흑연 복합재의 제조 및 전기화학적 특성평가 (Fabrication and Characterization of Pitch/Cokes/Natural Graphite Composites as Anode Materials for High-Power Lithium Secondary Batteries)

  • 고효준;임연수;김명수
    • 한국재료학회지
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    • 제25권6호
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    • pp.279-287
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    • 2015
  • In order to prepare anode materials for high power lithium ion secondary batteries, carbon composites were fabricated with a mixture of petroleum pitch and coke (PC) and a mixture of petroleum pitch, coke, and natural graphite (PC-NG). Although natural graphite has a good reversible capacity, it has disadvaantages of a sharp decrease in capacity during high rate charging and potential plateaus. This may cause difficulties in perceiving the capacity variations as a function of electrical potential. The coke anodes have advantages without potential plateaus and a high rate capability, but they have a low reversible capacity. With PC anode composites, the petroleum pitch/cokes mixture at 1:4 with heat treatment at $1000^{\circ}C$ (PC14-1000C) showed relatively high electrochemical properties. With PC-NG anode composites, the proper graphite contents were determined at 10~30 wt.%. The composites with a given content of natural graphite and remaining content of various petroleum pitch/cokes mixtures at 1:4~4:1 mass ratios were heated at $800{\sim}1200^{\circ}C$. By increasing the content of petroleum pitch, reversible capacity increased, but a high rate capability decreased. For a given composition of carbonaceous composite, the discharge rate capability improved but the reversible capacity decreased with an increase in heat treatment temperature. The carbonaceous composites fabricated with a mixture of 30 wt.% natural graphite and 70 wt.% petroleum pitch/cokes mixture at 1:4 mass ratio and heat treated at $1000^{\circ}C$ showed relatively high electrochemical properties, of which the reversible capacity, initial efficiency, discharge rate capability (retention of discharge capacity in 10 C/0.2 C), and charge capacity at 5 C were 330 mAh/g, 79 %, 80 %, and 60 mAh/g, respectively.

소결식 니켈극 제조기술 개발 (Development of Preparation Technique of Sintered Ni Electrode)

  • 김찬중;김대룡
    • 한국수소및신에너지학회논문집
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    • 제10권3호
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    • pp.159-170
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    • 1999
  • Recently Ni/MH secondary battery have been studied very extensively because of containing no pollutants as well as superior performance. However comparing to widely studying high capacity of hydrogen storage alloys electrode, the capacity of Ni electrode is inferior. Using for high capacity Ni/MH battery as a anodic materials, the study about high capacity Ni electrode is necessary. To making high capacity Ni electrode, active materials were impregnated in various polarization impregnation conditions. Plaque, milling for 6hr and sintered at $800^{\circ}C$, indicated porosity over 80%, and porosity were increased with proper condition electrochemical etching treatment. Proper impregnation condition was 40~80mA/cm, polarizing time was 5~10min.

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Seismic Performance of High-Rise Intermediate Steel Moment Frames according to Rotation Capacities of Moment Connections

  • Han, Sang Whan;Moon, Ki-Hoon;Ha, Sung Jin
    • 국제초고층학회논문집
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    • 제4권1호
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    • pp.45-55
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    • 2015
  • The rotation capacity of the moment connections could significantly influence on the seismic performance of steel moment resisting frames. Current seismic provisions require that beam-to-column connections in Intermediate Moment Frames (IMF) should have a drift capacity as large as 0.02 radian. The objective of this study was to evaluate the effect of the rotation capacity of moment connections on the seismic performance of high-rise IMFs. For this purpose, thirty- and forty-story high-rise IMFs were designed according to the current seismic design provisions. The seismic performance of designed model frames was evaluated according to FEMA P695. This study showed that the forty-story IMF satisfied the seismic performance objective specified in FEMA P695 when the rotation capacity of the connections was larger than 0.02. However, thirty-story IMFs satisfied the performance objective when the connection rotation capacity is larger than 0.03.

Battery State Estimation Algorithm for High-Capacity Lithium Secondary Battery for EVs Considering Temperature Change Characteristics

  • Park, Jinho;Lee, Byoungkuk;Jung, Do-Yang;Kim, Dong-Hee
    • Journal of Electrical Engineering and Technology
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    • 제13권5호
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    • pp.1927-1934
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    • 2018
  • In this paper, we studied the state of charge (SOC) estimation algorithm of a high-capacity lithium secondary battery for electric vehicles (EVs) considering temperature characteristics. Nonlinear characteristics of high-capacity lithium secondary batteries are represented by differential equations in the mathematical form and expressed by the state space equation through battery modeling to extract the characteristic parameters of the lithium secondary battery. Charging and discharging equipment were used to perform characteristic tests for the extraction of parameters of lithium secondary batteries at various temperatures. An extended Kalman filter (EKF) algorithm, a state observer, was used to estimate the state of the battery. The battery capacity and internal resistance of the high-capacity lithium secondary battery were investigated through battery modeling. The proposed modeling was applied to the battery pack for EVs to estimate the state of the battery. We confirmed the feasibility of the proposed study by comparing the estimated SOC values and the SOC values from the experiment. The proposed method using the EKF is expected to be highly applicable in estimating the state of the high-capacity rechargeable lithium battery pack for electric vehicles.

선단확장형 고강도강관 매입말뚝 지지력 분석 (Bearing Capacity Analysis of High Strength Steel Pipe Pile with an Extended Head)

  • 고준영;정상섬;이성준;이진형
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2010년도 추계 학술발표회
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    • pp.559-568
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    • 2010
  • Recently, because of mega foundations and grand bridges, the foundations require significant bearing capacity. In this study, bearing capacity of high strength steel pipe pile with an extended head (HSP) is calculated on the basis of domestic criteria and Japanese criteria. And bearing capacity of HSP is investigated based on 3 field tests. In comparison with the results of analysis and tests, it is shown that the field test results are bigger than analysis results. Therefore, it is proposed to estimate bearing capacity of HSP.

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