• 제목/요약/키워드: buildup

검색결과 232건 처리시간 0.02초

유통업체 의류 상표에 대한 소비자 태도 형성 (Consumer Attitude Formation on Private Apparel Brand)

  • 최미영;이은영
    • 한국의류학회지
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    • 제30권8호
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    • pp.1210-1221
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    • 2006
  • The strength of the PB(Private Brand) is that it can eliminate intermediary in the distribution channel and thoroughly control the quality under its own name. This study has developed traditional studies on private brand proneness in approaching data processing and empirical point of view of a consumer's attitude buildup process on PB through 'recognition-attitude-action(behavioral attitude)'. The subjects of this study are consumers in their $20s{\sim}40s$ who are main customer groups of PBs. A screening process has taken place to select consumers with purchasing experiences of retailor PBs. The data is analyzed by 'Structural Equation Modeling' of Amos 5.0 to verify consumer attitude formation model on private apparel brand. The results generated from this study are as follows: First, the proposed consumer attitude model on private apparel brand consists of store evaluation, experiential product evaluation, cognitive product evaluation, hedonic attitude, utilitarian attitude and purchase intention. Second, not only positively influence on utilitarian attitude but hedonic attitude can arouse positive emotional reaction of a consumer. Third, the store evaluation is ahead of the product evaluation because PB is more related to the image of a store. The influence of the store on PB is relatively stronger when compared with NB.

EGR Cooler Fouling 저감을 위한 촉매 장착 EGR Cooler System 평가 (Evaluation of Catalyst Assisted EGR Cooler System for EGR Cooler Fouling Reduction)

  • 홍광석;박정수;이교승
    • 한국자동차공학회논문집
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    • 제19권5호
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    • pp.76-81
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    • 2011
  • Exhaust gas recirculation is the well-known and widely used NOx reduction technology for diesel engines. More effective EGR cooler has been developed and applied to diesel engines to meet the reinforced emission regulation. However, the contaminated EGR cooler by diesel exhaust gas reduces the performance of the engine and NOx reduction rate. The buildup of deposits in EGR coolers cause significant degradation in heat transfer performance, often on the order of 20~30%. Deposits also increase pressure drop across coolers and thus may degrade engine efficiency under some operation conditions. In this study, as a solution for this problem, DOC assisted EGR cooler is designed and then investigated to reduce fouling and its impact on cooler performance. A single channel EGR cooler fouling test apparatus and soot particle generator were developed to represent the real EGR cooler and exhaust gas of diesel engine. EGR cooler effectiveness of the case with catalyst of pt 30g/ft3 decreased just up to 5%. This value was 45% less compared to the case without catalyst which decreased up to 9% after 10hours experiments.

미고결 퇴적물의 지질공학적 특성에 대한 수치해석적 연구 (Numerical Analysis for the Geological Engineering Characteristics of Unconsolidated Sediment)

  • 조태진
    • 한국수산과학회지
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    • 제23권3호
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    • pp.215-224
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    • 1990
  • 포화상태인 물질의 역학적, 수리학적 거동을 연구할 수 있는 유한요소법적 수치해석모델을 개발하여 부산 남항 인근해역의 미고결 퇴적물의 거동을 분석하였다. 하중재하에 의한 상부세립 퇴적물의 역학적 변형은 공극수의 확산에 따른 공극수압의 수리학적 변화에 크게 영향을 받는 것으로 나타났다. 하중이 일정지역에 편재되어 있을 경우 포아송효과 및 과잉공극수압의 영향에 의해 하중을 직접 받지 않는 표층부분이 융기되며, 하중경계지역에서 멀어질수록 점근적으로 증가한다. 세립점토층에 비해 높은 투수성을 갖는 하부 모래층은 공극수확산의 통로역할을 하여 과잉공극수압의 소멸을 촉진시키며, 결과적으로 상부점토층 변형의 시간적 변화에도 영향을 끼친다.

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금속분리판을 이용한 무인기항공기(UAV)용 경량화 DMFC 스택 개발 (Development of Lightweight Direct Methanol Fuel Cell (DMFC) Stack Using Metallic Bipolar Plates for Unmanned Aerial Vehicles (UAVs))

  • 이수원;김도환;노정호;조영래;김도연;주현철
    • 한국수소및신에너지학회논문집
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    • 제28권5호
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    • pp.492-501
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    • 2017
  • A 900 W scale direct methanol fuel cell (DMFC) stack is designed and fabricated for unmanned aerial vehicle (UAV) applications. To meet the volume and weight requirements, metallic bipolar plates are applied to the DMFC stack for the first time wherein POS470FC was chosen as bipolar plate material. To ensure good robustness of the metallic bipolar plate based DMFC stack, finite element method based simulations are conducted using a commercial ANSYS Fluent software. The stress buildup and deformation characteristics on bipolar plates and end plates are analyzed in details. The present DMFC stack exhibits the performance of 1,130 W at 32 V and 35.3 A, clearly demonstrating that it could successfully operate for UAVs requiring around 1,000 W of power.

Study of Short-Term Sunspot Motion toward Flare Onset Prediction

  • Suematsu, Yoshinori;Yatini, Clara Y.
    • 천문학회보
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    • 제36권2호
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    • pp.87.2-87.2
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    • 2011
  • Proper motion of sunspots in several active regions was studied to detect their indicator on flare onset, using data from the Solar Flare Telescope at Mitaka (four flaring active regions), TRACE (e.g. NOAA 0424, M1.7 flare on 5 Aug. 2003) and Hinode (e.g. NOAA 10930, X3.4 flare on 13 Dec. 2006). The proper motion of individual sunspots was derived using a local correlation tracking method. As a result, we found that the sunspots that are located under or close to a part of chromospheric flaring patches showed a change in their moving direction prior to the flare onset. The change in their movements took place a half to two hours before the flare onset. On the other hand, sunspots in non-flaring areas or non-flaring active regions did not show this kind of change. It is likely, therefore, that if a sunspot shows the particular movement, a chromospheric flare is to occur in its nearby region. In the most active regions, the part of flare ribbons was located on an emerging bipolar pair of sunspots. The disturbance in the usual motion of the bipolar sunspots and in other sunspots as well can be interpreted as a sign of magnetic shear development leading to final magnetic energy buildup before its sudden release. We suggest that the change in sunspot motion in a short time scale prior to the flare onset can be regarded as a good indicator in predicting the onset timing and location of chromospheric flares.

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연속압출공법(ILM)을 이용한 수저(水底)터널공법에 관한 연구 (The Continuously Underwater Tunnelling Methods by Incremental launching Methods)

  • 정병률;류동훈;김준모
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2009년도 춘계학술대회 논문집
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    • pp.28-41
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    • 2009
  • We know the several construction methods for underwater tunnel, but properly submerged concrete box type tunnel was mostly good structure stability and mostly shot length of tunnels. Submerged box type tunnel was buildup the unit segments in dry dock or ship yard by 10 to 20meters. The submerged box was composed with segments was join each together. It was installing the gate and waterproofing the coupling the front hull of a box. The complete submerged box rise up to the surface water, tow in the submerged box by tugboat, going to the destination of tunnel construction site. Beforehand dredge up soil at the bottom of a underwater, sinking the submerged box, connection together complete submerged box in underwater. The research and development ILM tunneling method is receiving careful study. Biggest weakness in submerged concrete box type tunnel was pressure waterproofing, box to box connecting, complete submerged boxes navigation and installation, after operation the submerged tunnel and management concrete box structure. It was positive evidence in submerged concrete box type tunnel. We make a practical application of the principle "the ILM tunneling method in underwater construction methods."

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정보기술환경에서 무결성, 능력, 배려 요인이 신뢰에 미치는 영향에 대한 분석 (Effects of Integrity, Ability, and Benevolence on Trust Buildup in Information Technology Environment)

  • 남수현
    • 디지털융복합연구
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    • 제9권6호
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    • pp.313-323
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    • 2011
  • 본 연구는 신뢰형성의 선행변수인 무결성, 능력, 배려라는 세 요인을 중심으로, 정보기술환경에서 이들 선행변수는 신뢰형성에 어떤 영향을 미쳤는지를 1981년부터 2010년까지 뉴욕타임즈에 게재된 관련 기사를 이용하여 분석하였다. 주요 분석결과는 무결성이 신뢰에 부정적 영향을 미쳤다고 보고한 사례가 86%, 능력과 배려는 신뢰형성에 긍정적 영향을 준 사례 비율이 70%와 71%로 나타났다. 통계적 검정결과는 무결성의 신뢰파괴에 영향 비율이 높을 것이라는 가설만이 유의적인 것으로 나타났고, 비구조적 성격이 높은 배려와 관련한 가설은 표본의 크기가 작은 근본적 문제로 지지되지 못하였다. 배려와 관련한 사회적 책임 이슈와 향후 기업에서의 정보기술 활용방향에 대한 제안을 한다.

Study on Combustion Characteristics of Unielement Thrust Chambers with Various Injectors

  • Seonghyeon Seo;Lee, Kwang-Jin;Han, Yeoung-Min;Kim, Seung-Han;Kim, Jong-Gyu;Moon, Il-Yoon;Seol, Woo-Seok
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2004년도 제22회 춘계학술대회논문집
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    • pp.125-130
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    • 2004
  • Experimental study on combustion characteristics of double swirl coaxial injectors has been conducted for the assessment of critical injector design parameters. A reusable, unielement thrust chamber has been fabricated with a water-cooled copper nozzle. Two principle design parameters, a swirl angle and a recess length, have been investigated through hot firing tests for the understanding of their effects on high pressure combustion. Clearly, both parameters considerably affect the combustion efficiency, dynamics and hydraulic characteristics of an injector. Internal mixing of propellants in a recess region increases combustion efficiency along with the increase of a pressure drop required for flowing the same amount of mass flow rates. It is concluded that pressure buildup due to flame can be released by the increase of LOx flow axial momentum or the reduction of a recess length. Dynamic pressure measurements of the thrust chamber show varied dynamic behaviors depending on injector configurations.

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AP계 추진제에서 황색산화철의 연소촉매 효과 (Effect of FeOOH on Burn Rate for AP Propellant)

  • 임유진;김준형;유지창
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2010년도 제34회 춘계학술대회논문집
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    • pp.390-393
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    • 2010
  • 황색 산화철인 FeOOH가 3% 첨가된 AP의 열분해 속도가 적색 산화철인 $Fe_2O_3$ 경우보다 매우 빠른 것으로 확인되었다. 연소속도 개선제로 HTPB/AP계 추진제에 황색 산화철을 적용한 결과, 적색 산화철의 경우보다 연소 속도가 10 ~ 25% 더 빠르게 나타났다. 황색 및 적색 산화철을 사용한 HTPB/AP 추진제 조성물에서 점도 상승이나 경도 상승에서 특이한 차이점은 없었다.

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Ex-vessel Steam Explosion Analysis for Pressurized Water Reactor and Boiling Water Reactor

  • Leskovar, Matjaz;Ursic, Mitja
    • Nuclear Engineering and Technology
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    • 제48권1호
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    • pp.72-86
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    • 2016
  • A steam explosion may occur during a severe accident, when the molten core comes into contact with water. The pressurized water reactor and boiling water reactor ex-vessel steam explosion study, which was carried out with the multicomponent three-dimensional Eulerian fuel-coolant interaction code under the conditions of the Organisation for Economic Co-operation and Development (OECD) Steam Explosion Resolution for Nuclear Applications project reactor exercise, is presented and discussed. In reactor calculations, the largest uncertainties in the prediction of the steam explosion strength are expected to be caused by the large uncertainties related to the jet breakup. To obtain some insight into these uncertainties, premixing simulations were performed with both available jet breakup models, i.e., the global and the local models. The simulations revealed that weaker explosions are predicted by the local model, compared to the global model, due to the predicted smaller melt droplet size, resulting in increased melt solidification and increased void buildup, both reducing the explosion strength. Despite the lower active melt mass predicted for the pressurized water reactor case, pressure loads at the cavity walls are typically higher than that for the boiling water reactor case. This is because of the significantly larger boiling water reactor cavity, where the explosion pressure wave originating from the premixture in the center of the cavity has already been significantly weakened on reaching the distant cavity wall.