• 제목/요약/키워드: Specific weight

검색결과 2,684건 처리시간 0.03초

현행 중량바닥충격음 평가방법 개선을 위한 주관평가실험 (Subjective Assessment of Simulated Heavy Floor Impact Sounds for Alternative Rating Method)

  • 신훈;백건종;송민정;장길수
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2008년도 추계학술대회논문집
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    • pp.581-586
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    • 2008
  • This study aims to examine the existing single rating index in terms of level reduction limit of heavy-weight floor impact sound. To achieve this goal, sounds which have same loudness according to rating methods were suggested to subjects. And followings are results. 1) The rating method of measurement frequency level average is more suitable than that of other methods which are dependent on specific frequency for rating heavy-weight floor impact sound. 2) Level average for measurement frequency of 31.5Hz - 500Hz is more correspondent to psycho-acoustic response than that of measurement frequency of 63Hz - 500Hz which is for KS F 2863-2, existing rating method.

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경량화용 혼성 알루미늄 CFRP 사각튜브의 축 압궤특성 (Axial Collapse Characteristics of Combined Aluminum CFRP Square Tubes for Light-Weight)

  • 이길성;차천석;정진오;양인영
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2004년도 추계학술대회 논문집
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    • pp.110-113
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    • 2004
  • Aluminum and CFRP tube is light-weight material representatively but collapse mechanism is different under axial loading. Aluminum tube absorbs energy by stable plastic deformation under axialloading. While CFRP(Carbon Fiber Reinforced Plastics)tube absorb synergy by unstable brittle failure but its specific strength and stiffness is higher than that of aluminum tube. In this study, for complement of detect and synergy effect by combination with the advantages of each member, the axialcollapsetests were performed for combined aluminum CFRP tubes which are composed of aluminum tubes wrapped with CFRP out side aluminum square tubes. Collapsecharacteristics were analyzed for combined square tubes which have different CFRP orientation angle and thickness. Test results were compared with that of aluminum tubes and CFRP tubes.

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내연기관 자동차의 주행모드 조건에 따른 연비 성능 비교 (Fuel Economy Comparison according to Driving Mode Conditions of the Internal Combustion Engine Vehicles)

  • 최용준;서영호
    • 융복합기술연구소 논문집
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    • 제3권1호
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    • pp.25-29
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    • 2013
  • The purpose of this paper is to determine the fuel change and weight change impact on the fuel economy and emission characteristic of ICE (Internal Combustion Engine) vehicle. According to fuel type, fuel consumption and emission characteristics were measured and fuel used in this paper was gasoline, diesel, and LPG. Four vehicles with different weight were tested and the fuel economy were compared and analyzed by using scatter graph. Test was carried out using chassis dynamometer, CVS (Constant Volume Sampler), and emission measurement system. Diesel vehicle less emited $CO_2$ compared to gasoline and LPG. Even if same $CO_2$ between gasoline and LPG, there are difference fuel economy depending on carbon proportion of specific fuel. The heavier weight of vehicle, the worse of fuel economy and Better fuel economy performance on highway driving mode.

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스포츠 레저용 차량의 진동절연을 위한 고무제품의 특성에 관한 연구 (A Study on the Characteristics of Elastomers for Vibration Isolation of Sports Utility Vehicle)

  • 사종성;김찬묵
    • 한국자동차공학회논문집
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    • 제10권5호
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    • pp.129-137
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    • 2002
  • Elastomers, which are used engine mounts and body mount rubbers, are traditionally designed for NVH use in vehicles, and for vibration isolation in specific frequency range. According to the measurement of the characteristics of the SUV's engine mounts, there are variability in same engine mount properties. Static and dynamic stiffness of the SUV's engine mounts are changed due to the driving miles accumulated. The pre-load of body mount rubbers are changed due to the empty vehicle weight, passenger's weight and gross vehicle weight. And the dynamic stiffness of body mount rubbers are changed very hard above 150Hz frequency range.

ESTIMATES OF GENETIC PARAMETERS OF SOME GROWTH TRAITS IN JERSEY CATTLE

  • Khan, R.N.;Akhtar, S.
    • Asian-Australasian Journal of Animal Sciences
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    • 제8권6호
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    • pp.567-570
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    • 1995
  • Data from 178 Jersey calves born at Livestock Experiment Station were analyzed to obtain estimates of heritability, genetic and phenotypic correlations of some growth traits. Sex-specific variance and covariance components were estimated for birth weight (BWT), 180-d weight (WWT), 365-d weight (YWT), birth to weaning daily gain (BWG), weaning to yearling daily gain (WYG) and brith to yearling gain (BYG). Heritabilities, genetic and phenotypic correlations were generally higher in males than females. Heritabilities estimated for males and females respectively were 0.98 and 0.49 for BWT; 0.70 and 0.76 for WWT; 0.71 and 0.26 for YWT. Genetic correlations were higher than phenotypic correlations in all the treats studied.

INFLUENCE OF HUMIC SUBSTANCE (HS) ADSORPTIVE FRACTIONATION ON PYRENE PARTITIONING TO DISSOLVED AND MINERAL-ASSOCIATED HS

  • Hur, Jin;Schlautman, Mark A.
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2003년도 추계학술발표회
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    • pp.123-127
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    • 2003
  • Changes in pyrene partitioning due to mineral surface adsorptive fractionation processes of humic substances (HS) were examined in model environmental systems. For purified Aldrich humic acid(PAHA), carbon-normalized pyrene binding coefficients ( $K_{oc}$ ) for the residual (i.e., nonadsorbed and dissolved) PAHA components were different from the original dissolved PAHA $K_{oc}$ , value prior to contact with mineral suspensions. A positive correlation between the extent of pyrene binding and weight-average molecular weight (M $W_{w}$) of residual PAHA components was observed, which appeared to be unaffected by the specific mineral adsorbents use and fractionation mechanisms. A similar positive correlation was not observed with the adsorbed PAHA components, suggesting that conformational changes occurred for the mineral-associated components upon adsorption. Nonlinear pyrene sorption to mineral-associated PAHA was observed, and the degree of nonlinearity is hypothesized to be dependent on adsorptive fractionation effects and/or structural rearrangement of the adsorbed PAHA components.s.

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현행 중량바닥충격음 평가방법 개선을 위한 주관평가실험 (Subjective Assessment of Simulated Heavy Floor Impact Sounds for Alternative Rating Method)

  • 신훈;김선우;장길수
    • 한국소음진동공학회논문집
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    • 제19권3호
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    • pp.282-287
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    • 2009
  • This study aims to examine the existing single rating index in terms of level reduction limit of heavy-weight floor impact sound. To achieve this goal, sounds which have same loudness according to rating methods were suggested to subjects. And followings are results. 1) The rating method of measurement frequency level average is more suitable than that of other methods which are dependent on specific frequency for rating heavy-weight floor impact sound. 2) Level average for measurement frequency of $31.5\;Hz{\sim}500\;Hz$ is more correspondent to psycho-acoustic response than that of measurement frequency of $63\;Hz{\sim}500\;Hz$ which is for KS F 2863-2, existing rating method.

기능성 경량기포콘크리트의 물리적 특성에 관한 실험적 연구 (A Study of Mechanical characteristics of functional Autoclaved Lightweight Concrete)

  • 김순호;김홍룡
    • KIEAE Journal
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    • 제7권5호
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    • pp.121-126
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    • 2007
  • This is the experimental study on the functional property of the light-weight concrete according to the mineral composite. According to the increase of the functional mineral, Autoclaved light-weight concrete (ALC) have a effect of high far infrared ray, deodorization, anion and change of chromaticity on D65 of light source. Compressive strength and change of specific gravity by foaming of Mixed Slurry in accordance with additive rates and Water. It chracterizes surface by SEM, chemical component and crystallization by XRD, XRF. the results of this experiment studied influences of ALC by functional minerals.

Distance Error Weight Function을 이용한 이동 로봇의 위치 추정 시스템의 설계 (Position Estimation of a Mobile Robot using Distance Error Weight Function)

  • 고재원;박재준;이기철;박민용
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 하계학술대회 논문집 G
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    • pp.3048-3050
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    • 1999
  • This paper suggests a position estimating algorithm using mono vision system with projective geometry method. Generally, 3-D information can not be easily extracted from mono vision system which is taken by a camera at a specific point. But this defect is overcome by adopting model-based image analysis and selecting lines and points on the ground as natural landmarks. And this paper suggests a method that estimates position from many natural landmarks by distance error weight function.

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무전해 니켈 도금법으로 제조된 니켈-다이아몬드 복합분체의 특성 (Characteristics of Nickel-Diamond Composite Powders by Electroless Nickel Plating)

  • 안종관;김동진;;이재령;이익규;정헌생
    • 한국분말재료학회지
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    • 제11권3호
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    • pp.224-232
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    • 2004
  • Ni-diamond composite powders with nickel layer of round-top type on the surface of synthetic diamond (140/170 mesh) were prepared by the electroless plating method (EN) with semi-batch reactor. The effects of nickel concentration, feeding rates of reductant, temperature, reaction time and stirring speeds on the weight percentage and morphology of deposited Ni, mean particle size and specific surface area of the composite powders were investigated by Atomic Adsortion Spectrometer, SEM-EDX, PSA and BET. It was found that nucleated Ni-P islands, acted as catalytic sites for further deposition and grown into these relatively thick layers with nodule-type on the surface of diamond by a lateral growth mechanism. The weight percentage of Ni in the composite powder increased with reaction time, feeding rate of reductant and temperature, but decreased with stirring speed. The weight percentage of Ni in Ni-diamond composite powder was 55% at 150 min., 200 rpm and 7$0^{\circ}C$ .