• 제목/요약/키워드: sMOE

검색결과 144건 처리시간 0.023초

죽령 및 벌채시기에 따른 맹종죽재의 물리적ㆍ기계적 특성 (Physical and Mechanical Properties of Phyllostachys pubescens According to Growth Age or Felling Time)

  • 안상열;신훈재;변희섭;박상범;공영토
    • 임산에너지
    • /
    • 제22권1호
    • /
    • pp.8-16
    • /
    • 2003
  • 경남 진주시 가좌동에 위치한 남부임업시험장내의 생육이 양호한 1년산, 2년산, 3년산의 맹종죽을 이용하여 2001년 6월부터 다음해인 2002년 5월까지 실험을 실시하여 죽령과 벌채시기(달별)에 따른 물리적ㆍ기계적 성질에 대한 실험 결과는 다음과 같다. 생장부위에 따라서는 상부위에서 밀도, MOEs, MOE/sub d/의 값이 가장 높게 나타났으며, 또한 전체 밀도와 3년생의 MOEs와 MOE/sub d/는 벌채시기가 늦어질수록 점차적으로 그 값이 증가하였다. 그러나 함수율과 1, 2년산의 맹종죽재에서는 뚜렷한 차이점을 보이지 않아 죽령과 벌채시기에 따라서는 아무런 경향을 나타내지 않았다. MOEs와 MOE/sub d/의 상관관계에 있어서 r값은 생재가 0.88, 기건재가 0.92로 나타났으며, MOE/sub d/가 MOEs의 값보다 생재가 18.5%, 기건재가 7%정도 높게 나타났다. 또한 죽령과 벌채시기에 따른 MOEs와 MOE/sub d/가 거의 동일한 경향으로 매우 잘 대응하여 맹종죽재의 탄성적 성질을 평가하는데 있어서 공진주파수를 이용한 비파괴 측정법이 일반 소재와 마찬가지로 맹종죽재의 경우에도 이용 가능하였다.

  • PDF

Effect of a Time Dependent Concrete Modulus of Elasticity on Prestress Losses in Bridge Girders

  • Singh, Brahama P.;Yazdani, Nur;Ramirez, Guillermo
    • International Journal of Concrete Structures and Materials
    • /
    • 제7권3호
    • /
    • pp.183-191
    • /
    • 2013
  • Prestress losses assumed for bridge girder design and deflection analyses are dependent on the concrete modulus of elasticity (MOE). Most design specifications, such as the American Association of State Highways and Transportation Officials (AASHTO) bridge specifications, contain a constant value for the MOE based on the unit weight of concrete and the concrete compressive strength at 28 days. It has been shown in the past that that the concrete MOE varies with the age of concrete. The purpose of this study was to evaluate the effect of a time-dependent and variable MOE on the prestress losses assumed for bridge girder design. For this purpose, three different variable MOE models from the literature were investigated: Dischinger (Der Bauingenieur 47/48(20):563-572, 1939a; Der Bauingenieur 5/6(20):53-63, 1939b; Der Bauingenieur, 21/22(20):286-437, 1939c), American Concrete Institute (ACI) 209 (Tech. Rep. ACI 209R-92, 1992) and CEB-FIP (CEB-FIP Model Code, 2010). A typical bridge layout for the Dallas, Texas, USA, area was assumed herein. A prestressed concrete beam design and analysis program from the Texas Department of Transportation (TxDOT) was utilized to determine the prestress losses. The values of the time dependent MOE and also specific prestress losses from each model were compared. The MOE predictions based on the ACI and the CEB-FIP models were close to each other; in long-term, they approach the constant AASHTO value. Dischinger's model provides for higher MOE values. The elastic shortening and the long term losses from the variable MOE models are lower than that using a constant MOE up to deck casting time. In long term, the variable MOE-based losses approach that from the constant MOE predictions. The Dischinger model would result in more conservative girder design while the ACI and the CEB-FIP models would result in designs more consistent with the AASHTO approach.

스트랜드/파티클 복합체의 기계적 성질에 관한 연구(I) - 단면구성이 기초물성에 미치는 영향 - (A Study on Mechanical Properties of Strand/Particle Composites(I) - Effect of Layer Constructions -)

  • 김유정;시부사와 타츠야
    • Journal of the Korean Wood Science and Technology
    • /
    • 제28권3호
    • /
    • pp.1-8
    • /
    • 2000
  • 본 연구는 미이용 자원인 소경목(小經木) 조생수(早生樹) 등의 저질원료로부터 고성능을 지니는 구조용 보드를 제조하는 기술을 개발하는 것을 목적으로 하여 할렬 스트랜드 (S)/파티클(P) 복합체의 층구조와 S와 P의 혼합비율을 바꾼 단면구성에 따른 기초적 물성을 검토했다. 그 결과 스트랜드층을 포함하고 있는 SP 복합체의 경우, 전체적으로 휨성능(MOR, MOE)이 매우 높았다. 또 S단층 보드는 현저한 이방성을 나타내었지만 층구조가 PB에 가까워질수록 이방성은 감소하여, 7층 구조의 복합체는 이방성이 적었으며 특히 SP7은 직교방향도 휨강도가 높았다. 습윤시 휨강도 성능도 같은 경향을 나타내었다. 박리강도(IB)는 PB가 가장 높았고, 스트랜드층을 가진 복합체는 거의 같은 값을 나타내었다. 두께팽창율(TS) 은 PB가 가장 적은 값을 나타내었으며, 표층이 P층인 구조가 S표층구조보다 적은 경향을 나타내었다. 복합체의 표면특성은 표층 엘리먼트의 영향을 받아, 적고 미세한 엘리먼트인 P표층의 복합체가 크고 두꺼운 S표층 복합체보다 양호하였다. S와 P의 혼합비율의 영향은, SP비(比)를 증가시켜도 강도물성(MOR, MOE, IB)은 향상되지 않으며, 오히려 저하되는 것도 있었다. 두께팽창율(TS)은 SP 비(比) 1:1 이상의 복합체에서는 S만으로 제조한 보드와 같은 정도의 값을 나타내었다.

  • PDF

전장 정보체계의 전투력 상승효과 측정을 위한 새로운 MOE 제안 (A Proposal of New MOE to Assess the Combat Power Synergistic Effect of Warfare Information System)

  • 이용복;정환식;김용흡;이재영
    • 산업공학
    • /
    • 제22권3호
    • /
    • pp.205-213
    • /
    • 2009
  • Warfare information system is a core factor of future combat operation under NCW(Network centric Warfare) environment. In this paper, we proposed a new MOE(Measure of Effectiveness) that can assess the combat power synergistic effect of warfare information system in the theater-level joint fire operation. This new MOE uses the rule of Newton's second law($F=(m{\Delta}{\upsilon})/{\Delta}t{\Rightarrow}(M{\upsilon}I)/T$). Four factors considered in combat power evaluation are network power(M), movement velocity(v), information superiority(I), command and control time(T). We applied this new MOE to the JFOS-K(Joint Fire Operating System-Korea) to assess its combat power effect and compared with other's effects obtained from different MOE.

님비와 폐기물처리시설 설치 방향 (The Nimby Syndrome and Basic Plan for Waste Treatment Facilities in 1994)

  • 신현국
    • 한국지반공학회:학술대회논문집
    • /
    • 한국지반공학회 1994년도 봄 학술발표회 논문집
    • /
    • pp.59-64
    • /
    • 1994
  • In order to democractically resolve the "not-in-my-backyard" (Nimby syndrome) which is widespread in Korea, the policy of the Ministry of Environmnt(MOE) is that the MOE is willing to negotiate with local inhabitants who refuse to allow the establishment of waste treatment facilities, and that such facilities will be safety and effectively constructed and managed. According to this policy, the MOE has developed a basic plan to construct 255 incinerators by the year 2001, and establish 42 sanitary landfill sites and 5 specific waste treatment facilities in 1994.s in 1994.

  • PDF

공진주파수에 의한 목재의 동적탄성계수 추정 (Estimation of the Dynamic MOE in Woods with Resonance Frequency)

  • 이원희;황권환
    • Journal of the Korean Wood Science and Technology
    • /
    • 제25권1호
    • /
    • pp.42-49
    • /
    • 1997
  • The purpose of this study was to investigate the relationships among density, moisture content, and modulus of elasticity in which are important characteristics in physical and mechanical properties of woods. In this study, the dynamic MOE was calculated through the combination with resonance frequency of transverse vibration method and density, and the estimated moisture contents were calculated with two different equations (1, 2) in order to compare with experimental moisture contents. The following results from this study were obtained: 1. According to the regression analysis with two different parameters (E and density), the two regression lines appeared to be straight intersecting at 0.6 density. As another factor, moisture contents in wood also influenced on the analysing regression at the below F.S.P. 2. When considering the relationship between moisture contents and E, the tendency of each moisture content and E showed very similar pattern suggesting that moisture contents in addition to density are very important parameter. 3. When together with moisture contents and density as parameters for multiple regression analysis, coefficiences of determinations are dramatically improved. Interestingly, the coefficiences of determinations are further increased when analysing at the below point of F.S.P. and when analysing higher and lower density separately. In summary, more correct estimation of the dynamic MOE of woods can be possible with only transverse vibration and density in wood. Therefore, with this indirect method, the calculation of MOE in all kinds of woods including timber, live tree and wood products can be feasible resulting in accelerating the efficiency of time and labor.

  • PDF

경사핑거접합법에 의한 소나무재의 휨강도성능개량 (I) (Improvement of Bending Performances by Sloped Finger-Joint Method in Pinus densiflora S. et Z. (I))

  • 변희섭;박한민;김종만
    • Journal of the Korean Wood Science and Technology
    • /
    • 제25권4호
    • /
    • pp.61-67
    • /
    • 1997
  • The bending performances of sloped finger-joints in Pinus densiflora S. et Z. were tested in order to improve the strength properties of finger-joint Sloped finger-cut pieces were jointed with four kinds of adhesives(resorcinol-phenol, oilic urethane, polyvinyl acetate, and polyvinyl-acryl acetate resin). The slope ratios of finger joints were 0, 0.5, 1.0, 2.0. The MOE, MOR and defletion to maximum load in bending of sloped finger-joints and solid wood specimen were measured. The results were: 1. The efficiencies of MOE to finger and sloped finger-joints were 82% or greater in every kind of adhesives except polyvinyl-acryl acetate resin adhesive and there were some effect of slope on the MOE in a sloped finger-joint for polyvinyl-acryl acetate and oilic urethane resin adhesives. 2. The effects of slope on the MOR to sloped finger-joints were showed in every kind of adhesive, because the efficiencies of MOR increased with increasing slope ratio in sloped finger-joints. The efficiencies of MOR to slope ratios of 0 and 2.0 ranged 43~65% and 76~82%, respectively. There was almost no effect of the kinds of adhesives on the MOR to the slope ratio of 2.0. 3. It was found impossible to estimate the bending strength of sloped finger-jointed Pinus densiflora S. et Z. by using MOE. The correlation coefficient(0.124) between MOE and MOR was very low and not significant at 5% level.

  • PDF

도료제조업종에서 취급하는 유독물의 GHS 분류 통일화 방안 연구 (A Study on the Harmonization of Poisonous Substance Used in Paint Manufacture)

  • 이종한;홍문기;김현지;박상희
    • 한국산업보건학회지
    • /
    • 제23권2호
    • /
    • pp.156-163
    • /
    • 2013
  • Objectives: Numerous poisonous substances are used in paint manufacture, but there are differences in the results of GHS classification between the Ministry of Labor(MOL) and the Ministry of Environment(MOE). Therefore, paint manufacturers suffer confusion as to how to classify a given chemical's risk and hazard level. This paper was designed to compare the classification results of chemicals by the MOL and the MOE and suggest a harmonization measure. Methods: After selecting 25 poisonous substances from among the organic solvents, pigments, and additives used in paint manufacturer, the GHS classification results by MOL and MOE were compared. Further the logic and classification of the GHS proposed by each Ministry was analyzed. Based on the derived results, a harmonization plan was proposed. Results: Based on the GHS classification of the poisonous substances, the concordance is 10.0-66.6 %, excluded flammable liquid. The GHS classifications differed based on the suggested building blocks, the sub-classification method used, the references(data sources), and subjective judgment of the experts from each Ministry. In order to pursue the harmonization plan, cooperation is demanded from the MOL and MOE.

전장 정보체계의 전투력 상승효과 측정을 위한 새로운 MOE 제안 (A proposal of new MOE to assess the combat power synergistic effect of warfare information system.)

  • 이용복;김용흡;이재영
    • 한국경영과학회:학술대회논문집
    • /
    • 한국경영과학회 2008년도 추계학술대회 및 정기총회
    • /
    • pp.104-112
    • /
    • 2008
  • In modern war information system development makes battlefield materialize, and combat factors can maximize combat power exhibition as that apply synchronization. Information system is the core of combat power operation under NCW(Network centric Warfare). This paper proposed a new MOE(Measure of Effectiveness) that can assess the combat power synergistic effect of information system at the theater joint fire operation in NCW environment. This methodology applied the rule of Newton's second law $F=(m{\Delta}{\upsilon})/t{\Rightarrow}(M{\upsilon}I)/T$) Details factor in combat power evaluation is as following. (1) M : Network power; (2) v : Movement velocity; (3) I : Information superiority; (4) T : C2(command and control) time. We applied this methodology to the "JFOS-K(Joint Fire Operating System-Korea) in Joint Chief of Staff" in the real military affair section.

  • PDF

톱밥-귤박 파티클보드의 역학적 성능에 미치는 밀도와 귤박첨가율의 영향 (Effect of Density and Mixing Ratio of Mandarin Peels on The Bending Performance of Sawdust-Mandarin Peels Particleboards)

  • ;강춘원;오승원;황정우
    • Journal of the Korean Wood Science and Technology
    • /
    • 제43권3호
    • /
    • pp.364-373
    • /
    • 2015
  • 본 연구는 밀도와 귤박첨가율이 다른 톱밥-귤박 파티클보드의 동적 정적탄성계수와 휨강도를 측정, 비교하여 밀도와 귤박의 첨가율이 파티클보드의 역학적 성능에 주는 영향과 동적탄성계수와 정적 휨강도 성능사이의 관계를 조사하였다. 톱밥-귤박 파티클보드의 밀도가 0.4에서 $0.6g/cm^3$로 증가할수록 휨성능은 증가하여, 밀도가 휨성능에 크게 영향하였으며, 밀도 $0.4g/cm^3$$0.5g/cm^3$의 톱밥-귤박 파티클보드에서 귤박의 첨가량이 증가할수록 휨성능은 감소하는 경향을 나타내었다. 톱밥-귤박 파티클보드의 동적탄성계수, 정적탄성계수 그리고 휨강도 사이에 높은 상관관계가 확인되었으며 양단 자유 휨진동시험에 의한 동적탄성계수로부터 비파괴적으로 정적 휨강도 성능의 예측이 가능할 것으로 사료되었다.