• 제목/요약/키워드: the strengthening ratio

검색결과 351건 처리시간 0.03초

지수치를 이용한 중국 성인여성의 체형 분석 -거주지역 및 세분시장을 중심으로- (The Analysis of Body Type of Chinese Women by the Body Index - Focusing on the residental district & specific markets -)

  • 김은희;손희순
    • 복식
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    • 제57권10호
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    • pp.35-49
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    • 2007
  • This study aims at strengthening the national competitiveness of Korea's clothing industry as it provides substantial information on type characteristics and body types for Chinese women and improves the fitness of clothing, considering human proportion in the production of clothing products for export to China. It divides the group by residental district and specific markets. It analyzes the part proportion of body types by each group. This selected specimen as 1,381 of Chinese women from 19 to 50 selected in random sampling in Shanghai and Beijing from 23th, June to 7th August in 2004. 1. Beijing women have long head length of 7.04 in proportion while Shanghai women have short head length of 7.14 in proportion. 2. For 19-24 years old women, head-to-height ratio (HHR) is 7.14, while 24-34 years old women and 35-50 years old women are 7.04 and 7.09 respectively.

응력의존성을 고려한 도로기초의 층변형 예측 (Prediction of Layer Rutting on Pavement Foundations Based on Stress Dependency)

  • 박성완
    • 한국지반공학회논문집
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    • 제21권7호
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    • pp.73-80
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    • 2005
  • 도로기초에서 입상재료의 응력의존 특성을 반영하면 응력의존 탄성계수와 응력 의존 포와송 비 모두를 동시에 고려할 수 있다. 이 방식은 기존 연속체 역학에 기초한 해석 방식과는 달리 층모형 내에서 인장력의 발생 대신 압축력의 구현이 가능하여 재료의 강성과 연성에 대한 거동을 동시에 반영하여 입상재료층의 변형 예측에 많은 영향을 주고 있다 따라서 본 논문에서는 도로기초를 대상으로 제안된 응력의존 및 변형 모형을 대상으로 유한요소법에 의한 도로기초 층변형 예측 알고리즘을 제안하였고 층변형 예측시 응력의존의 고려에 따른 영향을 분석하였다.

Study on strength of reinforced concrete filled circular steel tubular columns

  • Hua, Wei;Wang, Hai-Jun;Hasegawa, Akira;Shioi, Yukitake;Iwasaki, Shoji;Miyamoto, Yutaka
    • Structural Engineering and Mechanics
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    • 제19권6호
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    • pp.653-677
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    • 2005
  • Concrete filled steel tubular columns (CFT) are widely used in civil engineering works, especially in large scale of works because of high strength, deformation, toughness and so on. On the other hand, as a kind of strengthening measure for seriously damaged reinforced concrete piers of viaduct in Hansin-Awaji earthquake of Japan in 1995, reinforced concrete piers were wrapped with steel plate. Then, a new kind of structure appeared, that is, reinforced concrete filled steel tubular column (RCFT). In this paper, compression test and bending-shearing test on RCFT are carried out. The main parameters of experiments are (1) strength of concrete, (2) steel tube with or without rib, (3) width-thickness ratio and (4) arrangement of reinforcing bars. According to the experimental results, the effect of parameters on mechanical characteristics of RCFT is analyzed clearly. At the same time, strength evaluation formula for RCFT column is proposed and tested by experimental results and existed recommendations (AIJ 1997). The strength calculated by the proposal formula is in good agreement with test result. As a result, the proposed evaluation formula can evaluate the strength of RCFT column properly.

가시오가피의 종자 후숙처리시 배의 생장과 개갑 특성 (Characteristics of Embryo Growth and Dehiscence during the After-ripening Period in Eleutherococcus senticosus)

  • 박호기;박문수;김태수;김선;최경구;박기훈
    • 한국작물학회지
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    • 제42권6호
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    • pp.673-677
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    • 1997
  • 가시오가피 종자는 채종직후 미분화 상태의 배로 발아를 위해서는 후숙이 필요하다. 가시오가피 종자의 후숙을 위하여 습윤층적처리한 후 미분화 배의 생장과 개갑특성을 조사한 결과는 다음과 같다. 1. 가시오가피의 내과피를 포함한 종자의 형태는 길이 7.1$\pm$0.9mm, 폭 3.0$\pm$0.3mm, 두께 1.47$\pm$0.12mm 정도이었으며 1,000 입중 18.5$\pm$1.9g 정도이었다. 2. 가시오가피 종자의 후숙전 0.30$\pm$0.06mm 정도이며 배장율은 .4.8%의 미분화 배로 층적처리 20일 전후에 배의 생장이 시작되었고 40일 전후에 배축과 자엽이 분화되었다. 3. 후숙기간과 배장율과는 높은 정의 상관(r=0.845)을 보였으며 배의 생장은 층적처리 후 60~80일 사이에 급격히 증가하였고 후숙 80일 이후에는 증가폭이 다소 둔화되었다. 4. 가시오가피 종자는 배가 어느 정도 생장하면 종피의 봉선이 터져 열개되는 개갑종자이었으며 배장율 60~70%에서 가장 높은 개갑빈도를 나타냈다. 5. 개갑율은 후숙 40일에 15.3%가 개갑되었고 60일 이후 개갑율이 급격히 증가되었으며 후숙 150일에 76.5%가 개갑되었다.

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Flexural ductility of reinforced HSC beams strengthened with CFRP sheets

  • Hashemi, Seyed Hamid;Maghsoudi, Ali Akbar;Rahgozar, Reza
    • Structural Engineering and Mechanics
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    • 제30권4호
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    • pp.403-426
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    • 2008
  • Externally bonding fiber reinforced polymer (FRP) sheets with an epoxy resin is an effective technique for strengthening and repairing reinforced concrete (RC) beams under flexural loads. Their resistance to electro-chemical corrosion, high strength-to-weight ratio, larger creep strain, fatigue resistance, and nonmagnetic and nonmetallic properties make carbon fiber reinforced polymer (CFRP) composites a viable alternative to bonding of steel plates in repair and rehabilitation of RC structures. The objective of this investigation is to study the effectiveness of CFRP sheets on ductility and flexural strength of reinforced high strength concrete (HSC) beams. This objective is achieved by conducting the following tasks: (1) flexural four-point testing of reinforced HSC beams strengthened with different amounts of cross-ply of CFRP sheets with different amount of tensile reinforcement up to failure; (2) calculating the effect of different layouts of CFRP sheets on the flexural strength; (3) Evaluating the failure modes; (4) developing an analytical procedure based on compatibility of deformations and equilibrium of forces to calculate the flexural strength of reinforced HSC beams strengthened with CFRP composites; and (5) comparing the analytical calculations with experimental results.

Cyclic testing of steel I-beams reinforced with GFRP

  • Egilmez, O. Ozgur;Yormaz, Doruk
    • Steel and Composite Structures
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    • 제11권2호
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    • pp.93-114
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    • 2011
  • Flange and web local buckling in beam plastic hinge regions of steel moment frames can prevent beam-column connections from achieving adequate plastic rotations under earthquake-induced forces. This threat is especially valid for existing steel moment frame buildings with beams that lack adequate flange/web slenderness ratios. As the use of fiber reinforced polymers (FRP) have increased in strengthening and repair of steel members in recent years, using FRPs in stabilizing local instabilities have also attracted attention. Previous computational studies have shown that longitudinally oriented glass FRP (GFRP) strips may serve to moderately brace beam flanges against the occurrence of local buckling during plastic hinging. An experimental study was conducted at Izmir Institute of Technology investigating the effects of GFRP reinforcement on local buckling behavior of existing steel I-beams with flange slenderness ratios (FSR) exceeding the slenderness limits set forth in current seismic design specifications and modified by a bottom flange triangular welded haunch. Four European HE400AA steel beams with a depth/width ratio of 1.26 and FSR of 11.4 were cyclically loaded up to 4% rotation in a cantilever beam test set-up. Both bare beams and beams with GFRP sheets were tested in order to investigate the contribution of GFRP sheets in mitigating local flange buckling. Different configurations of GFRP sheets were considered. The tests have shown that GFRP reinforcement can moderately mitigate inelastic flange local buckling.

Ti-15-3합금의 결정립 미세화가 인장 특성에 미치는 영향 (Effect of Grain Refinement on Tensile Properties of Ti-15-3 Alloy)

  • 이찬영;박용민;이영국
    • 한국재료학회지
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    • 제19권11호
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    • pp.619-624
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    • 2009
  • Titanium alloys have been attractive due to a high ratio of strength to weight as well as good corrosion resistance. However, strengthening causes a decrease in ductility in Ti alloys, as is usual in other alloys. For enhanced strength without ductility reduction, grain refinement and tensile properties were investigated as functions of thickness reduction of cold rolling and annealing condition in Ti-15V-3Cr-3Sn-3Al alloy with a ${\beta}$ single phase. The average grain size of the specimen, which was cold-rolled by 90% and annealed at 700$^{\circ}C$ for 5 min, was decreased to approximately 19 ${\mu}m$. The grain refinement of 63 μm to 19 ${\mu}m$ increased yield stress by 90 MPa without a significant decrease in total elongation. The Ti-15-3 alloy exhibited very low work hardening during tensile test at a crosshead speed of 2 mm/min. This result was discussed based on dynamic recovery associated with dislocation annihilation in grain boundaries.

국제해상컨테이너운송에서 보안강화를 위한 전자태그(IC tag)의 적용과 대응방안 (A study on the application and counter measures of IC tag in international marine container transport)

  • 한상현;최준호
    • 통상정보연구
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    • 제12권2호
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    • pp.133-158
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    • 2010
  • Since 11 September 2001, the awareness of terrorists' actions has clearly risen. The potential threat of terrorists using containers poses a large risk to our economies and to our societies. In order to protect cargo from damage and terrorist threats, business and government turn to RFID and IC tags, and tradition container is replaced by IC smart container. In this study, presented application of IC tag and future tasks to Container transport by sea in viewpoint of security strengthening. First, realization and international SCM realization structural order that cover container supply chain whole of international standardization and association between industry are certainly needed. Second, it may have to try in technical development for IC tag Ratio that can read elevation moment develop suitable IC tag or reader in International Standard. Third, Need to establish concrete use policy as soon as possible in national dimension at the same time effort for international standard normalization of frequency. Finally, it shows to uses jointly with electron sealing and must solve problem about usable plan and information leak.

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변형경화형 시멘트 복합체(SHCC)로 보-기둥 접합부 단면이 증설된 휨항복형 철근콘크리트 보의 구조성능 (Structural Performance of Flexural Dominant Reinforced Concrete Beams strengthened in Beam-Column Joint with SHCC)

  • 송선화;장광수;김윤수;김선우;김용철;윤현도
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2008년도 추계 학술발표회 제20권2호
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    • pp.53-56
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    • 2008
  • 대부분의 철근콘크리트 라멘 구조물은 지진하중 작용 시 가장 취약한 부분인 보-기둥 접합부 영역에서 큰 피해를 유발할 수 있다. 이러한 피해를 방지하기 위하여 보수 및 보강에 관한 연구가 이루어지고 있으며, 전 세계적으로 내진규정이 강화되고 구조물의 내진성능이 중요시되면서 지진에 효율적으로 저항할 수 있는 성능을 확보한 재료 개발이 증가되고 있다. 변형경화형 시멘트 복합체(Strain-hardening cementitious composite, SHCC)는 연성능력이 우수하여 보-기둥 접합부 영역에서 상당한 보강효과가 기대된다. 따라서 본 연구에서는 SHCC로 접합부를 보강한 철근콘크리트 보의 보강특성을 평가하고자 총 3개의 실험체를 제작하였다. 실험을 통하여 균열 및 파괴양상에 대하여 휨거동 특성을 평가하고 섬유 혼입률에 따른 SHCC의 보강효과에 대한 강도를 비교하였다.

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중소기업 육성을 위한 기술혁신역량 평가모형개발 (Developing Technology Innovation Capability Evaluation Model for Small and Medium Enterprises)

  • 조중길;이상순;변민석;이종환;강경수;이승빈
    • 산업경영시스템학회지
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    • 제38권1호
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    • pp.162-169
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    • 2015
  • In this research, technology innovation capability evaluation model for small and medium enterprises was developed. To develop technology innovation capability evaluation model, two analytic technic was used. First one is AHP (Analytic Hierarchy Process) to give weight to each main index. Second one is fuzzy set theory to represent ambiguous index to numerical value. Finally, technology innovation capability evaluation model was achieved in combination with the same weight to AHP analysis and fuzzy set theory. With these results, small and medium enterprises can know important point in terms of strengthening the innovation capability evaluation.