• 제목/요약/키워드: Time Shortening

검색결과 664건 처리시간 0.024초

철도곡선부 개량에 따른 열차운행시간 단축효과에 관한 연구 (A Study on the Shortening Effect of Train Running Time as Railway curve sections improvement)

  • 조규전;이남수;정의환
    • 한국측량학회지
    • /
    • 제14권2호
    • /
    • pp.229-239
    • /
    • 1996
  • 교통기관으로서의 역할을 충분히 수행하기 위해서 철도속도향상을 통한 운행시간 단축은 인간의 생활양식 고급화 및 시간가치의 증대로 인해 절실히 요구되는 사항으로 부각되고 있다. 특히 열차운행속도에 매우 큰 영향을 주는 선형 요소는 곡선구간으로서, 우리나라의 경우 곡선구간이 많은 비율을 차지하고 있어 이 구간에서의 속도향상은 전체구간의 운행시간을 단축시킬 수 있기 때문에 우리나라의 선형에 대한 특성을 고려하여 곡선부 전체구간에 걸쳐서는 선형을 지배하고 있는 요소의 개량 및 부분적 개량방법으로 사용되는 완화곡선 연장기법을 각 단계에 걸쳐 주행안정성 및 승차감의 지표로서 이용하고 있는 횡가속도 값을 적용하여 속도향상를 통한 운행시간 단축효과를 얻었다. 이 결과 우리나라 선형조건상 곡선부 전구간을 개량하는 것이 운행시간을 단축하기 위해서는 완화곡선의 연장 방법 보다 효과적임을 나타내고 있다.

  • PDF

철근콘크리트 고층 건물의 부등 수직변위 해석 (Analysis of Differential Shortening of Reinforced Concrete High - Rise Building)

  • 신영수;성렬영;신성우
    • 한국콘크리트학회:학술대회논문집
    • /
    • 한국콘크리트학회 1993년도 봄 학술발표회 논문집
    • /
    • pp.142-147
    • /
    • 1993
  • In the reinforced concrete structure, as the height of building structure increases, the accurate estimation of differential column shortening is important factor in the structural design. In this study, the analysis of column shortening is applied to 36-story building structure to be built in time. As a result, it may found that, as the difference of compressive stress become larger, differential shortening effect due to creep and shrinkage are more signicant factor to structural designer.

  • PDF

고층건물 기둥의 부등축소량 예측 및 시공오차 보정에 관한 연구 (Prediction and Compensation of Differential Column Shortening in High-Rise Building Structures)

  • 조창휘;송진규;이현호;조석희
    • 한국전산구조공학회:학술대회논문집
    • /
    • 한국전산구조공학회 1996년도 가을 학술발표회 논문집
    • /
    • pp.258-266
    • /
    • 1996
  • The purpose of this study is to make a reasonable correction in construction stage through exact prediction of long-time differential column shortening that occurs in the high-rise RC building. For this, a self-developed program adopted PCA code is used to predict differential column shortening with sequential loading process. Using this program, the amount of the different column shortening of Amatapura Apartment in Indonesia is predicted and the effect is analyzed. From the result, the major factor affecting the shortening amount in columns is elastic strain and the effect of shrinkage is very small rather than creep. And maximun differential column shortening is appeared near the middle of the building.

  • PDF

기둥축소량 보정법에 있어서 시공성 향상을 위한 RC 슬래브 표면마무리에 관한 연구 (A study on the finish work of Reinforced Con'c slab for improving workability in the column shortening compensation.)

  • 소광호;이재옥;양극영
    • 한국건축시공학회:학술대회논문집
    • /
    • 한국건축시공학회 2003년도 학술.기술논문발표회
    • /
    • pp.147-152
    • /
    • 2003
  • Passage of time axial shortening in the cores and columns of tall concrete buildings requires special attention to ensure proper behavior for strength of the structure and the nonstructural element. The effects of column shortening, both elastic and inelastic, take on added significance and need special consideration in design and construction with increased height of structures. In this paper, the compensation method of column shortening for reinforced concrete structure are introduced. It could be concluded that the survey is a significant factor for the compensation instance of column shortening.

  • PDF

OFDM시스템을 위한 채널 shortening기법들의 비교 (A Comparative Studies of Channel Shortening Techniques for OFDM System)

  • 김재권
    • 한국정보전자통신기술학회논문지
    • /
    • 제6권4호
    • /
    • pp.262-266
    • /
    • 2013
  • 직교 주파수 분할 다중 (OFDM) 시스템에서는 채널의 지연확산 특성의해 발생하는 심볼간의 간섭 (ISI)을 제거하기 위해, 채널의 길이보다 길거나 같은 cyclic prefix (CP)를 삽입한다. 그러나 긴 CP는 전송률을 감소시 킨다는 단점이 있다. 대안으로, CP로 인한 성능 열화를 줄이기 위해 수신부에서는 channel shortening 필터를 이용하여 유효 채널의 길이를 줄이는 방법이 제안되어 왔다. 본 논문에서는 기존에 제안 된 채널 shortening 기 법인 minimum shortened signal to noise ratio (MSSNR), mimimum interblock interference (min-IBI)와 minimum intersymbol interference (min-ISI)을 비교분석한다.

초고층 건축물의 수직부재 보정 방법에 관한 연구 (A Study on The Compensation Method of Vertical Members for High-rise building)

  • 이재옥;소광호;유인근;양극영
    • 한국건축시공학회:학술대회논문집
    • /
    • 한국건축시공학회 2003년도 학술.기술논문 발표회
    • /
    • pp.33-36
    • /
    • 2003
  • Time-dependent axial shortening in the cores and columns of tall concrete buildings requires special attention to ensure proper behavior for strength of the structure and the nonstructural clement. The effects of column shortening, both elastic and inelastic, take on added significance and need special consideration in design and construction with increased height of structures. In this paper, the compensation method of column shortening are introduced. It could be conclued that the survey is a significant factor for the compensation of column shortening.

  • PDF

초고층 건축물의 수직부재 보정 방법에 관한 연구 (A Study on The Compensation Method of Vertical Members for High-rise building)

  • 이재옥;소광호;유인근;양극영
    • 한국건축시공학회:학술대회논문집
    • /
    • 한국건축시공학회 2003년도 학술.기술논문발표회
    • /
    • pp.33-36
    • /
    • 2003
  • Time-dependent axial shortening in the cores and columns of tall concrete buildings requires special attention to ensure proper behavior for strength of the structure and the nonstructural element. The effects of column shortening, both elastic and inelastic, take on added significance and need special consideration in design and construction with increased height of structures. In this paper, the compensation method of column shortening are introduced. It could be concluded that the survey is a significant factor for the compensation of column shortening.

  • PDF

슬괵근 길이가 정적 기립균형 능력에 미치는 영향 (The Effects of Hamstring Length on the Static Stance Balance Ability)

  • 남건우;박대성
    • 대한정형도수물리치료학회지
    • /
    • 제13권2호
    • /
    • pp.45-54
    • /
    • 2007
  • The purpose of this study was effect of hamstring length on one leg stance test(OLST) in 108 persons. (men 28, women 80). The active knee extension test(AKE) was applied 3 times on both leg and high score was selected. Then, one leg stance test(OLST) was applied 3 times on both leg and high score was selected. Also, persons divided two group that is normal hamstring length group and shortening group). The result were as follows : 1. The correlation analysis between Lt. hamstring length and one leg stance time was no significant relation($p_{Lt.}=0.271$, $p_{Rt.}=0.051$). 2. The correlation analysis between Rt. hamstring length and one leg stance time was no significant relation($p_{Lt.}=0.837$, $p_{Rt.}=0.334$). 3. The independent T -test between Lt. hamstring normal (knee extension > 150degrees) & shortening group (knee extension ${\leq}$ 150 degrees) in Lt. leg stance time was no significant difference(p=0.73), but in Rt. leg stance time was statistically significant difference(p=0.04). 4. The independent T-test between Rt. hamstring normal (knee extension > 150degrees) & shortening group (knee extension ${\leq}$ 150 degrees) in one leg stance time was no significant difference($p_{Lt.}=0.09$, $p_{Rt.}=0.16$).

  • PDF

Minimization of differential column shortening and sequential analysis of RC 3D-frames using ANN

  • Njomo, Wilfried W.;Ozay, Giray
    • Structural Engineering and Mechanics
    • /
    • 제51권6호
    • /
    • pp.989-1003
    • /
    • 2014
  • In the preliminary design stage of an RC 3D-frame, repeated sequential analyses to determine optimal members' sizes and the investigation of the parameters required to minimize the differential column shortening are computational effort consuming, especially when considering various types of loads such as dead load, temperature action, time dependent effects, construction and live loads. Because the desired accuracy at this stage does not justify such luxury, two backpropagation feedforward artificial neural networks have been proposed in order to approximate this information. Instead of using a commercial software package, many references providing advanced principles have been considered to code a program and generate these neural networks. The first one predicts the typical amount of time between two phases, needed to achieve the minimum maximorum differential column shortening. The other network aims to prognosticate sequential analysis results from those of the simultaneous analysis. After the training stages, testing procedures have been carried out in order to ensure the generalization ability of these respective systems. Numerical cases are studied in order to find out how good these ANN match with the sequential finite element analysis. Comparison reveals an acceptable fit, enabling these systems to be safely used in the preliminary design stage.

Prediction of Time-dependent Lateral Movement Induced by Differential Shortening in Tall Buildings Using Construction Stage Analysis

  • Ha, Taehun;Kim, Sangdae;Lee, Sungho
    • 국제초고층학회논문집
    • /
    • 제6권1호
    • /
    • pp.11-19
    • /
    • 2017
  • High-rise buildings move during construction due to time-dependent material properties of concrete (creep and shrinkage), construction sequences, and structural shapes. The building movements, including vertical and horizontal displacements, result from the sum of axial and lateral deformation of vertical members at each level. In addition to the vertical shortenings, the lateral movement induced by differential shortening can have adverse effects on the construction tolerance and serviceability of non-structural elements such as elevators and curtain walls. In this study a construction stage analysis method is developed to predict lateral movement induced by shortening, including the effect of creep and shrinkage. The algorithm of construction stage analysis is combined with the FE analysis program. It is then applied to predict lateral movement of a 58-story reinforced concrete building that was constructed in Kuala Lumpur, Malaysia. Gravity induced lateral movement of this building is predicted by the construction stage analysis. A field three-dimensional laser scanning survey is carried out to verify the prediction results, and satisfactory agreement is obtained.