• 제목/요약/키워드: Partial Safety Factors

검색결과 100건 처리시간 0.022초

지오그리드의 시공시 손상 및 크리프 복합효과에 대한 실험적 연구 (An Experimental Study on the Combined Effect of Installation Damage and Creep of Geogrids)

  • 조삼덕;이광우;오세용;이도희
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2005년도 춘계 학술발표회 논문집
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    • pp.561-568
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    • 2005
  • The factors affecting the long-term design strength of geogrid can be classified into factors on creep deformation, installation damage, temperature, chemical degradation and biological degradation. Especially, creep deformation and installation damage are considered as main factors to determine the long-term design strength of geogrid. Current practice in the design of reinforced soil is to calculate the long-term design strength of a reinforcement damaged during installation by multiplying the two partial safety factors, $RF_{ID} and RF_{CR}$. This method assumes that there is no synergy effect between installation damage and creep deformation of geogrids. Therefore, this paper describes the results of a series of experimental study, which are carried out to assess the combined effect of installation damage and creep deformation for the long-term design strength of geogrid reinforcement. The results of this study show that the tensile strength reduction factors, RF, considering combined effect between installation damage and creep deformation is less than that calculated by the current design method.

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Tubular composite beam-columns of annular cross-sections and their design practice

  • Kvedaras, A.K.;Kudzys, A.
    • Steel and Composite Structures
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    • 제10권2호
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    • pp.109-128
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    • 2010
  • The expediency of using tubular composite steel and concrete columns of annular cross-sections in construction is discussed. The new type space framework with tubular composite columns of multi-storey buildings and its rigid beam-column joints are demonstrated. The features of interaction between the circular steel tube and spun concrete stress-strain states during the concentrical and eccentrical loading of tubular composite members are considered. The modeling of the bearing capacity of beam-columns of composite annular cross-sections is based on the concepts of bending with a concentrical force and compression with a bending moment. The comparison of modeling results for the composite cross-sections of beam-columns is analysed. The expediency of using these concepts for the limit state verification of beam-columns in the methods of the partial safety factors design (PSFD) legitimated in Europe and the load and resistance factors design (LRFD) used in other countries is presented and illustrated by a numerical example.

간접 패턴을 이용하는 스마트폰 보안 키패드 설계 (Design of Smartphone Secure Keypad Using Indirect Pattern)

  • 최동민
    • 한국멀티미디어학회논문지
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    • 제25권7호
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    • pp.932-944
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    • 2022
  • Smartphones, are currently equipped with high-performance hardware to process large amounts of data and provide most of the functions provided by desktop PCs. In addition, the smartphones enable quick user authentication through biometric information collected from embedded sensors. However, the biometric authentication method is sometimes rejected due to social and cultural environment, security vulnerabilities, and misrecognition rate. Thus, conventional authentication methods such as PIN and pattern authentication are still mainly used. Consider the latest foldable and bendable smartphones. These devices may be vulnerable to social engineering attacks as they use conventional authentication methods without considering their form factors. In this study, therefore, we propose an authentication method using partial elements of PIN and pattern authentication as a way to increase the security of the conventional authentication methods and consider the recent form factors. According to the performance evaluation results, our method provides improved safety compared to the conventional methods.

응급부 진입구역과 환자분류구역의 감염관리를 위한 환자동선과 공간구성 계획에 대한 연구 (A Study on the Guideline of Spatial Composition and Circulation in Triages and Entrances Area in Emergency Departments for Efficient Infection Control)

  • 강지은;권순정
    • 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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    • 제25권1호
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    • pp.41-49
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    • 2019
  • Purpose: After Mers breakout in 2015, major hospital in Korea have been renovated the emergency department to make a separate infection control zone for high-risk patient with potential infection and to improve a triage area and an entrance area for efficient patient evaluation. However, there are no specific design standards to reinforce infection control for patients and staffs safety. Therefore, it is important to establish of initial design factors in the triage and entrance area as a guideline. Methods: 5 cases which had been recently renovated are selected to analyze patient circulation and spatial composition in a triage area and an entrance area. The partial floor plans of each case are represented as bubble diagrams to help understanding of different patient circulation flows. Based on this analysis, significant design factors which should be considered in planning stage for infection control have been extracted. Results: 13 design factors are established. Using these design factors, patient circulation diagram is generated to provide an optimized suggestion for efficient infection control. Implications: This suggestion provides basic databases to start to establish design guideline in the triage area and the entrance area to minimize infection spreading in the emergency department.

Efficacy and Safety of First Line Vincristine with Doxorubicin, Bleomycin and Dacarbazine (ABOD) for Hodgkin's Lymphoma: a Single Institute Experience

  • Ozdemir, Nuriye;Dogan, Mutlu;Sendur, Mehmet Ali Nahit;Yazici, Ozan;Abali, Huseyin;Yazilitas, Dogan;Akinci, Muhammed Bulent;Aksoy, Sercan;Zengi, Nurullah
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권20호
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    • pp.8715-8718
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    • 2014
  • Background: ABVD (doxorubicin, bleomycin, vinblastine (Vb) and dacarbazine) is the standard regimen in Hodgkin's lymphoma (HL).Vincristine (O) is a mitotic spindle agent like Vb. We aimed to evaluate the efficacy and safety of O as a part of ABOD in HL. Materials and Methods: Patients who had ABOD were enrolled. Stage I-II HL were evaluated for unfavorable risk factors according to NCCN. National Cancer Institute Common Toxicity Criteria was used for toxicity. Results: Seventy-nine HL patients in our center between 2003 and 2007 were evaluated retrospectively. Median follow-up was 54 months. Most of the patients were male in their third decade. Median ABOD cycles were 6 (2-8). Primary refractory disease rate was 17.7% whereas it was 5.1% for early relapse and 5.1% for late relapse disease. Response rates were as 82.3% for complete response, 11.4% for partial response, 5.1% for stable disease and 1.3% for progressive disease. Half of relapsed patients had autologous stem cell transplantation. Estimated 5-year failure-free survival was 71% and significantly longer in early stage patients without risk factors, bulky disease or radiotherapy (RT) (p=0.05, p<0.0001, p=0.02; respectively). Estimated 5-year overall survival was 74% and significantly longer in those who had no RT (p=0.001). Dose modification rate was 5.1% and chemotherapy delay rate was 19%. There were no toxicity-related deaths. Conclusions: ABOD seems to be effective with managable toxicity in HL, even in those with poor prognostic factors.

사면 안정해석에 적용되는 지반강도정수($C, _{\Phi}$)와 사면경사 민감도 분석 (Sensitivity Analysis of Shear Strength Parameters($C, _{\Phi}$)and Slope Angel in Slope Stability Analysis)

  • 백용;배규진;권오일;장수호;구호본
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2005년도 춘계 학술발표회 논문집
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    • pp.179-184
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    • 2005
  • Shear strength parameters obtained from filed survey are important factors in the analysis of slope stability. In this study, sensitivity analysis was performed to evaluate the effect of input parameters on the analysis of slope stability. The input parameters selected for sensitivity analysis were slope angle, cohesion, and friction angle. Monte-Carlo Simulation method was used for calculating input parameters and the factor of safety was computed by means of limit equilibrium method. A rock slope, which has failed in the field, was used for the sensitivity analysis in the analysis of slope stability. The result of analysis shows that the factor of safety of the rock slope was a little low. From partial correlation coefficient(PPC) of input parameters determined from the sensitivity analysis, slope stability was dependant on cohesion and slope angle. The effect of friction angle was lower than that of cohesion and slope angle on slope stability.

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A performance-based design method for chloride-induced cover cracking of RC structures

  • Yang, Dong-Hui;Yi, Ting-Hua;Li, Hong-Nan
    • Computers and Concrete
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    • 제20권5호
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    • pp.573-582
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    • 2017
  • Chloride-induced cover cracking will aggravate the performance deterioration for RC structures under the chlorideladen environment, which may endanger the safety of structures and occupants. Traditional design method cannot ensure that a definite performance is satisfied. To overcome the defects, a study on the performance-based design method was carried out in this paper. Firstly, the limit state functions were established for the corrosion initiation and cover cracking. Thereafter, the uncertainty analysis was performed to study the effects of random factors on the time-dependent performances. Partial factor formulae were deduced through the first-order reliability method for performance verification. Finally, an illustrative example was presented and the sensitivity of cover depth to other parameters was carried out. It is found that the uncertainties of the random variables have great effects on the required cover depth. It is demonstrated that the performance-based design method can ensure that the target performance can be satisfied and support to formulate a rational maintenance and repair strategy for RC structures under the chloride environment.

컨조인트 분석에 의한 터널 내 조명시설 설치조합별 경관 선호도 분석 (Analysis of Landscape Preference by the Installation Combination of Lightning in Tunnel based on Conjoint Analysis)

  • 이혜령;금기정;정현정
    • 한국도로학회논문집
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    • 제14권6호
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    • pp.111-120
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    • 2012
  • PURPOSES : This study is to suggest suitable lighting facility installation plans by finding out driver's preference for combination of lighting facility installation among landscape factors that affect driver visibility in tunnels. METHODS : SD method is used to extract emotional factors that affect drivers' preference, Components of tunnel lighting facility installation are evaluated through conjoint analysis and it suggested relative importance of attributes and utility values. RESULTS : In the aspects of satisfaction levels of components of tunnel lighting facility installation, Tunnel side, two lows, and solid line arrangement type has the highest level of satisfaction. Extract emotional factors that affect drivers' preference are "safety", "openness" and "amenity." In addition, the result of analyzing relative importance of attributes of tunnel lighting facility shows that numbers of lighting array has the highest importance and lighting facility arrangement has the lowest importance. Result of analyzing partial utility shows that the 2 low type among number of lows, the solid line arrangement type between arrangement types, placing in the middle part among lighting facility arrangement were highly preferred. CONCLUSIONS : In the case of lighting numbers, utility values of the first line and the second line showed us a big difference. Increasing the number arrays in the future reformation of lighting facility installation combination will be effective in enhancing the utility of the driver.

철근콘크리트 부재 저항능력의 통계적 모델 개발 (Development of Statistical Models for Resistance of Reinforced Concrete Members)

  • 김지상;김종호
    • 대한토목학회논문집
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    • 제31권4A호
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    • pp.323-329
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    • 2011
  • 대부분의 콘크리트구조설계기준은 구조물의 안전에 대한 여유를 확보하기 위해 하중계수 및 저항계수의 안전계수를 고려하고 있다. 이 안전계수는 하중과 저항의 통계적 불확실성을 적절하게 고려한 구조신뢰성 이론에 근거하여 결정되어야 하는데, 구조신뢰성 이론의 적용은 하중 및 저항에 대한 통계적 모델의 정립이 선행되어야 한다. 이 논문에서는 콘크리트 압축강도, 철근 항복강도 및 부재 단면치수의 통계적 변동성을 고려한 철근콘크리트 부재의 저항모델을 개발하였다. 통계모델 개발에 적용된 자료는 국내의 실험 및 시험 자료를 기초로 하였으며, 몬테칼로 시뮬레이션(Monte Carlo Simulation)기법을 적용하였다. 이 논문의 결과는 콘크리트 구조설계 기준의 검증 및 개정작업에 유용한 자료를 제공할 것으로 기대된다.

A Conceptual Framework to Study the Effectiveness of Interface Management in Construction Projects

  • KEERTHANAA, K.;SHANMUGAPRIYA, S.
    • Journal of Construction Engineering and Project Management
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    • 제9권3호
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    • pp.1-21
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    • 2019
  • The management of mega construction projects which incorporate a large number of stakeholders, technologies, data, work culture etc., is cumbersome. The experts in the construction arena advocate that interface management serves as a precise tool in resolving these conflict points due to the intricate nature of the construction projects. Interface management is a current trending management practice in the construction industry which is also a beneficiary to mega/fast track projects in enhancing the project performance. The main objective of this study is to validate a model for assessing the relationships among interface management, IT applications, project performance & project benefits. The mediating effect of interface management in relationship between project performance & interfacial factors was also investigated. The research model was validated using PLS-SEM (Partial Least Square-Structural Equation Modelling) approach. Data were collected from clients, contractors, consultants in large scale projects through questionnaire survey and smart-PLS software was used to analyse the conceptual model. The research model comprises eleven hypothesis and the significance of these hypothesis were tested using T- statistics values. The research implies that people/participants factor is greatly influenced by interface management with the path coefficient of 0.608 and also enhancement of project's schedule performance due to the interface management is strongly appealing (Path coefficient = 0.711). The results also reveal IT application is significantly associated with interface management practice (Path coefficient =0.723) and also the effect of IT application on project performance (schedule, cost, quality & safety) is successfully mediated through interface management practice. The practical application of this validated model was done through case study. The case study aims at measuring the impact of interface management on interfacial factors and role of interface management in improving the project performance in the construction organisations.