• Title/Summary/Keyword: Sensitivity analyses

검색결과 836건 처리시간 0.033초

패밀리 레스토랑의 가격 전략 수립을 위한 가격민감성 분석 사례 연구 (A Case Study for Pricing Strategy Planning of a Family Restaurant Using Price-Sensitivity Measurement)

  • 최미경;이봉식
    • 대한지역사회영양학회지
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    • 제11권2호
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    • pp.253-260
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    • 2006
  • The purpose of this study was to suggest menu pricing strategy based on understanding about customer perceived value of products and services. The technique known as PSM (Price Sensitivity Measurement) was used for analysis of price sensitivity for 3 menu items of a family restaurant in Seoul. A questionnaire was developed through literature review and modified after pilot test. Questionnaires for the main survey were distributed to 250 customers on their visit to the restaurant, and a total of 138 questionnaires were used for analysis (55.2%). The statistical analysis of price sensitivity was conducted using PSM, and descriptive analyses were conducted using SPSS Win (12.0). The main results of this study were as follows: the price sensitivity of beef tenderloin steak was higher than two other menus and the stress range of teriyaki chicken was almost 0, that is, the price sensitivity of teriyaki chicken was very low. Present menu prices of 3 menu items were within the range of acceptable prices, but had some distances from the optimal pricing point. From the result of this study, it was concluded that price adjustment or price promotion strategy would be effective for increase in sales of beef tenderloin steak, and marketing strategies to enhance consumers' perceptions of value should be conducted for all menu items by situations. Overall, PSM technique could be a helpful tool for researchers and managers of foodservice organizations to understand how consumers' perceptions of value are affected by the interaction of price and quality.

Seismic response modification factors for stiffness degrading soil-structure systems

  • Ganjavi, Behnoud;Bararnia, Majid;Hajirasouliha, Iman
    • Structural Engineering and Mechanics
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    • 제68권2호
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    • pp.159-170
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    • 2018
  • This paper aims to develop response modification factors for stiffness degrading structures by incorporating soil-structure interaction effects. A comprehensive parametric study is conducted to investigate the effects of key SSI parameters, natural period of vibration, ductility demand and hysteretic behavior on the response modification factor of soil-structure systems. The nonlinear dynamic response of 6300 soil-structure systems are studied under two ensembles of accelograms including 20 recorded and 7 synthetic ground motions. It is concluded that neglecting the stiffness degradation of structures can results in up to 22% underestimation of inelastic strength demands in soil-structure systems, leading to an unexpected high level of ductility demand in the structures located on soft soil. Nonlinear regression analyses are then performed to derive a simplified expression for estimating ductility-dependent response modification factors for stiffness degrading soil-structure systems. The adequacy of the proposed expression is investigated through sensitivity analyses on nonlinear soil-structure systems under seven synthetic spectrum compatible earthquake ground motions. A good agreement is observed between the results of the predicted and the target ductility demands, demonstrating the adequacy of the expression proposed in this study to estimate the inelastic demands of SSI systems with stiffness degrading structures. It is observed that the maximum differences between the target and average target ductility demands was 15%, which is considered acceptable for practical design purposes.

연성 방호구조물의 입력변수에 대한 동적 퍼포먼스 민감도 분석 (Performance Sensitivity of Flexible Barriers to Input Parameters)

  • 이규세
    • 한국방재학회 논문집
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    • 제10권3호
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    • pp.13-20
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    • 2010
  • 실물 충돌 실험을 실시하지 않고 하는 안전구조물의 성능 평가는 컴퓨터 해석에 의한 검토가 불가피하다. 그러나 이러한 컴퓨터 시뮬레이션의 정확도를 높이기 위해서는 연성방호구조물의 차량-가드레일시스템-지반의 상호작용을 고려한 특정 입력변수의 올바른 결정이 중요하게 된다. 본 연구에서는 가아드레일로 대표되는 연성방호구조물의 동적 퍼포먼스를 컴퓨터 시뮬레이션으로 측정하되, 시뮬레이션의 정확도를 높이기 위한 방안을 도출하기위하여 구조물 차량의 충돌 해석에 유용성 이 입증된 Barrier VII 프로그램을 이용하여 입력변수에 대한 출력변수의 변화 양상을 분석함으로써 안전성검토에 있어서 중요한 입력변수를 도출하고 정확한 입력변수를 결정하기 위한 방안을 제시하였다.

심해저 망간단괴 개발사업의 경제적 타당성 재평가 (An Economic Feasibility Study of Manganese Nodule in Korea Area: Clarion-Clipperton Fracture Zone)

  • 남광현;오위영;권석재
    • Ocean and Polar Research
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    • 제26권2호
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    • pp.187-197
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    • 2004
  • The purpose of this paper is to investigate economic feasibility of manganese nodules in Korea area (Clarion-Clipperton Fracture Zone). We assumed that the production scale of manganese nodules were 3.0MT or 1.5MT and analyzed that the capital cost and operating cost were estimated in the four sectors, exploration, mining, transportation and metallurgical process. The capital cost and operating cost evaluation reflects the latest technical practices. First, for analyzing economic feasibility, the scenario suggests that the production of 4 metals can be made for 25 years. Assuming the discount rate at 8.0%, equity capital at 50% and tax at 27%. When manganese nodule were mininged 3.0 MT, economic feasibility analyses showed that IRR was 12.8 and pay-back period was 9.2 years, and when manganese nodules were mininged 1.5 MT, economic feasibility analyses showed that IRR was 4.0 and pay-back period was 11.8 years. This study indicated there is economic validity of at the product of manganese nodules 3.0 MT. In addition, we carried out a sensitivity analysis at the change of cobalt price on mining 1.5 MT. The result of sensitivity analysis clearly showed that economic validity is high at increasing of cobalt price 50% up.

인공갯벌 조성에 관한 경제적 타당성 분석 (Analyzing an Economic Feasibility for Restoration/Creation of Artificial Tidal Flats)

  • 남광현;오위영
    • Ocean and Polar Research
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    • 제25권4호
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    • pp.593-601
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    • 2003
  • The purpose of this paper is to investigate economic feasibility of creating artificial tidal flats using cost-benefit analyses. We assumed that the cost factors are associated with designing, construction and monitoring, and the benefit factors are associated with fisheries production, habitation, prevention of disasters, water purification, aesthetic value and existence value. First, for analyzing economic feasibility, the scenario suggests that a design can be made in a year, construction can be completed in three years and monitoring must be made for 20 years. Assuming the discount rate of 7.5%, economic feasibility analyses showed that B/C was 2.26 and IRR was 14.50. This study indicated there is economic validity of implementing creation of artificial tidal flat. In addition, we carried out a sensitivity analysis at the change of discount rate and restoration rate. The result of sensitivity analysis clearly showed that economic validity is low when discount rate is over 15%, and changes in restoration rate did not significantly effect on the economic validity.

Structural Reliability of Thick FRP Plates subjected to Lateral Pressure Loads

  • Hankoo Jeong;R. Ajit Shenoi;Kim, Kisung
    • Journal of Ship and Ocean Technology
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    • 제4권2호
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    • pp.38-57
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    • 2000
  • This paper deals with reliability analysis of specially orthotropic plates subjected to transverse lateral pressure loads by using Monte Carlo simulation method. The plates are simply supported around their all edges and have a low short span to plate depth ratio with rectangular plate shapes. Various levels of reliability analyses of the plates are performed within the context of First-Ply-Failure(FPF) analysis such as ply-/laminate-level reliability analyse, failure tree analysis and sensitivity analysis of basic design variables to estimated plate reliabilities. In performing all these levels of reliability analyses, the followings are considered within the Monte Carlo simulation method: (1) input parameters to the strengths of the plates such as applied transverse lateral pressure loads, elastic moduli, geometric including plate thickness and ultimate strength values of the plates are treated as basic design variables following a normal probability distribution; (2) the mechanical responses of the plates are calculated by using simplified higher-order shear deformation theory which can predict the mechanical responses of thick laminated plates accurately; and (3) the limit state equations are derived from polynomial failure criteria for composite materials such as maximum stress, maximum strain, Tsai-Hill, Tsai-Wu and Hoffman.

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SENSITIVITY ANALYSES OF THE USE OF DIFFERENT NEUTRON ABSORBERS ON THE MAIN SAFETY CORE PARAMETERS IN MTR TYPE RESEARCH REACTOR

  • Kamyab, Raheleh
    • Nuclear Engineering and Technology
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    • 제46권4호
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    • pp.513-520
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    • 2014
  • In this paper, three types of operational and industrial absorbers used at research reactors, including Ag-In-Cd alloy, $B_4C$, and Hf are selected for sensitivity analyses. Their integral effects on the main neutronic core parameters important to safety issues are investigated. These parameters are core excess reactivity, shutdown margin, total reactivity worth of control rods, thermal neutron flux, power density distribution, and Power Peaking Factor (PPF). The IAEA 10 MW benchmark core is selected as the case study to verify calculations. A two-dimensional, three-group diffusion model is selected for core calculations. The well-known WIMS-D4 and CITATION reactor codes are used to carry out these calculations. It is found that the largest shutdown margin is gained using the $B_4C$; also the lowest PPF is gained using the Ag-In-Cd alloy. The maximum point power densities belong to the inside fuel regions surrounding the central flux trap (irradiation position), surrounded by control fuel elements, and the peripheral fuel elements beside the graphite reflectors. The greatest and least fluctuation of the point power densities are gained by using $B_4C$ and Ag-In-Cd alloy, respectively.

Probabilistic study on buildings with MTMD system in different seismic performance levels

  • Etedali, Sadegh
    • Structural Engineering and Mechanics
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    • 제81권4호
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    • pp.429-441
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    • 2022
  • A probabilistic assessment of the seismic-excited buildings with a multiple-tuned-mass-damper (MTMD) system is carried out in the presence of uncertainties of the structural model, MTMD system, and the stochastic model of the seismic excitations. A free search optimization procedure of the individual mass, stiffness and, damping parameters of the MTMD system based on the snap-drift cuckoo search (SDCS) optimization algorithm is proposed for the optimal design of the MTMD system. Considering a 10-story structure in three cases equipped with single tuned mass damper (STMS), 5-TMD and 10-TMD, sensitivity analyses are carried out using Sobol' indices based on the Monte Carlo simulation (MCS) method. Considering different seismic performance levels, the reliability analyses are done using MCS and kriging-based MCS methods. The results show the maximum structural responses are more affected by changes in the PGA and the stiffness coefficients of the structural floors and TMDs. The results indicate the kriging-based MCS method can estimate the accurate amount of failure probability by spending less time than the MCS. The results also show the MTMD gives a significant reduction in the structural failure probability. The effect of the MTMD on the reduction of the failure probability is remarkable in the performance levels of life safety and collapse prevention. The maximum drift of floors may be reduced for the nominal structural system by increasing the TMDs, however, the complexity of the MTMD model and increasing its corresponding uncertainty sources can be caused a slight increase in the failure probability of the structure.

조합하중이 작용하는 복합적층 패널의 최소중량화설계 (Minimum Weight Design of Laminated Composite Panel under Combined Loading)

  • 이종선
    • 한국공작기계학회논문집
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    • 제15권1호
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    • pp.95-101
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    • 2006
  • Minimum weight design of laminated composite panel under combined loading was studied using linear and nonlinear deformation theories and by closed-form analysis and finite difference energy methods. Various buckling load factors are obatined for laminated composite panels with rectangular type longitudinal stiffeners and various longitudinal length to radius ratios, which are made from Carbon/Epoxy USNl25 prepreg and are simply-supported on four edges under combined loading, and then for them, minimum weight design analyses are carried out by the nonlinear search optimizer, ADS. This minimum weight design analyses are constructed with various process such as the simple design process, test simulation process and sensitivity analysis. Subseguently, the buckling mode shapes are obtained by buckling and minimum weight analyses.