• Earthquakes and Structures
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• 제19권5호
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• pp.379-393
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• 2020

The purpose of this study is to first evaluate the seismic behavior of ageing arch bridges by using the Intensity Measure - based demand and DCFD format, which is referred to as the fragility-hazard format. Then, an investigation is performed for their seismic vulnerability. Analytical models are created for bridges concerning different features and these models are subjected to Incremental Dynamic Analysis (IDA) analysis using a set of 22 earthquake records. The hazard curve and results of IDA analysis are employed to evaluate the return period of exceeding the limit states in the IM-based probabilistic performance-based context. Subsequently, the fragility-hazard format is used to assess factored demand, factored capacity, and the ratio of the factored demand to the factored capacity of the models with respect to different performance objectives. Finally, the vulnerability curves are obtained for the investigated bridges in terms of the loss ratio. The results revealed that decreasing the span length of the unreinforced arch bridges leads to the increase in the return period of exceeding various limit states and factored capacity and decrease in the displacement demand, the probability of failure, the factored demand, as well as the factored demand to factored capacity ratios, loss ratio, and seismic vulnerability. Finally, it is derived that the probability of the need for rehabilitation increases by an increase in the span length of the models.

• 산업공학
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• 제17권spc호
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• pp.79-89
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• 2004

Supply Chain (SC) can balance demands with supply activities as executing Supply Chain Planning (SCP). The fluctuated demands, however, will break the balance between demand and supply. It means that the present SCP is useless in responding the changed demands. Thus it is necessary for SCP to be updated with changed demands. We call this procedure as Supply Chain Replanning. However, the existing measures for SC can not deal with the balance between supply and demand so that they can not detect effectively the timing of replanning. For this reason, a new performance measure, Balancing Point, is developed using momentum, a concept of Physics. It can treat the balance between supply and demand. Also, a replanning method based on Balancing Point is proposed. The proposed method is more effective than the existing replanning method, periodic replanning method and net inventory method.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2004년도 추계학술대회 및 정기총회
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• pp.371-374
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• 2004

The ultimate purpose of Supply Chain Management (SCM) is maximizing the profits of the overall Supply Chain (SC) through increasing customer satisfaction and decreasing operating cost. It can be successfully accomplished only when SC system balances demands with supply activities coordinated by aggregate planning, mid-term level of Supply Chain Planning(SCP). However, the existing measures to mainly estimate the specific function of SCM are not enough to evaluate the state of SC with respect to the balance between supply and demand in operating. To solve this problem, we develop a new SC performance measure, Balancing Point, using momentum concept. a fundamental knowledge of physics. Momentum concept can explain the relation among objects so that it can consider the balance between supply and demand in SC operating. The developed measure can not only consider the current state of the SC system but also take planned but not executed supply activities and upcoming demands into account. Therefore, using Balancing point, we can be aware of the unbalanced state of SC in advance.

• 산업경영시스템학회지
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• 제19권40호
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• pp.23-28
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• 1996

This paper deals with performance measures for recoverable item control where the demand process is time-dependent. The performance measure is essential for modelling a multi-echelon inventory problem for repairable items. Most repairable items are expensive and have a great influence on the performance of equipments. Thus the information on these items is very useful to the decision maker. The purpose of this paper is to derive the system performance measure and the part(component) performance measure considering a cannibalization policy under the dynamic environment.

• 산업경영시스템학회지
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• 제22권51호
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• pp.29-40
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• 1999

The distribution center location and routing problem involves interdependent decisions among facility, transportation, and inventory decisions. The design of distribution system affects the customers' purchase decision by sets the level of customer service to be offered. Thus the lower product availability may cause a loss of demand as falls off the customers' purchase intention, and this is related to the firm's profit reduction. This study considers the product availability of the distribution centers as the measure of the demand level change of the demand points, and represents relation between customer service and demand level with linear demand function. And this study represents the distribution center location and routing to demand point in order to maximize the total profit that considers the products' sales revenue by customer service, the production cost and the distribution system related costs.

• Journal of Information Technology Applications and Management
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• 제26권2호
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• pp.61-73
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• 2019

In 2019, 5G mobile communication technology will be commercialized. From the viewpoint of technological innovation, 5G service can be applied to other industries or developed further. Therefore, it is important to measure the demand of the Internet of things (IoT) because it is predicted to be commercialized widely in the 5G era and its demand hugely effects on the economic value of 5G industry. In this paper, we applied Bayesian method on regression model to find out the demand of 5G IoT service, wearable service in particular. As a result, we confirmed that the Bayesian regression model is closer to the actual value than the existing regression model. These findings can be utilized for predicting future demand of new industries.

• 기술사
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• 제7권28호
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• pp.9-15
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• 1974

• 기술사
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• 제7권27호
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• pp.8-13
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• 1974

• 한국융합학회논문지
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• 제10권8호
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• pp.137-144
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• 2019

본 연구는 디지털미디어 서비스를 제공하는 플랫폼 사업자들의 콘텐츠 공급과 이용의 다양성을 장기간에 걸친 종단적 데이터로 측정하고 그 함의를 논의하기 위한 연구이다. 유료방송 사업자의 승인 및 재허가에 있어 방송의 공공성, 공익성을 평가하는 항목으로 다양성 지표에 대한 측정시도가 있었으나 주로 횡단적인 공급측면의 다양성 측정 방법론에 그치고 있다. 따라서 연구자는 본 연구를 통해 두가지 측면의 평가 가능성을 확인하고자 한다. 첫째, 공급측면 이외에 이용자의 실제 시청 데이터를 활용한 수요측면의 측정방법론, 둘째, 장기적인 다양성 추구의 변화 과정을 평가하는 종단평가 방법론을 제안하고자 한다. 본 연구에서는 특정 플랫폼 사업자의 실제 공급, 수요 데이터를 확보하여 2012년에서 2017년에 이르는 50여개월간의 종단적 다양성 추구 지표의 추세를 확인하였다. 이 연구를 통해 횡단적 평가와 공급중심의 평가의 한계를 넘어 보다 균형 잡힌 방송의 공공성, 공익성 평가 방법으로 공급과 수요측면 및 종단적 다양성 평가가 새롭게 활용될 것으로 기대하는 바이다.

• 대한산업공학회지
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• 제35권3호
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• pp.203-212
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• 2009

The bullwhip effect refers to the phenomenon where demand variability is amplified when one moves upward a supply chain. In this paper, we exactly quantify the bullwhip effect for cases of seasonal demand processes in a two-echelon supply chain with a single retailer and a single supplier. In most of the previous research, some measures of performance for the bullwhip effect are developed for cases of non-seasonal demand processes. The retailer performs demand forecast with a multiplicative seasonal mixed model by using the minimum mean square error forecasting technique and employs a base stock policy. With the developed bullwhip effect measure, we investigate the impact of seasonal factor on the bullwhip effect. Then, we prove that seasonal factor plays an important role on the occurrence of the bullwhip effect.