• Journal of Distribution Science
• /
• v.11 no.9
• /
• pp.31-34
• /
• 2013

Purpose - This paper aims to explain that the Chinese distribution market will continue to bring tremendous business opportunities to commercial enterprises, given the relatively strong economic fundamentals and substantial government-led measures to boost domestic demand. Research design, data, methodology - A survey was conducted on China's retail market data during 2012. By empirically analyzing the data for retail sales of online markets and franchises, we conclude that the online retail market in China will continue to grow. Results - Based on data from 2012, 2013 is expected to be a challenging year for the retail sector, as both external and internal pressure is likely to persist. This paper outlines some major challenges facing retailers in China. Conclusions - The study shows that retailers in the Chinese market will face some major challenges: 1) the Chinese retail market is considerably affected by an uncertain economic outlook 2) an unfair environment of competition exists and 3) product safety is a serious issue. However, in the future, China's retail market will continue to bring tremendous business opportunities to commercial enterprises, given the relatively strong economic fundamentals and substantial government-led measures to boost domestic demand.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.4 no.1
• /
• pp.59-64
• /
• 1979

The application of optimization techniques to the planning of industrial, economic, administrative and military activities with random technological coefficients has been extensively studied in the literature. Stochastic (linear) programs with simple recourse essentially model the allocation of scarce resources under uncertainty with linear penalties associated with shortages or surplus. This work on a problem with a discrete random resource vector, "The allocation of aircraft under uncertain demand" given in (1), is easily and efficiently handled by the application of the recently developed Wets' algorithm (8) for solving stochastic programs with simple recourse, which approves that such class of stochastic problems can be solved with the same efficiency as solving linear programs of the same size. It is known that the algorithm is also applicable to stochastic programs with continuous random demands for their approximate solutions.

• Journal of the Korea Safety Management & Science
• /
• v.15 no.1
• /
• pp.217-229
• /
• 2013

As customers' demands for diversified small-quantity products have been increased, there have been great efforts for a firm to respond to customers' demands flexibly and minimize the cost of inventory at the same time. To achieve that goal, in SCM perspective, many firms have tried to control the inventory efficiently. We present an mathematical model to determine the near optimal (s, S) policy of the supply chain, composed of multi suppliers, a warehouse and multi retailers. (s, S) policy is to order the quantity up to target inventory level when inventory level falls below the reorder point. But it is difficult to analyze inventory level because it is varied with stochastic demand of customers. To reflect stochastic demand of customers in our model, we do the analyses in the following order. First, the analysis of inventory in retailers is done at the mathematical model that we present. Then, the analysis of demand pattern in a warehouse is performed as the inventory of a warehouse is much effected by retailers' order. After that, the analysis of inventory in a warehouse is followed. Finally, the integrated mathematical model is presented. It is not easy to get the solution of the mathematical model, because it includes many stochastic factors. Thus, we get the solutions after the stochastic demand is approximated, then they are verified by the simulations.

• Fire Science and Engineering
• /
• v.21 no.3
• /
• pp.24-32
• /
• 2007

The environment of fire service is more uncertain as cities become complicated and new combustibles are used. If fire service's budget is not allocated sufficiently for fire facilities and equipment, fire service's quality and firefighter's safety are affected seriously. Therefore project budget must be increased to prevent fire and disaster effectively. This study investigate the change of fire service demands, the change and priority of fire service budget and project budget. And this study examined the relationship between fire service demand and project budget using correlation and regression analysis. Analysis showed that a number of rescue and emergency medical service were significant variable for project budget.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.46 no.2
• /
• pp.109-115
• /
• 2023

This paper studied the problem of determining the optimal inventory level to meet the customer service target level in a situation where the customer demand for each branch of a nationwide retailer is uncertain. To this end, ISR (In-Stock Ratio) was defined as a key management indicator (KPI) that can be used from the perspective of a nationwide retailer such as Samsung, LG, or Apple that sells goods at branches nationwide. An optimization model was established to allow the retailer to minimize the total amount of inventory held at each branch while meeting the customer service target level defined as the average ISR. This paper proves that there is always an optimal solution in the model and expresses the optimal solution in a generalized form using the Karush-Kuhn-Tucker condition regardless of the shape of the probability distribution of customer demand. In addition, this paper studied the case where customer demand follows a specific probability distribution such as a normal distribution, and an expression representing the optimal inventory level for this case was derived.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.38 no.2
• /
• pp.43-63
• /
• 2013

Remanufacturing is a process of recovering end-of-life products into serviceable parts for producing new products. Due to the limited supply of recovery cores to remanufacture, a remanufacturing firm also needs to produce or procure new parts for fulfilling the demand. This paper is targeted for solving the problem of determining the optimal amount of newly produced and remanufacturing parts, which is called production and remanufacturing planning (PRP) problem, under uncertain supply of recovery cores. The new production mitigates the risk of insufficient core supply while it takes more costs than the remanufacturing. The PRP model in this paper also considers disassemble-to-order (DTO) environment, in which multiple kinds of parts are remanufactured from multiple products on order of the parts. Whereas existing studies presents only heuristic solutions for DTO remanufacturing, this paper provides an exact solution for this problem and analytical sensitivity of the involved cost parameters, adopting multi-dimensional newsvendor modeling and stochastic linear programming techniques. The result shows that production and remanufacturing plans for multiple products are mutually dependent, and a change of cost parameters involved in only one part is propagated to all other parts.

• Research in Community and Public Health Nursing
• /
• v.28 no.2
• /
• pp.182-195
• /
• 2017

Purpose: This study explores school nurses' emergency care experiences and their needs for systemic institutional support. Methods: Data were collected in 2016 from the interviews with five focus groups comprising thirty school nurses. Qualitative content analysis was then performed using the collected data. Results: The study found that school nurses were vulnerable to over-reaction in uncertain situations as the school's sole health service provider. The study's findings are divided into ten categories. 1) Major obstacles to overcome as the sole health service provider, 2) Assessing an uncertain situation and making appropriate decisions, 3) Providing limited first aid while maintaining control over the situation, 4) Referring or transferring a student to a hospital that creates tensions and raises cost, 5) Becoming an advocate for information disclosure and treatment, 6) Ensuring follow-up actions and proper transfer of responsibility, 7) Making preparations for future emergency, 8) Responding to conflicts arising from over-reaction as a safeguard and professional expertise, 9) Need for the development of standardized manual for school emergency care, 10) Need for practical case-based training. Conclusion: The findings of this study should contribute to the development of the programs aimed at improving school emergency care and the professional competence of school nurse.

• Journal of Korea Water Resources Association
• /
• v.36 no.1
• /
• pp.105-115
• /
• 2003

The computation model which evaluates combined hydraulic and mechanical reliability, is developed to analyze the integrated reliability in water distribution system. The hydraulic reliability is calculated by considering uncertain variables like water demand, hydraulic pressure, pipe roughness as random variables according to proper distribution type. The mechanical reliability is evaluated by analyzing the effect of pipe network with sequential failure of network components. The result of this study model applied to the real pipe network shows that this model can be used to simulate the uncertain factors effectively in real pipe network. Therefore, The pipe-line engineers can design and manage the network system with more quantitative reliability, through applying this model to reliable pipe network design and diagnosis of existing systems.

• Environmental and Resource Economics Review
• /
• v.24 no.2
• /
• pp.365-410
• /
• 2015

Block-rate structures are widely used in utility-pricing, including the Korean residential electricity sector. In the case of the current pricing structure, Korean citizens are highly concerned about incurring excessive electricity costs. For these reasons, there have been many discussions concerning mitigation of the strict pricing structure. Existing studies on the residential electricity demand function under block-rate structure have the following three issues - the consumer's budget constraint is non-linear, perceived price under block-rate structure is uncertain, block-rate structure has endogeneity in the price variable. In this context, this paper estimates the residential electricity demand function using micro-level household expenditure data and simulates the impact of alternative block-pricing schedules.

• Industrial Engineering and Management Systems
• /
• v.12 no.3
• /
• pp.207-223
• /
• 2013

Revenue management (RM) has been widely used to model products characterized as perishable. Classical RM model assumed that price is the sole factor in the model. Thus price adjustment becomes a crucial and costly factor in business. In this paper, an optimal pricing model is developed based on minimization of soft customer cost, one kind of price adjustment cost and is solved by Lagrange multiplier method. It is formed by expected discounted revenue/bid price integrating quantity-based RM and pricing-based RM. Quantity-based RM consists of two capacity models, namely, booking limit and overbooking. Booking limit, built by assuming uncertain customer arrival, decides the optimal capacity allocation for two market segments. Overbooking determines the level of accepted order exceeding capacity to anticipate probability of cancellation. Furthermore, pricing-based RM models occupancy/demand rate influenced by internal and competitor price changes. In this paper, a mathematical model based on game theoretic approach is developed for two conditions of deterministic and stochastic demand. Based on the equilibrium point, the best strategy for both hotels can be determined.