• 대기
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• 제30권4호
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• pp.405-420
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• 2020

In this study, we investigate the predictability of intraseasonal monthly temperature and precipitation variations using hindcast datasets from eight global circulation models participating in the operational multi-model ensemble (MME) seasonal prediction system of the Asia-Pacific Economic Cooperation Climate Center for the 1983~2010 period. These intraseasonal monthly variations are defined by categorical deterministic analysis. The monthly temperature and precipitation are categorized into above normal (AN), near normal (NN), and below normal (BN) based on the σ-value ± 0.43 after standardization. The nine patterns of intraseasonal monthly variation are defined by considering the changing pattern of the monthly categories for the three consecutive months. A deterministic and a probabilistic analysis are used to define intraseasonal monthly variation for the multi-model consisting of numerous ensemble members. The results show that a pattern (pattern 7), which has the same monthly categories in three consecutive months, is the most frequently occurring pattern in observation regardless of the seasons and variables. Meanwhile, the patterns (e.g., patterns 8 and 9) that have consistently increasing or decreasing trends in three consecutive months, such as BN-NN-AN or AN-NN-BN, occur rarely in observation. The MME and eight individual models generally capture pattern 7 well but rarely capture patterns 8 and 9.

• 한국철도학회논문집
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• 제13권3호
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• pp.290-297
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• 2010

현재 국내 표준열차하중은 일반철도와 고속철도로 나뉘어져 있으며, 일반철도의 경우 미국의 표준열차하중 혹은 과거 일본의 K하중을 기반으로 하는 L22, 고속철도의 경우 Eurocode의 LM71를 기반으로 하는 HL25 하중 모델을 적용하고 있다. 표준열차하중의 구조물 설계의 출발점이 되는 것으로 매우 중요한데 반하여 국내에서는 표준열차하중 개발과 관련한 연구가 진행된 바가 전무한 상황이다. 반면, 유럽과 일본에서는 선진 설계법 도입과 병행하여 합리적 표준열차하중에 대한 연구가 지속적으로 수행되고 있다. 최근 유럽에서는 새로운 표준열차하중인 LM2000 모델 개발 시 결정론적, 확률론적, 비용효과 분석 등 종합적이고 합리적인 방법에 의해 표준열차하중을 개발한 사례가 있다. 본 논문에서는 국내 표준열차하중 개발을 위한 단계적 접근 중 하나로서 결정론적 분석에 의한 표준열차하중 결정 과정을 분석하였다. 현재 국내 운행 중인 실열차를 기반으로 교량 단면력에 대한 여유도를 평가하여 합리적인 표준열차하중을 제시하고자 하였다.

• International journal of advanced smart convergence
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• 제11권3호
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• pp.1-6
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• 2022

In this paper, we estimate the mean number of objects in the M/H₂/1 model for web service when the mean object size in the M/H₂/1 model is equal to that of the M/G/1/PS and M/BP/1 models. To this end, we use the mean object size obtained by assuming that the mean latency of deterministic model is equal to that of M/H₂/1, M/G/1/PS, and M/BP/1 models, respectively. Computational experiments show that if the shape parameter of the M/BP/1 model is 1.1 and the system load is greater than 0.35, the mean number of objects in the M/H₂/1 model when mean object size of M/H₂/1 model is the same as that of M/G/1/PS model is almost equal to the mean number of objects in the M/H₂/1 model when the mean object size of M/H₂/1 model is the same as that of M/BP/1 model. In addition, as the upper limit of the M/BP/1 model increases, the number of objects in the M/H₂/1 model converges to one, which increases latency. These results mean that it is efficient to use small-sized objects in the web service environment.

• International Journal of Internet, Broadcasting and Communication
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• 제14권3호
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• pp.1-7
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• 2022

This paper aims to compare the mean object size of M/G/1/PS model with that of M/BP/1 model used in the web service. The mean object size is one of important measure to control and manage web service economically. M/G/1/PS model utilizes the processor sharing in which CPU rotates in round-robin order giving time quantum to multiple tasks. M/BP/1 model uses the Bounded Pareto distribution to describe the web service according to file size. We may infer that the mean waiting latencies of M/G/1/PS and M/BP/1 model are equal to the mean waiting latency of the deterministic model using the round robin scheduling with the time quantum. Based on the inference, we can find the mean object size of M/G/1/PS model and M/BP/1 model, respectively. Numerical experiments show that when the system load is smaller than the medium, the mean object sizes of the M/G/1/PS model and the M/BP/1 model become the same. In particular, when the shaping parameter is 1.5 and the lower and upper bound of the file size is small in the M/BP/1 model, the mean object sizes of M/G/1/PS model and M/BP/1 model are the same. These results confirm that it is beneficial to use a small file size in a web service.

• 경영과학
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• 제27권1호
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• pp.33-43
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• 2010

This paper presents a method for the estimation and analysis of the economic value of weather forecasts for CRM decision-making problems in the leisure industry. Value is calculated in terms of the customer's satisfaction returned from the user's decision under the specific payoff structure, which is itself represented by a customer's satisfaction ratio model. The decision is assessed by a modified cost-loss model to consider the customer's satisfaction instead of the loss or cost. Site-specific probability and deterministic forecasts, each of which is provided in Korea and China, are applied to generate and analyze the optimal decisions. The application results demonstrate that probability forecasts have greater value than deterministic forecasts, provided that the users can locate the optimal decision threshold. This paper also presents the optimal decision strategy for specific customers with a variety of satisfaction patterns.

• 한국경영과학회지
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• 제19권3호
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• pp.81-91
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• 1994

This paper is to build an economic production quantity model for situations, in which, during the stockout period, a fraction .betha.(backorder ratio) of the demand is backordered and remaining fraction (1-.betha.) is lost. This paper develops an objective function representing the average annual cost of a production system by defining a time-weighted backorder cost and a lost sales penalty cost per unit lost under the assumptions of deterministic demand rate and deterministic production rate, and provides an algorithm for its optimal solution. At the extreme .betha.= 1, the presented model reduces to the Fabrycky's model with complete backorders.

• 대한수학회보
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• 제47권6호
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• pp.1131-1138
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• 2010

In the present paper, we evaluate an analytic formula as a solution of Susceptible Infective (SI) model problem for communicable disease in which the daily contact rate (C(N)) is supposed to be varied linearly with population size N(t) that is large so that it is considered as a continuous variable of time t. Again, we introduce some Lie group of operators to make an extension of above analytic formula of the determin-istic epidemics model problem. Finally, we discuss some of its particular cases.

• 대한산업공학회지
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• 제24권4호
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• pp.485-492
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• 1998

Most forecasting models often fail to produce appropriate forecasts because we build a model based on the assumption of the data being generated from the only one stochastic process. However, in many real problems, the time series data are generated from one stochastic process for a while and then abruptly undergo certain structural changes. In this paper, we assume the basic underlying process is the simple state-space model with random level and deterministic drift but interrupted by three types of exogenous shocks: level shift, drift change, outlier. A Bayesian procedure to detect, estimate and adapt to the structural changes is developed and compared with simple, double and adaptive exponential smoothing using simulated data and the U.S. leading composite index.

• Journal of applied mathematics & informatics
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• 제41권1호
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• pp.215-228
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• 2023

The ready-made garments (RMG) have been making a crucial contribution about of 81% of total export and 12.36 % of total GDP of the country which is now the single biggest export earner for Bangladesh. The cheap production cost is the key important factor to explore this RMG sector. But these RMG sector is running on the basis of intuition based decisions. Though they are making profit it is not optimal. In this study, a deterministic model is developed to help the RMG to minimize the production cost and to maximize their profit along with optimal utilization of available resources. 10 different types of products are taken from one of the garments factories of Gazipur, Dhaka to prepare this research work. This model suggests the manufacturer on which products along with how much should be produced to meet the future demand by maintaining the lowest production cost that ultimately maximize the profit of the organization, and also helps Bangladesh to compete in the international market with 'Made in Bangladesh'. LINDO programming is used here to solve this LP model.

• 한국ITS학회 논문지
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• 제7권1호
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• pp.10-21
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• 2008

Wardrop(1952)의 확정적 사용자최적원리(Deterministic User Optimal Principle)에 의한 사용자의 통행행태는 교통망의 상황에 대하여 완전한 정보가 존재한다는 가정을 기반으로 하고 있다. 따라서 확정적 사용자최적원리에 따르면 사용자는 출발지와 도착지를 연결하는 최적경로를 선택하며, 사용자가 경로를 임의로 변경하여 통행비용을 줄일 수 없는 균형 상태에 도달함을 의미한다. 운전자의 통행경로선택기준은 다양하게 생각될 수 있으나, 일반적으로 확정적 사용자최적원리에서 운전자는 최소의 통행시간이 소요되는 경로를 선택한다. 그러나 현실의 교통망에서 발생하는 운전자의 통행행태는 통행시간으로 경로를 선택하지 않는 경향이 빈번하게 목격되며, 확정적 사용자최적원리에서처럼 통행시간만을 경로선택의 기준으로 적용하는 모형은 비합리적인 통행행태를 유도할 가능성이 높다. 이에 본 연구는 운전자의 경로를 인지하는 행태를 보다 현실적으로 모사하는 확정적 최적통행배정모형을 제안한다. 이를 위해 모형을 사용자가 경로를 결정함에 있어 출발지와 도착지에서 경로를 인지하는 일반적인 특성으로 통행시간 정보뿐만 아니라 도로주행 조건, 출발지와 도착지에 대한 교통망 정보의 유무 등을 동시에 반영한다고 가정한다. 또한 본 연구는 출발지를 기준으로 하는 통행을 전개하는 전방탐색기법과 도착지를 기준으로 통행을 후퇴하는 후방탐색기법을 동시에 수식과 알고리즘에 반영하여 사용자의 경로인지특성을 반영하는 노력이 주 내용이다.