• 산업경영시스템학회지
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• 제42권1호
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• pp.55-63
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• 2019

This paper develops an algorithm to determine the batch size of the batch process in real time for improving production and efficient control of production system with multiple processes and batch processes. It is so important to find the batch size of the batch process, because the variability arising from the batch process in the production system affects the capacity of the production. Specifically, batch size could change system efficiency such as throughput, WIP (Work In Process) in production system, batch formation time and so on. In order to improve the system variability and productivity, real time batch size determined by considering the preparation time and batch formation time according to the number of operation of the batch process. The purpose of the study is to control the WIP by applying CONWIP production system method in the production line and implements an algorithm for a real time batch size decision in a batch process that requires long work preparation time and affects system efficiency. In order to verify the efficiency of the developed algorithm that determine the batch size in a real time, an existed production system with fixed the batch size will be implemented first and determines that batch size in real time considering WIP in queue and average lead time in the current system. To comparing the efficiency of a system with a fixed batch size and a system that determines a batch size in real time, the results are analyzed using three evaluation indexes of lead time, throughput, and average WIP of the queue.

• 산업경영시스템학회지
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• 제36권2호
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• pp.17-24
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• 2013

This paper is to analyze the picking lead time for picking batch size in a warehouse system and to get minimum picking batch size that is the warehouse system feasible. The warehouse system consists of aisles and racks, which two racks face each other through aisle. The products are picked from the storage locations by batch size. The probability that items are picked in the each row of the rack in the aisle for order picking activity is derived. The picking lead time for picking batch size is the time passed from the first picking location to arrival at starting location in aisle picking all items included in a batch size. The picking lead time for picking batch size in an aisle is analyzed. The picking lead time for picking batch size in the whole warehouse system is obtained. The warehouse system is feasible if all items that customers order are picked from the storage locations for same period. The picking batch size that is the warehouse system feasible is obtained. The problem is analyzed, a solution procedure is developed, and a numerical example is shown to explain the problem.

• 산업경영시스템학회지
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• 제36권3호
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• pp.118-125
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• 2013

This paper deals with the picking batch size which a bi-directional carousel system can be feasible. The items that customers order are retrieved from the bins of carousel with batch size. The mathematical equations representing rotary travel distance and retrieval lead time to pick a given batch size are derived. Rotary travel distance represents the distance which carousel system rotates to retrieve items in a batch. The bi-directional carousel system rotates to minimize the travel distance in retrieving the items in a batch. Rotary travel distance and retrieval lead time are analyzed for the batch size through the simulation approach. From the simulation, the retrieval batch size that carousel system can be feasible is obtained. A numerical example is shown to explain the solution procedure.

• Nuclear Engineering and Technology
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• 제51권4호
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• pp.954-962
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• 2019

It is well known that the variance of tally is biased in a Monte Carlo calculation based on the power iteration method. Several studies have been conducted to estimate the real variance. Among them, the batch method, which was proposed by Gelbard and Prael, has been utilized actively in many Monte Carlo codes because the method is straightforward, and it is easy to implement the method in the codes. However, there is a problem when utilizing the batch method because the estimated variance varies depending on batch size. Often, the appropriate batch size is not realized before the completion of several Monte Carlo calculations. This study recognizes this shortcoming and addresses it by permitting selection of an appropriate batch size.

• 한국건축시공학회지
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• 제13권4호
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• pp.360-371
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• 2013

Fast delivery of construction projects provides more value to project owners. Batch production, which is production not in single pieces, but in batches, is a common approach in repetitive construction projects such as multi-unit residential building construction projects. In batch production, the use of a small batch size allows the early start of subsequent activities, and thus can lead to early completion of projects. In addition to batch size, balance between productivities in construction activities can affect project duration. However, the impact of the balance between productivities with regard to their order on project duration has not been studied. The main goal of this study is to test a hypothesis, which is that the order of construction activities' unbalanced productivities affects the amount of time reduction that can be achieved by using a small batch size. A computer-based simulation model was developed, and five different cases were simulated to test the hypothesis. The conclusion of the simulation result is that the order of productivities does not affect the time reduction achieved by using a small batch size. It is expected that the findings of this study can help general contractors make decisions in terms of batch size.

• 대한산업공학회지
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• 제33권2호
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• pp.246-253
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• 2007

All of the machines in a production line can be classified into bottleneck and non-bottleneck machines. A bottleneck is a resource whose capacity limits the throughput of the whole production facility. This paper addresses a batch sizing problem at the bottleneck machine. Traditionally, most batch sizing decisions have been made based on the EOQ (economic order quantity) model where setup and inventory costs are considered while throughput rate is assumed to be given. However, since batch size affects the capacity of the bottleneck machine, the throughput rate may not be constant. As the batch size increases, the frequency of the setup decreases. The saved setup time can be transferred to processing time, which results in higher throughput. But, the larger batch size may also result in longer lead time and larger WIP inventory level. This paper presents an alternative method to determine batch size at the bottleneck machine in a manufacturing line. A linear search algorithm is introduced to find optimal throughput rate and batch size at the same time. Numerical examples are provided to see how the proposed method works and to investigate the effects of some parameters.

• 한국방사선학회논문지
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• 제15권4호
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• pp.547-554
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• 2021

흉부 X선 영상의 폐렴을 신속하고 정확하게 진단하기 위하여 동일한 Xception 딥러닝 모델에 배치 사이즈를 4, 8, 16, 32로 다르게 적용하여 각각 3회의 모델링을 실시하였다. 그리고 성능평가 및 metric 평가에 대한 결과값을 3회 평균값으로 산출하여 배치 사이즈별 흉부 X선 영상의 폐렴 특징 추출과 분류의 정확도 및 신속성을 비교 평가하였다. 딥러닝 모델링의 성능평가 결과 배치 사이즈 32를 적용한 모델링의 경우 정확도, 손실함수 값, 평균제곱오차, 1 epoch 당 학습 소요 시간의 결과가 가장 우수한 결과를 나타내었다. 그리고 Test Metric의 정확도 평가는 배치 사이즈 8을 적용한 모델링이 가장 우수한 결과를 나타내었으며, 정밀도 평가는 모든 배치 사이즈에서 우수한 결과를 나타내었다. 재현율 평가는 배치 사이즈 16을 적용한 모델링이 가장 우수한 결과를 나타내었으며, F1-score는 배치 사이즈 16을 적용한 모델링이 가장 우수한 결과를 나타내었다. 그리고 AUC score 평가는 모든 배치 사이즈의 결과가 동일하였다. 이러한 결과를 바탕으로 배치 사이즈 32를 적용한 딥러닝 모델링이 높은 정확도, 안정적인 인공신경망 학습 및 우수한 신속성의 결과를 나타내었다. 향후 딥러닝을 이용한 흉부 X선 영상의 폐렴에 대한 특징 추출 및 분류에 관하여 자동진단 연구 시 배치 사이즈를 32로 적용한다면 정확하면서도 신속한 병변 검출이 가능할 것이라고 사료된다.

• 한국시뮬레이션학회논문지
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• 제5권2호
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• pp.59-72
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• 1996

The purpose of this study is to make an improvement to the batch-means method, which is a procedure to construct a confidence interval(c.i.) for the steady-state process mean of a stationary simulation output process. In the batch-means method, the data in the output process are grouped into batches. The sequence of means of the data included in individual batches is called a batch-menas process and can be treated as an independently and identically distributed set of variables if each batch includes sufficiently large number of observations. The traditional batch-means method, therefore, uses a batch size as large as possible in order to. destroy the autocovariance remaining in the batch-means process. The c.i. prodedure developed and empirically tested in this study uses a small batch size which can be well fitted by a simple ARMA model, and then utilizes the dependence structure in the fitted model to correct for bias in the variance estimator of the sample mean.

• 한국세라믹학회지
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• 제15권4호
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• pp.185-192
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• 1978

The effects of slag prticle size, $Na_2SO_4$ addition and sulphide in slag to the foam formation was investigated. This investigation showed that the slag particle size and the amount of $Na_2O$ had produced effects on the size of the foam, foam distribution and firing temperatures. In addition to that the amount of sulphide loss during the firing was controlling factor for the foam formation. The smaller slag particles and higher firing temperatures increased the loss of sulphide in the slag. The addition of $Na_2SO_4$ in the slag batch was likely to inhibit the foam formation. The larger slag particles resutled in the larger foam size and tended to be increasing the batch firing temperature. The main constituents of slag formed glass consisted of wallstonite and glassy phase. It is believed that the controlling the slag particle size and the amount of $Na_2SO_4$ in the slag batch will probably be main factors in foam formation.

• 공업화학
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• 제10권8호
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• pp.1180-1185
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• 1999

본 연구에서는 입경 제어가 용이하며 입자의 배열 상태가 치밀화된 매우 단분산된 실리카 미립자를 합성키 위하여 회분과 반회분의 적용 순서를 달리한 혼합 공정을 이용, TEOS(Tetraethylorthosilicate)의 가수분해로부터 실리카 미립자를 제조하였다. 실험은 회분과 반회분 각각의 공정을 회분-회분, 회분-반회분, 반회분-회분, 반회분-반회분의 네가지 형태로 순서를 바꾸어 혼합 적용하였으며, 각각의 공정에서 생성된 실리카 입자에 대하여 평균 입경, 입도분표, 수율, 그리고 입자의 치밀화 등을 측정, 비교하였다. 실험결과 최종 평균 입경과 수율은 반회분-반회분>회분-반회분>회분-회분>반회분-회분 공정의 순서로 컸으며, 입도 분포와 입자의 치밀화 정도는 회분-반회분>회분-회분>반회분-회분>반회분-반회분의 순서로 단분산되고 치밀한 결과를 보였다. 이중 반회분-회분, 반회분-반회분과 같이 반회분식으로 먼저 실험하여 입자를 생성한 경우는 두 번째 공정의 종류에 관계없이 모두 2차 핵 생성이 일어나는 결과를 보였으며, 이중 반회분-회분의 혼합 공정에 의해서 생성된 입자는 2차의 회분식 공정 단계에서 반응물이 첨가된 후 시간이 경과함에 따라 오히려 입자가 감소하는 결과를 보였다. 결과적으로 상기 네 가지 공정 중 회분-반회분 순서의 혼합 공정에 의해 생성된 실리카 미립자가 가장 단분산되고 입자의 치밀화가 양호한 상태로 쉽게 입경 제어를 할 수 있음을 알 수 있었다.