• Journal of Korean Institute of Industrial Engineers
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• v.12 no.1
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• pp.1-11
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• 1986

This research is concerned with n jobs, m parallel identical machines scheduling problem in which all jobs have a common due date. The objective of the research is to develop an optimum scheduling algorithm for determining an optimal job sequence, the optimal value of the common due date and the minimum makespan to minimize total cost. The total cost is based on the common due date cost, the earliness cost, the tardiness cost and the flow time cost of each job in the selected sequence. The optimum scheduling algorithm is developed. A numerical example is given to illustrate the scheduling algorithm.

• The Journal of Bigdata
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• v.5 no.1
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• pp.189-195
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• 2020

We consider the stale problem which makes the training speed slow in the field of deep learning. The problem can be formulated as a single-machine scheduling problem with generalized due dates in which the objective is to minimize the total earliness and tardiness. We show that the problem can be solved in polynomial time if the orders of the small and the large jobs in an optimal schedule are known in advance.

• Journal of applied mathematics & informatics
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• v.25 no.1_2
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• pp.183-199
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• 2007

In this paper we research the problem in which the objective is to minimize the sum of squared deviations of job expected completion times from the due date, and the job processing times are stochastic. In the problem the machine is subject to stochastic breakdowns and all jobs are preempt-repeat. In order to show that the replacing ESSD by SSDE is reasonable, we discuss difference between ESSD function and SSDE function. We first give an express of the expected completion times for both cases without resampling and with resampling. Then we show that the optimal sequence of the problem V-shaped with respect to expected occupying time. A dynamic programming algorithm based on the V-shape property of the optimal sequence is suggested. The time complexity of the algorithm is pseudopolynomial.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.33 no.4
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• pp.153-158
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• 2010

This study presents a single machine scheduling algorithm to minimize total cost(lateness cost, earliness cost and failure cost) by controlling machining speed. Generally, production scheduling uses the information of process planning and machining speed is not changed at production scheduling. And failure cost is not consider for scheduling algorithm. Therefore, the purpose of this study is to consider the change of machining speed for efficient production scheduling. And performance criteria for algorithm considers total cost. Especially, failure cost of product by increasing machining speed is considered.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.31 no.4
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• pp.1-9
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• 2008

JIT 생산시스템이 세계적으로 많은 회사에 적용됨에 따라 earliness와 tardiness의 페널티를 동시에 최소화하는 문제에 대한 많은 연구가 진행되어 왔다. 이 연구에서는 한정된 완료시간의 편차에 대해서는 페널티를 부과하지 않는, 즉 허용오차가 존재할 때, 공통의 납기로부터 평균제곱편차(MSD : Mean Squared Deviation)를 최소화하는 단일기계 문제를 다룬다. 허용오차가 존재하는 MSD 문제에서 최적의 공통 납기를 결정하는 방법을 개발한다. 스케줄과 허용 오차가 주어질 때, 최적의 납기를 찾는 두 개의 선형시간이 소요되는 알고리즘을 제시한다. 주어진 허용오차 중 하나는 가장 짧은 가공시간을 가지는 작업의 절반보다 작은 경우이며 다른 하나는 허용오차가 임의인 경우이다.

• The Korean Journal of Mycology
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• v.41 no.2
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• pp.91-96
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• 2013

Two strains Pleurotus eryngii 'Aeryni' and 'Na' carrying superior traits of a pileus and a earliness of harvest were selected to improve previously bred strains by single crosses. New hybrid, Aeryni 3 (Aeryni10 ${\times}$ Na5) showed superiority to other hybrids in yield, fruit body shape and days for harvest. The new strain, Aeryni 3 was harvested earlier than Keunneutari No. 2 by 2~3 days, and yielded 110.5 g/bottle (850 mL) which was 108% of that of Keunneutari No. 2. The ratio of diameter of pileus and stipe was 1.8 indicating that new stain will be likely low damage rate of fruit body during a distribution, and that was better than 2.1 of Keunneutari No. 2. A sensory test of taste of the new strain showed that 84.7% of evaluation panels selected "very good" while that of Keunneutari No. 2 was 55.5%. In purchasing intent test, 86.9% of panels will buy the new stain whereas 46.8% will buy Keunneutari No. 2 implicating that the new strain will likely be more marketability than previously bred strain.

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.620-624
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• 2009

"Egreen" rye (Secale cereale L.) was developed by National Institute of Crop Science (NICS), RDA. It was released in 2007 because of its excellent earliness and yield potential. Crossing was made by an open pollination with 10 rye lines in 1995. Many lines from the open pollinated population were handled in a mass selection program in subsequent generations. Among them the line 'SR95POP-S1-116-1-1-2'was selected for earliness and promising agronomic appearance and placed in yield trial for two years from 2003 to 2004. In 2005, it was designated "Homil 34" and subjected to regional yield trials. Over 3 years, "Egreen" averaged 8.34 MT ha-1 of forage yield (based on dry matter) harvested at the heading date of check variety "Olhomil", which was superior to other varieties such as "Olhomil" and "Koolgrazer" with an increase of 8% and 10%, respectively. Heading date of "Egreen" was April 22, 3 days earlier than that of "Olhomil". It would be recommended as a winter crop forforage and green manure before planting either maize or rice in Korea.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.29 no.3
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• pp.254-260
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• 1984

As a basic study for development of early wheats an experiment was carried out at four sites of Korea by use of 60 varieties. Analysis of variance for heading and maturing dates revealed that there were highly significant among varieties, but not significant among variety x location-interactions, thus indicating the stable response for earliness at all locations of each variety. Grain filling periods of each variety showed the stable response at all locations like those of heading and maturing dates, however, there showed significance among locations for early group, and among varieties for late group. High correlations were between growth habit and winter survival for early varieties, and between shortday length and grain filling period for late one. Interior factors most closely related to heading date were growth habit and winter survival, and winter survival showed highly negative correlation with heading date. It needs to breed the early wheats adaptable for southern and/or northern areas separatively. The earlier heading and maturing dates of wheats were, the shorter internodes of culm are, appearing the outstanding phenomenon in early wheats. Heading date appeared negative correlations with test weight and with number of culm before winter, but showed positive correlation with number of kernels/spike.

• Industrial Engineering and Management Systems
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• v.14 no.3
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• pp.299-311
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• 2015

Nowadays, the distribution centres aim to reduce costs by reducing inventory and timely shipment. Cross docking is a logistics strategy in which products delivered to a distribution centre by inbound trucks are directly unloaded and transferred to outbound trucks with minimum warehouse storage. Moreover, on-time delivery in a distribution network becomes very crucial especially when several distribution centres and customers are involved. Therefore, an efficient truck scheduling is needed to synchronize the delivery throughout the network in order to satisfy all stake-holders. This paper presents a mathematical model of a mixed integer programming for door assignment and truck scheduling in a multiple inbound and outbound doors cross docking problem according to Just-In-Time concept. The objective is to find the schedule of transhipment operations to simultaneously minimize the total earliness and total tardiness of trucks. Then, a multi-objective differential evolution (MODE) is proposed with an encoding scheme and four decoding strategies, called ITSH, ITDD, OTSH and OTDD, to find a Pareto frontier for the multi-door cross docking problems. The performances of MODE are evaluated using 15 generated instances. The numerical experiments demonstrate that the proposed algorithm is capable of finding a set of diverse and high quality non-dominated solutions.

• IE interfaces
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• v.19 no.2
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• pp.124-132
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• 2006

The system under study is a single item, multi-echelon distribution system with a capacitated production facility. All the nodes at the downstream ends are demand-sites, i.e., ordered items are delivered to the customers from the node. Also any transshipment depots in the midstream can be demand-sites as well. For a given planning period, at each of demand-site, demand is forecasted and known. Our objective is to minimize the average system cost per period which is the sum of holding and backorder costs in the entire network. Due to the capacity restrictions, it is difficult to establish efficient distribution planning. To overcome such a difficulty and obtain a reasonable and better solution, we convert this problem into a single machine earliness and weighted tardiness scheduling. We propose a simple but cost-effective heuristic for this problem. The experimental results showed that the proposed heuristic obtained much better solutions compared with another approach.