• 산업공학
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• 제7권2호
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• pp.107-120
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• 1994

This study introduces a scheduling policy to achieve unmanned operations in machining shops representing the feature of both FMS and machining centers. The proposed policy considers the practical constraints in the machining shops such as lot sizes, multiple pallets, and jig/fixtures. In addition, rescheduling to cope with extraordinary events(eg., arrival of high-priority jobs and breakdown of machines) is included. Basically, the scheduling policy consists of four procedures; (1) selection of a job according to dispatching rule, (2) selection of a machine, (3) assignment of jobs to a multiple pallet for the unmanned operation during a certain shift, and (4) prevention of unexpected machine idle caused by constraints on jig/fixture.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2007년도 추계학술대회
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• pp.373-385
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• 2007

Three major Asian countries, Korea, China, and Japan, shared 18.3% of global GDP and 14.2% of global trade volume in 2005. When considering this number, cooperation of these three countries is very important. Also, it is needless to say that we need efficient international logistics system in Asia. The key point to realize efficient international logistics system is unit load system utilizing pallets and containers. To build up efficient logistics system among Korea, China, and Japan, we need 'total palletization' with standardized pallets. We may regard 'total palletization' as an 'efficient highway of North-Eastern Asia logistics.' In this study, we will suggest two kinds of effects, which logistics standardization among Korea, China, and Japan will make. One is the effect on economy and trade, and the other is the effect on logistics business and environments.

• 한국항만경제학회지
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• 제22권1호
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• pp.1-15
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• 2006

This paper analyzes how levels of logistics standardization are related to logistics costs. The study surveyed ratios of standard pallet use in order to measure levels of firms' standardization in logistics management. Research focused on how firms' logistics costs were related to their levels of logistics standardization and ratios of standard pallet use. After measuring use of standard pallets and logistics costs, optimal levels of logistics standardization were estimated based on survey data. Logistics costs and standardization were more related to labor than to freight volume or export. Results indicated that firms could reduce logistics costs by raising levels of logistics standardization; optimal levels of standard pallet use out of Korean firms' total manufacturing cargo volume were estimated at 44.26% for multi-standard pallets and 57.99% for a single standard pallet (a unit load system). The study demonstrated that adopting a single standard pallet results in better cost saving logistics systems than use of multi-standard pallet types. These results may explain why firms pursue standardization in logistics systems.

• 대한안전경영과학회지
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• 제9권4호
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• pp.91-98
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• 2007

Three major Asian countries, Korea, China, and Japan, shared 18.3% of global GDP and 14.2% of global trade volume in 2005. When considering this number, cooperation of these three countries is very important. Also, it is needless to say that we need efficient international logistics system in Asia. The key point to realize efficient international logistics system is unit load system utilizing pallets and containers. To build up efficient logistics system among Korea, China, and Japan, we need 'total palletization' with standardized pallets. We may regard 'total palletization' as an 'efficient highway of North-Eastern Asia logistics.' In this study, we will suggest two kinds of effects, which logistics standardization among Korea, China, and Japan will make. One is the effect on economy and trade, and the other is the effect on logistics business and environments.

• 산업경영시스템학회지
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• 제39권3호
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• pp.56-63
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• 2016

For air express service providers offering various express delivery services such as overnight delivery and next-business day delivery services, establishing quickly cargo loading plans is one of important issues owing to the characteristics of air express business, i.e., a short amount of time is available to complete all cargo loading operations before flight departure after receiving air express containers, pallets and bulks. On the other hand, one of major concerns in the air cargo loading planning is to make a plan that insures the stability of an aircraft to avoid take-off, flight, and landing accidents. To this end, this paper considers an air cargo loading planning problem, which is the problem of determining locations in the aircraft cargo space where air containers, pallets and bulks to be loaded while insuring the aircraft stability, motivated from DHL and Air Hong Kong. The objective of the problem is to maximize the total revenue gained from loading air express containers, pallets and bulks. To solve the problem, this paper suggests a simulated annealing algorithm to overcome impracticality of the integer programming model developed by a previous study requiring excessive computation time. The results of computational experiments show that the heuristic algorithm is a viable tool for establishing express cargo loading plans as giving robust and good solutions in a short amount of computation time. Scenario analyses are performed to investigate the effect of the current activities of air express carriers on the revenue change and to draw practical implications for air express service providers.

• Agricultural and Biosystems Engineering
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• 제3권2호
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• pp.73-78
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• 2002

Cabbage is one of the most important vegetable in Korea. The cabbage production was mainly based on human labor A comprehensive research fur substituting the human labor by machines has been performed until now. In general, cabbage is cultivated on hillside in Korea. Picking up the harvested cabbages in field and carrying to a vehicle fur transportation are very laborious work. Manual transportation of cabbage is likely to damage the quality and is also a cause to increase the cost of cabbage production. This study was to develop and evaluate a prototype cabbage loader fur efficient and safe transportation of cabbage. The developed loader was a semi-tracked vehicle operated by a hydraulic system, allowing the safe transportation and loading of cabbage in a steep field. The maximum loading weight of the loader was 1.0 ton. By using two sets of safety devices attached to the loader to avoid the roll-over in a steep field, the static rollover slopes were increased up to 34.0% and 37.4% fur the left and the rear direction, respectively The maximum field speed was about 6km/hr with two cabbage pallets of 750kg at a 25% inclined field. The loading capacity of the loader was about 35 pallets/hr when picking up, carrying, and unloading two cabbage pallets for one loading operation. The loading capacity was more than 8 times in comparison with the conventional human labor. The developed loader could be used fur loading and carrying the other vegetables. The study suggested a possible approach for designing the field machines operated on hillside.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.II
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• pp.480-488
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• 2000

Cabbage is the most important vegetables in korea. The cabbage production was based on arduous human labor. A comprehensive research for substituting the human work by machines has been performed at present. In general, cabbage is cultivated on hillside in korea. The harvested cabbage in a field and carrying it to a vehicle for transportation are very laborious work. Hand labor in cabbage transportation to the market damages the quality of cabbage and is also a cause to increase the cost of cabbage production. This study was to design and evaluate a prototype cabbage loader for deserving efficient and safe transportation of cabbage. The developed cabbage loader was a semi-tracked vehicle operated by a hydraulic system, allowing the safe transporting and the loading of cabbage in a steep field. The maximum loading capacity of the loader was 1.0 ton. By using safety devices attached to the loader, the static slopes were 34.0% and 37.4% for the left and the rear roll-over, respectively. The maximum field speed was about 6km/hr with two cabbage pallets of 750kg at a 25% inclined field. The field capacity was about 35 pallets/hr in case of picking up, carrying and unloading two cabbage pallets. The field efficiency of the loader was analyzed to be more than 8 times in comparison of the conventional human labor. The developed loader would be applied for loading and carrying the other vegetables due to the similarity of operations. The study suggested a standard approach to the design of field machines operated in a steep field.

• 한국응용곤충학회지
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• 제39권4호
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• pp.245-250
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• 2000

진딧물류의 포식성 천적인 칠성풀잠자리붙이의 발육에 미치는 온도의 영향 및 계절적 발생소장을 조사하였다. 난부터 우화가지의 평균발육기간은 17, 22, 27, $32^{\circ}C$(75%RH, 16L:8D)에 서 각각 39.5, 32.0, 25.0, 19.8일로 온도가 증가할수록 발육기간이 단축되었다. 암컷의 수명은 위 조사 온도에서 각각 84.7, 79.6, 77.7, 69.8일이었고 산란수는 각각 973, 1085, 1637, 1735개로 고온일수록 수명은 짧았지만 산란수는 많아졌다. 또한 부화율은 84.1~95.9%이었고 우화율은 67.6~86.3%로 온도가 높을수록 높았으며, 성비는 대략 1:1이었다. 35, 55, 75%습도조건($27^{\circ}C$)에서 발육기간(난-우화)은 각각 26, 24, 22.9일 이었고 산란수는 1042.8, 1526.5, 1640개 였다. 칠성풀잠자 리붙이 성충은 $27^{\circ}C$에서 우화 5~6일 후부터 산란하기 시작하여 1일 평균 30~40개 정도 산란하며, 우화 후 22~28일 사이에 산란을 가장 많이 하였는데 이때에 1일 최고 산란수는 80~90개였다. 복숭아혹진딧물과 목화진딧물은 5월 하순~6월 중순에 발생 Peak를 보인 후 7~8월에는 밀도가 급격히 감소하다가 9월 상~중순경에 다시 증가하였다. 칠성풀잠자리붙이는 7월 중~하순에 1차 발생 Peak를 보였으며, 그 이후 밀도가 감소하다 9월 중~하순에 다시 2차 발생 Peak가 나타났다.

• 파렛트 뉴스
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• 통권74호
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• pp.3-13
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• 2014

본 원고는 지난 2013년 11월 29일부터 30일까지 이틀간 중국 중경에서 열린 2013 한 중 파렛트 국제 컨퍼런스 발표 원고로 아시아파렛트시스텀연맹(APSF) 박은규 전무이사가 "APSF 인증 파렛트를 아시아 국가에 도입 및 확산방안"에 대하여 설명하고 있다.

• 한국포장학회지
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• 제16권2_3호
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• pp.59-65
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• 2010

Starch was modified with epichlorohydrin(ECH) to improve the miscibility with LDPE and LLDPE. Native starch or epichlorohydrin treated starch was mixed with grycerol and LDPE/LLDPE resin using a kneader and extruded using a single screw extruder to make pallets. The pallets were compression-molded at 145 into composite boards to evaluate their color, oxygen permeation, mechanical and thermal properties, and degradability under UV irradiation. Sheets with epichlorohydrin treated starch generally showed higher L-value than that of native starch blend sheets. The hunter b-values in both native starch blends and epichlorohydrin treated starch blends increased with Increasing starch contents. Tensile strength and percent elongation of sheets decreased with increasing starch contents. Tensile strength and percent elongation of sheets decreased with increasing starch contents. The degradability of blends under UV radiation increased with increasing starch contents in both blend types. The results represents that crosslinking of starch with epichlorohydrin may be a good method to improve miscibility of starch with petroleum-based materials.