• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 2007.11a
• /
• pp.7-11
• /
• 2007

This paper considers a shipment planning of products from manufacturers to a third-party warehouse for demands with production time windows where a demand must be replenished in its time window. The underling lot-sizing model also assumes cargo delivery cost in each inbound replenishment to the warehouse. For this model, an optimal O($nT^4$) is presented where n is the number of demands and T is the length of the planning horizon.

• International Commerce and Information Review
• /
• v.11 no.1
• /
• pp.117-137
• /
• 2009

Although the third-party logistics are activated and researched in many ways in the advanced countries, China is still on the beginning phase of the third-party logistics and has announced few studies on them. Especially, the study on factors affecting formation for partnership between shippers and third-party logistics providers has never been announced in China, and few empirical studies on them have been done. In order to verify established hypothesis, the empirical analysis is conducted as follows. Totally 500 copies of questionnaire were drawn up and distributed. Amid them 160 copies were collected, finally 155 copies were used for this study as valid samples. The questionnaire used nominal scale and 5 Likert scale. Statistics of collected data were under the data coding process, and analyzed by applying SEM program.

• Proceedings of the Korean DIstribution Association Conference
• /
• 2000.10a
• /
• pp.151-162
• /
• 2000

철도소화물 부문의 택배시스템 도입은 원가절감이 가능하고, 경쟁력을 갖출 수 있는 장점을 갖추고 있으므로, 현실적으로 매우 필요하다. 택배시스템 도입은 철도청에서 제3자에게 위탁 운영케 하든지, 직접 운영하든지, 별도법인을 만들 수도 있다. 그러나 본고에서는 이러한 내용은 별도의 연구가 있어야할 것으로 보이므로 생략한다. 본고에서는 환경ㆍ제도적인 측면과 운영ㆍ시스템 측면에서 택배시스템을 도입하기 위한 대책방안 만을 강구한다. 본고는 철도소화물시장이 독점적으로 정부의 관할 하에 있기 때문에 철도소화물에 대한 연구가 국내에서 여러 전문가에 의하여 다양하게 전개되지 못하였다는 점이 취약점이다. 따라서 본고도 이러한 환경에서 폭넓은 연구사례를 제기하지 못한다는 한계가 있다. 그러나 설문조사나 인터뷰, 실증자료와 관련 기업과 단체의 내부자료를 통하여 이 문제를 극복하고자 노력하였다.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
• /
• v.13
• /
• pp.389-409
• /
• 2000

Recent demands of market forces are causing considerable attention to be forced on logistics functions and revitalizing interest in outsourcing them. The need to efficiently and economically adjust support to meet market demands is growing significantly. Logistics is playing a role it has never played before. In light of this, outsourcing to third parties has become a strategic issue demanding greater attention in corporate boardrooms. From the perspective of TPL users, this paper focuses on how best to make a strategic plan for the effective utilization of TPL. And the results are as follows : First, after deciding their logistics outsourcing, the companies have to set up the aim of TPL through development of logistical strategies. Second, the companies must decide service provider that fits to their business environment and conditions. Third, they have to conclude a contract with logistics service provider. Fourth, after doing the preparatory implementation they carry into effect the original implementation. Fifth, they use the result of original implementation to fix a partnership.

• Journal of Korea Port Economic Association
• /
• v.21 no.3
• /
• pp.259-270
• /
• 2005

This study applies the Analytic Hierarchy Process (AHP) to evaluate service quality of Third-Party Logistics (3PL) providers. For this, 3PL service quality is conceptualized and measured using SERVQUAL's five dimensions such as tangibles, reliability, responsiveness, assurance and empathy. Then, the AHP method is applied to determining the relative importance of five service quality dimensions and eventually selecting the best 3PL provider. Finally, this study conducts an empirical case study on four companies providing 3PL services in Korea to demonstrate the basic idea suggested in this paper. The results obtained in the present study indicate that responsiveness to customers is the most important factor perceived by 3PL customers and 3PL C is the best 3PL provider according to the overall service quality scores. In contrast to some previous researches, this study examined issues of service quality from the perspective of 3PL customers as opposed to the perspective of 3PL providers. In order for this study to be more complete, future research is needed in establishing a set of metrics to quantify each dimension of 3PL service quality proposed.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.45 no.4
• /
• pp.127-133
• /
• 2022

Many manufacturers applying third party logistics (3PLs) have some challenges to increase their logistics efficiency. This study introduces an effort to estimate the weight of the delivery trucks provided by 3PL providers, which allows the manufacturer to package and load products in trailers in advance to reduce delivery time. The accuracy of the weigh estimation is more important due to the total weight regulation. This study uses not only the data from the company but also many general prediction variables such as weather, oil prices and population of destinations. In addition, operational statistics variables are developed to indicate the availabilities of the trucks in a specific weight category for each 3PL provider. The prediction model using XGBoost regressor and permutation feature importance method provides highly acceptable performance with MAPE of 2.785% and shows the effectiveness of the developed operational statistics variables.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.37 no.1
• /
• pp.60-67
• /
• 2014

This paper considers an inbound ordering and outbound dispatching problem for multi-products and multi-vehicles in a third-party distribution center. The demands are dynamic over a discrete and finite time horizon, and replenishing orders are shipped in various transportation modes and the freight cost is proportional to the number of vehicles used. Any mixture of products is loaded onto any type of vehicles. The objective of the study is to simultaneously determine the inbound lot-sizes, the outbound dispatching sizes, and the types and numbers of vehicles used to minimize total costs, which consist of inventory holding cost and freight cost. Delivery time window is one of the general dispatching policies between a third-party distribution center and customers in practice. In the policy, each demand of product for a customer must be delivered within the time window without penalty cost. We derive mixed integer programming models for the dispatching policy with delivery time windows and on-time delivery dispatching policy, respectively and analyze the effect on a dispatching policy with delivery time windows by comparing with on-time delivery dispatching policy using various computational experiments.

• 한국신재생에너지학회:학술대회논문집
• /
• 2011.05a
• /
• pp.177.2-177.2
• /
• 2011

세계적인 자원고갈과 지구온난화와 같은 환경문제가 발생됨에 따라 대체에너지 개발에 대한 연구가 활발히 이루어지고 있다. 섬유소 기질을 이용한 바이오에탄올 생산은 세계적으로 막대한 자원이 있으며 광합성에 의해 재생산되는 무한한 재원으로서 환경적으로도 대기오염물질을 적게 배출하여 유용한 에너지원으로 각광받고 있다. 하지만 섬유소 기질은 cellulose, hemicellulose, lignin과 같은 고분자 화합물이 유기적으로 결합된 단단한 결정구조로 이루어져 있어 이를 분해하여 원하는 물질을 얻기 위해서는 전처리 과정이 필요하다. 전처리 공정은 바이오에탄올을 생산하는 당화 및 발효공정의 효율 및 반응시간 단축에 기여하며, 특히 섬유소 기질일 경우에는 필수불가결한 공정이다. 전처리 공정은 물리적, 화학적, 생물학적 방법으로 나누어지며, 이러한 방법들 중 기질의 특성과 처리효율에 따라 기술들을 병합하여 사용하기도 한다. 이에 본 연구에서는 산 처리, 암모니아 처리, 과산화수소 처리 및 효소를 이용한 생물학적 처리를 단독 또는 병행하여, 전환된 당 성분 및 함량을 조사함으로서 섬유소계 기질인 채소 음식물류 쓰레기를 대상으로 바이오에탄올을 경제적으로 생산하기 위한 적합한 전처리법을 검토하였다. 전처리 방법별 당화율을 살펴보면, 산 처리와 암모니아-과산화수소-계면활성제 처리가 각각 65.3 % 및 65.7 %로 가장 높았으며, 과산화수소 처리는 16.2 %로 가장 낮았다. 반면 전처리 공정 없이 효소를 이용한 당화만을 실시한 경우에는 4.3 %의 낮은 당화율을 나타내었다. 섬유소계 기질의 전처리 효율을 향상시키기 위해 첨가하는 계면활성제의 효과는 암모니아-과산화수소 및 암모니아-과산화수소-계면활성제 처리의 당화율을 비교한 결과, 뚜렷한 효과를 확인할 수 없었다. 전처리 방법별 당의 성분 및 함량을 비교한 결과 육탄당은 암모니아-과산화수소-계면활성제 전처리에서 가장 많이 검출되었다. 오탄당은 산 처리 후 그 함량이 현저히 높았으며, 오탄당 중 xylose의 함량이 60.49 mg/g로 가장 많이 차지하고 있었다. 이 결과로부터 전처리 방법에 관계없이 당화율은 유사한 수준을 보이지만, 당화된 당의 성분 및 함량에는 큰 차이가 있음을 알 수 있었다. 이당류의 경우 과산화수소 및 암모니아-과산화수소 처리를 제외한 나머지 전처리 방법에서 유사한 수준을 나타내었다. 암모니아 처리 및 과산화수소 처리를 순차적으로 병행한 암모니아-과산화수소 처리에서는 각각의 처리시보다 육탄당의 함량은 증가하였으나 암모니아 처리시보다 이당류의 함량은 감소한 것으로 나타났다.

• Journal of Advanced Navigation Technology
• /
• v.24 no.6
• /
• pp.491-499
• /
• 2020

There are policies that foster the drone industry, which either put a legal precedent on drones through the "Drone Act" or grant a delay or exemption in applying the safety measures of "the Aviation Safety Act". Yet, the definition of a drone is unclear, requiring further discussion on commercial usage. Therefore, we have studied cases domestically and abroad, and also analyzed issues with the current aviation legislation. It was found that a drone is defined as "an unmanned aircraft where a pilot is not on board, and its net weight is 150 kg or less". However, there are several issues, such as that a drone taxi requires a pilot on board, and its weight is 150 kg or more. Thus, we propose to define a drone as "an unmanned aerial vehicle (provided, that its own net weight should be 300 kg or under, or not be limited to weight) under Article 2 (3) of the "Aviation Security Act" as prescribed by Ordinance of the Ministry of Land, Infrastructure, and Transport, which operates either by remote, automatically, or autonomously; or an unmanned aircraft under Article 2 (6) of the "Aviation Security Act".

• Journal of Distribution Science
• /
• v.7 no.4
• /
• pp.47-56
• /
• 2009

The purpose of this study is to present an alternative improving the efficient and reasonable of the physical distribution system management is influenced by many factors. Therefore, the study depends on the documentary method and survey method to achieve the purpose of this study. The major components of a physical distribution system are refers to as elements, include warehouse·storage system, transportation system, inventory system, physical distribution information system. The factors used in this study are ① factor of product(quality·A/S·added value of product·adaption of product·technical competitive power to other enterprises), ② factor of market(market channel·kinds of customer·physical distribution share), ③ factor of warehouse·storage(warehouse design·size·direction·storage ability·warehouse quality), ④ factor of transportation(promptness·reliability·responsibility·kinds of transportation·cooperation united transportation system·national transportation network), ⑤ factor of packaging (packaging design·material·educating program·pollution degree measure program), ⑥ factor of inventory(ordinary inventory criterion·consistence for inventories record), ⑦ factor of unloaded(unloaded machine·having machine ratio), ⑧ factor of information system (physical distribution quantity analysis·usable computer part), ⑨ factor of physical distribution cost(sales ratio to product) ⑩ factor of physical distribution system(physical distribution center etc). The implication of this study can be summarized as follows: ① In firms that have not adopted a systems integrative approach, physical distribution is a fragmented and often uncoordinated set of activities spread throughout various functions with function having its own set of priorities and measurements. ② The physical distribution is recognized as more an important strategic factor than a simple cost reduction factor, ③ It can be used a strategic competition tool to enterprise.