• 한국항해항만학회지
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• 제29권9호
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• pp.801-806
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• 2005

The world of container shipping and container terminal business is changing and container ports need to know what the changes are in order to plan how to respond. In particular, the container transport industry has noticed two major developments such as globalization and consolidation. The purpose of this paper is to review the current trend towards globalization and consolidation of container liner shipping and container terminal business. It also investigates the impact of these market developments on container ports and presents its implications for port development, management and operation, and port competition policy. According to the discussion of this paper a greater exercise of market power of container terminal operators will have negative impacts on international trade and national economy, especially port users, including container lines, exporters and importers. An empirical evidence on the exercise of market power is required to develop competition rules on market dominance at a national and international level. This paper suggests 'port coopetition' as a solution for smaller and regional container terminal operators to survive in a competitive business environment.

• 산업공학
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• 제16권spc호
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• pp.99-104
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• 2003

While demands for express service are rapidly increasing according to recent progress of electronic commerce, express service companies are struggling to take a larger delivery service market share through ongoing improvement in their service processes. Extension of cut-off time for express service centers can provide the express company with increase of total sales, but it may also cause to increase the possibility not to satisfy customer needs due to work delay in the consolidation terminal. Therefore, compromised decision for cut-off time of each service center should be made by taking operation characteristics of the consolidation terminal into account. This study suggests an approach for determining the cut-off time for express service centers according to operational characteristics of the consolidation terminal with the objective of maximizing expected incremental sales. The problem defined in this study can be represented as two successive models; one is an integer programing model in which the best cut-off time for each sales center are determined, and the other is a single machine scheduling model in which a working schedule in the consolidation terminal is obtained. A genetic algorithm is developed to solve the two models simultaneously. Finally, an example problem is carried out to verify applicability and performance of the algorithm with the data set collected from an express company.

• 대한산업공학회지
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• 제33권2호
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• pp.282-289
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• 2007

While demands for express couriers service are rapidly increasing due to recent progress of electronic commerce, express courier service companies are struggling to take a larger market share through ongoing improvement in their service processes. Cut-off time is the time limit that all orders delivered before the limit are guaranteed for the delivery within the very next day. Extending cut-off time for express service centers can provide the express company with increase of total sales, but it may also cause increasing the possibility not to satisfy customer needs due to work delay in the consolidation terminal. We develop a design model for express courier service network based on a recursive optimization/simulation procedure. With the optimization model, we seek key design parameters such as the cut-off time for express service centers and the capacity of the consolidation terminal maximizing total sales profit while satisfying the desired level of performances. With the simulation model, we consider the dynamic nature of the network and obtain relationships between the design parameters and the performance measures with the multiple linear regression. The validity of the model is examined with an example.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1992년도 가을학술발표회 논문집
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• pp.113-120
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• 1992

The construction of container terminal at Brani, Singapore required the improvement of soft clay layer having the thickness of about 6.5m, average moisture content of 79.4%, liquid limit of 90.4%, plastic limit of 21.8%, field vane strength of 10 to 25 KPa, pre-consolidation pressure of 225 to 60 KPa and compression index of 0.4 to 1.0. For the improvement of this layer, Colbon drains of 1.3m spacing in triangular pattern were installed to the bottom of the layer and surcharge of more than 11.25m high sand fill was later applied to the treated area. The settlement and lateral displacement of the ground were measured and the speed of surcharge filling was controlled, based on these readings. The removal of surcharge was determinied using the estimated time for the 90% degree of consolidation under the design pressure of 180KPa. The field and laboratory test results show that the soft clay layer has been improved substantially in its strength and consolidation characteristics: increase in strength of about 50KPa and pre-consolidation pressure and decrease in void ratio and compression index.

• Industrial Engineering and Management Systems
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• 제9권2호
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• pp.80-87
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• 2010

As express courier market expands rapidly, companies are exposed to fierce competition. To cope with struggle for their survival, they are continuously making efforts to improve their service system. Even if most of service centers are directly linked to a consolidation terminal in courier service network, some of them with regional disadvantages are operated in milk run type from/to the consolidation terminal, which is a traditional PDP (Pick-up and Delivery Problem). This study suggests an approach to solve the PDP with the objective of maximizing the incremental profit, which belongs to PTP (Profitable Tour Problem) class. After the PTP is converted to TSP (Traveling Salesman Problem) with the same objective, a heuristic algorithm based on GA (Genetic Algorithm) is developed and examined through an example problem in practice of a courier service company in Korea.

• 대한산업공학회지
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• 제37권4호
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• pp.304-310
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• 2011

The express courier business in Korea has been recognized as one of promising business sectors with the annual growth rate of over 10 percent since 2001. As such many domestic and foreign companies have been established and are fiercely competing to extend their own market share. The severe competition has forced them to focus on achieving cost competitiveness and high level of customer service. Small and medium-sized enterprises( SMEs) with relatively poor network infrastructure in particular are facing tougher challenges to cost reduction and efficiency improvement in their logistics networks. Strategic alliances among SMEs may be an effective way to cope with these challenges. Therefore this study proposes an integer programming model for compromised network design and its solution procedure based on maxmin and maxsum criteria for strategic alliances. The applicability and efficiency of the proposed model are demonstrated through an illustrative numerical example.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2006년도 춘계 학술발표회 논문집
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• pp.1120-1125
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• 2006

Larger area will be constructed in a harbor land and container terminal which are constructed in reclaimed land using the dredged materials. Soil improvement work is to be carried out including constructibility, in which is monitoring devices, measuring frequency, installations etc. The ground water tables in the reclaimed area are affected by the several factors which are design reclamation level, consolidation settlement, remaining surcharge pressure and remaining excess pore water pressure. The plan wii be drawn up in which monitoring results for the ground water tables are capable to provide the reliable ground water table when designers and civil engineers construct the harbor structures considering constructibility.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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• pp.613-618
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• 2008

Because the flat dilatometer (DMT) is operated in appropriate strain level, it has been known as an adoptable in-situ tool to evaluate the compressibility of soils compare with other in-situ test tools, such as SPT and CPT. This study is concerned about prediction method of constrained modulus by DMT, and a series of DMT and consolidation tests are performed at Busan new-port, Yangsan and Noksan test sites. By comparing DMT results with lab tests, the suitability of constrained modulus correlation, which is suggested by Marchetti, is investigated in Busan clay and new correlation is suggested. In lab test result, the compression indices ($C_c$) of Busan clay are turned out to be 0.4~0.12, and the constrained moduli are found out 0.5MPa~3MPa and these are increase with depth. The predicted constrained moduli using Marchetti's correlation are turned out 0.5MPa~4MPa, and these are bigger than measured constrained moduli by lab tests. By analyzing lab test and DMT results, it is shown that the correlation coefficient ($R_M=M/E_D$) has a linear relationship with (1/$I_D$) in Busan.

• 한국지반공학회논문집
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• 제25권8호
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• pp.33-45
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• 2009

단일코어 연직 배수재 공법은 현재까지 폭넓게 사용되는 연약지반 개량공법이다. 그러나 얇은 플라스틱 보드 형태의 PBD 구조로 인해 압밀 도중 큰 횡 방향 토압과 이에 따른 necking 현상이 발생하고 이는 PBD의 통수능을 감소시킨다. 본 연구 대상인 부산신항만 조성 공사현장은 대심도의 연약지반으로서 PBD 설치 시, 큰 횡 방향 토압에 의한 통수능 감소를 예상되어 통수능 감소현상을 극복하기 위하여 이중코어 PBD를 도입, 시공하고, 기존 형태의 단일코어 PBD를 동시에 설치한 후, 현장에서의 배수재 성능을 비교분석하였다. 실내실험으로는 개량 델프트 실험을 수행하여 연직배수재의 통수능을 측정하고, 현장에서 채취한 시료를 이용해 기본 물성실험 및 CRS 압밀시험을 수행하여 수치 해석 프로그램인 ILLICON에 적용하여 침하거동 양상을 파악하였다. 개량 델프트 실험에서는 이중코어 PBD의 통수능이 단일코어 PBD보다 높게 측정되었으나, 현장 계측 및 수치해석에서는 차이가 나타나지 않았다. 이는 일발전인 대심도 지반에서 압밀시 발생되는 물의 배수량은 상대적으로 작은 단일코어 PBD의 통수능 범위 보다도 작기 때문에 실제 현장에서는 단일코어 PBD와 이중코어 PBD의 성능차이가 없음을 확인하였다.

• 한국항만경제학회지
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• 제39권1호
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• pp.149-172
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• 2023

한·중·일을 포함하는 동북아지역은 1990년대 이후 급속한 경제성장과 더불어 역내외 석유물류가 증대되고 있다. 우리나라는 이러한 대외적인 환경하에서 2000년대 중반 이후 동북아 석유물류허브화 정책을 추진해 왔다. 동북아 물류허브화를 위해서는 부가가치 석유물류의 비즈니스 활성화를 위한 비즈니스 모델의 구축과 촉진이 중요하다. 동북아 지역에서 우리나라 석유물류 비즈니스 모델을 분석함으로써 석유물류 활성화에 대한 정책적·실무적 시사점을 제시하는 데 목적이 있다. 전체 23개 탱키지 업체를 대상으로 면담조사에 의한 사례분석결과는 다음과 같다. 첫째, 면담조사한 대부분의 유류저장탱크터미널업체들은 블랜딩, 소분화, 집적화와 같은 부가가치 석유물류를 실시하고 있다. 둘째, 부가가치 석유물류의 발생은 주변국들간 수급의 불균형에 의해 발생하고 있는데 특히 일본, 오세아니아, 미국, 남미 등을 연결하는 소분화와 블랜딩 수요가 높다. 셋째, 부가가치 물류수요에 대응한 인프라, 제도 및 규제 등에 대한 개선을 통해 부가가치 석유물류의 활성화를 촉진해야 할 것이며 이는 우리나라의 동북아 오일허브 정책에 크게 기여하게 될 것이다.