• 한국자동차공학회논문집
• /
• 제16권1호
• /
• pp.78-85
• /
• 2008

The exhaust emission characteristics of a liquefied petroleum gas-di-methyl ether (LPG-DME) compression ignition engine was investigated under homogeneous charge, stratified charge and diffusion combustion conditions. LPG was used as the main fuel and injected into the combustion chamber directly. DME was used as an ignition promoter and injected into the intake port. Different LPG injection timings were tested to verify the combustion characteristics of the LPG-DME compression ignition engine. The combustion was divided into three region which are homogeneous charge, stratified charge, and diffusion combustion region according to the injection timing of LPG. The HC emission was reduced with LPG stratification. However, the carbon monoxide and particulate matter emissions were increased. The ignition timing was advanced with LPG stratification. This advance combustion was because of charge temperature and cetane number stratification with LPG.

• 대한기계학회논문집B
• /
• 제31권6호
• /
• pp.514-521
• /
• 2007

This study focused on the effects of the $CO_2$ gas concentration in fresh charge and induction air temperature on the combustion characteristics of homogeneous charge compression ignition with dimethyl ether (DME) fuel, which was injected at the intake port. Because of adding $CO_2$ in fresh charge, start of auto-ignition was retarded and bum duration became longer. Indicated combustion efficiency and exhaust gas emission were found to be worse due to the incomplete combustion. Partial burn was observed at the high concentration of $CO_2$ in fresh charge with low temperature of induction air. However, indicated thermal efficiency was improved due to increased expansion work by late ignition and prolonged bum duration. Start of auto-ignition timing was advanced with negligible change of burn duration, as induction air temperature increased. Burn duration was mainly affected by oxygen mole concentration in induction mixture. Bum duration was increased, as oxygen mole concentration was decreased.

• 한국항해항만학회:학술대회논문집
• /
• 한국항해항만학회 2002년도 춘계학술대회논문집
• /
• pp.21-30
• /
• 2002

Busan Port which is the representative social overhead capital facilities for international trade of goods has been the driving force for economic development in Korea. Therefore, the central government should play the major role in building a rear road to Busan Port in order that it may function as a mojor port of Northeastern Asia through the systemization of mutual assistance among connected facilities, completely equipped with port-related facilities befitting to the principal port of imports and exports. In this study, the validity of container tax is being examined, analyzing container tax which Is considered as an obstacle to the development of Busan Port and its purpose, and grasping the present conditions by the realistic speculation on container tax issues and its abolition. First, the port rear road as a social overhead capital facilities, which connects port and expressway, should be considered as part of port, and port is social overhead capital invested by government. Second, the susan City imposes on container tax. As a result, a shipper and a shipping company are paying a double charge by paying container tax with port dues. Third, someone argues that port rear road is constructed as container truck generates much traffic, but it is unreasonable to conclude that container truck is seed of traffic jam because according to traffic survey of Busan City, container truck occupies only 1.45% of total traffic Forth, it has bad influence upon the competitiveness of Busan Port as Northeastern logistics base, as other ports who are competing with Busan Port like Singapore. Hong kong, Kobe make their competitiveness strong by decreasing the cost of pore dues

• 한국항해항만학회지
• /
• 제30권1호
• /
• pp.53-59
• /
• 2006

해상 구간에서의 선박 운항과 관련된 단위 비용이 선박 대형화에 비례하여 감소한다는 규모의 경제에 근거하여 최근 8,000TEU급 선박이 운항을 개시하였고, 10,000TEU급 이상 초대형선(Mega Ship)이 설계 단계에 있다. 기존 연구들은 대형항만에서 대형항만까지의 총운항비 관점에서 연구가 진행되어졌으나, 본 연구에서는 운항비, 항만비용(하역비 포함), 피더비용 등 총비용적 관점에서 허브항으로 선택된 항만별 경제성 평가를 하는데 목적이 있다. 이를 위하여 먼저 기간항로를 운항하고 있는 국내선사의 자료를 토대로 초대형 킨테이너선의 운송네트워크를 설정하고, 10,000TEU급 컨테이너선이 운항할 경우의 비용과 물동량을 적용하여 시나리오별 경제성 분석을 실시한다. 본 연구에서 제시된 3개의 시나리오는 각각 부산항, 상해항 그리고 요코하마항을 허브포트로 설정하였는데, 연구결과 부산항이 허브포트가 되었을 경우 가장 경제성이 있는 것으로 나타났다.

• 한국항해항만학회:학술대회논문집
• /
• 한국항해항만학회 2017년도 추계학술대회
• /
• pp.39-41
• /
• 2017

본 연구에서는 해사영어어휘의 특징인 ballast water, fore peak bulkhead, container, freight station charges와 같은 n-gram의 복수 단어로 구성된 합성어 (multi-word compounds) 태깅(tagging)처리가 포함된 해사영어코퍼스를 구축하였다. 해사영어코퍼스는 백만 단어씩 수집한 학술, 법, 신문, 교과서 4개 하위 코퍼스로 구성된 총 400만 단어의 해사영어코퍼스로 구성되어 있다.

• 한국항해학회지
• /
• 제18권1호
• /
• pp.31-39
• /
• 1994

The practical shiphandlers, such as ship's captain, pilot and mooring master, in charge of the SBM app-roaches and mooring operations of loaded VLCC should have a highly advanced shiphandling skills because of taking advantage of the wind and current from ahead without assistance of big tugboats. But now except some approaching skills in the vicinity of SBM buoy or waiting anchorage we do not have an optimal controlled approaching maneuvers in the entire course of port approaches. Consequently this study presents the optimal SBM approaches to the practical shiphandlers of VLCC and puts to use with effect in the practical operations. The conclusions of this simulation study are as follows : 1) The optimal SBM approaches in combination of Woo's Approach and a large change of heading were presented for the practical shiphandlers, 2) According to simulation of the pilotship the angle of a large change of heading for reducing headway is more than 70 degrees approximately. 3) Applied this optimal approaches to the SBM operations of simulated Port of Ulsan and confirmed the control of ship and the economy of port approaches time.

• 한국항만학회지
• /
• 제9권2호
• /
• pp.9-24
• /
• 1995

The intensification of the competition among container terminals has led to important affect such as, decision making or aggressive intervention of customers for terminal operation. Therefore, in case of developed ports, the large transition of port operation is composed of the press of terminal customer than decision making of terminal manager. Overall port tariffs for using terminal is made out by the conference of terminal customers than the supreme headquarters of terminal operation, and the related investment of terminal has been made according to requisition or proposal of customers. Therefore, among decision making problems that shippers, shipping companies, and freight forwarder among decision making problems that shippers, shipping companies, and freight forwarder face, the choice of the container terminal is one of the most important problems. So, the decision making of the users seems to have a significant impact on the competitive power of container terminals. The main objective of this study is to design port marketing strategy for strengthening the competitive power of container terminals. The results of this study were found as follows: Firstly, port authority should establish user-oriented operation policy of terminal as the means of activating the opinion window, using terminal monitoring system(TMS). Secondly, terminal planning and development of government should be made to minimize the lead time, to induce the civil capital and to utilize the economies of scale. Thirdly, port authority needs to endeavor to analyze the information of competing foreign terminals as well to promote the concentrated marketing for the terminal on the users, to train the expert and to develop the new port charge system. Fourthly, to improve the competitive power of the container terminal, Port Authority should optimize the subsystems related to port marketing, far more these systems should be joined organically to work effectively. Finally, port authority system should be introduced, Namely, port should have the enterprise inclination as well s the public inclination.

• 한국항만학회지
• /
• 제11권2호
• /
• pp.145-156
• /
• 1997

The purpose in this study is development of model for the Container Terminals of Pusan Port, First of all, Quantitive and Qualititve factors are characterized which effects on Physical Distribution System in Container Terminals. The System Dynamics method is used to develope the model by using these factor. This model is able to present the timinig of investment in Container Terminals of Pusan Port. Six models are showed by change of parameters in System Dynamics, in this paper. In the model, Five feedback loop were found. Loop 1 : Number of Liners$\rightarrow$Number of Congested ships$\rightarrow$Port's Charges$\rightarrow$Export & Import Cargo Volumes$\rightarrow$Number of Liners$\rightarrow$The will to investment of government$\rightarrow$Length of berth→Number of Liners. Negative loop was acquired. Loop 2 : Port's Charge$\rightarrow$Economic of Port$\rightarrow$The will to Private management$\rightarrow$Efficiency for Port's Operation$\rightarrow$Port's Charges. Positive loop was acquired. Loop 3 : Number of Congested ships$\rightarrow$Planning for future development$\rightarrow$Information Service$\rightarrow$Support service for port's user$\rightarrow$Number of Congested ships. Negative loop was acquired. Loop 4 : Number of Congested ships$\rightarrow$Planning for future development$\rightarrow$Extent of stacking area$\rightarrow$Number of handling equipmint$\rightarrow$Number of Congested ships. Negative loop was acquired. Loop 5 : Export & Import Cargo Volumes$\rightarrow$Number of Liners$\rightarrow$Econmic of Port$\rightarrow$Support service for port's user$\rightarrow$Export & Import Cargo Volumes. Positive loop was acquired. System's level variables were selected as followings ; Number of Liners, Number of Congested ships, Export & Import Carge Volumes, Length of berth, and Port's Charges. As result of simmulation of model, fluctuation of respective year was found in level variables. This fluctuation can be used properly to present timing of investment.

• 한국항해항만학회지
• /
• 제28권8호
• /
• pp.709-714
• /
• 2004

본 연구는 최근 물동량이 빠른 속도로 증가하고 있는 대련항, 천진항, 청도항, 상해항 등을 화물의 목적항으로 설정하고, 선박의 운항패턴 시나리오를 바탕으로 부산항에서 환적하는 경우와 중국항 직기항 등의 총운송비용 차이를 분석하였다. 이를 바탕으로 하여 부산항에서 환적할 때 직기항하는 경우보다 초과 발생하는 비용을 항만 당국이 선사에게 보전해 주는 인센티브 규모로 하고, 이를 충당할 수 있는 전대사용료 산정 방법을 제시하였다.

• 한국항만경제학회지
• /
• 제32권3호
• /
• pp.21-33
• /
• 2016

두 국가에 위치한 국내 기업과 외국 기업이 경쟁하는 복점시장에서, 국가의 무역 정책에 따른 항만운영구조(국영화/민영화) 선택 전략을 분석한다. 그리고 항만 운영구조 선택에 따른 각 기업의 이윤, 항만 사용료 수준과 항만의 이윤, 사회후생을 비교분석하고, 자유무역 정책과 관세 정책의 각 균형 비교분석을 통해 최적 전략을 도출한다. 그 결과, (i) 관세 정책에서, 운송비와 상관없이 정부는 항만 국영화를 선택하는 것이 지배전략이다. (ii) 관세 정책에서, 항만은 높은 항만 사용료를 설정하는 민영화 정책의 경우 더 높은 이윤을 달성하며, 국가와 항만의 이해관계 불일치가 발생한다. (iii) 관세 정책과 상관없이 낮은 운송비 수준이라면, 정부는 항만 국영화 선택을 통해 더 높은 후생을 달성하며, 높은 운송비 수준이라면 항만 운영구조(민영화/국영화)에 상관없이 정부는 자유무역 정책의 경우가 더 높은 후생을 달성한다.