• Title/Summary/Keyword: container loading

Search Result 300, Processing Time 0.03 seconds

A Design of Adaptive Backstepping Controller for Improving Position Accuracy of Linear Motor-based Container Transportation System with Dynamic Friction (선형전동기기반 컨테이너 이송시스템의 위치정확도 향상을 위한 적응 Backstepping 제어기 설계)

  • Lee, Jin-Woo;Seo, Jung-Hyun;Han, Geun-Jo;Lee, Kwon-Soon
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
    • /
    • v.1
    • /
    • pp.405-413
    • /
    • 2006
  • In general mechanical servo systems, friction deteriorates the performance of controllers by its nonlinear characteristics. Especially, friction phenomenon causes steady-state tracking errors and limit cycles in position and velocity control systems, even though gains of controllers are tuned well in linear system model. Even if sensor is used higher accuracy level, it is difficult to improve tracking performance of the position to the same level with a general control method such as PID type. Therefore, many friction models were proposed and compensation methods have been researched actively. In this paper, we consider that the variation of mover's mass is various by loading and unloading. The normal force variation occurs by it an other parameters. Therefore, the proposed control system is composed of main position controller and a friction compensator. A parameter estimator for a nonlinear friction model is designed by adaptive control law and adaptive backstepping control method.

  • PDF

A Design of Adaptive Backstepping Controller for Improving Position Accuracy of Linear Motor-based Container Transportation System with Dynamic Friction (선형전동기기반 컨테이너 이송시스템의 위치정확도 향상을 위한 적응 Backstepping 제어기 설계)

  • Seo, Jung-Hyun;Han, Geun-Jo;Lee, Kwon-Soon;Lee, Jin-Woo
    • Journal of Navigation and Port Research
    • /
    • v.31 no.1 s.117
    • /
    • pp.55-64
    • /
    • 2007
  • In general mechanical servo systems, friction deteriorates the performance of controllers by its nonlinear characteristics. Especially, friction phenomenon causes steady-state tracking errors and limit cycles in position and velocity control systems, even though gains of controllers are tuned well in linear system model. Even if sensor is used higher accuracy level, it is difficult to improve tracking performance of the position to the same level with a general control method such as PID type. Therefore, many friction models were proposed and compensation methods have been researched actively. In this paper, we consider that the variation of mover's mass is various by loading and unloading. The normal force variation occurs by it and other parameters. Therefore, the proposed control system is composed of main position controller and a friction compensator. A parameter estimator for a nonlinear friction model is designed by adaptive control law and adaptive backstepping control method.

A Study on RFID Based QoS Guarantee between O/D Container terminals for Biz-Model (RFID을 활용한 기종점 컨테이너 터미널간 QoS 보장을 위한 비즈니스 모델 연구)

  • Park Doo-Jin;Kim Hyun;Nam Ki-Chan
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
    • /
    • 2005.10a
    • /
    • pp.303-309
    • /
    • 2005
  • This paper will suggest how can we guarantee terminal QoS like ship waiting time ratio and ship residing time applying RFID(Radio Frequence Identification) technology, raising up rapidly as a fundamental solution of new growing industry, to port information system. Also, lead time of whole port logistics can be decreased for reduction of loading & discharging time resulted from productivity improvement of Twinlift G/C(Gantry Crane) and Y/T(Yard Tract) etc as applying RFID technology to terminal operation. The purpose of this paper is suggesting of new business model of u-Port that port QoS can be guaranteed from mutual agreement of each terminals RFID technology applied and focusing on the implementation plan.

  • PDF

Verification of Effective Support Points of Stern Tube Bearing Using Nonlinear Elastic Multi-Support Bearing Elements (비선형 탄성 다점지지 베어링 요소를 이용한 선미관 베어링의 유효지지점 검증)

  • Choung, Joon-Mo;Choe, Ick-Heung;Kim, Kyu-Chang
    • Journal of the Society of Naval Architects of Korea
    • /
    • v.42 no.5 s.143
    • /
    • pp.479-486
    • /
    • 2005
  • The final goal of shift alignment design is that the bearing reaction forces or mean pressures are within design boundaries for various service conditions of a ship. However, it is found that calculated bearing load can be substantially variable according to the locations of the effective support points of after sterntube bearing which are determined by simple calculation or assumption suggested by classification societies. A new analysis method for shaft alignment calculation is introduced in order to resolve these problems. Key concept of the new method is featured by adopting both nonlinear elastic and multi-support elements to simulate a bearing support Hertz contact theory is basically applied for nonlinear elastic stiffness calculation instead of the projected area method suggested by most of classification societies. Three loading conditions according to the bearing offset and the hydrodynamic moment and twelve models according to the locations of the effective support points of sterntube bearings are prepared to carry out quantitative verifications for an actual shafting system of 8000 TEU class container vessel. It is found that there is relatively large difference between assumed and calculated effective support points.

Estimating Hydrodynamic Coefficients with Various Trim and Draught Conditions (흘수 및 트림 변화를 고려한 선박 유체력 미계수 추정에 관한 연구)

  • Kim, Daewon;Benedict, Knud;Paschen, Mathias
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.23 no.7
    • /
    • pp.933-940
    • /
    • 2017
  • Draught and trim conditions are highly related to the loading condition of a vessel and are important factors in predicting ship manoeuverability. This paper estimates hydrodynamic coefficients from sea trial measurements with three different trim and draught conditions. A mathematical optimization method for system identification was applied to estimate the forces and moment acting on the hull. Also, fast time simulation software based on the Rheinmetall Defense model was applied to the whole estimation process, and a 4,500 Twenty-foot Equivalent Unit (TEU) class container carrier was chosen to collect sets of measurement data. Simulation results using both optimized coefficients and newly-calculated coefficients for validation agreed well with benchmark data. The results show mathematical optimization using sea measurement data enables hydrodynamic coefficients to be estimated more simply.

A Study on the Improvement of Daily Inspection for the Safety of University Laboratory - Based on Delphi surney - (대학 연구실 안전을 위한 일상점검 개선방안에 관한 연구 - 델파이 조사를 기반으로 -)

  • Choi, Youn-Woo;Lee, yong-Hwan
    • The Journal of Sustainable Design and Educational Environment Research
    • /
    • v.18 no.1
    • /
    • pp.38-48
    • /
    • 2019
  • The purpose of this study is to present a more effective daily checklist than the formal routine check before the experiment to prevent accidents in the university laboratory. To do this, we reconstructed the current daily checklist and previous research data and conducted a second Delphi survey. As a result, there were four general safeties such as arranging the laboratory, three mechanical safeties such as abnormal condition of machine and tool tightening parts, three electric safeties such as prohibition of loading around the electric distribution panel, six chemical safeties such as handling and managing harmful factors, three items of fire safety such as fire extinguisher inspection, five cases of gas safety gas container inspection, one item of biological safety such as the state of hand sterilizer management and one other item, which were provided in the daily checklist as twenty six categories in total. According to the opinions of related experts, it is necessary to have an easy and simplified daily checklist for actual daily checkups.

A Berth Allocation Problem to Maximize the Available Rate of Naval Vessels (함정 가동률 최대화를 위한 선석할당문제)

  • Won, Hyun-Sik;Ahn, Tae-Ho;Lee, Sang-Heon
    • Journal of the Korea Society for Simulation
    • /
    • v.18 no.2
    • /
    • pp.19-27
    • /
    • 2009
  • This paper addresses the berth allocation problem in naval ports. Navy vessels need various services such as emergency repair, missile loading, oil supply and many others while commercial vessels only unload and load container at the port. Furthermore, naval vessels have to shift frequently due to a limited capacity of the port. The objective of this paper is to minimize the total number of nesting vessels at the naval port. In other word, the objective is to maximize the total number of naval battleships engaging in the sea. A mixed integer programming(MIP) model is developed and experiments are conducted with ILOG CPLEX 11.0. We compare the computational results of the MIP model to the current scheduling approach by the ROK Navy. The results showed that MIP model performed well by minimizing the number of nesting vessels. and avoiding unnecessary shifts.

Meta Analysis of Trade Insurance Using Text Mining (텍스트 마이닝을 활용한 무역보험분야의 메타분석)

  • Hyun-Hee Park;Sung-Je Cho
    • Korea Trade Review
    • /
    • v.45 no.6
    • /
    • pp.157-179
    • /
    • 2020
  • This study presented the results of meta-analysis through topic modeling among the papers published in the Journal of the International Trade Association for the purpose of presenting academic research trends in the field of trade insurance and future research directions. Among the total 2,010 papers included in the Journal of the Korea International Trade Association, the analyzed paper covers the subject of trade-related insurance. According to detailed topics, 33 marine insurance (42.31%), 16 export insurance (20.51%), 11 hull insurance (14.10%), and 18 others (23.08%), and 4 other products liability insurance. According to the empirical analysis results, Topic 1 was classified as marine insurance, airworthiness, notice obligation, and collateral, and Topic 2 was derived as a representative topic for loading insurance, emergency risk, and immunity as export insurance. And Topic 3 was classified as vessel, sinking and container in relation to ship insurance, and Topic 4 was analyzed as an important topic such as manufacture and British marine insurance. Through the analysis results, we selected the representative topic used for the trade insurance topic and looked at the status of major research. Trade insurance is an area that requires the development of more theoretical and practical research subjects as an optimal risk management means in international trade transactions. To this end, first, support from the Korea International Trade Association is needed to establish a continuous research subject sharing system for the development of research subjects in the field of trade insurance. Second, academic journal operation management must be continuously managed in which academic research papers can be submitted and published.

Strategies of Car-Ferry Shipping Companies According to the Korea-China Free Trade Agreement (한·중 FTA 체결에 따른 수도권항만 카페리선사의 발전방안)

  • Park, Sung-Eun;Ahn, Seung-Bum
    • Journal of Korea Port Economic Association
    • /
    • v.34 no.1
    • /
    • pp.111-132
    • /
    • 2018
  • As China continues to evolve as a major economic power and the Free Trade Agreement (FTA) between the Republic of Korea and China was ratified on June 1, 2015, market volume between the two countries is expected to grow more rapidly. This study aims on improving the efficiency of car-ferry lines. We conducted two surveys- for shippers and forwarders of car-ferry companies, and container liners. The study analyzes the decision factors for delivery companies and their importance for shippers and forwarders of car-ferry companies and container liners. Based on analysis of prior studies on the competition for car-ferry companies and liners, three primary variables are selected-promptness, economics, and safety. The promptness variable consists of shipping time, loading/unloading time, and customs clearing time. The economic variable consists of marine transportation cost from a domestic harbor to China, loading/unloading cost in the harbor, and overland transport cost from the harbor to shippers inland. Finally, the safety variable consists of cargo damage rates, safety facilities, such as lashing and shoring, and punctuality of transportation time. The survey and AHP results show that the promptness, safety, and economics factors are 0.549, 0.309, and 0.142 in the shipper groups of car-ferry companies' category, respectively. It indicates that there is considerable difference in the importance of each factor. In contrast, the factors are 0.350, 0.348, and 0.302 in the forwarders category, which suggests that there is little difference in each factor's importance. As for shippers and forwarders of liners, the importance of each factor is found to be in the following order: economics, safety, and promptness.

E-Commerce in the Historical Approach to Usage and Practice of International Trade ("무역상무(貿易商務)에의 역사적(歷史的) 어프로치와 무역취인(貿易取引)의 전자화(電子化)")

  • Tsubaki, Koji
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
    • /
    • v.19
    • /
    • pp.224-242
    • /
    • 2003
  • The author believes that the main task of study in international trade usage and practice is the management of transactional risks involved in international sale of goods. They are foreign exchange risks, transportation risks, credit risk, risk of miscommunication, etc. In most cases, these risks are more serious and enormous than those involved in domestic sales. Historically, the merchant adventurers organized the voyage abroad, secured trade finance, and went around the ocean with their own or consigned cargo until around the $mid-19^{th}$ century. They did business faceto-face at the trade fair or the open port where they maintained the local offices, so-called "Trading House"(商館). Thererfore, the transactional risks might have been one-sided either with the seller or the buyer. The bottomry seemed a typical arrangement for risk sharing among the interested parties to the adventure. In this way, such organizational arrangements coped with or bore the transactional risks. With the advent of ocean liner services and wireless communication across the national border in the $19^{th}$ century, the business of merchant adventurers developed toward the clear division of labor; sales by mercantile agents, and ocean transportation by the steam ship companies. The international banking helped the process to be accelerated. Then, bills of lading backed up by the statute made it possible to conduct documentary sales with a foreign partner in different country. Thus, FOB terms including ocean freight and CIF terms emerged gradually as standard trade terms in which transactional risks were allocated through negotiation between the seller and the buyer located in different countries. Both of them did not have to go abroad with their cargo. Instead, documentation in compliance with the terms of the contract(plus an L/C in some cases) must by 'strictly' fulfilled. In other words, the set of contractual documents must be tendered in advance of the arrival of the goods at port of discharge. Trust or reliance is placed on such contractual paper documents. However, the container transport services introduced as international intermodal transport since the late 1960s frequently caused the earlier arrival of the goods at the destination before the presentation of the set of paper documents, which may take 5 to 10% of the amount of transaction. In addition, the size of the container vessel required the speedy transport documentation before sailing from the port of loading. In these circumstances, computerized processing of transport related documents became essential for inexpensive transaction cost and uninterrupted distribution of the goods. Such computerization does not stop at the phase of transportation but extends to cover the whole process of international trade, transforming the documentary sales into less-paper trade and further into paperless trade, i.e., EDI or E-Commerce. Now we face the other side of the coin, which is data security and paperless transfer of legal rights and obligations. Unfortunately, these issues are not effectively covered by a set of contracts only. Obviously, EDI or E-Commerce is based on the common business process and harmonized system of various data codes as well as the standard message formats. This essential feature of E-Commerce needs effective coordination of different divisions of business and tight control over credit arrangements in addition to the standard contract of sales. In a few word, information does not alway invite "trust". Credit flows from people, or close organizational tie-ups. It is our common understanding that, without well-orchestrated organizational arrangements made by leading companies, E-Commerce does not work well for paperless trade. With such arrangements well in place, participating E-business members do not need to seriously care for credit risk. Finally, it is also clear that E-International Commerce must be linked up with a set of government EDIs such as NACCS, Port EDI, JETRAS, etc, in Japan. Therefore, there is still a long way before us to go for E-Commerce in practice, not on the top of information manager's desk.

  • PDF