• Journal of Navigation and Port Research
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• v.32 no.2
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• pp.133-140
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• 2008

In this paper, a fault detection method for operator failures using the observation technique is proposed. The suggested algorithm is extended using the conventional sensor/actuator fault detection method. First, it is assumed that operator failure affects human work operations, as it is an external input signal. With this assumption, a human work model with operator failure is suggested. Second, an unknown input observer with proportional and integral gains is introduced. The characteristic of this observer of estimating an external signal without an exact input is shown, and the conditions for the detection of an operator failure are proposed. Finally, by simulating the container crane operations, it is verified that the observer can accurately detect an operator failure and estimate its magnitude from the given internal signal.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2000.11a
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• pp.33.2-42
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• 2000

This study probes the necessity of establishing a logistic free zone in Port of Busan. It considers the economic effects of establishing the logistic free zone of Busan Port, and suggests policy prescriptions for introducing the free zone system and improving the logistics functions of Busan Port. Using input-output table data, the regression analysis was able to provide a quantitative prediction on effects of making the Busan Port a tariff-free zone. Influence for the regional economy due to the enforcement of the free zone system this research found that a strong positive effects should be expected on the Busan regional economy once the logistic free zone would be set up at the Port of Busan. The positive economic effects on Busan regional industries might be further strengthened if the value-added logistics function of Busan Port could be supplemented by linking to the hinterland of Busan Port.

• Journal of Korea Port Economic Association
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• v.25 no.4
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• pp.83-106
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• 2009

This study estimated the regional economic effects by development of the logistics complex in Incheon New Port, applying the regional Input-Output tables in Incheon. And thereby, we tried to find some strategic implications on the priority to induce more effective industries for activated operation of the logistics complex in ports. According to the results, development of Incheon New Port will generate 2,579 billion KRWs(2.2 billion USDs) of production and 1,783 KRWs(1.5 billion USDs) of value-added annually. And we expect it to induce 38.8 thousand jobs, which is over the national average on the input-output table. By the business type, port logistics industry will contribute to develop regional economy more than any other ones in Incheon. We suggest business firms in port logistics industry to be induced to the logistics complex in Incheon New Port strategically. Until now, development of the logistics complex in Incheon New Port are planned to be postponed to 2015 when construction of the berth facilities, the access sea routes and the hinterland highways are completed. We suggest to invest more public fund, to induce the private capital, and then, to develop the logistics complex in Incheon New Port earlier in an appropriate scale.

• Journal of Korea Port Economic Association
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• v.32 no.3
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• pp.139-154
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• 2016

The port incentive scheme currently implemented in various Korean ports is used as a marketing tool to increase price competitiveness. Typically, ports implement piecemeal imitation strategies to enhance their competitiveness, rather than a precisely designed system. A precise analysis of the effectiveness of a port's system and scheme redesign are lacking because budget allocation is done without input from customers and freight groups. This study models the incentives faced by ports using a linear programming model. We use the Gwangyang port as the base case. Our analysis of the Gwangyang port reveals that there are insufficient incentives implemented when a traditional qualitative analysis is used. We also identify any excess, deficiency, or absence of the incentive effect for each type of customer and freight group. We find the overall budget of the incentive scheme to be more rational when ports allocate funds to minimize port mileage, and allocate 61.77 percent and 38.23 percent of the budget on existing and new (or increased) cargo inventory, respectively. Future studies can build on our work by further considering basic inputs, and by adding a system to estimate the input data of our model to identify constraints and thus provide a more accurate incentive scheme.

• Journal of Biomedical Engineering Research
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• v.28 no.6
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• pp.803-810
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• 2007

Although synthetic aperture focusing techniques can improve the spatial resolution of ultrasound imaging, they have not been employed in a commercial product because they require a real-time N-channel beamformer with a tremendously increased hardware complexity for simultaneous beamforming along M multiple lines. In this paper, a hardware-efficient beamformer architecture for synthetic aperture focusing is presented. In contrast to the straightforward design using NM delay calculators, the proposed method utilizes only M delay calculators by sharing the same values among the focusing delays which should be calculated at the same time between the N channels for all imaging points along the M scan lines. In general, synthetic aperture beamforming requires M 2-port memories. In the proposed beamformer, the input data for each channel is first upsampled with a 4-fold interpolator and each polyphase component of the interpolator output is stored into a 2-port memory separately, requiring 4M 2-port memories for each channel. By properly limiting the area formed with the synthetic aperture focusing, the input memory buffer can be implemented with only 4 2-port memories and one short multi-port memory.

• Journal of Korea Port Economic Association
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• v.20 no.1
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• pp.57-77
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• 2004

The meaning of seaport has always been translated into something concerned with nation-wide goals and viewpoints, which used to be in developing country. The time developing countries have tried to be in pursuit of their economic development, one of important sectors is SOC investment that is needed into huge capital input which they couldn't easily afford to it. Another one which we have to mention in terms of seaport at contemporary maritime matters is privatization of port, that is strongly connected with efficiency to achieve port productivity. All these factors can produce high quality of service, and port co-operation and diversification of their business areas, etc. Therefore we then have to think of private port management companies such as P&O Ports, Hutchison Whampoa in HK, etc. in order to provide better port service to the customers, and they can also get involved into capital port investment as well. This kind of concept already comes from Denholm Ship management companies in shipping. So, it is necessary for us to look into port management company in our side, which means, we have to be involved into such a business to invest and manage foreign ports as well as our ports. Then, port competitiveness will follow in our ports.

• Proceedings of the KIPE Conference
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• 2012.11a
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• pp.137-138
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• 2012

In this paper, three-port flyback inverter with Active Power Decoupling(APD) circuit is analyzed. Conventional flyback inverter with passive power decoupling circuit needs the electrolytic capacitor with large capacitance for decoupling between constant DC power and instantaneous AC power. However the electrolytic capacitor has low lifespan about 50000 to 100000 hours. So the active power decoupling techniques are applied to reduce input capacitance of flyback inverter. Thus the overall system can achieve smaller size and longer lifespan. Proposed three-port flyback inverter is verified by design optimization, simulation and experimental result.

• Proceedings of the Safety Management and Science Conference
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• 2000.05a
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• pp.339-349
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• 2000

Inchon Port is the second largest import-export port of Korea, and has the point at issue such as the excessive logistics cost because of the limits of handling capacity and the chronic demurrage. There are few research activities on the analysis and improvement of the whole port operation, because Inchon Port not only has the dual dock system and various facilities but also handles a various kind of cargo. The purpose of this paper is to develop the simulation program as a long-term strategic support tool, considering the dual dock system and the TU(Terminal Operation Company) system executed since March, 1997 in Inchon Port. The basic input parameters such as arrival intervals, cargo tons, service rates are analyzed and the probability density functions for these parameters are estimated. The main mechanism of simulation model is the discrete event-driven simulation and the next-event time advancing. The program is executed based on the knowledge base and database. From the simulation model, it is possible to estimate the demurrage status through analyzing various scenarios and to establish the long-term port strategic plan.

• IE interfaces
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• v.9 no.2
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• pp.203-218
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• 1996

This paper deals with a Direct-Input-Output Manufacturing System (DIOMS) which has a number of machine centers placed along a built-in automated storage/retrieval system (AS/RS). During its operations, the storage/retrieval(S/R) machine picks up a pallet from the pickup/deposit port of a machine center and then moves it either to an empty rack opening of the AS/RS for temporary storage or to place it on the port of another machine center for subsequent operation. The machine layout problem in DIOMS is formulated as an integer mathematical programming whose objective is to minimize the total expected distance of the loaded S/R machine during a production period. Recognizing the limit of the exact solution procedure(the Branch and Bound method), two improvement-type heuristics are proposed. One is based on the simulated annealing method and the other the pairwise interchange method. The validity of the heuristics is examined with example problems.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2017.11a
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• pp.58-60
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• 2017

In the offshore crane system, the requirements on the operating safety are extremely high due to many external factors. This paper describes a model for studying the dynamic behavior of the offshore crane system. The obtained model allows to evaluate the fluctuations of the load arising from the elasticity of the rope. Especially, in this paper, the authors design control system in which just winch rotation angle and rope tension are used without load position information. The controller design based on input-output feedback linearization theory is presented which can handle the effect of the elasticity of the rope and track the load target trajectory input. Besides that, a full order observer is designed to estimate unknown states. Finally, By the experiment results, the effectiveness of proposed control method is evaluated and verified.