• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.79-83
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• 2003

Multi-port($2{\times}2$port, 1port) rectangular waveguide discontinuity problem has been analyzed by use of $TE^x_{mn}$ (mono)mode matching method. Matrix size can be reduced significantly in comparison with $TE_{mn}&TM_{mn}$(full-wave)mode matching method. the present results is compared with those by CST MicroWave Studio to validate the presint method.

• Journal of Fisheries and Marine Sciences Education
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• v.21 no.2
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• pp.325-334
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• 2009

The aims of this study is to suggest the strategic development plan of Ulsan Port using SWOT/AHP method. In order to do this, 16 detailed factors for SWOT Matrix were identified both from previous studies and from brainstorming professionals of the port and these made into a 3 level hierarchy structure. AHP method identified the relative weight of SWOT level as threat(0.311), opportunity(0.259), strength(0.218) and weakness(0.212), also the composite relative weight of detailed factors as recession of global economy(0.125), strengthening of economic function in port(0.085), insufficiency of port facilities(0.080) and a government regulation of port management(0.075). As a result, the study suggests S/T strategy, W/T strategy, S/O strategy, W/O strategy as a strategic development plan of the Ulsan Port.

• Journal of Korean Port Research
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• v.12 no.2
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• pp.261-268
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• 1998

The productivity of port labor in Pusan port is very low and the ratio of port accident is high in comparision with other advanced foreign ports. The aim of this paper is to find why the productivity in Pusan port is much lower than that of other countries in terms of port labor education systems. To obtain the objective of this study, the writers used 163 questionnaire for port labor in BCTOC, PECT and UTC for the survey of training method of cargo equipment handling. The result of this study shows as follows; (1) From the fact that ratio of labor who were trained by KPTI was 2.5%, we could say the public training system of port labor is not operated properly (2) As most of laborers are trained by the experienced associate, they do not recognize how the level of cargo handling equipment is set to increase the productivity. (3) In order that the port public training system plays a good role in port industry, a new license system should be introduced and an expert education system should be developed.

• Proceedings of the IEEK Conference
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• summer
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• pp.23-26
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• 2004

Five-port reflectometer which consists of a ring with 5 arms (two inputs, three outputs) and three RF power detectors has been used as a vector network analyser, a demodulator in the homodyne receiver as well as in Phase Looked Loop (PLL) and so on. Calibration of five-port reflectometer is an important task. In this paper, we present a calibration method of five-port for a propagation channel sounder. The method is based on measurement of the phase differences between the three voltages at the five-port's outputs in order to determine the ratio of two input incident waves. The frequency channel sounder based on five-port is calibrated for each frequency from 2.2 GHz to 2.6 GHz with 1 MHz step. This method can also determine the absolute delays of each propagation path in the propagation channel. The calibration method is validated using measurement data.

• Journal of Satellite, Information and Communications
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• v.4 no.2
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• pp.52-56
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• 2009

The design method of a four-port stripline circulator with a single ferrite disk is proposed using Green's function method. The four-port circulator gives the flexibility of the design of the communication system. Two cascaded three-port circulators has been used as a four-port circulator. However, if a four-port circulator with a single ferrite disk replace the present four-port circulator, then it will give less weight and volume and so has the advantage in satellite application.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1998.10a
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• pp.263-269
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• 1998

The forecasting of container cargo volumes should be estimated correctly because it has a key roles on the establishment of port development planning, and the decision of port operating system. Container cargo volumes have a dynamic characteristics which was changed by effect of competitive ports. Accordingly forecasting was needed overall approach about competitive port's development, alternation and information. But, until now, traffic forecasting was not executed according to competitive situation, and that was accomplished at the point of unit port. Generally, considering the competition situation, simulation method was desirable at forecasting because system's scale was increased, and the influence power was intensified. In this paper, considering this situation, the objectives can be outlined as follows. 1) Structural model constructs by System dynamics method. 2) Structural simulation model develops according to modelling of competitive situation by expended SD method which included HEP(Hierarchical Fuzzy Process) And actually, effectiveness was verified according to proposed model to major port in northeast asia.

• Journal of Korean Port Research
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• v.10 no.2
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• pp.17-29
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• 1996

It is required to consider pricing and non-pricing factors and external economy in order to achieve the objects of physical distribution system in a port. Recently, among the three factors, much attention has been paid to non-pricing factor in the system. Although physical distribution service in a port(PDSP)has been frequently mentioned in documents and literature related to port and shipping studies, few study on it has not been systematically and scientifically made due to the following problems; $\circ$ there are not proper criteria to evaluate level and quality of PDSP and as a result it is difficult to set up a unified standard for doing so. $\circ$ algorithms to evaluate problems with complex and ambiguous attributes and multiple levels in PDSP are not available. This thesis aims to establish a paradigm to evaluate PDSP and to abvance existing decision making methods to deal with complex and ambiguous problems in PDSP. To tackle the first purpose, extensive and thorough literature survey was carried out on general physical distribution service, which is a corner stone to handle PDSp. In addition, through interviews and questionnaire to the expert, it have extracted 82 factors of physical distribution service in a port. They have been classified into 6 groups by KJ method and each group defined by the expert's advice as follows; a. Potentiality b. Exactness c. safety d. Speediness e. Convenience f. Linkage Prior to the service evaluation, many kinds of its attributes must be identified on the basis of rational decision owing to complexity and ambiguity inherent in PDSP. An analytical hierarchy process (AHP) is a method to evaluate them but it is not applicable to PDSP that have property of non-additivity and overlapped attributes. Therefore, probablility measure can not be used to evaluate PDSP but fuzzy measure is required. Hierarchical fuzzy integral method, which is merged AHP with fuzzy measure, is also not effective method to evaluate attributes because it has vary complicated way to calculate fuzzy measure identification coefficient of attributes. A new evaluation algorithm has been introduced to solve problems with multi-attribute and multi-level hierarchy, which is called hierarchy fuzzy process(HFP).Analysis on ambiguous aspects of PDSP under study which is not easy to be defined is prerequisite to evaluate it. HFP is different from algorithm existed in that it clarified the relationship between fuzzy measure and probability measure adopted in AHP and that it directly calculates the family of fuzzy measure from overlapping coefficient and probability measure to treat and evaluate ambiguous and complex aspects of PDSP. A new evaluation algorithm HFP was applied to evaluate level of physical distribution service in the biggest twenty container port in the world. The ranks of the ports are as follows; 1. Rotterdam Port, 2. Hamburg Port, 3. Singapore Port, 4. Seattle Port, 5. Yokohama Port, 6. Long beach Port, 7. Oakland Port, 8. Tokyo Port, 9. Hongkong Port, 10. Kobe Port, 11. Los Angeles Port, 12. New york Port, 13. Antwerp Port, 14. Felixstowe Port, 15. Bremerhaven Port, 16. Le'Havre Port, 17. Kaoshung Port, 18. Killung Port, 19. Bangkok Port, 20. Pusan Port

• The KIPS Transactions:PartC
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• v.17C no.2
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• pp.205-214
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• 2010

As network traffic is dramatically increasing due to the popularization of Internet, the need for application traffic classification becomes important for the effective use of network resources. In this paper, we present an application traffic classification method based on fixed IP-port information. A fixed IP-port is a {IP address, port number, transport protocol}triple dedicated to only one application, which is automatically collected from the behavior analysis of individual applications. We can classify the Internet traffic more accurately and quickly by simple packet header matching to the collected fixed IP-port information. Therefore, we can construct a lightweight, fast, and accurate real-time traffic classification system than other classification method. In this paper we propose a novel algorithm to extract the fixed IP-port information and the system architecture. Also we prove the feasibility and applicability of our proposed method by an acceptable experimental result.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.2
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• pp.119-126
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• 2015

The information about noise parameters is essential in the design of low noise amplifier. In the past, the noise parameters were measured using an impedance tuner and noise figure analyzer. Recently, the authors proposed the method of measuring the noise parameters using the 8-port network without the aid of the mechanically driven impedance tuner. However, the 8-port method still requires the noise source and causes the complexity in the measurements. In this paper, a novel measurement method of the noise parameters without the noise source using 6-port network is proposed. Based on the proposed 6-port method, the noise parameters of 10 dB attenuator whose noise parameters can be theoretically determined were measured and the measured noise parameters are compared with those measured using the previous 8-port network method. As a result, the accuracy of the measured noise parameters using 6-port network is found to be comparable to the previous 8-port network method.

• Journal of Fisheries and Marine Sciences Education
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• v.22 no.2
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• pp.195-204
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• 2010

As the throughout of transshipment oil cargo in Korea has been increasing, the importance and competition of the oil hub port has also been increasing. The aim of this study is to suggest how the factors influence the competitiveness of the oil hub port based on the specialists' opinions. For doing this, the evaluating factors were obtained from both previous studies and brainstorming of the professionals from the oil hub port. These were divided into groups by the ‘KJ method' according to 5 criteria and were made into a 3 level hierarchy structure. The ‘AHP method' identified the relative importance of factors and trends from the preferences of the specialists. This study presents the factors influencing the competitiveness of the oil hub port.