• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1999.05a
• /
• pp.247-250
• /
• 1999

In this study, three kinds of Mn-Zn ferrite/Ni-Zn ferrite/$Ni_2Y$ ferroxplana prepared by the coprecipitation method was compounded with silicon rubber, and thereafter made ring-type specimens with various compositional ratio. The material constant of ferrite/rubber composite absorbers was obtaibed by the 2-port method. The material constants of the ferrite/rubber composite absorber with various compositional ratio of three kinds of ferrite were used to design the matching frequency and thickness with the impedance matching map. We were able to predict the matching condition from the design method.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.6 no.3
• /
• pp.26-33
• /
• 1998

An experimental study has been conducted for the three-dimensional in-cylinder swirl flow under steady conditions. Velocity fields are measured by using an LDV at various valve lifts. Effects of geometry of inlet ports on swirl flows are investigated for standard and helical ports. Swirl distributions evaluated from velocity measurements are compared with those obtained from an impulse torque swirl meter. Results show that the helical port generates more intensive swirl than the standard one but it causes red- uction in air flow coefficient. At the lower valve lift, no significant difference is observ- ed in non-dimensional swirl values between two ports because of limited pre-swirl effect, while it becomes significant as the valve lift increases.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.13 no.4
• /
• pp.282-290
• /
• 2013

This paper describes a spread spectrum clock generator (SSCG) circuit for DisplayPort 1.2 standard. A Hershey-Kiss modulation profile is generated by dual sigma-delta modulators. The structure generates various modulation slopes to shape a non-linear modulation profile. The proposed SSCG for DisplayPort 1.2 generates clock signals with 5000 ppm down spreading with a Hershey-Kiss modulation profile at three different clock frequencies, 540 MHz, 270 MHz and 162 MHz. The measured peak power reduction is about 15.6 dB at 540 MHz with the chip fabricated using a $0.13{\mu}m$ CMOS technology.

• Journal of Korean Port Research
• /
• v.9 no.2
• /
• pp.1-8
• /
• 1995

Generally, berth assignment problem has conflicting factors according to the interested parties. In the view of shipping company, it is desirable that berth assignment is made according to the order of arrival. But in the view of port operator, it is better to be assigned regardless the order of arrival to promote the efficiency of berth operation. Thus, it is necessary to establish berth assignment planning which reflects both of interests in a practical situation. This paper aims to develop a reasonable berth assignment algorithm in a container terminal by considering the prescribed factors, and suggests three types of models minimizing the objective functions such as total port staying time, total mooring time and total maximum mooring time by using MPS concept. These models are formulated by 0-1 integer programming and min-max type function, but as the number of variables increases, an optimal solution cannot be achieved easily within a desired computational time. Thus, to tackle this problem this paper proposes a heuristic algorithm, and also the heuristic algorithm proposed in this paper is verified through the several examples.

• Journal of Korea Port Economic Association
• /
• v.30 no.3
• /
• pp.231-257
• /
• 2014

In general, furniture industry, with its high foreign dependency, has serious logistics issues that are commonly raised in such countries as Korea, China and Japan. This leads to my different possibilities & ways of rationalizing the logistics systems that utilize port hinterlands. Thus the purpose of the present paper is to create new logistics systems which will work effectively across the three countries. In this research study, we came up with 2 logistics models in which the port hinterland of Busan serves as the distribution center for furniture industry, and the models were suggested as the cooperative logistics business systems for the North-east asian region. In the proposed models, 'Busan furniture logistics center' has the dual functions of 'the cross-docking center from China to Japan' and 'the assembly & delivery center for furniture imported by Japan'. To have this logistics business center materialized, we propose that policy-level supports from the relevant port authorities be provided in the following three aspects: overseas investment promotion focused on the furniture industry of Japan, protection & enhancement of competitiveness for the port of Busan, and uilization plans for the new port hinterland of the city.

• Journal of Navigation and Port Research
• /
• v.39 no.6
• /
• pp.499-506
• /
• 2015

To analyze the port choice hierarchy, factorial and AHP analysis were conducted based on the survey for shippers using west coastal ports. As the result of analysis with 17 factors, 6 main factors; port service, port operation and geographical condition, connectivity to hinterland, port cost, accessibility and facilities were chosen. Based on this, AHP and correlation analysis of each factor were conducted. And the results were shown as cost, service, facility, connectivity, accessibility and operation in order. In addition, several ways for incentive program, the most important factor based on AHP analysis, to influence shippers around west coastal port were reviewed. As the result of review for the incentive program of domestic container ports, it was shown that three ports, Gun-san, Dae-san and Mok-po, offer incentive to shipper while two ports, Pyeong-tak and Dang-jin, do not. Therefore, the former three ports need to reinforce the existing incentive program while the latter ones introduce it.

• Korea Trade Review
• /
• v.48 no.1
• /
• pp.215-241
• /
• 2023

As competition between ports intensifies, port efficiency has always been a hot topic in the port and shipping economy. Boosting regional and national economies by improving port efficiency and promoting sustainable development of ports is also a concern for port operators and local and national governments. In this situation, this study has the following objectives. First, using panel data from 2010 to 2017, the efficiency of 14 major inland ports along the Yangtze River was analyzed, and changes in port efficiency over time were examined. Second, 14 inland ports are divided into the middle, upper, and lower Yangtze River port groups to compare and review differences in efficiency levels of ports by basin. For the study, we applied a three-step DEA analysis method, which evaluated the pure relative efficiency of the port itself by removing the effects of environmental factors and statistical noise that could affect the efficiency evaluation and presented the results. As a result, it was confirmed that there was a clear difference in the efficiency value of the port between the first-stage and the third-stage efficiency evaluation result. In addition, the downstream ports showed relatively high efficiency compared to the middle and upstream ports.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.34 no.4
• /
• pp.1251-1259
• /
• 2014

This study presents the linkage method combining the existing Port Management Information System (PORT-MIS) DB with the scattered vessel activity data sets including the hotelling and maneuvering characteristics and specification information of the vessels arriving and departing from the port of Busan from January 2009 to June 2010. By linking the data sets, this study made three types of vessel activity databases: L-PORT-MIS DB with low-level vessel activities, M-PORT-MIS DB with medium-level vessel activities such as hotelling time, H-PORT-MIS DB with high-level vessel activities such as hotelling time, engine power, etc. The greenhouse gas (GHG) emissions estimation results show that total GHG emissions decreases when the detailed vessel activities are employed. This decrease in the total GHG emissions by the level of vessel activities implies that the GHG emissions from the low and medium level vessel activities are overestimated due to the aggregated hotelling/maneuvering times and speeds resulting from the past vessel specifications. Therefore, the GHG emissions using the H-PORT-MIS DB are more reliable GHG emission estimates in that the vessel specifications and the observed hotelling time of each vessel are employed in the estimation process. Hence, the high-level vessel activity dataset should be constructed to implement more suitable countermeasures for reducing the GHG emissions in the port of Busan.

• Journal of Korea Port Economic Association
• /
• v.37 no.3
• /
• pp.19-34
• /
• 2021

Yeosu Gwangyang Port, along with Busan Port, Incheon Port, Ulsan Port, and Pyeongtaek Dangjin Port, serves as Korea's top five ports for trade on the southern coast. It is the second largest port in Korea after Busan Port, and the largest port in terms of import and export volume. Yeosu Chemical Industrial Complex, the world's largest chemical industrial complex, has continued to grow rapidly, but recently, the increase in volume has been decreasing. Therefore, this study sought to find major development strategies for the development of Yeosu Gwangyang Port and to derive the priorities of the strategies. To this end, the development strategy of Yeosu Gwangyang Port was divided into three major categories: operation revitalization, infrastructure construction, and policy support using the AHP analysis technique and analyzed again in two aspects: short, medium, and long term. As a result of the analysis, 'integrated operation of container docks and strengthening competitiveness' were considered the most important in short- and medium-term policies. It is believed that it will be necessary to integrate container operators, establish routes in preparation for entry of super-large ships, and install large cranes. In the long-term policy, the most important thing was to foster high value-added industries based on local industries. It is believed that strategies are needed to attract companies from outside regions through the settlement support system. The results of this study are expected to be used to establish development strategies for Yeosu Gwangyang Port and to establish investment priorities.

• Journal of Navigation and Port Research
• /
• v.34 no.10
• /
• pp.781-786
• /
• 2010

In this study, a new concept of ocean transport system, called the mobile harbor serving for a short distance transport of containers with cargo handling cranes between mother containerships and coastal ports, is introduced. Instead of direct berthing a very large containership at the coastal port, Mobile Harbor is moving to the offshore mooring basin with enough water depth condition. Therefore, investigation of the coastal environment, technical condition and limitation of the domestic trade ports for the application of Mobile Harbor, is essential process. To figure out the accessibility of mobile harbor, the environmental conditions, the cargo handling capacity and marine traffic volume and flow pattern has been analyzed with the tools for marine traffic simulation and virtual navigation aids system. The most proper Mobile Harbor mooring areas among trade ports of the south and east coast are selected by analyzing the obtained information and evaluating its application: (1) Under natural environmental conditions such as air and sea weather, three candidate areas are selected such as Masan port, Ulsan port, and Busan(New port) port. (2) Under marine traffic and appropriateness of water facilities, three candidate areas are selected as Mokpo port, Busan(New port) port, and Donghae & Mookho port (3) For a region-based analysis considering handling capacity and the local managed trade ports in vicinity, three candidate areas are selected as Busan region, Yosu & KwangYang region, and Mokpo region. Through this study, the basic guideline for selection of optimum trade port and offshore mooring basin for mothership and Mobile Harbor is recommended. In order to apply the Mobile Harbor to the real water, navigaton aids as the virtual route identification with AIS must be introduced for maritime safety in the vicinity of Mobile Harbor area which berthing and cargo handling is being conducted.