• Korean Architects
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• no.10 s.151
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• pp.43-54
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• 1981

• Korean Architects
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• no.9 s.150
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• pp.45-90
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• 1981

• Journal of Korea Port Economic Association
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• v.21 no.1
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• pp.133-151
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• 2005

The purpose of this paper is to investigate the international competition power between Korean ports and Chinese ports according to the port efficiency scores of DEA(Data Envelopment Analysis) by newly introducing the priority vector of AHP(Analytic Hierarchy Process) to the DEA method. Empirical analysis shows the followings: First, there was not big changes of DEA rankings when we use the input-oriented CCR and BCC models after introducing the AHP priority vectors to the input variables. Yantian Port's competition power was declined, but that of Busan Port was up in the BCC model. Second, there was some changes of DEA rankings when we use the output-oriented CCR and BCC models after introducing the AHP priority vectors to the output variables. Rankings of Dalian, Qingdao, Shanghai Ports were up. But Shekou, Yantian Ports showed the declined ranking position in the CCR model. In the BBC model, rankings of Shanghai and Busan Ports were up. But those of Shekou and Yantian Ports were declined. The main policy implication based on the findings of this study is that The Ministry of Maritime Affairs & Fisheries in Korea and China should introduce AHP and DEA approaches when they measure the international competition power by using the porrt efficiency scores of DEA.

• Journal of Korea Port Economic Association
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• v.21 no.3
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• pp.19-34
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• 2005

The purpose of this paper is to introduce the new way of location choice for free trade zone in Busan area by using Obata and Ishii(2003) model of preference discrimination score. And also, this paper investigates the result of Choi, Bong-ho(200l) that deals with the choice of tariff free area in Busan area. Empirical main results are as follows: First, the North Port(Sinsundae)and the New Busan Port are efficient. Final winer of location choice for free trade zone is the North Port(Sinsundae). Second, the ranking result of this paper for 10 potential sites of free trade zone shows the almost similar to that of Choi, Bong-ho(200l). Policy planner for location choice of free trade zone should introduce the preference discrimination score method by Obata and Ishii(2003), because this method shows the very positive empirical results like questionaire method by expert groups and common people in Busan which should cause the much time and much money.

• Journal of the Korean Society of Propulsion Engineers
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• v.25 no.4
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• pp.36-42
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• 2021

In this study, the impregnation of Lyocell fabrics was performed using phosphoric acid, ammonium phosphate, diammonium hydrogen, triammonium phosphate as phosphorus flame retardant, to fabricate continuous graphite fabrics using lyocell fiber. The physical and chemical structure changes were investigated by thermogravimetric, Fourier-transform infrared spectroscopy, C-nuclear magnetic resonance, X-ray diffraction, and weight analyses, By analyzing the thermal behavior of phosphorus flame retardant, conditions for the temperature, gas, and residual time of the pyrolysis process were set. Graphite fabrics with a tensile strength of 1,007.19±11.47 N/5 cm and yield of 25.3% were fabricated using continuous pyrolysis, carbonization and graphitization process.

• Journal of the Korean Society of Propulsion Engineers
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• v.23 no.6
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• pp.21-27
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• 2019

Cellulose-based carbon fabrics are used in aerospace nozzles have low thermal conductivity and high ablation resistance. However, there is a disadvantage in that the weight is reduced by 70~90% in the pyrolysis process and graphitization process and the residual rate is low when the final carbon fabric is produced. In this study, phosphoric acid as a phosphorus flame retardant and Citric acid as a cross-linking agent were treated on the lyocell fabrics. After that the functional groups were identified and thermal properties were confirmed by FT-IR, XRD and TGA. The yields of the final carbon fabrics were also compared through the pyrolysis and graphitization process. The graphitized yield increased to 8.1% with increasing citric acid to 16 wt% added.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.12 s.103
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• pp.1194-1205
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• 2005

This paper proposes a uni-planar elliptical element UWB antenna with band-notched characteristic and modified pound plane fed by CPW. The antenna achieves VSWR below 2 for UWB band(3.1 GHz${\~}$10.6 GHz). In addition, a band-notched characteristic is achieved by inserting a horizontal slot on the radiation element to avoid the interference with 5 GHz(5.15 GHz${\~}$5.825 GHz) band limited by IEEE 802.1la. The antenna has a thin profile, compact size, and ease of manufacture by adopting a CPW feed structure without any additional background plane. Measured data show that the proposed antenna has good return loss below -10 dB, about 2.1 dB${\~}$4.75 dB maximum gain over the bandwidth, omni-directional radiation patterns, linear phase response.

• Journal of Korea Port Economic Association
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• v.31 no.3
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• pp.75-91
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• 2015

This study aims to assess the competitiveness of 30 logistics centers that operate in the hinterland of the North Container Port at Busan New Port. Thirty-two key factors were selected from previous studies to analyze and improve competitiveness and expand business opportunities in the hinterland. Suggestions from logistics experts were also canvassed. These variables were then put through first- and second-factor analysis to verify validity and measure confidence levels; they were later categorized into five factors and 15 sub-factors impacting on competitiveness. The categorized factors were compared using the analytic hierarchy process (AHP) to assess the importance of each factor and sub-factor in the case of logistics centers in the North Container hinterland of Busan New Port. The findings indicate that factors related to the securing of significant amounts of container cargoes were of greater importance. On the other hand, relatively basic factors proved to be less important in improving the competitiveness of the port hinterland.

• Journal of the Korean Society of Propulsion Engineers
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• v.23 no.5
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• pp.36-42
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• 2019

In this study, the pre-treatment of lyocell fabrics was performed using phosphoric acid (PA) as a phosphorus flame retardant and melamine resin (MR) as a cross-linking agent to fabricate carbon fabrics using lyocell fibers. The physical and chemical changes were investigated by thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), X-ray diffractometry (XRD) and weight analysis. We confirmed that the weight yield of the carbon fabrics compared to the untreated fabrics increased by 14.7%, and width and length yield of the fabrics increased by 15% and 15.5%, respectively. This may be due to the effect of promoting the dehydration reaction of cellulose, forming char on the fiber surface, which induces a crosslinking reaction in the cellulose molecule and stabilizes the structure upon pyrolysis.

• Journal of Korea Port Economic Association
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• v.23 no.2
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• pp.109-120
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• 2007

The purpose of this paper is to verify the two problems(normalization for the different inputs and outputs data, translation invariant for the negative data) which will be occurred in measuring the seaport DEA(data envelopment analysis) efficiency. The main result is as follow: Normalization and translation invariant in the BCC model for measuring the seaport efficiency by using 26 Korean seaport data in 1995 with two inputs(berthing capacity, cargo handling capacity) and three outputs(import cargo throughput, export cargo throughput, number of ship calls) was verified. The main policy implication of this paper is that the port management authority should collect the more specific data and publish these data on the inputs and outputs in the seaports with consideration of negative(ex. accident numbers in each seaport) and positive value for analyzing the efficiency by the scholars, because normalization and translation invariant in the data was verified.