• Proceedings of the KSME Conference
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• 2000.04b
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• pp.899-905
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• 2000

The characteristics of air flow and engine performance with swirl ratio variance of intake port In a turbocharged DI diesel engine was studied in this paper. The intake port flow is important factor which have influence on the engine performance and exhaust emission because the properties in the injected fuel depend on the combustion characteristics. The swirl ratio for ports was modified by hand-working and measured by impulse swirl meter. For the effects on performance and emission, the brake torque and brake specific fuel consumption were measured by engine dynamometer and NOx, smoke were measured by gas analyzer and smoke meter. As a result of steady flow test, when the valve eccentricity ratio are closed to cylinder wall, the flow coefficient and swirl intensity are increased. And as the swirl ratio is increased, the mean flow coefficient is decreasing, whereas the gulf factor is increasing. Also, through engine test its can be expected to meet performance and emission by optimizing the main parameters; the swirl ratio of intake port, injection timing and compression ratio.

• Journal of the Korean Society of Clothing and Textiles
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• v.45 no.5
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• pp.770-787
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• 2021

This study examines the types of cotton, silk, and woollen products imported from Japan during the port-opening period and explores the characteristics of import trade related to these textile products. Data were obtained from the Japanese trade statistics published by the Japanese government between the late 19^th and the early 20^th centuries. Several key findings were made from these data. First, at least 24 types of cotton fabrics, 13 silk fabrics, and 16 woollen fabrics imported from Japan were identified. Several types of weaves that can be found in the present day were also identified. Second, the total import of textiles during the port-opening period made up 33.7% of the total imports from Japan, indicating that textiles were an important aspect of import trade with Japan. The value of textile imports from Japan tended to increase overall during this time. Cotton fabrics and silk fabrics showed a tendency to increase continuously, while woollen fabrics showed a trend of gradual increase over repeating periods of increase and decrease. It is apparent from examining the ratio of Japanese and foreign products that cotton fabrics, silk fabrics, and woollen fabrics show different characteristics.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.13 no.5
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• pp.353-358
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• 2020

In the case of a general spiral inductor, the orientation of the port is affected as it has an asymmetric structure. In this paper, a single-layered spiral inductor that can have a symmetrical structure is proposed, and the simulation and frequency characteristics are analyzed. The general spiral inductor shows a large difference in frequency-inductance characteristics, frequency-quality factor characteristics, and self-resonant frequency according to the standard of the port, while the proposed symmetric spiral inductor has an inductance of 2.7nH, a quality factor of about 7.86, and a self-resonant frequency of about 14.1GHz without changing the port. Compared to the general spiral inductor having a large difference depending on the port, it was confirmed that the influence on the port direction was small. However, it was confirmed that the mutual inductance decreased compared to the occupied area of the coil, resulting in a low inductance, and the resistance of the coil increased more than the increase in the inductance, and the quality factor was also lowered. In the future, it is expected that inductance and quality factor can be improved through a 2-layer symmetrical spiral structure.

• Journal of Korea Port Economic Association
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• v.35 no.4
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• pp.121-146
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• 2019

This study investigates the innovation resistance when blockchain technology is introduced for the shipping and port industry. For the development of a research model with suitable measures, we review and focus on innovation resistance factors with the blockchain technology derived from previous studies. In this research, we consider four factors (innovation characteristics, consumer characteristics, environmental characteristics, and cost characteristics) with innovation resistance as dependent variables. The innovation characteristics include relative benefits, complexity, and perceived risk. The consumer characteristics consider attitude toward existing products, innovation, and self-efficacy. Social impact variables are environmental characteristics and rationality of cost. In the statistical analysis, we set up eight hypotheses to test the significances between variables and find the following four empirical results. First, the relative advantage and the perceived risk have a significant effect on innovation characteristic, but the complexity of this characteristic has no significant effect on innovation resistance. Second, the rationality of cost has no significant effect on innovation resistance. Third, the attitude toward existing products has a positive effect and the innovation of the consumer characteristic has a negative effect on innovation resistance, while the self-efficacy has no significant effect. Finally, the social impact has a significant effect on innovation resistance to blockchain in the shipping and port industry.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.28 no.11
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• pp.428-433
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• 2016

The fin and tube heat exchanger using a two-port tube has in air-conditioner heat exchanger because heat transfer performance. This study investigates the feasibility of a fin and tube heat exchanger using two-port copper tube by mechanical expansion. The optimum size of the tube-expanding bullet for the heat exchanger using two-port tube was through numerical calculation. The heat exchanger using a two-port tube was fabricated by mechanical expansion, and the heat exchanger performance was evaluated condensation and evaporation experiments. Compared to the heat exchanger of a conventional circular tube, the pressure drop per unit length of the heat exchanger with a two-port tube decreased. Compared to the heat exchanger using a conventional circular tube, the overall heat transfer coefficient of heat exchanger with a two-port tube increased up to 13% in the case of condensation, and up to 25% in the case of evaporation. The two-port tube heat exchanger outperforms conventional heat exchanger for air conditioner with a inner grooved circular tube.

• Journal of ILASS-Korea
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• v.2 no.4
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• pp.15-21
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• 1997

In a gasoline engine with port injection system, the fuel behavior in the intake port has significant influence on the HC emission and the precise A/F control. That is to say, it is inevitable that the injection direction and behavior of fuel injected in the intake port have an effect on the generation of unburned HC within a cylinder. In this paper, we visualized fuel behavior in the intake port using micro CCD camera synchronized with the stroboscope and investigated the fuel-film characteristics formed at the wall of intake port by processing image captured with VCR in the transparent intake port made of acryl. Using these measuring methods, it was found that fuel behavior and the formation of fuel-film in the intake port could be evaluated qualitatively. And results obtained by these methods show that 2-spray injector minimizes the fuel-film formed in the intake port of a DOHC gasoline engine.

• Journal of Fisheries and Marine Sciences Education
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• v.26 no.4
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• pp.749-759
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• 2014

With the rapid development of global economic and trade, the ports in the North-east Asia region have developed rapidly. Ocean shipping plays an irreplaceable role in China's foreign trade. Improvement of China's economy and continuous increase of trade in North-East Asia have made China as the number one in the world in container transport. Tianjin port which is the biggest international trade port in North-east China. Tianjin Binhai New District has incorporated in (CPC Central Committee on the outline of the Eleventh Five-Year Plan for national economic and social development proposals) which had adopted by The Fifth Plenary Session of the 16th CPC Central Committee. However, the competitions between ports are getting intense, the construction of Northeast Asia shipping center is in the ascendant, which bring new opportunity and challenge to the development of Tianjin port logistics. Therefore, Tianjin should according to its characteristics, integrating port resources, exert great efforts in developing port logistics, thus promoting regional economic development. Therefore, it is necessary to make the main study on the development strategy of Tianjin port logistics.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2011.06a
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• pp.415-416
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• 2011

As the has been brought out in 1997, many ports pay attention to greenhouse gas emission reduction and try to develop the port as an Green Port. The purpose of this paper is to establish the activities priority for Green Port construction and analysis its efficiency for the port competition. First of all, the activities for Green Port is introduced and showed its characteristics. To analysis these effectiveness for Green Port, the questionnaire survey is done by considering the opinion of port specialists. And by using AHP analysis method, the priority between the port activities is obtained and its effect for Green Port is taken by considering port competitiveness.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.1 s.116
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• pp.15-23
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• 2007

A simple six-port direct conversion QPSK receiver which is made up of a six-port phase correlator, a signal power detector, and I/Q channel signal de-modulator is designed and implemented in this paper. The output phase signals of six-port phase correlator are also analysed. On the basis of $90^{\circ}C$ phase relation among the six-port phase correlator output signals, the QPSK de-modulation circuit is designed by a simple circuit. The six-port phase correlator is made up of $90^{\circ}$ hybrid branch line and power detector. The six-port phase correlator, which is designed in frequency range of 11.7 to 12.0 GHz, gets the phase error characteristics less than $5^{\circ}$. By considering matching network and amplitude balance in the designed fiequency range, the designed six-port direct conversion QPSK receiver demodulates the I and Q signals with performance less than $5^{\circ}$ phase error.

• Journal of Korea Port Economic Association
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• v.24 no.4
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• pp.407-441
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• 2008

The interest of Cruise has been increased because of economic development and income growth in the world during last several decades. In Asian area the Cruise service also has been enlarged, especially in East Asia countries such as Korea, Japan, Singapore, Hongkong, Taiwan and China. This paper reviewed previous researches and clarify its concept and characteristics of Cruise Industry. And This paper aims to study the correct concepts and characteristics of Cruise marketing and investigate the current status and trend of Cruise Industry of the world and Korea. And it has groped and suggested various countermeasures, strategies and tactics in the 4Ps perspectives, considering the problems and conditions of Cruise service of Incheon Port.