• Journal of the Korean Society of Safety
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• v.10 no.3
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• pp.11-20
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• 1995

In recent years, the study on the high efficiency of the internal combustion engine has been mainly proceeding. In this study, we developed rotary valve to achieve the improvement of volumetric efficiency and to be simple construction. And then made a comparative analysis between rotary and poppet valve. In this experiment, rotary valve enlarged the flow area of valve port to minimize the resistance of the fluid flow and to flow smoothly in intake and exhaust process. Indeed, valve timing was controlled properly lest positive pressure in exhaust process should affect intake process. Motoring and firing experiments were using engine speed and air-fuel ratio as the principle parameter and the full opening of throttle valve and minimum spark advance for best torque (MBT) as engine operating variables.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 1993.07a
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• pp.122-123
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• 1993

Bangkok Bar Channel is a unique approach channel to Bangkok(on Toi)Harbor that is the representative river port constructed along the river mouth of Chao Praya River. Various facilities are scattered along the both sides of the river between the river mouth and the bridge located about 50km upward. The construction of the channel began in 1951 and was completed in 1954. (omitted)

• Journal of the Korean Institute of Navigation
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• v.16 no.1
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• pp.37-64
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• 1992

A study on the changes of the oceanographical environment caused by Mokpo coastal zone development was carried out. Special emphasis was placed on the clarification of the water level changes and coastal current structure and influence of the environmental factors on the coastal area. In order to understand the structure oceangraphical environemnt, such as water temperature, salinity, suspended solids, pH, dissolved oxygen, chemical oxygen demand, biochemical oxygen demand, distribution of bottom sediment, tide and current were measured. To investigated the structure of tide and current for the future development, a numerical analysis was carried out. In certain zones, it was found to be flooding problems near the lowlying commercial area.

• Journal of the Korean Institute of Navigation
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• v.19 no.1
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• pp.9-16
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• 1995

We are confronted with the serious EMI(electromagnetic interference) problems in company with the development of electronic equipments. Accordingly it is also required to construct some anechoic chambers for EMI measurement. Furthermore it is very important to evaluate the chamber characteristics in advance of its construction. For that purpose we have analyzed the characteristics by computer simulation in base on the image method, and compared the results with the measured ones. In case of 3-meter method as a result, the curved line of height pattern of open site varies similarly as that of height pattern of anechoic chamber. When we measure the electromagnetic strength and can get the height pattern curves by frequencies, we utilized it effectively because we can protect instrumental errors in measurement. On the other hand, there is a little difference in site attenuation above 700MHz. When the ferrite grid was used however, the calculated values agree well with the measured values up to 1000MHz with the exception of 30-40 MHz range. The reason is that we don't consider the antenna coupling in the low frequencies of 30-100MHz range.

• Journal of the Korean Institute of Navigation
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• v.7 no.2
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• pp.115-128
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• 1983

Ship technology has advanced in many diverse directions in recent years, a trend that can be expected to continue. The effect of this both on the physical equipment now being usedand under construction and on the attitude of mind of many of those responsible for its operation is profound. The technological changes in shipping have brought about an increasing trend towrard more delegation of authority from shoreside to ship management. With increased shipboard responsibility the shipping industry would benefit from seeming that more of the management subjects were learned by nautical students. It is clear advantage that companies should draw into their general management structure men with seafaring experience. At the same time the the boards of shipping companies should include more men with high technological qualificatiions and experience.

• Journal of Drive and Control
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• v.10 no.4
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• pp.22-28
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• 2013

Mechanical and electrical properties of a DDV(Direct Drive servo Valve) with electric feedback are analysed via reverse analysis technique in this work. The DDV is disassembled and mechanical parameters, such as spool mass, spring stiffness and port size are identified. The servo amplifier, which is built in the valve, is reversely analysed and the control scheme and gains for several control actions are also identified. The electrical feedback for spool displacement improves much better the valve performance, such as hysteresis and dynamic bandwidth frequency, than an ordinary mechanical feedback valve. Integrating control action with very large gain was adopted in the valve amplifier, and it seemed to give high performance.

• Journal of the Korea Society of Computer and Information
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• v.7 no.1
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• pp.62-67
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• 2002

Construction of automated terminal is urgently demanded to gain the foundation of hub-port in north east Asia. Therefore I suggest an adequate operating system model of automated terminal in Korea. In this paper the aim of automated terminal operating system is satisfied, four basic models are divided according to moving course of export and import cargo of each automated equipments, several input data are changed and analyzed dynamically by Trial and Error method, and then an optimized operating system model is designed. It is a Premise that all the yard equipments described in this paper must be automatic except quay crane.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.34 no.5
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• pp.89-96
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• 2018

Ami-dong Crematorium in Busan was established as one of the public facilities in 1929(the period of Japanese Occupation). It is the originator of Busan Yeongnak-Park(永樂公園), the funeral facilities of Busan municipality. The crematorium of Busan region was accepted at an earlier stage inside Japanese Concession in accordance with the opening a port. As Ami-dong Crematorium was constructed as a public facilities, the precedent has been maintained so far, providing a background equipped with the leading public corporation facilities in Busan area. This study was based on the expansion construction document founded by National Archives in Korea. Above all things, this research revealed the establishment and change of Busan Ami-dong Crematorium as the historical point for the formation process of recent public funeral facilities.

• Journal of the Korean Institute of Rural Architecture
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• v.22 no.4
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• pp.17-25
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• 2020

This preliminary study examines historical background of construction, establishment process, and destroy process for the Goryeo-sa-haeng-guan in Myeong-Ju during the Song Dynasty. The research was conducted based on local journals at that time. The Myeong-Ju is one of the famous port cities for marine trade. The Myeong-Ju had a good relationship with the Goryeo. Especially, the Song Dynasty built the Goryo-sa-haeng-guan for Goryeo envoys and traders to maintained a good partnership with Goryeo. A comprehensive review on records and historical issues of the Goryeo-sa-haeng-guan helps us to understand foreign policy and inter-relationship between Korean and China.

• The Journal of Engineering Geology
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• v.32 no.1
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• pp.1-12
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• 2022

Based on the extended spatial mobilization plane (SMP) criterion, we present an elastic-brittle-plastic solution for an axisymmetric cylindrical tunnel. The influences of the intermediate principal compressive stress and material strain-softening behavior are considered. Closed-form formulas for the critical support force, radius of plastic zone, and distributions of stress and displacement in surrounding rock are proposed. The elastic-plastic solution based on SMP is compared with the Kastner solution to verify the credibility of the obtained elastic-plastic solution. The elastic-brittle-plastic solution following the SMP criterion and the current solution based on the Mohr-Coulomb criterion are also compared. The rock strain-softening rate and the intermediate principal stress affect the stability of the surrounding rock. The results provide guidance for optimizing the design of support systems for tunnels.