• Journal of the Korean Institute of Navigation
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• v.24 no.1
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• pp.13-22
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• 2000

The collisions at sea among marine casualties are not reduced as the tonnage and speed of ship's increase as well as the traffic quantity increase at sea, in spite of the improvement of nautical equipment, enforcement of crew's education and training as well as improvement of quality standard according to the implementation of ISM code. The measures to prevent the collisions at sea are simple, and are composed of six stage.: The first stage is that the officer on duty detect the target from his eye or radar information. The second stage is determining the type and kind of target-ship. The third stage is target tracking; calculation of target speed, course, CPA and TCPA from radar information or visual check. The fourth stage is determination of vessel in danger after calculation of third stage. The fifth stage is the judgement of situation if own ship is stand-on or give way vessel according to the 1972 COLREG. The last stage is to carry out proper action according to 1972 COLREG, under the circumstances. But by the case, the situations are so different under the different external conditions; for example, natural/navigational conditions, crew's human factors, ship's particular, rule or regulation, management system on board, the condition of watch keeping. Therefore the reasons and casualties are so complicated. This study aims to investigate the collision casualty at sea which needs to clarity all these causal factors of afore-mentioned, and to analyze the causes of problems so as to utilize them to establish the measures of preventing marine accidents. This study, described the concepts of causal factors into three groups; environmental factor, and company/on board management system and navigator's act. Also described how to investigate and analyzes the casual factors. Even though it was described in this paper how to detect the causal factors and reasons of collisions, and how to analyze the inter-relation of each causal factors, it is necessary to do further study how to analyze between the liability of concerned parties and the casual factors involved.

• Journal of the Korean Institute of Navigation
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• v.4 no.2
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• pp.7-38
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• 1980

Nowadays researchers attach a great importance to the problems concerned with scientific information in the field of science and engineering. There are some reasons for it, that is, ⅰ) the amount of scientific information increases in proportion to the activities of scientists and engineers, so it is difficult to pick up a real valuable information ⅱ) it becomes more important to use a variety of information in proportion to the spread ofthe branch of science ⅲ) since the medium of scientific information is mostly technical papers, it is very difficult to mechanically transact these papers and to keep all documents and scientific informations for a long time. To cope with these difficult situations, many technical skills have been developed, for example, data-base, automatic information retrieval, micro-film and so on. But there are comparatively few investigation on the matter how the researchers who are users and producers think about the systematization of scientific information usage, so this paper investigates the thought and information needs of researchers, and proposes a basis of a method for systematization of scientific information usage. The author inspects the actual conditions of scientific information, reconsider the method which has been used and investigates the matter of how researchers whose interest is closely related to the study of marine affairs think about problems of scientific information usage by thequestionarie of Fuzzy-DEMATEL method. Also, FSM which is method for structuring hierarchy for the several complex problems on the basis of fuzzy sets theory is adopted as a tool of analysis. We can understand the key problems and make a story to solve the systematization of scientific information usage from the results of the analysis and those results will be directly applicable to construct a new system for scientific information usage.

• Proceedings of the KIEE Conference
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• 2004.11a
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• pp.212-214
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• 2004

In this study, we fabricated the organic thin film by self-assembly method by using nitro-group and methoxy-group organic molecule. Also, we selected the organic single molecule in organic thin film and measured current-voltage characteristics by using scanning tunneling microscopy. The Organic molecules that use in an experiment is 4,4'-(diethynylphenyl)-2'-nitro-1-benzen ethiol and 4-[2,5-dimethoxy-4-ph enylethynylphenyl]ethynylphenylethanthiol. 4,4'-(dimet hynylphenyl)-2'-nitro-1-benzenethiol is applied widely in molecular electronic device and 4-[2,5-dime thoxy-4-phenylethynylphenyl]ethynylphenylethanthiol composed in Korea Research Institute of Chemical Technology. To be confirmed the formation of the self-assembled monolayers, we observed the real time frequency shift of the QCM and investigated surface of the self-assembled monolayers the using STM. With this, we measured current to the organic single molecule, in condition of the air state. As a result, we confirmed in constant voltage that properties of negative differential resistance. Using properties of negative differential resistance to get from this study, application is expected to be molecular switching device, memory device and logic device.

• Journal of the Korean Institute of Navigation
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• v.25 no.3
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• pp.257-268
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• 2001

Marine traffic engineering is the technical field that observe flows of vessel traffic in accurate and describe the features of ships' movement statistically or analytically, then contribute to the improvement of the traffic flow and safety of traffic. Recently, marine traffic engineering has been developed until that possible to estimate a changes in traffic flow caused from some transformations of the traffic condition, and to assess the feasibility and validity of the changes by computer simulation. This paper aims to assess the present traffic safety at the sea area adjacent to Pusan harbour, and the validity of the suggested roundabouts traffic separation scheme at the Pusan approaching water(by Park in 1998) using environmental stress aggregation model There are couple of steps to describe the marine traffic situation and to assess it's safety by computer simulation. The first step is observe the movement of vessel traffic concerned waters and to obtain the relevant data for computer simulation. Second step is to carry out computer simulation to assess the simulated traffic flows by using suitable indexes of assessment model - environmental stress aggregation model. Eventually, this paper conclude that the environmental stress aggregation model is a useful technique to assess the traffic safety and the suggested roundabouts traffic separation scheme could make the concerned area safer than present traffic situation.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.30 no.3
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• pp.123-133
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• 2018

We studied the change process in the design parameters (conditions) of structural sections of vertical/slope breakwaters in Korea over the long term based on an analytical review of the latest design recommendations. This study found the following. 1) Design wave heights have increased gradually with the increase in the wave height of deep sea waves. 2) The relative design wave height ($H_{1/3}/h$) changed from 0.5 in the 1970s to 0.6~0.7 today. This means that design wave heights are overestimated compared with the water depth. 3) Before 1999, the design water level was based on high water during an average spring tide, but this has been increased since 2000 because of additional consideration of anomalous sea levels. 4) Before 1999, the relative crest heights of the investigated breakwaters was 0.6~0.7, but after 1999 this increased to a mean of 1.0 and maximum of 1.26.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.5
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• pp.732-740
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• 2009

The purpose of this study is to discuss Joseon dynastyis first perspective on the Western-style Court Costume which was newly introduced to Joseon through the problems receiving the credential that Japan had sent in new style. For this study, the records of Joseon and Japan at that period have been analyzed. The followings are the results of this research; First, a critical argument on the Western-style Court Costume occurred just before the Port Opening because whether wearing a western costume was the key factor in Joseon dynastyis receiving the credential that Japan had send in new style. Second, Japan received western costume as its domestic courtesy system by establishing the Court Costume of Civil servants in 1872 and consequently Japan established new ceremony procedure of western-style bow in 1875. Third, Joseon dynasty officially opposed to the Western-style Court Costume when Japan sent the credential, because the western costume selected by Japan had beenregarded as that of western barbarian at that time in Joseon. Accordingly, it seems reasonable that before the introduction of western costume into Joseon dynasty, an open-door policy for the West had been a prior settlement for Joseon dynasty regardless of the details of Western-style Court Costume. And also, the pride of civilization of Joseon dynasty, which has been used to express Joseon dynastyis identity as Joseon-centrism, had to be converted before the open-door policy. Ultimately, it could be inferred that the reception of the Western-style Court Costume had been raised as the political and diplomatic problems in the circumstances when the submissive relationship in the traditional Eastern- Asia had been forced to be converted to modern sovereign international relationship.

• Environmental Analysis Health and Toxicology
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• v.27
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• pp.12.1-12.8
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• 2012

Objectives: The aim of this study was to identify the health and environmental risk factors of air contaminants that influence environmental and respiratory diseases in Gyeongju, Pohang and Ulsan in South Korea, with a focus on volatile organic compounds (VOCs). Methods: Samples were collected by instantaneous negative pressure by opening the injection valve in the canister at a fixed height of 1 to 1.5 m. The sample that was condensed in $-150^{\circ}C$ was heated to $180^{\circ}C$ in sample pre-concentration trap using a 6-port switching valve and it was injected to a gas chromatography column. The injection quantity of samples was precisely controlled using an electronic flow controller equipped in the gas chromatography-mass spectrometer. Results: The quantity of the VOC emissions in the industrial area was 1.5 to 2 times higher than that in the non-industrial area. With regards to the aromatic hydrocarbons, toluene was detected at the highest level of 22.01 ppb in Ulsan, and chloroform was the halogenated hydrocarbons with the highest level of 10.19 ppb in Pohang. The emission of toluene was shown to be very important, as it accounted for more than 30% of the total aromatic hydrocarbon concentration. Conclusions: It was considered that benzene in terms of the cancer-causing grade standard, toluene in terms of the emission quantity, and chloroform and styrene in terms of their grades and emission quantities should be selected for priority measurement substances.

• Journal of the Korean Society of Safety
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• v.15 no.3
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• pp.115-123
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• 2000

Pneumatic actuators are widely used in a variety of hazardous working environments. Any process that involves pneumatic actuation is also recognized as "eco-friendly". In most cases, applications of pneumatic actuators require only point-to-point control. In recent years, research efforts have been directed toward achieving precise position tracking control. In this study, a tracking position control method is proposed and experimentally evaluated for a linear positioning system. The positioning system is composed of a pneumatic actuator and a 3-port proportional valve. The proposed controller has an inner pressure control loop and an outer position control loop. A PID controller with feedback linearization is used in the pressure control loop to nullify the nonlinearity arising from the compressibility of the air. The position controller is also a PID controller augmented with the friction compensation by a neural network. Experimental results indicate that the proposed controller significantly improves the tracking performance.rformance.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.2
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• pp.239-244
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• 2004

In this paper, we have developed a frequency mixer which can be used as a microwave phase conjugator in the LS band retrodirective antenna system. The mixer as a phase conjugator must have an If signal of which frequency is nearly as high as that of an RF signal, so this fact brings difficulty in the combination of input signals and the design of impedance matching circuit. The circuit configuration is chosen to be of the gate mixer using a pseudomorphic HEMT device. The operating frequencies are 4.00 ㎓, 2.01 ㎓, and 1.99 ㎓ for LO, RF, and IF, respectively. Conversion gain is measured to be 12.5 ㏈ and 1 ㏈ compression point -34 ㏈m at the LO power of -7 ㏈m. The mixer fabricated in this research is the single-ended type, where RF leakage signal appears inevitably at the If port because RF and If frequencies are almost the same. The circuit topology suggested here can be applied directly to the design of balanced-type mixers and phase conjugators.

• Journal of the Korean Institute of Navigation
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• v.16 no.1
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• pp.77-91
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• 1992

How does the youth feel the sea affairs\ulcorner Concerning this question, this paper aims to measure the images of the youth toward the sea affairs - the sea, the ship and the seafarer and to examined the above subject. As sample 3, 250 students of middle and high school were selected by considering geographical environment. The data obtained using Semantic Differential Method were analyzed by principal component analysis, and the obtained factor scores were examined the significance of difference between sex, age and geographical environment. By introducing the principal component analysis, the authors extracted from each of the images, that is, factors of dynamics and affection to the image on these a and the former the factors and pleasure on the ship, and also the former two factors and factor of professional evaluation on the seafarer, The following results are obtained. 1) In the image of the sea, dynamic image of the student in high school were higher than the of the student in middle school in spite of geographic environment and affective image were opposite. 2) In the images of the ship, affective image of the student in middle school and high school in inland were high than the of the male and female student in near the sea. And also, male female students in middle school and male student s in high school of inland showed the highest score to the pleasure image. 3) In the image of the seafare, professional evaluation of the female student in middle school were higher than the others, but the students in high school showed the highest score to dynamic image. Especially, in the case of the majority of students in high school living in the city or town near the, their images of the seafarer were not so good in spite of their explorative experiences about the sea affairs.