• Speech Sciences
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• v.8 no.4
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• pp.87-98
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• 2001

Vocal nodule is one of the representative chronic diseases of vocal folds, and it can be cured by surgical removal or voice therapy. The aim of this study is to evaluate the effect of the accent method, one of the popular effective voice therapy, in the patients with vocal nodule. Authors executed the accent method in 17 patients with vocal nodule who visited the Voice & Speech Therapy Clinic, Pusan National University Hospital analysed the voice before and after treatment using the local findings, acoustic analysis and aerodynamic analysis MPT. The voice was analysed with MDVP of CSL and MPT was checked using stop watch. The parameters included Fo, Jitter, Shimmer and noise to harmonic ratio(NHR) as acoustic analysis. The results were obtained as follows. In the evaluation by the local findings, it was improved to 77% in the patients of vocal nodule. Jitter and Shimmer were shown to be improved significantly. In particular, it was shown to be improved significantly in patients with vocal nodule. As the result of this study, the improvement of aerodynamic aspect was more statistically significant than that of acoustic parameters. When I generalized the above mentioned results, we suggest that it is a useful voice therapy which can be helpful to the improvement of voice, applying the accent method to the vocal nodule patients, and there are currently many methods to be used in the voice therapy, but it is thought which the accent method is the good treatment as the alternatives of keeping the continuous medical treatment.

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.5
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• pp.1308-1318
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• 2016

In order to prevent the maritime accident, all seafarers who work on fishing vessels over G/T 20 tons are required to undergo the basic safety training by the Seafarer's Act. 45% of domestic crews have boarded on the fishing vessels. However, the fishermen have been trained in accordance with the STCW(International convention on standards of training certification and watch-keeping for seafarers) Convention. But safety training courses for seaman do not reflect on the safety equipment and the limitation of the fishing vessel in the training contents which is organized in accordance with the merchant ship by STCW convention and code. Most of the fishing vessels are small fishing boat of less than G/T 80 tons. Small fishing vessels are operating with only a minimum of safety equipment that has been defined by the fishing vessel safety equipment standard. Due to the safety training that does not fit the situation of the fishing boat, the level of satisfaction by the crews onboard is low for the training. Furthermore, there is a difficulty in achieving the goal of safety education. In order to carry out the safety training that is suitable for fishermen, it is required to provide appropriate standards for the safety education of workers of small fishing boat, by understanding the current state of the domestic fishing vessels. The purpose of this study is to define the aforementioned problems and to provide the standard for the safety education of fishermen. In order to complete the purpose, the research team has conducted a analyzation for registered domestic fishing vessel and safety equipment standard.

• 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.14 no.4
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• pp.53-70
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• 1990

Much efforts have been made to improve the training education system for last decades. however, it still leaves much room form improving the system. The reason for this is that the have been many changes in given educational conditions, national and international, and that there existed the lack of training facilities on shore and the limits of capacity on the training ship. The existing program adopts a straight-through system of which the course has to be completed at same time, and also forces students to study the course, disregarding their aptitude for sea life. Consequently, the program resulted in frustrating the learning desire of some students and, as a consequence, in deteriorating the quality of the entire training education. This paper aims to develop an efficient training program including curriculla by the literature survey and the teaching and sea experiences on the training ship "HANBADA" and merchant ships, where the authors have been for many years. Compared with the existing one, the new training model suggested in this paper has some advantages as follows : First, the new model adopts multi-state system which consists of various short-term training courses according to each purpose. This system will be helpful for student to find their aptitude for sea life earlier and to understand classes of major subjection shore. Second, the model includes new curriculla which consist of core subjects (for example, navigation, marine operation, marine transportation, watch keeping and nautical English for deck cadets and internal and external combustion engine, auxiliary machinery, electric and electronics and engine maintenance for engine cadets), by incorporating existing 20 subjects in 5 subjects. These curriculla may contribute to embodying the characteristics of training education where the above mentioned subjects must be linked with each other. In order to implement this new training model efficiently and effectively, the following prerequisties must be prepared : $\circled1$ The contents of each subject included in the new model should be systematically developed. $\circled2$ The educational schedule should be adjusted according to the new model.new model.

• International Journal of Highway Engineering
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• v.11 no.1
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• pp.25-36
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• 2009

Everyday congestion length (distance) and duration (time) data are collected and recorded in Expressway Traffic Information Center. These records are based on the information that the operators watch CCTV and decide traffic condition in order to present information about congestion on VMS. Using VMS message has some merits like that it doesn't need a great lot of cost to construct hardware such like FTMS because operators can check traffic condition by watching CCTV only. Of cause in the aspect of accuracy, using VMS message has the limitation that it is based on subject decision compared with FTMS. However, it can be said that the value of using VMS message is very large. The object of this study is to use the VMS information record (log file) usefully to provide information of traffic condition on expressway for users (drivers) without keeping the VMS information record in dead storage. To do so, in this research, congestion calculation method able to understand traffic congestion condition on expressway was developed.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.43 no.1
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• pp.62-70
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• 2007

Marine casualties of vessel are serious problems on social and national aspects, because it results in sacrifice of lives, a great lose of properties and marine pollution. According to recent statistics of marine casualties of vessel, fishing boats are more likely to be ended in the casualty, and especially, small fishing boats cause much more accidents than any other big vessels. Most of marine casualties were caused by the human factors such as poor watch keeping, inadequate manoeuvering and negligent action for engine, etc. This study is intended to provide navigator of small fishing boat with a specific information of necessary to assist both the manoeuvering and the avoidance of capsizing. The manoeuvering characteristics of ship can be adequately judged by the results of typical ship trials manoeuvres. For this purpose, the author measured the roll responses of a small fishing boat in waves using the real sea experimental measuring system, and analyzed the experimental data by the statistical and spectral analyzing methods to get the characteristics of the roll motion responses of the small boat through the wave directions and the ship's speed.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.3
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• pp.278-285
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• 2016

The key features of maritime accidents are the change of their attributes by new risks from time to time. To prevent maritime accidents in Korea, the impacts by new risks on domestic safety environments should be identified or predicted. The purpose of this paper is to find the hazard factors by new risks on maritime safety in Korea. The meaning of new risks is the elements of accident hazard which is compiled from new or rare or unprecedented events in the worldwide maritime transportations. The problems of new risks are the lacks of optimum countermeasures to mitigate accident risks. Using the questionnaires with 152 event scenarios classified by 20 accident causes, the hazard identification and risk analysis of new risks was performed based on the Formal Safety Assessment (FSA) by IMO. A total of 22 Influence Diagrams, which is to depict the transit flows between accident causes to consequences, is used in the construction of 152 event scenarios. A total of 20 accidents causes is the same contents as the causation factors represented in Statistical Year Book for Maritime Accidents of Korean Maritime Safety Tribunals. After defining the evaluation equations to the response results of questionnaires by 46 experts, the work for risk analysis is carried out. As results from the analysis of 152 scenarios, it is known that the root cause to affect on maritime safety in Korea is the pressure of business competition and it led to the lacks of well experienced crews, the overload of vessel operations and crew's fatigue. In addition, as results from the analysis of 20 accident causes, the three accident causes are to be candidate as main issues in Korea such as the inadequate preparedness of departure, the neglecting of watch keeping in bridge and the inadequate management of ship operations. All of the results are thought to be as basic hazard factors to safety impediments. It is thus found that the optimum Risk Control Options to remove the hazard factors and to mitigate consequences required are the following two factors: business competition and crewing problems.

• Journal of the Korean Society of Marine Environment & Safety
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• v.16 no.3
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• pp.295-300
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• 2010

The international convention on standards of training, certification and watch-keeping for seafarers, 1978(1978 STCW convention) has been established as a minimum standard and competence of seafarers, and contributed to reduce marine accidents caused by human errors. The convention has been partly amended several times according to environmental change of ship's operation and there were comprehensive revisions in so called 1995 amended STCW convention. In these years, ships are in tendency of increasing size and speed, and also adopted high technologies. These kinds of changes brought STW sub-committee up for discussions to modify the convention to cope with new environments from the year of 2006. As the result, major amendaments to STCW convention have been adopted at a diplomatic conference in Manila, Philippine in June 2010, thereby new global standards will be in force to train and certify seafarers to operate technologically advanced ships before long. This paper is to introduce major amendaments such as ship's security, ECDIS and leadership etc. in this Manila amendments and to clarify some articles to be adopted in programs for education and training of seafarers in Korea.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.1
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• pp.26-32
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• 2017

Enlargement and speed-up of a ship and diversification of ship's type have served to greatly increase the importance of marine transport means. It's reported that accident occurrence frequency of collision is high next to engine damage among the ship accident types, and that the accident ratio according to human factors is also high. In addition, ship accidents come to occur caused by complex cause factors rather than a sole cause factor, it is necessary to investigate the cause factors through the written verdict. This study proposed the cause factors of collision ship accident on the basis of human factors in collision ship accident among the written verdicts provided by the Korean Maritime Safety Tribunal, and inquired into the cause factor and effect through the correlation analysis of accident occurrence factors. Also, this study predicted the collision accident through analyzed the major cause factor of the occurrence at the zero minute when collision on the basis of the time taken from the time point of detecting collision of ships to the time point of collision occurrence. This study used commercial software-Statistical Package for Social Sciences (SPSS Ver21.0) to do correlation analysis. For time analysis, this study analyzed the cause factor and time by analyzing the time taken from the time point of detected ships to the time point of collision occurrence on the basis of the written verdicts. The study analysis showed that there were many cases of collision ship accidents occurrence caused by more than two sorts of cause factors, and that the case (zero minute) where there is no time to spare for collision avoidance accounted for 36.1 %, and negligence in guard or surveillance of the other ship, and sailing while drowsy, or drinking was a contributor to an accident. Poor watch keeping is very strong relationship with pool ready for sail.

• Journal of Intelligence and Information Systems
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• v.28 no.4
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• pp.157-177
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• 2022

Investors are trading stocks by keeping a close watch on the order information submitted by domestic and foreign investors in real time through Limit Order Book information, so-called price current provided by securities firms. Will order information released in the Limit Order Book be useful in stock price prediction? This study analyzes whether it is significant as a predictor of future stock price up or down when order imbalances appear as investors' buying and selling orders are concentrated to one side during intra-day trading time. Using classification algorithms, this study improved the prediction accuracy of the order imbalance information on the short-term price up and down trend, that is the closing price up and down of the day. Day trading strategies are proposed using the predicted price trends of the classification algorithms and the trading performances are analyzed through empirical analysis. The 5-minute KOSPI200 Index Futures data were analyzed for 4,564 days from January 19, 2004 to June 30, 2022. The results of the empirical analysis are as follows. First, order imbalance information has a significant impact on the current stock prices. Second, the order imbalance information observed in the early morning has a significant forecasting power on the price trends from the early morning to the market closing time. Third, the Support Vector Machines algorithm showed the highest prediction accuracy on the day's closing price trends using the order imbalance information at 54.1%. Fourth, the order imbalance information measured at an early time of day had higher prediction accuracy than the order imbalance information measured at a later time of day. Fifth, the trading performances of the day trading strategies using the prediction results of the classification algorithms on the price up and down trends were higher than that of the benchmark trading strategy. Sixth, except for the K-Nearest Neighbor algorithm, all investment performances using the classification algorithms showed average higher total profits than that of the benchmark strategy. Seventh, the trading performances using the predictive results of the Logical Regression, Random Forest, Support Vector Machines, and XGBoost algorithms showed higher results than the benchmark strategy in the Sharpe Ratio, which evaluates both profitability and risk. This study has an academic difference from existing studies in that it documented the economic value of the total buy & sell order volume information among the Limit Order Book information. The empirical results of this study are also valuable to the market participants from a trading perspective. In future studies, it is necessary to improve the performance of the trading strategy using more accurate price prediction results by expanding to deep learning models which are actively being studied for predicting stock prices recently.