• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2015.07a
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• pp.259-261
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• 2015

The model for ship maneuvering simulation is to enhance the competence of officer's ship maneuvering skills such as navigation equipment operation, collision avoidances, countermeasure an emergency situation so on. Despite using such ship maneuvering model, critical maritime accidents are occurred periodically in the world. To find adequate simulation model to evaluate competence abilities of deck officer who have maneuvering skills with some competence levels, we search the standard ship maneuvering method representing on the part 3 Person Overboard(POB) to onboard emergences of IAMSAR manual. Moreover we monitor the officer's human factors appearing during education and training and consider the use of human factors as fundamental data.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.4
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• pp.594-601
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• 2006

Coding of occupational and industrial codes is a major operation in census survey of Korean statistics bureau. The coding process has been done manually. Such manual work is very labor and cost intensive and it usually causes inconsistent results. This paper proposes an automatic coding system based on example-based learning. The system converts natural language input into corresponding numeric codes using code generation system trained by example-based teaming after applying manually built rules. As experimental results performed with training data consisted of 400,000 records and 260 manual rules, the proposed system showed about 76.69% and 99.68% accuracy for occupational code classification and industrial code classification, respectively.

• Journal of the Korean Society of Safety
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• v.24 no.2
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• pp.89-93
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• 2009

The muscular-skeletal disorders that have become a major issue recently in Korean industrial safety area are mainly caused by manual material handling task. The objective of this study is to provide scientific data for the establishment of work safety standard for Korean workers through the experiments of lifting task under various conditions, in order to prevent the muscular-skeletal disorders in the industrial work site. This study used the psychophysical approach to determine the maximum acceptable weight(MAWL) for seven young male subjects, and used isometric and isoinertial strength variables as predictors to develop prediction models. Also, the oxygen consumption, heart rate, and RPE were measured or recorded while subjects were lifting their MAWL. Three different lifting frequencies(1, 3, 5lifts/min) with two lifting range from floor to knuckle height and knuckle to shoulder height for one hour's work shift using free style lifting technique were studied. These results may not only provide scientific data in establishing the safety standards for Korean workers' lifting tasks, but also contribute preventing the rapidly increasing muscular-skeletal disorders lately on the industrial site.

• Journal of Ocean Engineering and Technology
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• v.13 no.2 s.32
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• pp.51-57
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• 1999

In this study, one side fillet welded T-joint, used in box type girder and other welding structure, was investigated by stress analysis and bending fatigue test without edge preparation, with variation of joint shape. The purpose of this study is to give the welding condiltion and design standard on manufacturing one side fillet welded T-joint. As a result, the following conclusions were obtained. 1) In one side fillet welded T-joint, the larger the leg length and the penetration depth, the greater the bending fatigue strength because reduction of stress and strain on toe and root. The increase of the longitudinal leg length rather than vertical leg length contributed to the increase in bending fatigue strength. 2) In one side fillet welded T-joint without edge preparation, both general manual welding and general automatic welding were carried out with same condition. In this case, automatic welding showed deeper penetration and more increased longitudinal leg length than manual welding, so that automatic welding offers greater bending fatigue strength. 3) For one side fillet welded T-joint without edge preparation with automatic welding, the ratio(h/t) of the leg length(h) and the main plate thickness(t) in which toe crake can occur was 1.0 over.

• Journal of Advanced Marine Engineering and Technology
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• v.31 no.5
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• pp.622-629
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• 2007

Some worker is occupationally exposed to cold and freezing environment. The cold stimuli in the working environment impose physiological and psychological loads on workers to decrease the task performance. The purpose of this study is to investigate the cold stimuli of cold and freezing stores widely used in Busan can make an effect on human's physiological responses and task performance, experimentally and analytically. In the experiment, 5 workers are selected as subjects, and then their skin temperatures of hand and ear, heart rates, blood pressure, and ring test performances in cold($3^{\circ}C$) and freezing($-22^{\circ}C$) stores were measured for 21 minutes and analyzed by using statistical method. It is observed that a physiological variation and the task performance are significantly influenced by an exposure time as well as a strength of cold stimuli. Also, it is suggested the exposure limiting times for the useful manual work and the performance predict model of the ring tasks. The result of this study will be useful for a fundamental data of which design the standard task time of manual tasks and solve the job placement problem of worker selection and placement in cold environment.

• Journal of the Korean Society of Safety
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• v.29 no.4
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• pp.153-159
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• 2014

Low back pain is one of major issues in musculoskeletal diseases mainly caused by MMH (Manual Material Handling) tasks. In Korea, the standards of NIOSH(National Institute for Occupational Safety and Health) Lift Equations in U. S. A. have been most widely used. However, there is no standard in case the height of one feet is higher than that of another one. Moreover, since the standards are developed in U. S. A., there are many limitations for the applicability of Korean workers. In this study, MVC(Maximum Voluntary Contraction) for four postures are measured and an empirical model based on SVR(Support Vector Regression) is constructed. Constructing SVR model, PSO(Particle Swarm Optimization) is employed to investigate the optimal parameters of SVR. The results show that the performance of this empirical model is approximately accurate, even if the deviation of experimental values is large due to the individual differences. This empirical model may contribute to establish the standards of MMH tasks in Korea.

• Journal of Welding and Joining
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• v.29 no.6
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• pp.77-81
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• 2011

In most industry, manual GTAW welding is preferred for formation of stable back bead in root weld of butt joint. However, manual GTAW welding has low productivity as compared with GMAW, also it has unstable bead quality which depend on skilled workers. So it is necessary to develop process of root pass welding by using automation GMAW that have stable back bead formation and high productivity. In this paper, the design of U-groove with 3mm root face was applied to extend the tolerance of misalignment in condition of standard root gap 1.5mm. Consequently, for the formation of stable back bead in root pass of butt welding, in case of the narrow root gap(0.5mm) the large arc force was applied by increasing the current and voltage. In case of the large root gap(2.5mm), the small arc force was applied by decreasing the current and voltage. Considering the various root gap, the required deposited metal was controlled by welding speed only.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.24 no.2
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• pp.17-27
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• 2018

Background: This study investigated the effects of pelvic floor stabilization exercise of pain, disfunction, psychosocial, electromyography (EMG) activity on the lower back pain with postpartum. Methods: The study included 20 postpartum women who were randomly assigned to a sling exercise group (SEG, n=10) or a general physical therapy group (GPTG, n=10). Outcomes were assessed using to lower back pain with postpartum the quadruple visual analogue scale (QVAS), the Korean version of the Oswestry disability index (KODI), the fear avoidance belief questionnaire (FABQ), the inventory of functional status after childbirth (IFSAC), the edinburgh postnatal depression scale-Korean (EPDS-K), and trunk muscle activity before and after a 4-week exercise intervention. Statistical analysis were performed using a mean, standard deviation, crosstab test, paired t-test, independent t-test. Kolmogorove-Smirnov test was used for test of normality. Results: Compared to the GPTG, the SEG showed significant improvement in the QVAS, KODI, FABQ, IFSAC, and EPDK-K scores (p<.05) after 4 weeks. Conclusion: Postpartum pelvic strengthening exercise proved to have a positive effect.

• Journal of the Korean Society of Hazard Mitigation
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• v.10 no.3
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• pp.61-69
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• 2010

Disasters have been diversifying and the scale of disaster has been increasing worldwide due to the global warming and urbanization. Consequently, it is essential to establish the systematic disaster management because the scale of damages has been rapidly increasing. Nowadays, the importance of the standardized disaster management have been realized internationally due to the 9.11 terror and Tsunami. Also, the activities of research and development to utilize and establish the disaster management standards have been increasing. This study mainly focused on generating an efficient operating manual to support the systematic disaster management of the central administration office based on disaster management standard in South Korea. Firstly, the activities and status of disaster management performed by the central administration office were investigated. Accordingly, libraries of work, functions, organizations, references and behavior for disaster management were designed. Then, a method to make the efficient operation manual based on the constructed libraries was presented to maximize the efficiency of disaster management. This emergency operation manual could support the systematic disaster management by defining the work, function, references and the codes of conduct. Thus, central administration office would be able to define methods and procedures from preparation to recovery through the utilization of the operation manual.

• The Journal of Korean Academy of Prosthodontics
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• v.38 no.5
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• pp.695-703
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• 2000

The purpose of this study was to evaluate the effects of fabrication and tightening methods of gold cyliner on the preload of the standard abutment. Three linear strain gauges (KFR-02N-120-C1-23, Kyowa, Japan) were mounted longitudinally on the 5.5mm Standard abutment (Nobel Biocare, Sweden) and three kinds of gold cylinders such as, as-received gold cylinder, gold cylinder after casting, and plastic cylinder after casting with type IV gold alloy were connected over the top of the standard abutment. Two kinds of tightening methods, such as manual torque with handhold screwdriver and electronic torque using Electronic torque controller were used to generate preload on the abutment. The result were as follows; 1. The preload generated by tightening cast plastic cylinder with handhold screw driver, was the lowest among the six groups. 2. The preload generated by cast plastic cylinder was lower than those by gold cylinders regardless of the tightening methods. 3. The electronic torque controller produced higher torque values than the handheld screwdriver.