• Biomaterials and Biomechanics in Bioengineering
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• v.2 no.4
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• pp.249-269
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• 2015

A problem faced by oil companies is the maintenance of the location register of pipelines that cross the surf zone, the regular survey of their location, and also their inspection. A survey of the state of art did not allow identifying operating systems capable of executing such tasks. Commercial technologies available on the market also do not address this problem and/or do not satisfy the presented requirements. A possible solution is to use robotic systems which have the ability to walk on the shore and in the surf zone, subject to existing currents and ripples, and being able to withstand these ambient conditions. In this sense, the authors propose the development of a spider crab biologically inspired robot to achieve those tasks. Based on these ideas, this work presents a biomechanical study of the spider crab, its modeling and simulation using the SimMechanics toolbox of Matlab/Simulink, which is the first phase of this more vast project. Results show a robot model that is moving in an "animal like" manner, the locomotion, the algorithm presented in this paper allows the crab to walk sideways, in the desired direction.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1672-1677
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• 2005

The Heat exchanger to be used in the place of business that is presented an utility period comes to be long and the problem of the length of life shares by the manufacture course and using environment factor. Consequentl, it is came to the front problem of inspection, repair, exchange, the utility stopping, safety and confidence. As a result the possibility which the large safety accident can happen comes to be high. It leads mostly to the large accedent when the explosion accident happens. to keep this, The system which the regular period passes to disuse the structure is prepared but The phenomenon which Time and the strength characteristic of the material change, namely Deradation. but It can't be a preventable solution by accident to the damage. Consequentl, This research can take important role to prevent an every kind accident for domestic pressure vessel by evaluating the mechnical characteristic change of meterial, the structure safety and residual life etc.

• Journal of radiological science and technology
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• v.41 no.5
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• pp.479-485
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• 2018

Radiologic technologists working at the second and third medical institutions are classified as radiation-related workers and radiation workers according to their working departments, and are subject to double regulation by the Ministry of Health and Welfare and the Nuclear Safety Commission. We will try to understand the system of dualization and to understand the investigation of recognition. The dualized system of radiation-related workers and radiation workers includes the difference in name and terminology, the effective dose limit, the maintenance education and training of radiologic technologists, the period of medical examination, the radiation zone, dose of the woman whose pregnancy is confirmed in radiologic technologists, the qualification criteria of the safety officer, and the period of the regular inspection of the radiological equipment. In the questionnaire survey on the dualization system, there were various items showing significant differences between the radiation-related workers and radiation workers Overall, the radiation workers were more aware of the radiation workers' education and related terms than the radiation-related workers.

• Proceedings of the KIEE Conference
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• 2000.07a
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• pp.501-503
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• 2000

Since an arrester has been generally used at the distribution line and abroad for the protection of electrical equipments against overvoltage (or abnormal surge) taking place in or from an electrical system, a fault, especially, in the distribution line is very likely to result in the destruction of insulation of other protection devices to cause an overall paralysis of a power system, a chaos. Considering the importance of arresters, its earlier replacement than its proposed life cycle causes an economical loss, and a negligence not to replace or repair it in time gives rise to a crucial accidence. The purpose of this paper is to invent an electric leakage current detector and to solve such problems by the continuous and regular inspection of an arrester.

• Journal of the Korean Society for Nondestructive Testing
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• v.30 no.6
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• pp.569-577
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• 2010

Nonplanar surface geometries of components are frequently encountered in real ultrasonic inspection situations. Use of rigid array transducers can lead to beam defocusing and reduction of defect image quality due to the mismatch between the planar array and the changing surface. When a flexible array is used to fit the complex surface profile, the locations of array elements should be known to compute the delay time necessary for adaptive heam focusing. An alternative method is to employ the time reversal focusing technique that does not require a prior knowledge about the properties and structures of the specimen and the transducer. In this paper, a time reversal method is applied to simulate beam focusing of flexible arrays and imaging of point-like defects contained in specimens with nonplanar surface geometry. Quantitative comparisons are made for the performance of a number of array techniques in terms of the ability to focus and image three point-like reflectors positioned at regular intervals. The sinusoidal profile array studied here exhibits almost the same image quality as the flat, reference case.

• International Journal of Railway
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• v.1 no.1
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• pp.1-5
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• 2008

The railway system requires safety and reliability of service of all railway vehicles. Suitable technical systems and working methods adapted to it, which meet the requirements on safety and good order of traffic, should be maintained. For detection of defects, non-destructive testing methods-which should be quick, reliable and cost-effective - are most often used. Since failure in railway wheelset can cause a disaster, regular inspection of defects in wheels and axles are mandatory. Ultrasonic testing, acoustic emission and eddy current testing method and so on regularly check railway wheelset in service. However, it is difficult to detect a crack initiation clearly with ultrasonic testing due to noise echoes. It is necessary to develop a non-destructive technique that is superior to conventional NDT techniques in order to ensure the safety of railway wheelset. In the present paper, the new NDT technique is applied to the detection of surface defects for railway wheelset. To detect the defects for railway wheelset, the sensor for defect detection is optimized and the tests are carried out with respect to surface and internal defects each other. The results show that the surface crack depth of 1.5 mm in press fitted axle and internal crack in wheel could be detected by using the new method. The ICFPD method is useful to detect the defect that initiated in railway wheelset.

• Journal of Fisheries and Marine Sciences Education
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• v.25 no.2
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• pp.448-457
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• 2013

The media is an effective means of preventing crime. It can be known to members of the media presiding over the most widely and rapidly. Because of this, the mass media is a good way to prevent such crime. Related to general crime, marine crime will have unique characteristics and about Crimes reported by the media, it is also true. The results of this study are as follows. Firstly, it is required that the more accurate present article must be published and reported. Secondly, for more accurate presentation of measure, there is a need to enhance professional training for reporters. Thirdly, the marine weather report is the most important political purpose of considering marine crime prevention. Forthly, marine crime is likely to be a lack of evidence. Therefore, in order to supplement the lack of evidence maritime security agency should be utilized for a news source.qualification Fifthly, the need for regular inspection of the articles is requested. Sixthly, for judicial control maintenance of the media related laws should be strengthened. Finally, the arbitration institution for media rights should be established under the Korea Ministry of Land Infrastructure and Transport. This is practical action for marine crime prevention.

• Journal of Environmental Health Sciences
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• v.31 no.5 s.86
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• pp.365-371
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• 2005

This study was peformed to explore the current situation of university environmental health and safety (EHS) system and evaluate the effects of such system on university EHS practices. Essential elements for the university EHS system were identified based on the representative examples of foreign universities, and Hey were incorporated into a questionnaire, which was used in this study. Among the academic institutions we surveyed in this study, 89% of the universities employed health and safety manager, and 65% kept departments. However, less than 50% of universities maintained EHS policies, maintained health and established safety committees within the university headquarters, and held health and safety meetings on regular basis. Several basic requirements such as chemical hygiene program and laboratory safety training program lacked in many universities. Some basic surveillance was performed in many universities, however, only few universities carried out surveillance on biological safety, medical examination, and chemical exposure monitoring. EHS system had significant influence on university EHS program (p<0.05). Performances of EHS activities were influenced by presence of EHS policies, and university health and safety committees.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1940-1945
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• 2007

The wheelsets are one of most important component: damages in wheel tread and press fitted axle are a significant cost for railway industry. Since failure in railway wheelset can cause a disaster, regular inspection of defects in wheels and axles are mandatory. Ultrasonic testing, acoustic emission and eddy current testing method and so on regularly check railway wheelset in service. However, it is difficult to use this method because of its high viscosity and because its sensitivity is affected by temperature. Also, due to noise echoes it is difficult to detect defects initiation clearly with ultrasonic testing. It is necessary to develop a non-destructive technique that is superior to conventional NDT techniques in order to ensure the safety of railway wheelset. In the present paper, the new NDT technique is applied to the detection of surface defects for railway wheelset. To detect the defects for railway wheelset, the sensor for defect detection is optimized and the tests are carried out with respect to surface and internal defects each other. The results show that the surface crack depth of 1.5 mm in press fitted axle and internal crack in wheel could be detected by using the new method. The ICFPD method is useful to detect the defect that initiated in the tread of railway wheelset.

• Structural Engineering and Mechanics
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• v.46 no.5
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• pp.615-627
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• 2013

One of the most common defects in reinforced concrete bridge decks is corrosion of steel reinforcing bars. This invisible defect reduces the deck stiffness and affects the bridge's serviceability. Regular monitoring of the bridge is required to detect and control this type of damage and in turn, minimize repair costs. Because the corrosion is hidden within the deck, this type of damage cannot be easily detected by visual inspection and therefore, an alternative damage detection technique is required. This research develops a non-destructive method for detecting reinforcing bar corrosion. Experimental modal analysis, as a non-destructive testing technique, and finite element (FE) model updating are used in this method. The location and size of corrosion in the reinforcing bars is predicted by creating a finite element model of bridge deck and updating the model characteristics to match the experimental results. The practicality and applicability of the proposed method were evaluated by applying the new technique to a two spans bridge for monitoring steel bar corrosion. It was shown that the proposed method can predict the location and size of reinforcing bars corrosion with reasonable accuracy.