• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06a
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• pp.17-21
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• 1996

• International Journal of Naval Architecture and Ocean Engineering
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• v.8 no.4
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• pp.386-397
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• 2016

Given the growing interest in damage control training for the naval ships and their organizations, expectations for a new concept of training program have also increased. The existing training programs and its concept focus on training crew to be more proficient and skilled so that they can respond better to damage situations, i.e., fires and flooding. This paper suggests a development procedure of damage control training scenarios using the survivability analysis results as a new concept of damage control training programs employing advanced systems such as damage control console, automation system, and kill cards. This approach could help the decision maker not only enhance his or her capability but also improve the reacting capability of crew members for complex situations induced by a weapon hit.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.205-210
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• 1993

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.291-296
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• 1993

Taking a bledes axle of rotary tiller as a example, this paper discusses influences of four loading essential factors, which are strengthened amplitude, cycle times, loading sequence and loading frequency. in fatigue life. Determination principles of above four factors and monitoring methods of fatigue damage by local strain are dealt with. The actual field testing check of farm machinery is rapidly simulated by laboratory program fatigue test can shorten the period of development and improvement of a product. In the time of in-door simulation test, damage monitoring and four loading essential factors, which are strengthened amplitude , cycle times, loading sequence and loading frequency, have to be dealt with . If these problems are solved successfully, it is possible to accelerated test speed, reduce costs and manhours, and raise accuracy of test result. However strengthening method, loading pattern and influence of loading frequency on test result have not so far been discu sed systematically, damage monitoring is even more a difficult problem. Authors have studied above problems with the object of blades axle of rotary tiller.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06c
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• pp.878-885
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• 1996

The brown rice drying is effective for energy saving and cost reduction. However, deterioration after drying is one problem, because the skin damage occurs during the drying. So, the measures to preserve the quality has been investigated. One of major quality deteriorations is the oxidation of fat which is contained in the bran layer. So, milling should be carried out to remove the fat as soon as possible after brown rice drying. And the low temperature storage is also worth to be examined for prevention of oxidation. The effect of skin damage on the increase of fat oxidation was clarified. For the grain of skin damage, the increased of fatty acid vaule was remarkable after 70 days elapsed from occurrence of skin damage even in $15\;^{\circ}C$ condition. Therefore it is impossible to keep grain as brown rice form after brown rice drying. For the clean rice and excessively milled rice, the quality can be preserved even in high temperature of $30\;^{\circ}C$. Therefore the brown rice drying can b applied practically using the clean rice technique.

• Corrosion Science and Technology
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• v.12 no.4
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• pp.179-184
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• 2013

Pipe wall thinning caused by erosion and corrosion can adversely affect the operation of aged nuclear power plants. Some injured workers owing to pipe rupture has been reported and power reduction caused by unexpected pipe damage has been occurred consistently. Therefore, it is important to develop erosion-corrosion damage prediction model and investigate its mechanisms. Especially, liquid droplet impingement erosion(LDIE) is regarded as the main issue of pipe wall thinning management. To investigate LDIE mechanism with corrosion environment, we developed erosion-corrosion damage simulation apparatus and its capability has been verified through the preliminary damage experiment of 6061-Al alloy. The apparatus design has been based on ASTM standard test method, G73-10, that use high-speed rotator and enable to simulate water hammering and droplet impingement. The preliminary test results showed mass loss of 3.2% in conditions of peripheral speed of 110m/s, droplet size of 1mm-diameter, and accumulated time of 3 hours. In this study, the apparatus design revealed feasibility of LDIE damage simulation and provided possibility of accelerated erosion-corrosion damage test by controlling water chemistry.

• Journal of the Society of Naval Architects of Korea
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• v.44 no.4
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• pp.439-444
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• 2007

A damage analysis simulator, which is applicable for evaluating the residual strength of damaged ship, was developed in this paper. For this process, CDM (Continuum Damage Mechanics) approach has been implemented to the simulator by virtue of the numerical technique for evaluation of crack initiation and/or enlargement. A damage calculation program has been linked with a commercial finite element analysis code (NASTRAN) and a ultimate strength evaluation program (LSAP) in order to assess residual strength of damaged ship. As a results of series calculation for the frigate model, giving the quantitative structural damage to the ultimate strength evaluation, a residual strength with damage is predicted to be at least 70 percentage lower than the case of intact condition. It was found that the proposed technique can be used as a design support tool in the field of simulation based ship design.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.22 no.3
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• pp.203-207
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• 2012

The noise emitted from an excavator has long been a cause of environmental disputes, while causing displeasure to the nearby residents. So, the ministry of environment adopted the construction machinery noise labeling system to encourage the construction machinery manufacturing companies to develop the low noise construction machinery voluntarily. But, as the quality of life improves, a growing number of people desire the comfortable and quite environment to live in. Under the situation, noise from the construction machinery has been a major cause for stress and complaints. When the noise dispute happened in the construction site, the sound pressure level of the construction machinery like a excavator was measured at the lot boundary of the noise victim's residence to judge how much noise damage occur. But the sound pressure level of the construction machinery is measured differently according to the acoustic environment of construction site and the measuring position, respectively, which makes it difficulty to judge whether the noise damage occur or not. As the sound power level of noise source is not affected by the acoustic environment of construction site and the measuring position, if we use the information of the sound power level, it will be easy to judge whether the noise damage occur and to establish the soundproofing measures. Therefore, we derive the sound power level regression model of the excavator to judge whether the noise emitted from the excavator damages to residents near the construction site. Also, the sound power level regression model of the excavator drawn in this paper will help construction companies to plan the noise reduction program in the construction sites.

• Journal of the Korean Society of Safety
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• v.17 no.1
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• pp.6-10
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• 2002

This paper presents the impact behavior and damage of laminated composite plates subjected to low-velocity impact. For this purpose, a pendulum impact test for impact behavior and C-scan for impact damage are done. Test materials are carbon/epoxy laminated composite plates and stacking sequences $[0/90_4\;[0/45_2/-45]_s,\;[0/45/-45/90]_s$ and [0/26/51/77/-77/-51/-26/0].

• The KSFM Journal of Fluid Machinery
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• v.15 no.6
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• pp.64-69
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• 2012

This paper deals with the study on repair case of journal shaft and bearing damage in 25MW industrial gas turbine caused by sudden blackout, operation mistake, and logic abnormal, etc. When a serious accident such as journal and bearing damage in a gas turbine occurs, the domestic local companies having the gas turbine are dependent on manufacturer for all maintenance and repair schedule until now. This case study shows that the damaged gas turbine is normally re-operated itself in domestic by establishing repair schedule in a short period of time, repairing damage journal shaft and tilting pad bearings, and performing rotating test for a reliability check. This paper can be regarded as the important case study of emergency test run experience of the refurbished 25MW gas turbine rotor.