• Fire Science and Engineering
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• v.31 no.3
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• pp.97-105
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• 2017

Because asphalt is a solid at normal temperature and is not a hazardous material as stipulated in the Safety Management Act on Hazardous Materials, it is often recognized as having no risk of fire or explosion. On the other hand, it is as dangerous as flammable liquid because it is heated to $170-180^{\circ}C$ and stored in a storage tank. This study analyzed the risk of fire and explosion during the storage and handling of asphalt and the actual conditions of asphalt regulations by fire service organizations. Moreover, this study analyzed the domestic case of explosions in the production process of asphalt concrete (ASCON) and domestic and foreign cases of asphalt storage tank explosions. The analysis suggested that unlike Japan, Korea has no asphalt regulations in fire service organizations. Explosions can occur when ignition is delayed after fuel is sprayed on the dryer drum burner of the aggregates during the production of ASCON. A physical explosion can occur in the storage tank when environmental purification facilities suddenly work strongly to remove air pollutants or bad smells during the heating of asphalt in an asphalt storage tank. In addition, explosions can occur when fires such as welding is performed in the asphalt storage tank.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.10-10
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• 2017

우리나라 고추 재배는 ha당 총 노동투하시간 2,436 hr 중 수확작업시간은 954 hr으로 총 노동투하시간의 39.2%를 점유하고 있어 수확작업의 생력화를 위해 고추수확작업의 기계화가 절실히 필요하다. 고추 수확의 기계화를 위해 국내 T사에서 자주식 고추 수확기를 개발 중에 있다. 현재 고추를 기계로 채취하게 되면 많은 양의 줄기달린 고추가 유입되므로 수확 후 분리하는 작업에 있어 많은 인력과 시간이 소요되는 실정이다. 따라서 본 연구에서는 드럼 회전 타입의 2차 탈실부 요인시험 장치를 제작하여 드럼의 회전속도, 드럼과 급치 사이 간격에 대해 요인시험을 수행함으로써 자주식 고추수확기 2차 탈실부의 적정 작업조건을 파악함에 목적을 두었다. 탈실부 요인시험 장치는 급치가 부착된 3개의 드럼 형태의 탈실부와 이송벨트로 구성된다. 공시재료인 고추는 광주광역시 남구 승촌동 소재의 개인농가에서 Plastic 온실로 재배된 '천상' 품종을 사용하였다. 본 요인시험은 드럼의 회전속도(40, 70, 100, 130 rpm)와 드럼과 급치 사이 간격(2, 5, 10 mm)으로 요인을 설정하여 시험을 수행하였다. 시험은 각 요인 당 3반복으로 실시하였으며, 투입되는 시료는 줄기달린 고추를 3가지의 형태로 구분하여 제작하였다. 각 요인에 따라 고추의 탈실률, 손상률에 대해 통계프로그램인 SAS를 이용하여 분석하였다. 드럼의 회전속도에 따른 요인시험결과, 손상 대비 탈실률로 비교했을 때 회전속도 40 rpm에서 탈실률 47.69%, 손상률 8.33%로 성능이 가장 낮았으며, 회전속도 70 rpm에서 탈실률 63.89%, 손상률 12.96%로 성능이 가장 높았다. 드럼과 급치 사이의 간격에 따른 요인시험결과, 간격이 클수록 탈실률 및 손상률이 줄어드는 경향을 보였으며, 5 mm일 때 성능이 가장 높았다. 반복이 있는 이원배치법을 이용하여 분석한 결과, 고추 탈실률과 손상률은 드럼의 회전속도와 드럼과 급치 사이 간격 모두에서 유의차가 발생한다고 나타났다. 요인시험 결과를 종합적으로 고려해 보았을 때, 드럼 회전속도 70 rpm, 드럼과 급치 사이 간격 5 mm에서 가장 높은 성능을 보였다. 고추 탈실률이 낮고, 손상률이 높아 탈실장치로서의 기능에 어려움이 있을 것으로 보이므로 추후 급치 타입의 변경 등 탈실장치의 보완 및 개선이 필요할 것으로 판단된다.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.18 no.2_spc
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• pp.317-325
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• 2020

The Korea Radioactive Waste Agency plans to expand the storage capacity of radioactive waste by constructing a radioactive waste inspecting building to solve the problem of the lack of inspection space and drum-handling space in the radioactive waste receipt and storage building for the first-stage disposal facility. In this study, the exposure doses of radiation workers that handle new disposal containers for decommissioning waste in the storage areas of the radioactive waste inspecting building were calculated using the Monte Carlo N-particle transport code. The annual collective dose was calculated as a total of 84.8 man-mSv for 304 new disposal containers and an estimated annual 306 working hours for the radiation work. When the 304 new disposal containers (small/medium type) were stored in the storage areas, it was found that 25 radiation workers should be involved in acceptance/disposal inspection, and the estimated exposure dose per worker was calculated as an average annual value of 3.39 mSv. When the radiation workers handle the small containers in high-radiation dose areas, the small containers should be shielded further by increasing the concrete liner thickness to improve the work efficiency and radiation safety of the radiation workers. The results of this study will be useful in establishing the optimal radiation working conditions for radiation workers using the source term and characteristics of decommissioning waste based on actual measurements.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.36 no.3
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• pp.166-174
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• 2000

Anchovy, EngrauEis japonica scoop nets are used in the coastal of Southern and Cheju of Korea. Especially in the Cheju, the fishing gear of scoop nets consists of upper boom, lower boom, pressing stick and bag net. They are operated by fishing boats of 6 to 10 ton class and 8 persons on board. The booms are controlled by side drum, and the net and pressing stick are hauled by only human power in operating. Therefore this fishery needs to large labor and heavy human power and has much risk. Three kinds of hydraulic winding device which controls two booms was designed and manufactured to reduce heavy labor force of scoop nets, and trial in the sea was carried out to test their performances using the commercial fishing boats of 6 ton class. The proper capacity of hydraulic pump and motor were determined by model test of boom 1/5 scale. The results obtained are as follows, 1. Tension of boom which is being drawn was the strongest and 187.5kgf when the boom's end is in the depth of 4m under the water. 2. The hydraulic motor of the fittest kind of winder has the least leakage per time than the other kinds. 3. In the best type of several winder devices, when the pressure difference was fixed $130kg/^2$ for the safe fishery, the winding velocity of boom line was 2m/sec, is faster 0.48/sec than traditional fishing method and this winder can catch the anchovy of 1.6 tonnage. 4. As a result, the crew were decreased from 8 to 6 and the problem of heavy human power and risk on fishing operation were solved by using the this winder.

• Proceedings of KOSOMES biannual meeting
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• 2006.05a
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• pp.79-83
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• 2006

Displayed result that handle particle contaminant and hydrospace organism included in number of ballast that is happened in ship using automatic bade washing filter. Reason that remove first contaminant that is included in number of ballast is that heighten processing effect of after processing process. of the filter. Another advantage is to drop off the solids with controlling revolution of drum screen in pretreatment filtration process. The fact that it is easy to attach and detach a several type of screen for getting the expected water quality is another advantage. Filter rotation speed at 1.0rpm is filter resistance 3.0bar and 3.0rpm is filter resistance 2.8bar. Filter out impurities from ballast water over 6.0rpm is filter resistance 26bar and 10rpm is filter resistance 2.5bar. Filtration system removal aquatic organism over $80{\mu}m$ in ballast water. This study shows that the filtration treatment system has a potential for the treatment of ballast water.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.11 no.4
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• pp.271-280
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• 2013

Since the decommissioning of nuclear plants and facilities, large quantities of slightly contaminated concrete waste have been generated. In Korea, the decontamination and decommissioning of the KRR-1, 2 at the KAERI have been under way. And concrete waste was generated about 800 drums of 200 L. The conditioning of concrete waste is needed for final disposal. The concrete waste is conditioned as follows: mortar using coarse and fine aggregates is filled void space after concrete rubble pre-placement into 200 L drum. Thus, this research has developed an optimizing mixing ratio of concrete waste, water, and cement and has evaluated characteristics of a cement waste form to meet the requirements specified in disposal site specific waste acceptance criteria. The results obtained from compressive strength test, leaching test, thermal cycling test of cement waste forms conclude that the concrete waste, water, and cement have been suggested to have 75:15:10wt% as the optimized mixing ratio. Also, the compressive strength of cement waste form was satisfied that including fine powder up to maximum 40wt% in concrete debris wastes about 75%. As a result of scale-up test, the mixture of concrete waste, water, and cement is 75:10:15wt% meet the satisfied compressive strength because the free water increased with and increased in particle size.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.4
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• pp.1373-1380
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• 2010

The plate loading test(PLT) and the field density test are mainly used on the construction of embankments to control the compaction of a limited layer thickness. These two test methods are very time consuming and inefficient, but they are still commonly used as the methods of quality control for soil compaction. In the last 3 decades, many devices such as geogauge, light falling weight deflectometer(LFWD) and dynamic cone penetrometer(DCP) etc., have been introduced into the engineering market with the objective of acquiring in situ stiffness properties of the compacted soil layers. Recently, a new type of sensor, called compactometer, which in mounted on the drum of a roller and measures impact forces continuously with GPS, called as Continuous Compaction Control(CCC), has come into use in many countries such as America, Germany, Japan and so on. The main objective of this paper is to assess the potential use of these new devices as quality control and assurance devices for compacted soil layers. Based on this study, compactometer and the LFWD results werestrongly correlated with the result obtained from the PLT and the field density test.

• The Journal of the Acoustical Society of Korea
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• v.23 no.2
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• pp.146-161
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• 2004

There have been always some difficulties in target setting and conditioning of acoustic performances of the Korean traditional music hall due mainly to the lack of the information on the sound radiation characteristics of Korean musical sources. In this study, the radiation characteristics of four typical Korean traditional musical sources were investigated in precision and their usage was demonstrated: The selected musical sources were Gayageum (string), Daegeum (woodwind), Jango (drum), and Pansori Chang (vocal performance). Each sound source was located at the center of a semi-anechoic chamber and the directivity was determined by the measured sound pressure levels in every 10° angular position, for both vertical and horizontal directions. The directivity pattern of Gayageum varies from a uniform to a complex pattern having many side lobes with the increase of frequency. The main radiation of Daegeum is toward the upward direction. The directivity pattern of Jango is clearly a side-oriented one and the left direction intensity is sharper than its right side at low frequencies. For the Chang, the directivity pattern change from a uniform pattern to a frontally directed one as the frequency goes high. Measured directional and spectral characteristics of traditional Korean music sources were implemented into the computation of architectural acoustic measures for the Busan National Korean Traditional Music Hall which is under construction. Parameters such as RT, SPL, C80, IE, STI were calculated at two receiver positions by using a ray tracing technique. Significant differences in the acoustic measures at receiver positions were observed between the results in using the omni-directional source and the directional one. It is thought that the suggested source data and design method can be used as a basic reference in the future acoustic design of performance halls for the Korean traditional music.

• Culinary science and hospitality research
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• v.23 no.2
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• pp.159-168
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• 2017

This study was conducted to compare the food quality of domesticated species. Consumers surveyed for safe food intake and proper culture of food distribution. The results of the comparison study are as follows. Muscle moisture content, protein content, and fat content. K, P, and C showed relatively high values in the muscle of the sea bream. Fe showed low contents. As a result of measuring heavy metal component, Cd was not detected in sea bream and mullet, but $0.01{\pm}0.00mg/kg$ was detected in red mine. Other heavy metals were below the reference value or were not detected. Electrophoresis results showed that the band appeared at in red minefish. In the case of sea bream and swordfish, no distinctive features of the band were shown. In the case of sea bream, there was little difference in food science between the similar fish species and the red sea bream fish, but price was different. An environment should be created for consumers to buy the right ingredients at the price they want. It is necessary to educate consumers about food ingredients immediately.

• The Journal of Engineering Geology
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• v.26 no.3
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• pp.315-324
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• 2016

Because of a fissility characteristics of shale in the Gyoungsang super-group, it breaks down to debris when daylighted by construction work and causes a slope unstability. To assess the durability property of shale, a series of slake durability tests was conducted by controlling test conditions such as shape of specimen, number of specimen, revolution speed, revolution number, drying temperature and pH of submerging liquid. For the specimen shape, cube one showed relatively lower durability index than cuboid and/or fan shape one. The test with the more number of specimens showed the less durability index because of a higher friction among specimens in the drum. The durability index is linearly decreased by increasing the total number of revolution, while the revolution velocity could not affect the index. And the durability index is also decreased by increasing the drying temperature of specimen and by decreasing the pH of submerging liquid. Because the durability index of shale is almost similar to that of crystalline rocks, the disintegration characteristics of shale could not be assessed by the slake durability test recommended by ISRM, and thus a new test method by changing the total revolution number may be required for the shale having fissility characteristics.