• KIEAE Journal
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• 제7권3호
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• pp.89-96
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• 2007

The purpose of this experimental study is to investigate the compressive strength, shear strength, bending strength, and crack control by the mixture of the hwang-toh. The size of compressive specimens is $200{\times}200{\times}400(mm)$, and the size of shear, bending specimens is $200{\times}200{\times}600(mm)$. Finally, crack control specimens for comparative comparison is $200{\times}200{\times}15(mm)$. The mixture of the hwang-toh is as follows; Hwangtoh( H)+Water(W), H+W+Sand(S), H+W+S+sTraw(0.5%), H+W+S+sT(1.0%). The actual height, width, and the length are measured at the center of all specimens. The main parameters are mixture ratio of hwang-toh, straw and age of specimens. The test results are as follows. (1) The compressive strength is linearly increased until 15 weeks according to specimen ages. (2) About crack control, the specimen added in 1% straw is the most effective.

• KIEAE Journal
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• 제12권3호
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• pp.53-60
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• 2012

This research is an illustrative research to verify the thermo environmental change created after introduction of indoor pond through abridged model test and simulation analysis. Especially, temperature and comfort level are analyzed by adjusting factors like size of water space, distance length, and location. Summary of the research is as follows. First, the most effective size of water space is 7% of the indoor size, from southern side. Temperature reduction effect is about $1.6^{\circ}C$(5.5%), and for the comfort level, it is found that pmv index increases 8%. Second, based on the simulation of distance length with the sphere, it is more effective as it is close to the surface. If distance length is more than 0.5m, there is no effect on reduction of temperature and comfort level of indoor environment. Lastly, for the analysis by location of the introduced water space, simulation is undertaken by dividing the water space (14% of the indoor size) with front, side, rear and center types. Temperature reduction effect is found to be : front type ($-1.53^{\circ}C$), side type ($-0.82^{\circ}C$), rear type ($-0.44^{\circ}C$), center type ($-0.28^{\circ}C$), respectively. The indoor environment change data by introduction of water space, found in this research, is at initial phase, but it is deemed to be a basic data to refer when planning actual water space.

• 대한조선학회논문집
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• 제48권5호
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• pp.390-395
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• 2011

The main purpose of ice model basin is to assess and evaluate the performance of the Arctic ships and offshore structures because the full-scale tests in ice covered sea are usually very expensive and difficult. There are various ice conditions, such as level ice, brash ice, pack ice and ice ridge, in the real sea. To estimate their capacities in ice tank accurately, an appropriate model ice sheet and prepared ice conditions copied from actual sea ice conditions are needed. Pack ice is a floating ice that has been driven together into a single mass and a mixture of ice fragments of varying size and age that are squeezed together and cover the sea surface with little or no open water. So Ice-class vessels and Icebreaker are usually operated in pack ice conditions for the long time of her voyage. The most ice model tests include the pack ice test with the change of pack ice concentration. In this paper, the effect of pack ice size and channel breadth in pack ice model test is conducted and analyzed. Also we presented some techniques for the calculation of pack ice concentration in the model test. Finally, we developed a new model test methodology of pack ice condition in square type ice tank.

• 대한조선학회 특별논문집
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• 대한조선학회 2005년도 특별논문집
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• pp.144-150
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• 2005

The size of ship is being larger than the past in the shipping industry thanks to the increased quantity of goods transported by ship. Therefore, HHIC (Hanjin Heavy industries & Construction co., LTD) invented innovative construction method, so called 'DAM', to build a ship which is longer than the length of the HHIC's dry dock. On Erection at the sea by the application of DAM Method, Squeezing & Detachment of A/F film may occur as a result of the wave and the constriction between A/F film pre-applied on the side shell and DAM's Rubber Packing. Thus, the test for finding the minimum curing time of A/F film was performed to protect Squeezing & Detachment of A/F film on the hull. To verify the soundness of paint and to find the optimum condition during the erection period of the DAM, laboratory test was carried out under no immersion condition through the application of various coatings on the Rubber Packing. And two methods were selected from the results of laboratory test for actual MOCK-UP Test. In addition, the test for the film profile per temperature of silicone A/F coat and the film Squeezing was performed.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2015년도 춘계 학술논문 발표대회
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• pp.185-186
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• 2015

The use of non-bearing lightweight wall has increased recently due to the increase of high-rise buildings and supply of long-life housing. Lightweight wall has advantages such as reducing the self-weight of the building, convenience in installation, and shortening construction period, however, must have a sufficient strength to external force. This study standardized the stiffness (static horizontal load resistance) test method for lightweight walls by using the actual impact load obtained through the load analysis test conducted in the previous studies. The size of specimen was set up as height 2.4m and width 3.0m. Test apparatus and test methods were referred to BS 5234-2:1992. However, the loading level applied to the specimen was divided into 3 steps (3000N, 1000N, 500N) that can be applied selectively depending on the purpose of the wall. The deformation characteristics according to the same loading level were vary depending on the specimen's type, and the evaluation criteria for functional damage may vary depending on the material, method of construction, and purpose of wall. Therefore, we did not suggest unified evaluation criteria of the stiffness to the test results.

• 한국의류학회지
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• 제27권8호
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• pp.992-1003
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• 2003

This study analyzes the actual state of the working uniforms worn by burning waste workers to protect their body from the hazardous environment. Directions for improvement of the clothing fabrics is also suggested. We visited and interviewed those persons who worked in the burning waste plant in Seoul and in Gyunggi Province. 245 workers were surveyed by questionnaires, and 211 workers out of 245 were statistically analyzed. Frequencies and percentages were calculated and $\chi$$^2$ test, ANOVA and Scheffe Post hoc comparison methods were utilized to test some hypothesis. The working uniforms were classified as four general types: separate type, disposable-coverall. overall, and winter clothes. At present, the working uniforms are not suitable for the conditions which they are used. There is a lack of ventilation and an inability to absorb perspiration limited elasticity, and the uniforms are prone to static shock. The degree of satisfaction varied significantly, based on the worker's educational background and main work. However, only a small percentage of workers interviewed were satisfied with the appearance and the fit of the present working uniforms. The working duration had a negative impact on the satisfaction of the worker. This results suggest that materials, colors, design and size of working clothes must be improved. The suggestions are as follows: Firstly. to use disposable non-woven fabrics finished to increase moisture regain. Secondly. to use the bad air permeability fabrics to protect the skin from absorbtion of harmful gases, flying dust, heavy metals, etc.

• 한국지반공학회논문집
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• 제27권5호
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• pp.61-74
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• 2011

본 연구는 석탄회와 폐타이어, 그리고 두 재료의 혼합재료 등 경량 폐기물의 성토재 활용을 위한 기본적인 연구로서, 이들 재료의 입도분포, 비중, 다짐밀도, 전단강도, 투수특성 등 기본물성 및 지반공학적 물성 평가를 위한 실험을 수행하였으며, 현장 조건에 따른 함수비와 온도변화를 고려한 1차원 압축 침하특성 등을 평가하였다. 석탄회 재료의 경우 대표적인 성토재료인 풍화토와 유사한 입도분포를 가지면서, 경량의 특정을 확인할 수 있었다. 그러나 강도측면에서는 풍화토와 유사한 수준을 보이고, 투수특성은 입도에 따라 매우 큰 차이를 나타냈다. 폐타이어가 포함된 재료들의 경우에도 강도값은 성토재로 충분한 값을 보였다. 이들 재료의 1차원 수직압축특성 실험 결과에서도 일정 수직응력 수준 하에서는 모래와 유사한, 비교적 압축성이 낮은 재료로 평가할 수 있었으며, 함수비변화와 반복적인 동결융해조건 하에서는 석탄회가 포함된 재료들이 풍화토 및 풍화토-폐타이어 혼합재료에 비해 낮은 압축침하거동을 보였다.

• KIEAE Journal
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• 제7권2호
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• pp.71-76
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• 2007

For the many years the children's running noise has caused perpetual frictions between neighbors in apartment houses. For this reason the government established a regulation to reduce the floor impact noise, as a result almost all apartment houses have been enforced to use the floor structure with 210mm thickness concrete slab and 120mm thickness of floor heating system since July 2005. If do not want to apply this kind of system, a system which obtain the certification from the institution appointed by government must be applied. In this reason a lot of construction material companies and construction companies have been trying to develop the system with 180mm thickness concrete slab for the purpose of reducing the cost. To develop the optimized floor system, actual size test building were constructed and the materials related with reducing floor impact noise were composited and tested in the test building. Through this procedure the most effective system was found.

• 대한안전경영과학회지
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• 제18권1호
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• pp.65-73
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• 2016

In this paper which was performed to bring public attention to the need for developing an photoelectric smoke detector that detects smokes emitted from diverse fire sources, it was confirmed that the photoelectric smoke detector may not respond to certain smoke types depending on the size and color of smoke particles. The test was performed on a photoelectric smoke detector which is being used generally for specific fire targets specified in UL268, including paper fire, wood fire and flammable liquid fire, while the actual response performance of the fire detector, as well as respective smoke particles collected from different fire source which were photographed with a SEM(Scanning electron microscope) were analyzed in the test for this study.

• 제어로봇시스템학회논문지
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• 제10권4호
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• pp.357-363
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• 2004

Earlier models of card vending machines have generally motion drives with high cost and large size. However, current trend in card vending machines requires low-cost, compact-sized and readily installable motion drives. This paper shows the operational principle of the motion drive of a card vending machine and then presents the performance test results of the motion drive with improved mechanisms proposed in the paper. The results show that the proposed mechanism is valid and improves the card dispensing performance. The proposed model in the paper is accepted and introduced in the actual production line.