• 대한건축학회논문집:구조계
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• 제34권1호
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• pp.53-60
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• 2018

For test on flooring board laminated with PVC decoration materials in order to replace the current surface materials such as HPL in decoration wood-based flooring board. the Results of comparison and analysis are as follows: For thermal conductivity, flooring board decorated with PVC did not show huge differences when temperature was rising and lowering compared to the flooring materials laminated with the existing HPL surface materials. It seems the most meaningful results for using it as indoor flooring materials. That is, in Korea where there is the culture focusing on ondol heating, use amount of heat energy and efficiency of flooring materials are very important and sensitive issues, involving immediately with household economy of final consumers, and it might be a criteria to judge basic performances required as flooring materials. As a result of the analysis on mandatory durability test items such as abrasion resistance, absorption width expansion rate, impact resistance, surface hardness, and impact absorption for flooring materials, compared to flooring board laminated with general HPL surface decoration materials, decoration wood-based flooring board laminated with PVC surface decoration materials which is higher abrasion resistance with smaller transformation and has better durability and impact absorption of the surface, is available for actual application as indoor flooring board, and for replacing surface decoration materials impregnated with heat-hardened resion such as HPL.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2005년도 추계학술대회 논문집
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• pp.295-298
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• 2005

This paper is concerned with the precision material property measurement of a micro metal thin foil that is used in MEMS technology. Since these MEMS components require great precision and accuracy, evaluation of reliability such as the lift cycle endurance test, impact test, and residual stress test is necessary for these components. However, in practice, real reliability tests are not easy to perform due to consideration of various factors. Rather than actual testing, it would be much easier to evaluate the reliability of components by the analytical approach. Although the analytical method is utilized by software tools, it is obviously necessary to acquire fundamental properties of materials through real test methods. In this paper, the oriented mechanical properties of aluminum thin foil are measured by nano scale material property measurement system.

• 한국환경농학회지
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• 제36권4호
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• pp.288-292
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• 2017

BACKGROUND: Silicon tetrachloride reacts with moisture in the atmosphere to generate hydrogen chloride, which affects the environment. Since silicon tetrachloride and its by-products are dispersed in the atmosphere in a short time after the silicon tetrachloride release into the atmosphere, it is difficult to directly assess the extent of environmental impact. In the present study, the exposure test of silicon tetrachloride or hydrogen chloride was examined in order to establish the criterion of the range affected by the silicon tetrachloride release, and the actual crops in the area exposed to silicon tetrachloride leakage were analyzed. METHODS AND RESULTS: For the experiment of exposure to silicon tetrachloride or hydrogen chloride, the leaves of red-pepper and corn were used in glass sealed containers. In the actual accident area, 59 samples from 10 different kinds of crops were collected. The pretreatment of the sample was performed by freezing and grinding, and then extracted using distilled water. The pH and concentration of chloride ($Cl^-$) ion of the extracted solution were measured using pH meter and ion chromatograph, respectively. CONCLUSION: Exposure to silicon tetrachloride caused visible damage, increasing the concentration of chloride ion, and decreasing the pH as well as hydrochloric acid. In the actual crops of the affected area, the tendency was the same as the result of the laboratory test, and the range of influence could be estimated through the concentration of $Cl^-$ ion over 2,000 mg/kg, and the correlation evaluation between the concentration of $Cl^-$ and pH. Therefore, the concentration of $Cl^-$ ion and the correlation between $Cl^-$ and pH would be considered as the factors to estimate the influence range of silicon tetrachloride release.

• 한국콘텐츠학회논문지
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• 제10권6호
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• pp.175-187
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• 2010

본 연구의 목적은 웹페이지에서 제공하는 제품정보수준에 따른 소비자 행동의 차이를 조망하는 것이다. 연구를 위해 우리는 제품정보수준이 다른 2개의 웹페이지를 만들었다. 그 후, 학습효과를 제거하기 위하여 각각의 웹페이지를 다른 사람에게 보여준 후 응답을 받았고, 각 웹페이지당 178개와 162개의 응답을 얻었기 때문에, 개인의 편견이나 오류를 줄였다. 그 후 응답값을 토대로 제품정보수준이 다른 두 개의 웹페이지를 본 응답자들이 느끼는 유용성, 프라이버시, 소비자 태도, 실제행동간에 차이와 두 개의 모형간에 설정된 인과관계의 가중치에 차이가 있는가를 분석하였다. 본 연구의 결과는 다음과 같다. 첫째, 제품정보제공수준이 다른 두 개의 웹페이지에서 느끼는 변수간의 차이를 분석하기 위해 t-test를 실시하였다. 분석결과, 제품정보수준이 다른 두 개의 웹페이지를 본 응답자들이 느끼는 유용성, 프라이버시, 소비자 태도, 실제행동간에는 차이가 있었다. 둘째, 높은 제품정보를 제공하는 웹페이지와 낮은 제품정보를 제공하는 웹페이지 사이에 설정된 인과관계 가중치에는 차이가 있었다. 셋째, 제품정보수준은 유용성 및 프라이버시에, 유용성은 프라이버시, 소비자 태도, 실제행동에, 프라이버시는 소비자 태도와 실제행동에, 소비자 태도는 실제행동에 유의한 영향을 나타내었다.

• 대한조선학회논문집
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• 제57권6호
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• pp.322-330
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• 2020

This study deals with underwater explosion (UNDEX) characteristics of various non-explosive underwater shock sources for the development of non-explosive underwater shock testing devices. UNDEX can neutralize ships' structure and the equipment onboard causing serious damage to combat and survivability. The shock proof performance of naval ships has been for a long time studied through simulations, but full-scale Live Fire Test and Evaluation (LFT&E) using real explosives have been limited due to the high risk and cost. For this reason, many researches have been tried to develop full scale ship shock tests without using actual explosives. In this study, experiments were conducted to find the characteristics of the underwater shock waves from actual explosive and non-explosive shock sources such as the airbag inflators and Vaporizing Foil Actuator (VFA). In order to derive the empirical equation for the maximum pressure value of the underwater shock wave generated by the non-explosive impact source, repeated experiments were conducted according to the number and distance. In addition, a Shock Response Spectrum (SRS) technique, which is a frequency-based function, was used to compare the response of floating bodies generated by underwater shock waves from each explosion source. In order to compare the magnitude of the underwater shock waves generated by each explosion source, Keel Shock Factor (KSF), which is a measure for estimating the amount of shock experienced by a naval ship from an underwater explosionan, was used.

• 한국구조물진단유지관리공학회 논문집
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• 제19권4호
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• pp.18-24
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• 2015

콘크리트구조물의 진단에 사용되는 비파괴실험법들은 구조물에 손상을 입히지 않고 구조물의 결함이나 강도를 추정할 수 있다는 장점이 있지만 추정값에 대한 신뢰성이 떨어진다는 문제점이 있다. 본 연구에서는 이러한 문제점을 해결하기 위해 2가지 배합으로 총 180개의 공시체를 제작하였고, P파와 S파에 의한 초음파속도 측정, 종진동과 변형진동에 의한 충격공진법 총 4가지의 비파괴실험을 실시하였다. 그리고 실제압축강도 측정을 통해 비파괴실험 결과값의 신뢰성을 비교 분석하였다. 각 비파괴실험법의 결과값에 대한 통계적 분석결과 변동계수값이 가장 낮은 실험법은 S파에 의한 초음파속도법으로 가장 안정적인 관측이 가능한 것으로 나타났다. 한편, 실제압축강도와의 관계를 통해 압축강도 4개의 압축강도 추정식을 제안하였으며 S파에 의한 초음파속도법의 결정계수값이 가장 높은 것으로 나타났다. 향후 다양한 배합조건에 따른 비파괴실험 신뢰성에 대한 보완 연구가 필요할 것으로 판단된다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2008년도 춘계 학술논문 발표대회
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• pp.173-176
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• 2008

There are researches are in progress on ensuring the safety of the high impact concrete in cases of fire which is a current rising social problem and this research institute also developed PFB technology, the explosion preventing technology. PFB technology is to apply POSCO E&C Fire Board, a fireproof board, with an adhesive agent on the construction site, and this technology passed 3-hour fireproof test and this technology was proven from a previous research that the temperature of main root is maintained under 200 ℃. Therefore, tests on basic contents to be examined before the actual construction in this research by with a wooden prototype of a full scale to apply PFB technology to actual construction sites and tests are being done on the workability of fireproof board, the adhesive power, the resistance against imprint of wooden nail, the heat conductivity and etc. As the results of those tests, PFB technology was proven to have an excellent workability at a construction site and to be easy for processing and also this technology was proven to have a great the resisting power against imprint of wooden nail, so this research has confirmed that PFB technology has no problem to be applied on a construction site.

• 한국지하수토양환경학회지:지하수토양환경
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• 제8권3호
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• pp.74-85
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• 2003

지속적인 지하수개발 및 함양기술 사업의 일환으로 각종 암석에서 착정된 관정의 산출량을 증대시키기 위해서 12개소의 우물에 인공수압파쇄시험을 실시하였다. 시험정은 쥬라기 화강암 4개 지역에서 5공, 백악기 화산암 2개 지역에서 2공, 백악기 퇴적암 3개 지역에서 4공, 그리고 선캠브리아기 편마암 지역에서 1공을 선정하였다 12공의 시험정에서 11공은 비양수량이 7％에서 366%까지 증대되었다. 단지 백악기 퇴적암 지역의 1공만이 단층점토의 폐색으로 비양수량이 43.4%정도 감소하였다. 4개소의 군정지역에서 시험결과는 시험정으로부터 5.4m에서 82.7m까지 영향을 미치는 것으로 나타나며, 인공수압파쇄의 영향으로 사후 대수성 시험시 관측정에서 강하 폭은 적어졌지만, 균형잡힌 수위강하현상을 보이고 있다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.352-364
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• 2007

It is essential to reduce track maintenance costs and to extend the periodic replacements of continuous welded rails based on accumulated passing tonnage. As recently train load decrease and rail joints wear down less, the periodic replacements of continuous welded rails can be extended. There are many kinds of rail damage like squat, head-check and corrugation. These can be taken nondestructive or naked eye test. So the periodic replacements of continuous welded rails based on accumulated passing tonnage were examine with focusing on a crack of rail bottom of continuous welded rail. Therefore, this study measure dynamic response of track by metro train load, it compute impact coefficient and track spring coefficient for estimating a condition of actual track system. Also, it is converted the measured stress waveform into stress frequency histogram by the rain-flow counting methods, and then the equivalence of stress is calculated. As apply s-n curve of a new welded rail, accumulated fatigue damage ratio of laid rail and remaining service lives is estimated. This study suggest a plan of the periodic replacements of continuous welded rails based on accumulated passing tonnage classified by the types of track system.

• 한국분무공학회지
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• 제23권4호
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• pp.221-226
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• 2018

Despite the increasingly stringent automotive emissions regulations, the impact of vehicle emissions on air pollution remains large. In addition, since the issue of emission of more exhaust gas than the exhaust gas measured in the test room when the vehicle passing the exhaust gas regulation standard is run on the actual road, many countries studied and introduced gas regulations about Real Driving Emission using Portable Emission Measurement System. At present, Korea regulations restrict the number of NOx and PN in diesel vehicles. In the case of gasoline vehicles, there is no regulation on emission gas, but there is a problem of continuing automobile exhaust gas problems and a large amount of gasoline GDI vehicle's PN emission. So research and interest are increasing due to this problem. In this study, characteristics of exhaust gas depending on changes of ambient temperature were analyzed among various factors affecting exhaust gas measurement of gasoline vehicles. As a result, at the low temperature test, the lower the ambient temperature, the more the exhaust gas was emitted. At ordinary temperature test, no specific tendency was observed due to changes of ambient temperature.