• 한국소음진동공학회논문집
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• 제15권1호
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• pp.72-80
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• 2005

Recent studies have dealt with brake squeal in terms of the coupled vibration of brake component parts. In this paper, we assemble the mode models derived from FE analysis of the individual components of the drum brake system into the system model by considering the friction interaction of the lining and drum at the interface. The validity of the component models are backed up by the experimental confirmation work. By scrutinizing the real parts of the complex eigen-values of the system, the unstable modes, which may be strong candidate sources of squeal noise, are identified. Mode participation factors are calculated to examine the modal coupling mechanism. The model predictions for the unstable frequencies pointed well the actual squeal noise frequencies measured through field test. Sensitivity analysis is also performed to identify parametric dependency trend of the unstable modes, which would indicate the direction for the squeal noise reduction design. Finally, reduction of the squeal noise tendency through shape modification is tried.

• 한국전기전자재료학회논문지
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• 제27권4호
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• pp.244-249
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• 2014

In this research, it have developed a sensor that could diagnose inner deterioration of covered wires. With this sensor it observed results from simulation, and the attribute required for realization. For simulation it have used FLUX, it have considered all of geometric and electromagnetic information from coil and base metal that influences eddy current sensor's property in order to predict the final result. It assumed there is no mutual inductance in the coil with N number of turns, because equivalent current flows in coil that is continuously connected in eddy current sensor. It assumed circular coil loop draws a circle, always have self inductance, and they are connected in series and overlapped according number of turns (N) in coil, and bobbin configuration. Actual sensor was produced with consideration of inductance and number of turns (N). In conclusion, it were able to test the dependency through results from simulation, actual measurement, and modeling of simulation. It is considered that attributes of respective base metal and structure can be predicted by simulating in advance.

• 대한기계학회논문집A
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• 제33권10호
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• pp.1158-1162
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• 2009

Fatigue limit of the copper film coated by Sn was estimated using Goodman diagram and Gerber diagram. To obtain the high cycle fatigue life curve, S-N curve, of the film, the high cycle fatigue test was carried out by applying the constant amplitude load to the film specimen with three different stress ratio of 0.05, 0.3 and 0.5 and the frequency of 40 Hz at room temperature in air. The free-standing film specimen 15.26${\mu}m$ thick was fabricated by etching process. The fatigue limits and S-N curves at the respective stress ratios were determined from the experimental works. It was shown that the S-N curves were dependent on the stress ratio and the fatigue limit was increased with decreasing the stress ratio. The dependency of the fatigue behavior was presented in empirical relationship. Using these relationships, the fatigue limit was predicted.

• 대한기계학회논문집A
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• 제27권1호
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• pp.200-207
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• 2003

In this paper, the effect of the compressive residual stresses which were obtained under the various shot velocities of shot balls on the fatigue behaviors of a spring steel, were investigated. The examination of CT specimen test were executed with the materials(JISG SUP9) which are being commonly used for the springs of automotive vehicles. As a result, the optimal shot velocity of shot balls were acquired considering the peak values of the compressive residual stresses on the surface of specimen and effect on the speed of the fatigue crack propagation da/dN in stage II and the threshold stress intensity factor range Δ$K_{th}$ in stage I. Also the material constant C and the crack propagation index m in the formula of paris law da/dN= C $({\Delta}K^m)$ were suggested in this work to estimate the dependency on the shot velocity.

• Journal of Microbiology and Biotechnology
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• 제15권6호
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• pp.1164-1169
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• 2005

Characteristics of sophorolipid and rhamnolipid were evaluated as antifungal agents against plant pathogenic fungi. Eight percent of mycelial growth of plant pathogen (Phytophthora sp. and Pythium sp.) was inhibited by 200 mg/l of rhamnolipid or 500 mg/l of sophorolipid, and zoospore motility of Phytophthora sp. decreased by $90\%$ at 50 mg/l of rhamnolipid and $80\%$ at 100 mg/l of sophorolipid. The effective concentrations for zoospore lysis were two times higher than those of zoospore motility inhibition. The highest zoospore lysis was observed with Phytophthora capsici; $80\%$ lysis at 100 mg/I of di-rhamnolipid or lactonic sophorolipid, showing the dependency of structure on the lysis. In the pot test, the damping-off disease incidence ratio decreased to $42\%\;and\;33\%$ of control value at 2,000 mg/l sophorolipid and rhamnolipid, respectively. These results showed the potential of microbial glycolipid biosurfactants as an effective antifungal agent against damping-off plant pathogens.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2001년도 추계학술강연 및 발표대회
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• pp.46-46
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• 2001

The microstructure of the 1020 mild steel target in the region ahead of craters, made by colliding against Cu and W-Cu shaped-charge jets. has been investigated in the present work. The region ahead of the crater impacted by the Cu shaped-charge jet reveals grain refinement implying the formation of sub-grains, while that of W-Cu one leads to martensitic transformation indicating that the region was heated up to an austenitic region which was followed by rapid cooling. The pressure of W-Cu shaped-charge jet impacting against the target when calculated is higher than that of Cu one. The microhardness of the region ahead of the crater impacted by the W-Cu shaped-charge jet is also higher than that of the Cu one. The microstructure of W-Cu slug that remains inside of the crater depicts the occurrence of the remarkable elongation of W particles during the liner collapse. The microstructural evolution of the region ahead of the crater is discussed on the basis of the pressure dependency of the ferrite/austenite transformation in the steel.

• Journal of Applied Biological Chemistry
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• 제42권1호
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• pp.19-24
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• 1999

Plants have been shown to contains $Ca^{2+}$/calmodulin-stimulated GAD and NAD kinase. To test how calmodulin and calmodulin methylation affect the activation of GAD and NAD kinase, GAD and NAD kinase were partially purified from tobacco plants. GAD was also partially purified from E. coli transformed with a plasmid carrying a cloned tobacco GAD gene. We find that GAD from the transformed E. coli showed 60-fold $Ca^{2+}$/calmodulin-dependent activation. However, GAD from tobacco plants was stimulated only about 3.8-fold by the addition of calmodulin in the presence of calcium, suggesting high background activity of the enzyme was possibly due to bound endogenous tobacco calmodulin. There were no significant differences in the tobacco GAD activator properties between calmodulins. A monoclonal antibody against petunia GAD interacted strongly with both GAD from tobacco plants and GAD from cloned gene. NAD kinase from tobacco plants showed a complete $Ca^{2+}$/calmodulin dependency for activity. Unmethylated calmodulins activated GAD in a manner similar to methylated calmodulin. However, the maximum level of NAD kinase activation obtained with unmethylated calmodulins is approximately 4-fold higher than methylated calmodutins. These data suggested that endogenous tobacco calmodulin may interact more tightly with GAD than NAD kinase and that calmodulin methylation affects the activator properties of calmodulins for tobacco NAD kinase but not for GAD.

• 한국생활과학회지
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• 제15권1호
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• pp.129-139
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• 2006

The purpose of this study is to compare the hairstyles between Korean and Australian women, who have different individual hair characteristics, social backgrounds, and culture from each other. Data were collected through a survey of 208 Australian females and 392 Koreans. Frequency analysis, t-test, and two-way ANOVA were used to analyze the data. The results are as follows: Korean and Australian women maintain a hairstyle for six months or less in most of the cases. They preferred a hairstyle with bang, and the elderly especially a shorter hair length. Choosing their hairstyles depended on such factors as hair length, dyeing, form of face, harmony with clothing, and social status. There was no difference, however, in a preferred hair length. Korean women possessed brown and black hair colors in a descending order, whereas Australians light blonde and brown in a descending order as well. There was a big difference in the preference for a permanent wave. Korean women preferred to give a volume or curl to their hair, while Australians wanted to have a straight hair. According to the study on a hairstyle behavior, it was found that there were differences in fashion and individuality between two countries and also in dependency among age groups, whereas no differences existed in beauty.

• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제5권8호
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• pp.377-384
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• 2016

본 연구의 목적은 트위터에서 수집된 트윗들의 감성을 분석하고 각 문장의 감성 정보를 반자동으로 부착하여 감성 말뭉치를 구축할 수 있는 시스템의 구현이다. 트위터 API를 이용해 트윗을 수집한 후 각 트윗이 어떤 감성을 갖는지 감성사전을 이용해 분석한다. 사용자는 감성 분석 결과를 확인하고 누락된 감성 정보를 추가하거나 의존구조 사이에 존재하는 감성 정보를 추가할 수 있다. 감성 정보는 JSON 구조로 부착함으로써 감성 말뭉치 구축 및 활용에 용이하게 하였다. 제안 시스템은 긍정, 부정, 중립 문장에 대한 감성 분석 결과 약 76%의 성능을 보였다.

• 한국철도학회논문집
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• 제12권1호
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• pp.81-87
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• 2009

최근의 컴퓨터 기술의 발달에 따라 열차제어시스템들이 컴퓨터 소프트웨어에 의존성이 더욱 증가되고 있으며, 이에 따라 이러한 열차제어시스템 소프트웨어의 안전성에 대한 테스팅이 더욱 중요하게 되었다. 본 논문에서는 이러한 열차제어시스템 소프트웨어를 위한 코딩규칙의 테스팅 자동화 도구의 적용을 제안하였으며, 코딩규칙 테스팅 자동화 도구의 구현 및 적용결과를 제시하였다. 구현 툴에서의 테스팅 항목은 철도시스템 소프트웨어 관련된 국제규격과 MISRA-C 기준을 참조하였다. 본 열차제어시스템 테스팅 자동화 도구는 열차제어시스템 소프트웨어 평가단계에서도 활용될 수 있고 또한 소프트웨어 개발단계에서도 유용하게 활용될 수 있을 것으로 예상된다.