• 한국재료학회지
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• 제17권8호
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• pp.433-436
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• 2007

Nano-structured polyaniline have been synthesized by interfacial polymerization method at room temperature. An aqueous solution of aniline in chloroform and another solution of ammonium peroxydisulfate in doping acid were prepared at different times terminated with methanol at room temperature. SEM, UV-vis were used to characterize the polyaniline with regard to their morphology and structure. The diameter and length of polyaniline can be controlled by the reaction time. Nano-structured polyaniline were found to have superior sensitivity for volatile organic compounds(VOCs). As the reaction time to increase from 30minute to 2hours the sensitivity were decreased to VOCs vapors. The sensitivity of Nano-structured polyaniline sensor appeared to VOCs better than the sensitivity of chemical synthesis sensors. The sensitivity of Nano-structured polyaniline sensor improved benzene vapors.

• 산업경영시스템학회지
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• 제18권36호
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• pp.31-39
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• 1995

This study reflected sensitivity cognition in using color and evaluated the performance in task regarded GUI environment. Largely, three experiments were conducted. First, the searching time in text environment was compared with the searching time in color environment. Second, to know relationship of hue, saturation, lightness which are factors of color, and searching time, the searching time was measured using two-way ANOVA with interaction with three independent variables: hue, saturation, and distance. Third, sensitivity cognition about color was investigated and the performance of searching task was analyzed in the environment designed by color regarded sensitivity cognition. According to statistical results, the average searching time was decreased about 50.31% in color environment. The searching time was significant among the difference of hue and saturation. For the factor of color, the more the ratio of green and red was increased, the more searching time was decreased. The more the ratio of gray was increased, the more searching time was increased. And the searching time was developed in the environment designed by color regarded sensitivity. The purpose of this study is the presentation of sensitivity realization method and verification in the reflection and application of sensitivity to the industrial environment and design.

• 한국정밀공학회지
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• 제23권8호
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• pp.54-63
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• 2006

Enhancement methods of sensitivity to in-plane strain measurement by micro-ESPI(Electronic Speckle Pattern Interferometry) technique were proposed using TiN and Au thin films. Micro-tensile strain over the micro-tensile specimens, prepared in micro-scale by those films, was measured by micro-tensile loading system and micro-ESPI system developed in this study. The subsequent measurement of in-plane tensile strain in the micro-sized specimens was introduced using the micro-ESPI technique, and the micro-tensile stress-strain curves for these films were determined. To enhance the sensitivity to measurement of in-plane tensile strain, algorithms of the phase estimation by using curve fitting of inter-fringe and the discrete Fourier Transform with object-induced dynamic phase shifting were developed. Using these two algorithms, the micro-tensile strain-stress curves were generated. It is shown that the algorithms for enhancement of the sensitivity suggested in this study make the sensitivity to measurement of the in-plane tensile strain increase.

• 한국생산제조학회지
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• 제22권6호
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• pp.950-956
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• 2013

This paper describes a sensitivity-coefficient-based iterative method for detecting cracks in a structure. The sensitivity coefficients of a cracked structure are obtained by changing its eigenvectors. The proposed method is applied to a cracked cantilever. The crack is modeled as a rotational stiffness. The predicted cracks are in good agreement with those from a structural reanalysis of the cracked structure.

• 한국정밀공학회지
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• 제31권11호
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• pp.1041-1050
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• 2014

A design and analysis for new foot sensor that measures pressure distribution while walking or running in daily life is introduced. In the process of the sensor design, the shape, mechanism composing of the sensor, and variables that dominate sensor's sensitivity are investigated. Through these variables analysis, an optimal shape and dimension were determined. The effects of variables on sensor's sensitivity and the relationship between each variable are proved by analyses and experiments.

• International Journal of Precision Engineering and Manufacturing
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• 제2권3호
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• pp.54-60
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• 2001

A newly designed inductive micro displacement detecting system is presented. The proposed inductive system consists of driving coils, position-detecting coils, cores, and closed-loop formed magnetic blocks. The cores and magnetic blocks are made of Mn-Zn ferrite. When AC sine wave is applied to the driving coils, the time derivative flux is generated within the system, and then induced voltages arise in the position-detecting coils according to the core\`s position. Putting the cores to be moved proportionally to the input displacement, the induced voltage is proportional to input displacement. The parameters that affect the system characteristics are turn ratio, air-gap size, excitation frequency, overlap area, load resistance, capacitance effect, and so forth. Based on the experimental results, the system parameters are selected in such a way as to have high sensitivity ad stable responses. The sensitivity of the proposed inductive displacement-detecting system is greater than 2800mV.V-1mm-1 and the linearity error is below $\pm$0.10% in the range of $\pm$200㎛.

• Fibers and Polymers
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• 제5권3호
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• pp.239-244
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• 2004

Solution-cast films of polymethylmethacrylate (PMMA) and polyurethane (PU) containing polymeric styryl dye up to 5 % by weight were prepared to investigate their acid-sensitivity and mechanical and thermal properties. Original red samples due to styryl dye turned out yellow very rapidly as they were exposed to acid vapor of hydrochloric acid or p-toluenesulfonic acid. According to UV/VIS spectroscopic measurements, characteristic peak intensities near 430 nm and 520 nm increased or decreased relatively with exposed amounts of acid, respectively. Both PMMA and PU samples showed uniform color distribution due to a good miscibility between polymer and dye which can be evidenced by measurements of glass transition temperature. No significant difference in acid-sensitivity was found between PU and PMMA except relative absorbance. However, dependence of their mechanical properties on dye content was somewhat different with PU or PMMA. In case of PMMA, modulus and breaking stress increased up to about 50 % with increasing dye content, whereas those of PU samples showed only slight increase. It was ascribed to whether the matrix polymer was in the glassy or rubbery state.

• Structural Engineering and Mechanics
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• 제68권5호
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• pp.549-561
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• 2018

Sobol method is applied as a powerful variance decomposition technique in the field of global sensitivity analysis (GSA). The paper is devoted to increase convergence speed of the extracted Sobol indices using a new proposed sampling technique called genetic based Latine hypercube sampling (GBLHS). This technique is indeed an improved version of restricted Latine hypercube sampling (LHS) and the optimization algorithm is inspired from genetic algorithm in a new approach. The new approach is based on the optimization of minimax value of LHS arrays using manipulation of array indices as chromosomes in genetic algorithm. The improved Sobol method is implemented to perform factor prioritization and fixing of an uncertain comprehensive high speed rotor-bearing system. The finite element method is employed for rotor-bearing modeling by considering Eshleman-Eubanks assumption and interaction of axial force on the rotor whirling behavior. The performance of the GBLHS technique are compared with the Monte Carlo Simulation (MCS), LHS and Optimized LHS (Minimax. criteria). Comparison of the GBLHS with other techniques demonstrates its capability for increasing convergence speed of the sensitivity indices and improving computational time of the GSA.

• Korean Chemical Engineering Research
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• 제49권4호
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• pp.387-392
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• 2011

생촉매인 효소의 기질선택성은 다양한 분야에서 유용하게 이용되고 있다. 그 중에서도 효소결합면역흡착검사(enzyme-linked immunosorbent assay, ELISA)는 항원항체의 결합을 항체와 공유결합된 효소의 반응으로 나타냄으로써 다양한 항원들의 진단을 가능케 했다. 하지만 기존의 효소결합면역흡착검사는 하나의 항체당 하나의 효소가 결합된 형태이기 때문에 감도(sensitivity)의 증가 폭에 그 한계가 있으며, 이를 극복하기 위한 방안으로 하나의 항체당 결합된 효소의 수를 증가시킴으로써 혁신적인 감도의 향상을 가져오는 연구가 진행되었다. 최근 나노바이오촉매(nanobiocatalyst, NBC) 접근방식을 이용한 효소활성의 안정화는 효소결합면역흡착검사의 감도 향상뿐만 아니라 그 성능의 안정성을 확보할 수 있는 연구결과로 이어지고 있다. 본 총설에서는 일반적인 효소결합면역흡착검사의 기본적인 원리와 감도향상을 위한 연구, 그리고 성능안정성(performance stability)을 향상시키기 위한 나노바이오촉매-결합면역흡착검사(Nanobiocatalyst-Linked Immunosorbent Assay, NBC-LISA)에 대하여 살펴보고자 한다.

• 한국전산구조공학회논문집
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• 제27권4호
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• pp.297-303
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• 2014

페리다이나믹스 이론과 이진분해 기법의 병렬연산을 이용하여 동적 균열진전 문제에 대한 애조인 형상 설계민감도 해석법을 개발하였다. 페리다이나믹스에서는 균열의 연속적인 분기를 다룰 수 있으며, Explicit 시간적분법을 채택한다. 설계민감도 해석은 애조인 변수법은 경로의존성 문제에는 적합하지 않으나 여기서는 응답해석의 경로를 이미 알고 있으므로 채택하여 사용할 수 있었다. 얻어진 해석적 설계민감도는 유한차분과 비교하여 그 정확성을 검증하였다. 유한차분법은 설계섭동량에 민감하여 비선형성이 강한 페리다이나믹스 문제에서 부정확한 설계민감도를 제시할 수 있다. 정확한 설계민감도 해석을 위해서는 이산화과정에서 $C^1$ 연속성을 가지는 체적율이 필요함을 알 수 있었다.