• 한국감성과학회:학술대회논문집
• /
• 한국감성과학회 1999년도 춘계학술발표논문집 논문집
• /
• pp.153-157
• /
• 1999

Voigt Model assumed for creep was used to obtain the viscoelastic properties of fabrics in thickness direction and the governing equation was derived. The weights were specially designed and calibrated for constant stress applied to fabrics and the 1 ${\mu}{\textrm}{m}$ resolution laser displacement sensor was attached in order to measure the variation of strain. Ten fabric samples were used. The few steps of strain showed according to the internal structure of fabrics. Also correlations the Hand Values from KESF with the spring and damping coefficients were considered.

• 한국자동차공학회논문집
• /
• 제4권1호
• /
• pp.75-85
• /
• 1996

The gas pressure acting on the rings in internal combustion engine influences the friction, wear and HC emission. In order to understand their characteristics, it is necessary to measure the interring gas pressure during engine operations. In this study, miniature type pressure transducer was developed to measure inter-ring gas pressure. And measurements of cylinder and inter-ring gas pressure were made on a gasoline engine running at full and part load conditions. Finally the characteristics of inter-ring gas pressure variation during engine operation were obtained form analysis of measured date.

• 한국정밀공학회지
• /
• 제8권2호
• /
• pp.89-105
• /
• 1991

A method to apply the approximation formulae[1] for tooth fillet and root stresses of a thin-rimmed rack to the calculation of stress state of thin-rimmed external and internal spur gears is introduced. The stress values by the method proposed in this paper have shown good agreement with those by the REM analysis and also by the stress measurement of strain survey investigation. By this method, reliable stress state at tooth fillet and root areas in the thin-rimmed external and internal spur gears can be easily calculated, and a practical design method for the bending strength of such thin-rimmed gears is established.

• 한국정밀공학회지
• /
• 제29권1호
• /
• pp.48-55
• /
• 2012

Pressure vessels in vehicle industries, power plants, and chemical industries are often affected by flaw and defect generated inside the pressure vessels due to production processes or being used. It is very important to detect such internal defects of pressure vessel because they sometimes bring out serious problems. In this paper, an optical defect detection method using digital shearography is used. This method has advantages that the inspection can be performed at a real time measurement and is less sensitive to environmental noise. Shearography is a laser-based technique for full-field, non-contacting measurement of surface deformation (displacement or strain). The ultimate goal of this paper is to detect flaws in pressure vessels and to measure the lengths of the flaws by using unwrapping, phase images which are only obtained by Phase map. Through this method, we could decrease post-processing (next processing). Real length of a pixel can be calculated by comparing minimum and maximum unwrapping images with shearing angle. Through measuring several specimen defects which have different lengths and depths of defect, it can be possible to interpret quantitatively by calculating gray level.

• 비파괴검사학회지
• /
• 제26권5호
• /
• pp.321-328
• /
• 2006

본 논문에서는 전단간섭계를 이용하여 감육 곡관부의 변형을 계측하고 내부 감육 결함의 위치를 찾고자 하였다. 전단간섭법은 비파괴검사(NDT)와 응력/변형률 해석에 적용되어왔던 광학적 방법의 한가지이다. 이 기술은 간섭계에서 tilt mirror를 조작함으로써 조절이 가능한 민감도를 갖는 변위의 1차 도함수를 직접 측정할 수 있다는 이점을 지니고 있다. 본 논문에서는, 국부적으로 감육이 발생한 탄소강 곡관부에 대해 실험하였으며, 전단간섭법을 곡관부의 변형량 측정과 내부 감육결함 검사에 적용하였다. 실험 결과로부터, 이 기술이 내부 결함이 있는 배관부에도 적용이 가능함을 확인하였다.

• 대한한방내과학회지
• /
• 제34권3호
• /
• pp.278-288
• /
• 2013

Objectives : Methicillin-resistant Staphylococcus aureus (MRSA) has a cephalosporin and beta-lactam antibiotic-resistant strains. MRSA is one of the major pathogens causing hospital infection and the isolation ratio of MRSA has gradually increased. Consequently, increased resistance to antibiotics is causing serious problems in the world. Therefore, there is a need to develop alternative antimicrobial drugs for the treatment of infectious diseases. Methods : The antibacterial activities of Ipyo-san were evaluated against 2 strains of MRSA and 1 standard Methicillin-susceptible staphylococcus aureus (MSSA) strain by using the disc diffusion method, minimal inhibitory concentrations (MIC) assay, colorimetric assay using MTT test, checkerboard dilution test and time-kill assay performed under dark. Results : The MIC of Ipyo-san water extract against S. aureus strains ranged from 1000 to $2,000{\mu}g/ml$, so we confirmed that it had a strong antibacterial effect. Also, the combinations of Ipyo-san water extract and conventional antibiotics exhibited improved inhibition of MRSA with synergy effect. We suggest that Ipyo-san water extract against MRSA has antibacterial activity so it has potential as alternatives to antibiotic agents. For the combination test, we used Triton X-100 (TX) and DCCD for measurement of membrane permeability and inhibitor of ATPase. As a result, antimicrobial activity of Ipyo-san water extract was affected by the cell membrane. Conclusions : We suggest that the Ipyo-san water extract lead the treatment of bacterial infection to solve the resistance and remaining side-effect problems that are the major weak points of traditional antibiotics.

• 한국구조물진단유지관리공학회 논문집
• /
• 제5권2호
• /
• pp.111-120
• /
• 2001

This paper aims at estimating instantaneous prestress losses by measuring the actual prestress forces in prestressed concrete (PSC) box girder bridges. Measurement were taken to study initial prestress losses such as friction losses and slip losses. A new strain gauge system was developed to measure strains in internal tendons. The system was installed on a total of 20 tendons in a PSC box girder bridges. The variation of prestress forces were monitored during prestressing tendon and after prestress transfer. The prestress losses are also calculated including friction losses and slip losses. The measured data were compared with the theoretical values. The result shows that the measured prestress forces agree well with the theoretical values. It is shown that prestress force of each strand in the same tendon is a bit different. This study also shows that prestress losses of continuity tendons during prestress transfer are significantly different each other, which results from the variety of buttress location and tendon profile. The present study provides realistic information on the estimation of actual prestress forces and losses in PSC box girder bridges.

• 대한기계학회논문집A
• /
• 제36권2호
• /
• pp.217-221
• /
• 2012

노트북용 액정 모듈 내부의 광학 시트(Optical Sheet) 변형에 기인한 시인성 품질 불량을 개선하기 위한 기초 연구의 일환으로 변형 유발의 요인인 온도 및 습도의 영향을 분석할 수 있는 측정 시스템이 필요하였다. 액정 모듈 내부에는 0.5mm 미만의 미세한 공기 층이 존재하는데, 이 공간으로 외부의 습한 공기가 내부로 확산되는 것으로 추정된다. 이러한 현상을 규명하기 위하여 초소형 온도 및 습도 센서를 실장한 초박형 센서 PCB 를 액정 모듈 내부에 삽입하여 실시간으로 온/습도 변화를 측정 및 분석하였으며, 향후 변형 거동 시뮬레이션 및 구조 설계 시 필요한 기초 데이터로 활용하고자 한다.

• 대한기계학회논문집A
• /
• 제24권11호
• /
• pp.2688-2695
• /
• 2000

In multi-axis force sensor, compliance matrices representing structural behaviour of internal sensor bodies play an important role in decoupled sensing and accuracy, Recently, error propagation through compliance matrices has been studied via approximation approach. However the upper bound of measured force error has not been known. In this paper, error propagation in force sensing is analysed in a unified way when both strain measurement error and compliance matrix error exist, and the upper bound of the measured force error is derived exactly(not approximately). The analysis is examined through a numerical example.

• 대한수의학회지
• /
• 제29권4호
• /
• pp.503-515
• /
• 1989

Critical parameters affecting sensitivity and specificity of an enzyme-linked immunosorbent assay(ELISA) for detection of antibodies to avian infections bronchitis virus(IBV) were standardized. By adopting the optimized conditions an equation calculating ELISA antibody titers from the observations at single serum dilution was formulated. The purified antigen of IBV Mass-41 strain was dispensed into polystyrene microplate wells at a concentration of 300ng per well($100{\mu}l$) and the plates were coated by completey drying at $37^{\circ}C$. Diluted chicken serum and horseradish peroxidase conjugated goat anti-chicken IgG were added in order in $100{\mu}l$ volumes per well and allowed to react for 30 minutes each at room temperature. Just before use and after each reaction the plates were washed three times with distilled water. Finally o-phenylenediamine solution was added as an enzyme substrate. After incubation for another 15 minutes at room temperature absorbances were read at 492nm. Hyperimmune serum against Mass-41 strain was used as internal reference positive(IRP) serum. After repeated titration of IRP and negative serum, a constant titer of IRP was determined. Serum titrations were carried out for various sample sera together with IRP and negative sera and the observed titers of sample sera were corrected by reflecting the ratio between observed and constant titers of IRP serum. These corrected titers of the sample sera were plotted against sample/positive(S/P) OD ratios. All the OD's measured in the serum titrations were also corrected by substracting negative serum OD. The following equation was formulated from the above data; $Log_{10}$ ELISA titer=$5.568({\log}_{10}S/P)+4.161$ Thus it was possible to calculate ELISA titer by measuring absorbance at 1/400 single serum dilution. Titer measured by cross ELISA tests employing Mass-41 strain and three local IBV isolates were similar. These results suggest that the ELISA tests standardized in this study can be used for evaluating not only vaccinal immunity but also for infection status against fields IBV's.