• Title/Summary/Keyword: non-contact measurement

Search Result 494, Processing Time 0.025 seconds

Verification of Multi-point Displacement Response Measurement Algorithm Using Image Processing Technique (영상처리기법을 이용한 다중 변위응답 측정 알고리즘의 검증)

  • Kim, Sung-Wan;Kim, Nam-Sik
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.30 no.3A
    • /
    • pp.297-307
    • /
    • 2010
  • Recently, maintenance engineering and technology for civil and building structures have begun to draw big attention and actually the number of structures that need to be evaluate on structural safety due to deterioration and performance degradation of structures are rapidly increasing. When stiffness is decreased because of deterioration of structures and member cracks, dynamic characteristics of structures would be changed. And it is important that the damaged areas and extent of the damage are correctly evaluated by analyzing dynamic characteristics from the actual behavior of a structure. In general, typical measurement instruments used for structure monitoring are dynamic instruments. Existing dynamic instruments are not easy to obtain reliable data when the cable connecting measurement sensors and device is long, and have uneconomical for 1 to 1 connection process between each sensor and instrument. Therefore, a method without attaching sensors to measure vibration at a long range is required. The representative applicable non-contact methods to measure the vibration of structures are laser doppler effect, a method using GPS, and image processing technique. The method using laser doppler effect shows relatively high accuracy but uneconomical while the method using GPS requires expensive equipment, and has its signal's own error and limited speed of sampling rate. But the method using image signal is simple and economical, and is proper to get vibration of inaccessible structures and dynamic characteristics. Image signals of camera instead of sensors had been recently used by many researchers. But the existing method, which records a point of a target attached on a structure and then measures vibration using image processing technique, could have relatively the limited objects of measurement. Therefore, this study conducted shaking table test and field load test to verify the validity of the method that can measure multi-point displacement responses of structures using image processing technique.

Experimental Study for Removing Lacquer Layer on Iron Surface by Nd:YAG Laser System (Nd:YAG 레이저를 이용한 철제 표면 옻칠 제거 실험 연구)

  • Park, Chang Su;Cho, Nam Chul;Hwang, Hyun Sung
    • Journal of Conservation Science
    • /
    • v.32 no.3
    • /
    • pp.377-384
    • /
    • 2016
  • There are physical and chemical method for removement of a lacquered layer existing on the surface when gilding an iron Buddha, these caused environmental pollution by surface degradation and is very noxious for conservation scientist's health. Thus, on this study, we conducted a lacquered layer removement experiments using Nd:YAG Laser which is contactless and eco-friendly. Specimens were made by polishing $5{\times}5$ size of iron(99.9%) specimens surfaces evenly and by differing of number of coating of unrefined lacquer, so there were thickness differences of $10{\mu}m$, $20{\mu}m$, and $30{\mu}m$. The laser machine used in this study was Nd:YAG Laser, and we used two wavelength modes; 1064 nm(160~180 mJ) for infrared light region and 532 nm(50~350 mJ) for ultraviolet light region. The experiment done by investigating the transition of specimens' surfaces with laser wavelength, energy, and numbers of investigation. The remain amount of lacquered layer surfaces before/after laser irradiation was investigated by stereoscopic microscope, observation by SEM, Non-contact Surface Roughness Measurement Device, and FT-IR etc. As a result of each analysis, we could verify the thickness of $10{\mu}m$, $20{\mu}m$ of lacquered layer removed without surface degradation when using 1064 nm wavelength with $1.0J/cm^2$ density. We could find out that Nd:YAG Laser is effective for removing remained lacquered layers when gilding an iron Buddha. In the future, when not only the metal has made various studies also wood lacquered furniture or the like, it seems to be utilized to remove the lacquer without surface damage.

A Study of the Variation Factors of Intraocular Pressure (안압 변동 요인에 관한 연구)

  • Kim, Sang-Moon
    • Journal of Korean Ophthalmic Optics Society
    • /
    • v.13 no.1
    • /
    • pp.131-135
    • /
    • 2008
  • Purpose: To measure and quantify the factors of intraocular pressure (IOP) variation for normal Korean youth. Methods: The IOP of normal youth 805 persons (male: 367, female: 438) were measured as a function of time and quantity for fixation, reclining posture, hard blinking, drinking water, drinking hard liquor, tobacco and coffee by using non-contact tonometer (AT555, Reichert Co.). In the case of fixation, reclining posture and hard blinking, the intraocular pressure of right and left eye were measured for 6 males and 6 females every 10 minutes during 30 minute. In the case of water, liquor, tobacco and coffee, the measurement for 4 or 5 groups (6 persons/ group) having similar IOP were done for the IOP variation of right eye. Results: The mean IOP was 15.2 mmHg for males and 15.8 mmHg for females (slightly higher than male's), respectively and the 99% of those were in the range of the normal IOP. The measured IOP was increased by fixation, reclining posture and hard blinking with males and females. The gradient of increasing slope was 0.15/0.13/0.07/0.08, 0.09/0.08/0.08/0.08 and 0.19/0.08/0.26/0.31, respectively. The IOP variation was elevated by drinking water (especially in the case of 1000 ml) and lowered in proportion to the amount of drinking by hard liquor. Cigarette smoking was associated with rise in intra ocular pressure, but was not shown a definite relation. And coffee had virtually no effect. Conclusions: Fixation, reclining posture, hard blinking and Tobacco caused a transient increase in IOP, but alcohol elicited a slight reduction in IOP overall.

  • PDF

Effects of Sm:Ba:Cu Composition Ratio on the Superconducting Properties of SmBCO Coated Conductor Prepared by using a Composition Gradient Method (SmBCO 초전도 선재 특성에 대한 Sm:Ba:Cu 조성비의 영향)

  • Kim, H.S.;Oh, S.S.;Jang, S.H.;Min, C.H.;Ha, H.S.;Ha, D.W.;Ko, R.K.;Youm, D.J.;Moon, S.H.;Chung, K.C.
    • Progress in Superconductivity
    • /
    • v.13 no.1
    • /
    • pp.7-11
    • /
    • 2011
  • The effects of Sm:Ba:Cu composition ratio in SmBCO coated conductor on their superconducting properties were investigated. The SmBCO coated conductors were fabricated by reactive co-evaporation method using EDDC(Evaporation using Drum in Dual Chamber) system. In this system, we could obtain various samples with different composition ratios in a batch by the technique providing composition gradient at deposition zone. From the specimens prepared by EDDC system, we found that composition ratio is uniform parallel to the drum axis, but gradient along the circumferential direction of the drum. We installed a shield having parallelogram open area between the deposition chamber and the evaporation chamber in EDDC system, and attached a 30 cm long template, which is parallel to drum axis, onto the drum surface. In this configuration, we could obtain SmBCO coated conductors having a gradient composition along the length of template. We measured the composition ratios and surface morphologies with periodic interval by SEM and EDAX, and confirmed the profile of composition ratio. We also measured critical current using non-contact Hall probe critical current measurement system and thereby could plot composition ratio vs. critical current. The maximum critical current was obtained, and the surface morphology with the shape of roof tile was observed at the corresponding composition ratio of Sm:Ba:Cu = 1.01:1.99:4.87. It was also found that composition ratio had an effect on not only critical current but also surface morphology.

A Comparison of Laser Flash and the Divided-bar Methods of Measuring Thermal Conductivity of Rocks (암석 열전도도 측정을 위한 Laser Flash Method와 Divided-bar Method 비교)

  • Oh, Jae-Ho;Kim, Hyoung-Chan;Park, Jeong-Min
    • Economic and Environmental Geology
    • /
    • v.44 no.5
    • /
    • pp.387-397
    • /
    • 2011
  • In this study, we conducted the study of the merits and demerits of the laser flash and the divided-bar methods for measuring the thermal conductivity of rocks and investigated applicability of the divided-bar apparatus which was developed by KIGAM. The laser flash method can measure thermal diffusivity, specific heat capacity, and thermal conductivity of rocks with even small thickness (< ~3 mm) in the high temperature range($25-200^{\circ}C$) in non-contact mode. For the laser flash method, samples must be uniform and homogeneous. In the case of the divided-bar method, the apparatus measures only thermal conductivity of rock samples at the room temperature. We measured thermal conductivities of 12 rock samples with low density and high porosity using two methods. In the laser flash method, there exist potential errors caused by the effect of pulse dispersion and reflection by various minerals and porosity in rock samples; the difference in thermal conductivity values measured on the front surface and the opposite surface ranges from 0.001 to 0.140 W/mK with the standard deviation of 0.003~0.089 W/mK, which seems to be caused by heterogeneity of rock samples. On the contrary, the divided-bar apparatus shows stable thermal conductivity measurements and relatively small measurement errors; the difference in thermal conductivity values, just as we applied to the laser frash method, is 0.001~0.016 W/mK with the standard deviation 0.001~0.034 W/mK. In turn, the divided-bar method can be applied to more thick samples that are more representative of bulk thermal conductivity.

Cell Patterning on Various Substrates Using Polyelectrolyte Multilayer and Microstructure of Poly(Ethylene Glycol) (다양한 기판 위에서 고분자 전해질 다층 막과 폴리에틸렌글리콜 미세 구조물을 이용한 세포 패터닝 방법)

  • Shim, Hyun-Woo;Lee, Ji-Hye;Choi, Ho-Suk;Lee, Chang-Soo
    • Korean Chemical Engineering Research
    • /
    • v.46 no.6
    • /
    • pp.1100-1106
    • /
    • 2008
  • In this study, we presented rapid and simple fabrication method of functionalized surface on various substrates as a universal platform for the selective immobilization of cells. The functionalized surface was achieved by using deposition of polyelectrolyte such as poly(allyamine hydrochloride) (PAH), poly(diallyldimethyl ammonium chloride) (PDAC), poly(4-ammonium styrene sulfonic acid) (PSS), poly(acrylic acid) (PAA) and fabrication of poly(ethylene glycol) (PEG) microstructure through micro-molding in capillaries (MIMIC) technique on each glass, poly(methyl methacrylate) (PMMA), polystyrene (PS) and poly(dimethyl siloxane) (PDMS) substrate. The polyelectrolyte multilayer provides adhesion force via strong electrostatic attraction between cell and surface. On the other hand, PEG microstructures also lead to prevent non-specific binding of cells because of physical and biological barrier. The characteristic of each modified surface was examined by using static contact angle measurement. The modified surface onto several substrates provides appropriate environment for cellular adhesion, which is essential technology for cell patterning with high yield and viability in the micropatterning technology. The proposed method is reproducible, convenient and rapid. In addition, the fabrication process is environmentally friendly process due to the no use of harsh solvent. It can be applied to the fabrication of biological sensor, biomolecules patterning, microelectronics devices, screening system, and study of cell-surface interaction.

Interaction of Schwann Cells with Various Protein- or Polypeptide-Coated PLGA Surfaces (다양한 단백질과 폴리펩타이드로 코팅된 PLGA 표면과 슈반세포와의 상호관계)

  • Park Ki-Suk;Kim Su-Mi;Kim Moon-Suk;Lee Il-Woo;Rhee John-M.;Lee Hai-Bang;Khang Gil-Son
    • Polymer(Korea)
    • /
    • v.30 no.5
    • /
    • pp.445-452
    • /
    • 2006
  • In this study, we investigated interaction of Schwann cells (SCs) with various cell-adhesive coated polymer surface. We used cell-adhesives that like a fibronectin (FN), fibrinogen(FG), laminin(LM), vitronectin (VN), poly-D-Iysine (PDL), and poly-L-Iysine (PLL) to coat PLGA film surface and evaluated the surface property of coated or not PLGA films by measurement of water contact angle and ESCA. SCs were cultured on coated or non-coated PLGA film surface, and then examined the cell adhesion and proliferation by cell count and SEM observation. Cell count results revealed initial cell adhesion related to protein adsorption on PLGA surface. In addition, serum content in media related to cell proliferation rate. In this result, we recognized that adhesion and proliferation of SCs were affected by specific cell-adhesives. In these results, we recognized that is important to provide the suitable surface environment according to cell types and culture condition for improvement of cell adhesion and proliferation.

Study of Multi-stacked InAs Quantum Dot Infrared Photodetectors Grown by Metal Organic Chemical Vapor Deposition (유기금속화학기상증착법을 이용한 적층 InAs 양자점 적외선 수광소자 성장 및 특성 평가 연구)

  • Kim, Jung-Sub;Ha, Seung-Kyu;Yang, Chang-Jae;Lee, Jae-Yel;Park, Se-Hun;Choi, Won-Jun;Yoon, Eui-Joon
    • Journal of the Korean Vacuum Society
    • /
    • v.19 no.3
    • /
    • pp.217-223
    • /
    • 2010
  • We grew multi-stacked InAs/$In_{0.1}Ga_{0.9}As$ DWELL (dot-in-a-well) structure by metal organic chemical vapor deposition and investigated optical properties by photoluminescence and I-V characteristics by dark current measurement. When stacking InAs quantum dots (QDs) with same growth parameter, the size and density of QDs were changed, resulting in the bimodal emission peak. By decreasing the flow rate of TMIn, we achieved the uniform multi-stacked QD structure which had the single emission peak and high PL intensity. As the growth temperature of n-type GaAs top contact layer (TCL) is above $600^{\circ}C$, the PL intensity severely decreased and dark current level increased. At bias of 0.5 V, the activation energy for temperature dependence of dark current decreased from 106 meV to 48 meV with increasing the growth temperature of n-type GaAs TCL from 580 to $650^{\circ}C$. This suggest that the thermal escape of bounded electrons and non-radiative transition become dominant due to the thermal inter-diffusion at the interface between InAs QDs and $In_{0.1}Ga_{0.9}As$ well layer.

Performance evaluation of Surface Temperature Reduction by using Green infrastructure Surface Temperature Measurement for Urban Heat Island Mitigation (도시열섬완화를 위한 그린인프라시설의 표면온도 저감 성능평가)

  • Ko, Jong Hwan;Bae, Woo Bin;Park, Dae Geun;Jung, Won Kyong;Park, Yun mi;Kim, Yong Gil;Kim, Sang Rae
    • Ecology and Resilient Infrastructure
    • /
    • v.5 no.4
    • /
    • pp.257-263
    • /
    • 2018
  • This study is to develop a GSTM (Green infrastructure Surface Temperature Measurment) equipment for reducing the surface temperature of GI by using LID Method. The tests were conducted including GI products such as Greening block, Pervious Block, Soil Block and so on. The GSTM equipment developed by considering the literature surveys are characterized as follows. The non-contact infrared temperature sensor was used to measure the surface temperature, and it was improved to measure the overall average temperature including the center and the corner temperature of the specimen. The developed GSTM equipment was used to compare performance of asphalt and GI products. As a result, the Greening Block show a high difference of $18.4^{\circ}C$ and it contributes to the decrease of surface temperature.

Experimental Study on Biological Activity Analysis through Measuring Skin Temperature of Honeybee and Butterfly using Thermographic Camera (열화상카메라를 이용한 유시아강 곤충 꿀벌과 나비의 피부온도 측정과 이를 활용한 생체 활동 특성에 대한 실험 연구)

  • Kim, Jeongbae
    • The Journal of the Korea Contents Association
    • /
    • v.21 no.4
    • /
    • pp.60-66
    • /
    • 2021
  • Various insects live around us. Nowadays, insects are raised as a hobby at home or medicinal insects are bred in large quantities for commercial purposes. In addition, various studies have been conducted to understand the various growth characteristics of insects. In the laboratory, environmental factors were changed to do that, but only the growth characteristics could be analyzed. However, it is almost not easy to measure the skin temperature or body temperature basically needed to reveal the growth characteristics in the case of insects. In particular, the results of experiments on the skin temperature of winged insects are very insufficient. In this study, the skin temperature of insects was photographed and measured for bees and butterflies living in natural conditions under various biological activity conditions such as at rest and during flight using a thermal imaging camera, a non-contact temperature measurement method. Through quantitative analysis of the experimental results, the relationship between the biological activity characteristics of each insect and the skin temperature resulting from such biological activity was investigated. In addition, it was confirmed that honeybees maintained different skin temperatures for three important activities, such as flying, honey collection, and relocation, and that the butterflies performed a warm-up stage for flight similar to the characteristics of moths.