• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2009년도 IWAIT
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• pp.158-163
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• 2009

In recent years, there has been increased interest in characterizing and extracting 3D information from 2D images for human tracking and identification. In this paper, we propose a single view-based framework for robust estimation of height and position. In the proposed method, 2D features of target object is back-projected into the 3D scene space where its coordinate system is given by a rectangular marker. Then the position and the height are estimated in the 3D space. In addition, geometric error caused by inaccurate projective mapping is corrected by using geometric constraints provided by the marker. The accuracy and the robustness of our technique are verified on the experimental results of several real video sequences from outdoor environments.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집A
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• pp.108-113
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• 2001

Recently, the mechanical structures applied to many industrial products, especially in electronic products, appear to be miniaturized and complicated. This trend makes it difficult to analyze the stress distribution of those mechanical structures and generates new challenges for precise measurement of strain. Therefore, generally most of those cases largely depend on the finite element analysis. But the development of optical metrology which has the capability of non-contact, full-field and precise measurement makes it possible to solve these measuring problems. Among the optical measurement techniques, the electronic speckle pattern interferometry (ESPI) has been developed and considered as one of the most useful tools for measuring displacement and deformation. But the shortage of recognition and difficulties of measurement have limited its industrial applications in spite of its excellent capabilities. Therefore in this study, in order to enhance the industrial application of ESPI, the measurement of in-plane displacement of mechanical structure with ESPI, which is applied to washing machine and cannot be measured by strain gauges, was performed. And the verification of validity of FEA results was also done.

• 한국정밀공학회지
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• 제26권4호
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• pp.91-99
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• 2009

Because of both precise measurement and efficient quality control, coordinate measuring machines(CMMs) have been widely used in the industry. The purpose of this paper is to present a method to estimate the CMM measurement uncertainty using design of experiments. A factorial design is applied to carry out the performance test proposed by ISO 10360 and to investigate CMM measurement errors associated to orientation and length of the length bar. In order to assess the measurement uncertainty for the performance test, an analysis of the uncertainty components that make up the uncertainty budget has been carried out. The procedure for evaluating the uncertainty of it follows GUM ("Guide to the expression of uncertainty in measurement"). The results show that the proposed method is suitable to investigate CMM performance and determine the contribution of machine variables to measurement uncertainty.

• 한국정밀공학회지
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• 제34권2호
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• pp.107-114
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• 2017

In this investigation, we describe a metrological technique for surface and thickness profiles of a silicon (Si) wafer by using a 6 degree of freedom (DOF) stitching method. Low coherence scanning interferometry employing near infrared light, partially transparent to a Si wafer, is adopted to simultaneously measure the surface and thickness profiles of the wafer. For the large field of view, a stitching method of the sub-aperture measurement is added to the measurement system; also, 6 DOF parameters, including the lateral positioning errors and the rotational error, are considered. In the experiment, surface profiles of a double-sided polished wafer with a 100 mm diameter were measured with the sub-aperture of an 18 mm diameter at $10\times10$ locations and the surface profiles of both sides were stitched with the sub-aperture maps. As a result, the nominal thickness of the wafer was $483.2{\mu}m$ and the calculated PV values of both surfaces were $16.57{\mu}m$ and $17.12{\mu}m$, respectively.

• Natural Product Sciences
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• 제24권1호
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• pp.47-53
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• 2018

Callophylum symingtonianum (Guttiferae), an evergreen broad-leaved tree that usually grows in hill forests, can be found distributed in the Malay Peninsula. The barks, leaves, flowers and seeds is often used medicinally to treat diarrhea and rheumatism. In the present study, we isolated two inophyllum type coumarins, 12-O-ethylinophyllum D (1) and iso-soulattrolide (2) from the stembarks of C. symingtonianum together with their antibacterial activity. The compounds were isolated by chromatographic methods on a silica gel. The structures were established by spectroscopic methods including UV, IR, (1D and 2D) NMR and mass spectrometry as well as by comparison with several literature sources. The antibacterial activity of those compounds was tested using a disc-diffusion assay against Staphylococcus aureus, Bacillus cereus, Escherichia coli and Pseudomonas aeruginosa. Both compound exhibited mild inhibition against P. aeruginosa with both $111{\mu}g/ml$ MIC value. Compound 2 also inhibits S. aureus with $25{\mu}g/ml$ MIC value.

• 한국정밀공학회지
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• 제16권8호
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• pp.203-212
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• 1999

This paper describes a deadweight force standard machine with the weight change mechanism which can be used as a primary force standards at a national metrology institute. Since commercial deadweight force machine can generate forces by hanging weights to the weight supporter serially, force steps from deadweight force measuring devices of each having different capacity. In order to increase the force steps, we have specially designed a weight mechanism in which the machine can select the necessary weights and generate the load by hanging the selected weights to the weight supporter. The machine can generate 속 force of the range of 2 kN to 110 kN with force step of 1 kN. All weights have been accurately compensated and calibrated by a mass comparator and its standard uncertainty is less than 2.2 ${\times}\;10^{-6}$. The relative expanded uncertainty of the machine is 1.3 ${\times}\;10^{-5}$.

• Applied Science and Convergence Technology
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• 제25권2호
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• pp.25-27
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• 2016

The surface flatness of metal meshes in a deflector of particle beam mass spectrometer (PBMS) required ideally flat, and this can specify the particle trajectories which goes through the detector. In this research, charged particle current was measured using the different surface roughness deflectors. NaCl particles were generated monodispersed in its size by using differential mobility analyzer and the whole processes were followed the way calibrating PBMS. The results indicate that the mesh surface morphology in the deflector can affect to the particle size and the concentration errors, and sensitivity of PBMS.

• 대한기계학회논문집
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• 제17권6호
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• pp.1389-1403
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• 1993

본 논문에서는 초기 변형소재가 이미 결정된 상태에서 제품의 최적 성형 방향 을 구하는 방법을 기술하였다. 초기 변형소재는 블랭크 호울더 곡면에 의해 변형된 중간 단면들에서의 형상을 에너지 최소화 개념을 적용하여 스플라인 곡선으로 나타내 고 이것들로 부터 곡선망을 구성한 후 최종적으로 양방향 스키닝기법(bi-directional skinning technique)에 의해 구현 하였다.

• Natural Product Sciences
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• 제23권1호
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• pp.5-8
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• 2017

An antimicrobial compound has been isolated from the leaves of Glochidion superbum. The compound was determined as methyl 3, 4, 5-trihydroxybenzoate (methyl gallate), based on ultraviolet (UV), infrared (IR), nuclear magnetic resonance (NMR) and mass spectroscopy (MS) analysis. The isolated compound exhibited potent antimicrobial activity against three clinical isolates of methicillin resistant Staphylococcus aureus (MRSA) by qualitative agar disc diffusion method and quantitative broth dilution method. Agar disc diffusion was done in a dose-dependent manner for each bacterial isolate at disc potencies of 25, 50, 100, and $150{\mu}g/disc$. The zones of inhibition were on average equal to 12.27, 14.20, 15.43, and 24.17 mm respectively. The inhibition zones were compared with that of vancomycin disc at $30{\mu}g$ as a reference standard. The MIC and MBC values were $50{\mu}g/ml$ and $100{\mu}g/ml$ respectively. The results of anti MRSA activity were analyzed using one-way ANOVA with Turkey's HSD and Duncan test. In conclusion, methyl gallate which was isolated from G. superbum showed the inhibition activity against methicillin resistant S. aureus.

• 센서학회지
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• 제14권4호
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• pp.231-236
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• 2005

Calibration capability was evaluated using the reference-grade platinum resistance thermometer (PRT) in the temperature range of $-50^{\circ}C$ to $250^{\circ}C$ for the national calibration centers. The reference-grade PRT was calibrated at the several fixed points, which was composed by the freezing points of Sn, In, the melting point of Ga and the triple point of water and Hg, before and after the round-robin test (RRT) experiments. The temperature scale of reference-grade PRT was compared to the local standard PRT's using the system of the national calibration centers. $E_{n}$ values was calculated by the temperature difference between the reference-grade PRT and the local standard PRT, and the best measurement capability. Finally, the capability of the national calibration centers was evaluated by the $E_{n}$ values.