• Tribology and Lubricants
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• 제27권3호
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• pp.147-155
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• 2011

The ceramic coatings are excellent materials of cutting tools and sliding parts. To evaluate the wear characteristics of very thin ceramic coated layer, it is very important to investigate its wear process microscopically. An effective method for investigating the wear of a thin layer is the observation of wear process in microscopic detail using in-situ system. In this study, using the SEM Tribosystem as in-situ system, the microscopic wear mode of TiN coatings was investigated in repeated sliding. As results, four modes were observed for TiN coatings: Ploughing, powder formation, flake formation and coating delimitation. The observation of the microscopic wear by in-situ system can clarify the allowable stress of TiN coating.

• International Journal of Precision Engineering and Manufacturing
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• 제9권3호
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• pp.51-54
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• 2008

A novel stereolithography method using evanescent light has been proposed as a means to realize 100-nanometer resolution. An in-process measurement system with high accuracy has been introduced to the nanostereolithography apparatus. Specifically, an optical microscopic system was developed to monitor the exposure process and a confocal positioning system was established to improve the longitudinal positioning accuracy in the layer-by-layer process. A high-power objective lens, a tube lens, and a charge coupled device (CCD) were included in the optical microscopic system, whereas a laser, a high-power objective lens, a piezoelectric (PZT) stage, a condenser lens, a pinhole, and a photomultiplier (PMT) made up the confocal microscopic system. Two verification experiments were conducted, and the results indicated that the optical microscopic system had a horizontal resolution of 200 nm and that the confocal positioning system provided a depth resolution of 30.8 nm. These results indicate that nanostereolithography can be successfully performed with this system.

• 한국정밀공학회지
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• 제14권9호
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• pp.146-154
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• 1997

Ion implantation has been used successfully as a surface treatment technology to improve the wear. fatigue and corrosion resistances of materials. A modified surface layer by ion implantation is very thin(under 1 m), but it has different mechanical properties from the substrate. It has also different wear characteristics. Since wear is a dynamic phenomenon on interacting surfaces with relative motion, an effective method for investigtating the wear of a thin layer is the observation of wear process in microscopic detail using in-situ system. The change of wear properties produces the transition of wear mode. To know the microscopic wear mechanism of this thin layer, it is very important to clarify its microscopic wear mode. In this paper, using the SEM and AFM Rribosystems as in-situ system, the microscopic wear of Ti ion-implanted 1C-3Cr steel, a material for roller in the cold working process, was investigated in repeated sliding. The depth of wear groove and the speciffc wear amount were changed with transition of microscopic wear mode. The depth of wear groove with friction cycles in AFM tribosystem and specific wear amount of Ti ion-implanted 1C-3Cr steel were less about 2-3 times than those of non-implanted 1C-3Cr steel. The microscopic wear mechansim of Ti ion-implanted 1C-3Cr steel was also clarified. The microscopic wear property was quantitatively evaluated in terms of microscopic wear mode and specific wear amount.

• 한국기계가공학회지
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• 제10권3호
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• pp.100-107
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• 2011

To evaluate the wear characteristics of very thin ceramic coated layer, it is very important to investigate its wear process in great detail. An effective method for investigating the wear of a thin layer is the observation of wear process in microscopic detail, using in-situ system. In this study, based on the SEM Tribosystem as in-situ system, the microscopic wear mode of TiN coatings was investigated in repeated sliding. Consequently, four modes were revealed for TiN coatings: Ploughing, powder formation, flake formation and coating delimitation. Sc(Severity of contact) can clarify transition condition of those microscopic wear modes.

• 한국축산식품학회지
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• 제38권2호
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• pp.362-375
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• 2018

This study proposed a rapid microscopic examination method for pork freshness evaluation by using the self-assembled hyperspectral microscopic imaging (HMI) system with the help of feature extraction algorithm and pattern recognition methods. Pork samples were stored for different days ranging from 0 to 5 days and the freshness of samples was divided into three levels which were determined by total volatile basic nitrogen (TVB-N) content. Meanwhile, hyperspectral microscopic images of samples were acquired by HMI system and processed by the following steps for the further analysis. Firstly, characteristic hyperspectral microscopic images were extracted by using principal component analysis (PCA) and then texture features were selected based on the gray level co-occurrence matrix (GLCM). Next, features data were reduced dimensionality by fisher discriminant analysis (FDA) for further building classification model. Finally, compared with linear discriminant analysis (LDA) model and support vector machine (SVM) model, good back propagation artificial neural network (BP-ANN) model obtained the best freshness classification with a 100 % accuracy rating based on the extracted data. The results confirm that the fabricated HMI system combined with multivariate algorithms has ability to evaluate the fresh degree of pork accurately in the microscopic level, which plays an important role in animal food quality control.

• Applied Microscopy
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• 제37권3호
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• pp.199-208
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• 2007

본 장치는 실험자가 레이저 빔과 광학 렌즈를 조정하여 이미지 및 회절도형의 형성, 보강 및 소멸간섭과 같은 파동광학 현상을 이해하도록 제작된 실험 장치이다. 실험장치는 광원으로 쓰이는 레이저빔과 빔의 광축을 정렬하는 광원 부분과 시료대, 대물렌즈, 중간렌즈, 확대렌즈, CCD system, 컴퓨터, 그리고 렌즈를 상하 조절하는 경통부분으로 구성된다. 본 장치를 통해서 다양한 회절격자의 이미지 및 회절도형을 최대 약 44배 확대할 수 있고, 최대 약 5um의 분해능을 가지고 분석할 수 있다. 이 장치는 전자현미경 이용자들이 TEM의 원리를 보다 쉽게 이해하는데 도움을 주리라 기대한다.

• 한국표면공학회지
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• 제37권3호
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• pp.137-145
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• 2004

This study surveys the microscopic wear of CVD TiN coatings in repeated sliding, using the SEM Tribosystem as in-situ system. According to the research, the depth of wear groove and the specific wear amount are changed by the transition of the microscopic wear mode. This investigation leads to the fact that the change of wear characteristics produces the transition of the wear mode. In this survey, four modes are observed for CVD TiN coatings with the thickness of 1.6$\mu\textrm{m}$: ploughing, powder formation, flake formation and coating delimitation. The microscopic wear properties is quantitatively evaluated in terms with the microscopic wear mode and the specific wear amount. These relationships prove that the observation of wear modes with a SEM Tribosystem is useful to evaluate wear properties.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 정기총회 및 추계학술대회 논문집 학회본부
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• pp.356-358
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• 1993

With a focused laser beam, we make a microscopic change on a thin film, and organize the overall system that can observe the change with a microscope. This system utilizes the energy of a laser beam which is focused by a simple lense system. That is a laser beam which has its waist at working distance of a lense. The microscopic change induced by the energy of laser beam focused through a lense can be observed in real time. The experiment with this system shows that the 10mW He-Ne 632.8nm laser can change the black vinyl instantaneously.

• Journal of Korean Neurosurgical Society
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• 제40권6호
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• pp.406-411
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• 2006

Objective : The authors have developed a procedure, termed posterior microscopic lesionectomy, that creates a minimal laminotomy site according to the location of the shifted disc using the $METRx^{TM}$ system in the lumbar spine. This study compared the usefulness and surgical outcomes of this procedure with those of traditional standard lumbar discectomy. Methods : From June 2003 to June 2004, Twenty-two patients with one-level radiculopathy due to lumbar disc herniation underwent posterior microscopic lesionectomy with the assistance of an operating microscope and the $METRx^{TM}$ tubular retractor. Surgical results of the new procedure were compared to those of 39 patients who underwent traditional lumbar discectomy from April 2003 to September 2004. All patients were evaluated for pain score, clinical assessment according to the VAS, and Roland-Morris scores pre-operatively and at 1, 3, 6, and 12 months post-operatively. Results : Mean blood loss, operation time, and admission date showed significant improvements for microscopic lesionectomy compared to traditional lumbar discectomy [P < 0.001]. Also, both measures of short-term functional improvement, the Visual Analogue Scale[VAS] and Roland-Morris[RM] scores, were statistically better for microscopic lesionectomy than for traditional discectomy [P < 0.001]. Conclusion : Posterior microscopic lesionectomy can be performed more safely and provide greater benefit than traditional discectomy. The procedure is associated with less post-operative pain, shorter hospital stays, and quicker rehabilitation.

• Tuberculosis and Respiratory Diseases
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• 제55권6호
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• pp.623-630
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• 2003

저자들은 급성신부전과 미만성 폐포출혈이 있으면서 중추신경병증이 동반된 현미경적 다발성 혈관염 환자 l예와 특발성 괴사 사구체신염 진단 후 스테로이드 감량 도중 폐침윤이 동반된 전신적인 현미경적 다발성 혈관염의 형태로 재발한 환자 l예를 경험하였기에 문헌 고찰과 함께 보고하는 바이다.