• 한국정밀공학회지
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• 제14권11호
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• pp.50-57
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• 1997

In order to make unmanned machining systems with satisfactory performances, it is necessary to incorporate appropriate condition monitoring systems in the machining workstations to provide the required intelligence of the expert. This paper deals with condition monitoring for chatter, tool wear and breakage during turning operation. To develop economic sensing and identiffication methods for turning processes, sound pressure measurement and digital signal processing technique were proposed. We suppressed chatter by stability control methodology, which was studied through manipulation of spindle speeds regarding to chatter frequencies. It was shown that tool wear and fracture were identified and to be estimated by using the wear indices. The validity of the proposed system was confirmed through the large number of cutting tests.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2006년도 하계학술발표대회 논문집
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• pp.1219-1224
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• 2006

This paper presents the friction and anti-wear characteristics of nano-oil with n mixture of a refrigerant oil and carbon nano-particles in the thrust slide-bearing of scroll compressors. Frictional loss in the thrust slide-bearing occupies a large part of total mechanical loss in scroll compressors. The characteristics of friction and anti-wear Lising nano-oil is evaluated using the thrust bearing tester for measuring friction surface temperature and the coefficient of friction at the thrust slide-bearing as a function of normal loads up to 4,000 N and orbiting speed up to 3,200 rpm. It is found that the coefficient of friction increases with decreasing orbiting speed and normal force. The friction coefficient of carbon nano-oil is 0.015, while that of pure oil is 0.023 under the conditions of refrigerant gas R-22 at the pressure of 5 bars. It is believed that carbon nano-particles can be coated on the friction surfaces and the interaction of nano-particles between surfaces can be improved the lubrication in the friction surfaces. Carbon nano-oilenhances the characteristics of the anti-wear and friction at the thrust slide-bearing of scroll compressors.

• 대한치과보철학회지
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• 제57권3호
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• pp.280-287
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• 2019

구강이라는 특수한 환경 속에서 치아는 평생을 거쳐 마모, 부식 등을 겪게 된다. 점진적이며 일정한 치아의 마모는 노화의 자연스러운 현상이나, 특정 요소에 의한 마모나 부식 등은 병적인 요소이며 교합면의 병리적 손상과 이에 따른 교합 부조화, 심미적 문제, 턱관절 장애 등을 야기할 수 있다. 본 증례는 26세의 젊은 여성 환자로 전반적인 치아의 마모와 부식이 동반된 상태였다. 디지털 안모 분석, 생리적 안정위, 전치부 치관 길이 평가 등을 통해 진단 납형을 제작하였다. 디지털 분석을 통해 치관연장술에 필요한 가이드를 제작하여 수술을 진행하였고 임시 보철물을 통하여 저작 기능 및 심미성을 회복하였다. 지르코니아 최종 보철로 수복하여 심미적, 기능적으로 만족할만한 결과를 얻었으므로 이 증례를 보고하고자 한다.

• 대한치과보철학회지
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• 제60권4호
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• pp.320-329
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• 2022

생리적 마모는 일생 동안 불가피하게 일어나고 정상현상이라고 볼 수 있다. 하지만, 병적인 마모는 교합면에 치명적 손상을 야기하고 심미 및 적절한 전방유도를 파괴 할 수 있다. 따라서 교합면 마모 회복을 위해서는 철저한 평가와 진단이 필요하다. 본 증례의 환자는 하악 치아 순면과 상악 치아 설면의 심한 마모를 보였다. 수직교합고경을 분석 하였고, 부족한 보철수복공간을 회복을 위해 수직교합고경을 높여서 치료하기로 하였다. 수직교합고경이 결정 된 후에는 보통 진단 왁스업을 하여 치료를 진행한다. 본 증례는 심한 마모로 인한 교합붕괴 및 수직교합고경이 상실된 환자에서, 기존의 진단왁스업 과정을 다양한 디지털 도구를 사용하는 방법으로 대체하였다. 진단왁스업은 소프트웨어에서 디자인되어 디지털로 임시보철물을 제작하였다. 임시보철물 검증을 통해, 수직교합고경 및 적절한 전방유도로 회복되었다.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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• pp.457-458
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• 2002

The fractal dimension is the characteristics that can quantitatively define the irregularity in natural. It is useful in describing the morphology or various rubbed surface for hydraulic piston motor instead of the stylus profiling method. But fractal parameters had not constructed on the morphological characteristic or rubbed surface because of the insufficient knowledge about a conception of fractal dimension. In this study, for the purpose or applying fractal I parameters practically, we have suggested way to establish the morphological characteristic of rubbed surface with fractal parameters, and we carried out an experiment on the lubricant friction and wear by using Ball-ON-Disk type tester. Materials were the brass and the bronze which are used to slipper-pad in the hydraulic piston motor. We searched for fractal parameters or surface structure with the digital image processing, Surface fractal dimension can be determined by sum of intensity difference of surface pixel. Using the image processing and fractal parameters for rubbed surface in the friction and wear test, morphology of rubbed sur race can be effectively obtained by fractal dimensions.

• 복식
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• 제59권2호
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• pp.70-86
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• 2009

Today, digital technology is extending its influence to fashion design, which is closely related to people's lifestyle. In order for people to access information all the time, every place, people have to wear these devices all the time, every place. Intelligent wear allows people to communicate with their own body, other persons or surrounding real-time. The purposes of this study are to define 'Intelligent wear' by looking through the similar terms of intelligent wear on related fields, to analyze characteristics of intelligent wear and to provide not only theoretical data but also, practical data far product development on both functional and aesthetic sides. In this study, usefulness provided by intelligent wear were identified in the concept of instrumental & expressive function. For the aim of the study, literature and case study were considered at the same time. The conclusions are as the following. The characteristics of intelligent materials were found to be information, intelligence and protection, the characteristics of intelligent manufacture were combination and virtual reality. And The characteristics of intelligent products were multi-function, transformation, camouflage. Integration of operability function extends human ability and the area of human activity, entertainment, and communication, and provides convenience. Consequently, development of intelligent wear should promote through not only computer engineering but also, connection to other fields. Most of all, there is a need for active research in clothing design and the fashion design since intelligent wear is after all, clothing.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1997년도 춘계학술대회 논문집
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• pp.82-87
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• 1997

In order to make unmanned machining systems with satisfactory performances, it is necessary to incorporate appropriate condition monitoring systems in the machining workstation to provide the required intelligence of the expert. This paper deals with condition monitoring for tool wear and fracture during turning operation. Developing economic sensing and identification methods for turning processes, sound pressure measurement and digital signal processing technique are proposed. The validity of the proposed system is confirmed through the large number of cutting tests.

• 복식문화연구
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• 제17권1호
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• pp.40-54
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• 2009

Many studies make us difficult for understanding the specific concept of NOW avant garde by misusing avant garde or by using the over wide-ranging concept. The purpose of this study is to define the concept of NOW avant garde fashion by analyzing its fashion and its paradigm characteristics, after considering modern avant garde fashion history. This study was used with bibliographic research as well as internet search of qualitative method for analyzing fashion show clothes since 2005 women's wear. The characteristics of NOW avant garde fashion are classified into plural deconstructivism, econonism that integrates the last avant garde factors with logical economics, and the aesthetic of Tech-Human. To conclude, the concept of NOW avant garde fashion is defined as the fashion expressing either the digital-hybrid images or the deconstructive images meaning elimination, unification or confinement, being pilled up one on another, bizarre connection, transposition, and distortion.

• 대한기계학회논문집
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• 제17권8호
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• pp.2061-2068
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• 1993

Condition monitoring technology is of great importance for the maintenance of complex machinery in view of its early monitoring of the abnormal condition and the protection against failure. Several methods have been used for the detection of failure of journal bearings, one of the main elements of mechanical system. The methods most frequently used are vibration and temperature monitoring, but these are unable to monitor the wear conditions exactly. In this study, an ultrasonic measument method, one of the non-destructive testing methods, was introduced as the monitoring technology. Furtermore a pattem recognition method was applied to analyze the ultrasonic signal. The monitoring system using the pattern recognition method is composed of digital signal processing units and uses Hamming net algorithm for the recognition of ultrasonic waves. From the journal bearing wear test, the occurrence of adhesive wear of the white metal in rubbing contact with the shaft was exactly detected by this system, and the wear status of the journal bearing was monitored by measuring the wear thickness.

• The Journal of Advanced Prosthodontics
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• 제11권1호
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• pp.23-31
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• 2019

PURPOSE. To investigate and compare the surface roughness (SR), weight and height of monolithic zirconia (MZ), ceramometal (CM), lithium disilicate glass ceramic (LD), composite resin (CR), and their antagonistic human teeth enamel. MATERIALS AND METHODS. 32 disc shaped specimens for the four test materials (n=8) and 32 premolars were prepared and randomly divided. SR, weight and height of the materials and the antagonist enamel were recorded before and after subjecting the specimens to 240,000 wear-cycles ($49N/0.8Hz/5^{\circ}C/50^{\circ}C$). SR, height, weight, and digital microscopic qualitative evaluation were measured. RESULTS. CM ($0.23+0.08{\mu}m$) and LD ($0.68+0.16{\mu}m$) exhibited the least and highest mean difference in the SR, respectively. ANOVA revealed significance (P=.001) between the materials for the SR. Paired T-Test showed significance (P<.05) for the pre- and post- SR for all the materials. For the antagonistic enamel, no significance (P=.987) was found between the groups. However, the pre- and post- SR values of all the enamel groups were significant (P<.05). Wear cycles had significant effect on enamel weight loss against all the materials (P<.05). CR and MZ showed the lowest and highest height loss of 0.14 mm and 0.46 mm, respectively. CONCLUSION. MZ and CM are more resistant to SR against the enamel than LD and CR. Enamel worn against test materials showed similar SR. Significant variations in SR values for the tested materials (MZ, LD, CM, and CR) against the enamel were found. Wear simulation significantly affected the enamel weight loss against all the materials, and enamel antagonist against MZ and CM showed more height loss.