• Journal of Broadcast Engineering
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• v.19 no.1
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• pp.96-108
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• 2014

In case of contrast of the image enhancement by using the conventional histogram equalization, over-enhancement, false contouring and distortion such as the details disappearance of the image occurs due to the excessive brightness change. Especially, these distortion appears when the brightness distribution is concentrated in a particular brightness level. In order to solve these problems, improved histogram equalization methods to transform the input histogram by clipping using threshold have been proposed, but contrast enhancement effect is reduced because it does not consider the characteristics of the input image's histogram to apply the same threshold for the entire histogram, and unnatural image is obtained because it does not retain the characteristics of the image. In this paper, to solve the problems of existing methods, we propose new equalization method that suppress excessive brightness changes by applying to the differential compression according to the histogram frequency, and maintain the characteristics of the input image. In addition, we propose a more effectively method to improve contrast by controlling the strength of the compression ratio depending on the characteristics of the input image.

• Journal of International Society for Simulation Surgery
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• v.1 no.2
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• pp.71-74
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• 2014

Purpose The prominent mandible angle, otherwise known as "square face", has been recognized as an aesthetic problem that needs correction by many in the Asian community. Many surgeons considered that mandible angle ostectomy alone, brings about hypotrophy of the masseter muscle. However, it was only proven indirectly (by clinical experience and histological animal experiments) and not objectively. In this study, we evaluated the volume of masseter muscle to prove the effect, objectively. Materials and method Computed tomography (CT) images were used to measure the masseter muscle volume of normal female group (n=6), and of female patient group n=8, preoperative and early & late postoperative volumes) presenting the symptom of prominent mandible angle. The data was analyzed statistically by two-sample t-test and paired t-test using SAS (version 8.2). Results In normal female group, volume average was $16,142{\pm}2,829.8mm^3$. In patient group, preoperative volume averaged $24,447{\pm}4,544.5mm^3$ (p<0.0001), early postoperative volume measured average of $31,966{\pm}50,421mm^3$ which is a 30% increase from the preoperative volume (p<0.0001). Late postoperative measurement was $20,202{\pm}4,092.3mm^3$, which is a 20% decrease from the preoperative volume (p<0.0006). Conclusion The bone reduction of prominent mandible angle induce the hypotrophic effect of masseter muscle after long term follow up (5 more months). This result mean that the result of mandible angle contouring surgery can be considered as combined effect of bony angle reduction and subsequent masseter muscle hypotrophy.

• The Research Journal of the Costume Culture
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• v.29 no.4
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• pp.585-602
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• 2021

The purpose of this study is twofold: First, to develop new sustainable design methods (aligned with ethnic elements and traditional culture) combined with three-dimensional digital clothing technology throughout the design process, which can be presented as guideline materials for various fashion designs to be developed in contemporary sensibilities. Second, it is the intention to produce creative fashion designs by incorporating the characteristics and methods of Miao's Huangping batik dyeing technique and to present various possibilities in the fashion design field. The overall design characteristics sought by Miao minority are in line with the complex terrain and the ecological and climatic conditions. Miaoist batik dyeing (registered as part of Chinese national intangible cultural heritage) features unique production methods and patterns. The study results are as follows. First, this attempt has enabled understanding of the national costume culture as Chinese Miao's traditional cultural heritage to be promoted, while the direction of contemporary design development using traditional elements has been presented. Second, the study demonstrated new and innovative expressions and styles relying on three-dimensional digital contouring technology and identified the possibility of developing various designs. Third, it was confirmed that the dyed batik pattern design created by the three-dimensional digital contouring technology could be recombined or expanded as digital printing to express the traditional ethnic designs in a practical manner utilizing digital printing techniques based on traditional characteristics.

• 한국기계연구소 소보
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• s.17
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• pp.157-165
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• 1987

The SWATH concept hull form which is capable of high speed navigation with small oscillatory motions in waves, was developed from the catamaran type hull forms. This paper describes how the motion of a SWATH ship in irregular waves can be reduced by regulating the stabilizing fins. The optimal regulator and LQG (Linear Quadratic Gaussian) controller for vertical plane motion have been applied for both platforming mode and contouring mode controls. The calculations of hydrodynamic coefficients and external forces are possible for defining the system equation for the design purpose of motion control. Performances of the controlled system are compared with those of original system.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.13 no.2
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• pp.13-24
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• 2004

In everyday dental practice, one of the most important procedures is fixed prosthodontics which includes gold and ceramic restorative treatments. This procedure can be divided into tooth preparation, impression taking, laboratory work, occlusal adjustment and cementation. The first step is tooth preparation and it needs not only good techniques but also deep knowledge and understanding of oral biology. Also, there must be good knowledge of the principles and materials of the procedure. The patient's satisfaction can be achieved from natural contour, good shade, and precise margin fit, especially in ceramic restorations on anterior regions. It is essential to fastidiously prepare the tooth to make aesthetic restorations with a good margin fit. Tooth preparation techniques and three case reports of ceramic restorations on the anterior region are presented and discussed in this paper.

• Transactions of the Korean Society of Mechanical Engineers
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• v.6 no.4
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• pp.341-345
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• 1982

The interpolator is usually built in hardware (logic circuitry), and the interpolator fabricated in a single LSI chip is recently made use of in most NC controllers, making the system more compact. However, the LSI interpolator not only has the technical difficulties but also requires high cost, in its fabrication. To solve these problems, we tried to find the method of interpolation by software, and succeeded in developing a program which, executed by INTEL's 8085 microprocessor, can distribute the input pulses of up to 4.0 [Kpps] for the linear interpolation and 3.0 [Kpps] for the circular interpolation. This paper presents the algorithm used to reduce the execution time and the flow chart of the interpolation program, and also shows the possibility of software interpolation. The interpolation program designed in assembly language is presented in the appendix.

• Proceedings of the KACD Conference
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• 2002.11a
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• pp.719-719
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• 2002

Aesthetic and cosmetic dentistry is becoming a major source of the dentists practice and source of income. Patients are demanding dentists to improve and enhance their appearance and function by means of aesthetic contouring and orthodontics and are willing to pay for such services. This creates a challenge for the dental profession to gain more knowledge and skill in this important area of their practice. Ceramic and composite veneers provide a comprehensive solution to the dentition that are severely hypoplastic or deeply stained by the ingestion of tetracycline during tooth development. A large number of dental materials and new techniques are now available that will render extremely satisfactory and beautiful solutions to these previously unsightly dentitions. This presentation will present the most commonly used dental materials and techniques of fabrication of composite and porcelain veneers. Using clinical cases, the step by step cavity preparations.Impression taking, laboratory fabrication, clinical try-in and cementation materials and techniques and repairs of broken veneers as well as long term follow up will be presentedesented

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.528-535
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• 2002

In order to achieve high precision machine tools, the research for performance enhancement of feed drive systems is required. Development of the high speed feed drive system has been a major issue for the past few decades in machine tool industries. The reduction of the tool change time as well as rapid travel time can enhance the productivity. However, the high speed feed drive system generates more heat in nature, which leads thermal expansion that has adverse effects on the accuracy of machined parts. Stick-slip friction has a great influence on the contouring accuracy of CNC machine tools. In this paper table levitation system has been developed for the stick-slip in a feed drive systems. And also, the driving position is set near the center of the main slideway. From the results, it is confirmed that yaw error and straightness can be improved.

• IE interfaces
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• v.9 no.2
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• pp.119-128
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• 1996

A procedure is presented for a 3D-contour machining without cutter interferences. The 3D-contouring machining along a spatial curve is often required for manufacturing trimming and flange dies in motor industries. Input data for the machining contour is a spline curve with polynomial vector equation provided by CATIA system. Points are sampled on the contour curve and line segments and helical curves are approximated from the point data. Cutter interference is checked on the approximated spline and all of interference curves are substituted with interference-free helical curves for a tool path generation. The non-machined curve areas are locally machined by tools with smaller diameters. A tool radius offset is considered for generating NC data to be free with tool size.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.1033-1038
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• 1995

NC 공작기계의 contour 운동 오차를 측정하기 위하여 사용되는 Ball-Bar에 의한 원호 보간 시험 데이터를 이용하여 NC controller의 성능을 평가 할 수 있는 S/W에 의한 방법을 제시한다. 본 논문에서 지금까지는 분석이 어려웠던 Masrer-Slave Changeover의 분석을 가능하게 하였으며, Ball-Bar로 부터 얻어지는 데이터를 Weighted Residual Method에 의한 종합적인 분석을 하였으며, 오차 원인별 비교를 위해 Eztra Sum of Squares Method를 도입하였다. 본 연구의 실제 적용을 위한 측정 및 분석 S/W를 개발하였으며, 결과적으로 NC controller의 성능평가에 유용함을 알 수 있었다. 무부하 조건에서의 Ball-Bar에 의한 분석 데이터와의 비교를 위하여 원형 시편을 가공하고, 진원도 측정 및 분석을 통하여 유사한 오차 pattern을 가짐을 알 수 있었다.