• Radiation Oncology Journal
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• 제29권3호
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• pp.214-217
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• 2011

To avoid improper tumor volume contouring in radiation therapy (RT) and other invasive procedures, we report a case of uterine adenomyosis showing increased $^{18}F$-fluorodeoxyglucose (FDG) uptake on positron emission tomography (PET)/computed tomography (CT) mimicking malignant tumor in a 44-year-old woman during concurrent chemoradiation therapy (CCRT) for uterine cervical cancer. The adenomyosis was not associated with her menstrual cycle or with normal endometrium uptake, and it resolved one month after completion of RT. This case indicates that uterine adenomyosis in a premenopausal woman may show false positive uptake of $^{18}FDG$-PET/CT associated with CCRT.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.1040-1043
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• 1996

The accuracy of the servo control in CNC system has a great influence on the duality of machine product. Tracking performance of the servo control is deteriorated mainly by the time delay of the servo system and the inertia of the work table or bed. Contouring errors occur in every interpolation steps by the effect of the tracking performance. In this paper, $H_{\infty}$ two-degree-of-freedom(TDF) controller is designed for improvement to improve the tracking performance. The designed controller is applied 3-axis machining center model and the cutting accuracy is simulated in case of corner cutting, circular and involute interpolation. Simulation results show that $H_{\infty}$ TDF controller designed in this paper has a good effect to improve tracking performance in CNC system.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.844-847
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• 1996

This paper describes the servo position control for the 2-axis positioning table the servo controller consists of conventional feedback loops, disturbance observer. To reduce the contour error, which occurs in the multi-dimensions machines, cross-coupled controller(CCC) is suggested. A weak point of the CCC is their low effectiveness in dealing with arbitrary nonlinear contour such as circles and parabolas. This paper introduces a new nonlinear CCC that is based on control gains that vary during the contour movement The gains of CCC and adjusted in real time according to the shape of nonlinear contour. The feedback controller based on the disturbance observer compensated for external disturbance, plant uncertainty and bad effectiveness by friction model. Suggested servo controller which improve the contouring accuracy, apply to the 2-axis system. Simulation results on 2-axis table verify the effectiveness of the proposed servo controller.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제30권5호
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• pp.473-479
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• 2008

Asians tend to have prominent mandibular angle. The causes of wide lower third of the facial contour are obtuse mandibular angle and hypertrophy of masseter muscles. In cases of hypertrophy of masseter muscles, conventional treatment intends to the contraction of masseter muscle. Recently, volumetric reduction of masseter muscles using botulinum toxin type A injection and radiofrequency (RF) reduction have been introduced. The use of RF energy for masseter muscle reduction is known as a safe, simple, and effective method for aesthetic lower facial contouring. The purpose of this study is to present the effects of RF reduction applied to hypertrophy of masseter muscles, to review and to encourage RF practices in oral and maxillofacial region.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 춘계 학술발표회 논문집
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• pp.417-422
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• 2005

The appropriate ventilation system in vehicular tunnel should be the most economical solution with regard to both construction and maintenance. The damages on tunnel lining was affected by formula of ventilation system in long vehicular tunnel. In this study, carbonation, one of main experimental items in precision safety diagnosis, was analyzed by contouring damage area with ventilation system. Considerations of carbonation were also given to the design and maintenance which manage the long-term safety in tunnel.

• 대한두개안면성형외과학회지
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• 제19권2호
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• pp.131-134
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• 2018

Treacher Collins syndrome is a congenital disorder that is characterized with a wide range of cranio-facial deformities. Zygomatic hypoplasia or aplasia is one of the key features, and surgical reconstruction of the consequent depression on the zygomatic area is deemed necessary by many patients. Various surgical options are available-injectables, alloplastic materials, autologous grafting, and autogenous tissue transfer. It depends on each patient which technique to use. Here, we present a clinical case, in which bilateral free groin flaps were adopted in attempt to resolve the remnant aesthetic deformity associated with zygomatic depression, despite a series of previous surgical efforts, in a 25-year-old Treacher Collins syndrome male patient.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2006년 제4회 한국유체공학학술대회 논문집
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• pp.535-538
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• 2006

The Objective of this study is to document the three-dimensional flow in a turbine cascade with Contoured endwall in terms of Stanton number distribution to proposes an appropriate contraction ratio of endwall contouring which show the best performance. This study was numerically performed. The results show that heat transfer coefficient on the contoured endwall which has the height of 15% of the axial chord showed best performance. The numerical method and results in this study can be applied to the design of gas turbine cascade with high performance.

• 한국공작기계학회논문집
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• 제11권5호
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• pp.7-14
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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 indestries. Because table levitation system decrease the table weight, an effect of reaction by weight is minimized and lost motion can be removed at maximum. In case fled system is designed with drive motor, ball screw and support bearing load capacity selection, an effect of decrease of the table weight exist. So, the table weight through an effect of decrease call it into the realization of cost down. 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 fled drive systems.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1992년도 추계학술대회 논문집
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• pp.34-38
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• 1992

Geometry based CAD/CAM system is hard to achieve "net shape machining" For a net shape machining, the machining errors should be compensated by off-line CAD/CAM system followed by on-line control system. In this paper, we investigate an off-line compensation scheme for the machining errors due to tool deflection in contouring operation. The significance of the deflection errors is first shown, and a compensation is sought via modifying the nominal tool path. In modification, tool deflection amount is iteratively compensated until the deflection amount is iteratively compensated until the deflected path results in the desired contour within a tolerance. The path modification algorithm has been tested via computer simulation. The developed algorithm can be used as a postprocessor for the current CAD/CAM system based on geometric modeling as a means for enhancing the machining accuracy.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.895-898
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• 2003

The higher precision is demanded in modem manufacturing and it requires the more accurate servo controller. Cross-coupling control (CCC) has been developed to improve contouring motion. In this paper we introduce a new nonlinear CCC that is based on contour-error-vector using a parametric curve interpolator. A vector from the actual tool position to the nearest point on the desire path is directly adopted. The contour-error-vector is determined by constructing a tangential vector of nearest point on desired curve and determining the vector perpendicular to this tangential vector from the actual tool position. Moreover, the vector CCC can apply directly and easily to free-form curves include convex and concave form. The experimental results on a three-axis CNC machine center show that the present approach significantly improves motion accuracy in multi-axis motion