• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2008년도 춘계 종합학술대회 논문집
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• pp.193-197
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• 2008

애니메이션의 캐릭터 디자인은 인물의 성격, 극중 역할, 성장배경 등 캐릭터의 설정내용에 외관을 일치시킴으로써 시각적 개연성을 확보하기 위한 수단으로 사용된다. 그중 일본 로봇 애니메이션에서 흔히 볼 수 있는 뿔은 로봇물의 전형성인 동시에 서양의 그것과 비교하여 문화적 차이를 확인할 수 있는 사례이기도 하다. 로봇 디자인에 뿔이 적용된 사례는 쉽게 찾아볼 수 있으나 그중에서도 "마징가Z"나 "게타로보", "UFO로보 그랜다이저"와 같은 나가이 고의 작품은 뿔이 애니메이션의 로봇 디자인에 있어 하나의 유형으로 자리 잡는데 결정적인 역할을 하였다. 나가이 고의 작품에 있어서 뿔은 단순한 장식적인 기능을 넘어 그가 말하고자하는 인간성 저변에 깔려 있는 폭력적 본성을 시각화하고자 하는 도구로 사용되었다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.988-992
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• 2002

Ultrasonic machining technology has been developed over recent years for the manufacture of and quality-assured precision parts for several industrial application such as optics, semiconductors, aerospace, and automobile application. The past decade has seen a tremendous in the use of ceramics in structural application. The excellent thermal, chemical and wear resistance of these material can be realized because of recent improvements in the overall strength and uniformity of advanced ceramics. Ultrasonic machining, in which abrasive particles in slurry with water are presented to the work surface in the presence of an ultrasonic-vibrating tool, is process which should be of considerable interest, as its potential is not limited by the electrical or chemical characteristics of the work material, making it suitable for application to ceramics. This paper intends to further the understanding of the basic mechanism of ultrasonic machining for brittle material and ultrasonic machining of ceramics based in the fracture-mechanic concept has been analyzed.

• 한국공작기계학회논문집
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• 제13권2호
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• pp.104-111
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• 2004

Ultrasonic machining is a non-thermal, non-chemical, md non-electorial material removal process, and thus results in minimum modifications in mechanical properties of the brittle material during the process. Also, ultrasonic machining is a non-contact process that utilize ultrasonic vibration to impact a brittle material. In this research characteristics of micro-hole machining for brittle materials by ultrasonic machining(USM) process have been investigated. And the effect of ultrasonic vibration on the machining conditions is analyzed when machining fir non-conductive brittle materials using tungsten carbide tools with a view to improve form and machining accuracy.

• 소성∙가공
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• 제19권6호
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• pp.363-371
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• 2010

In ultrasonic vibration drawing, the drawing forces can be reduced by applying ultrasonically oscillating dies. Ultrasonic vibration drawing has been considered as a means of accommodating high-level drawing processes such as shaped wire, ultrafine wire, and the wire drawing operation in semidry or dry condition. Prior studies were attempted to analyze the mechanism of improved drawing performances, such as reduced drawing force and improved lubrication characteristic. However, researches on design rule for ultrasonic vibration drawing system are not yet carried out. The principal objectives of this work are to design a set of tooling capable to superimpose the oscillations and to observe by experiments the influence of the ultrasonic oscillations on the wire drawing.

• 한국공작기계학회논문집
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• 제11권1호
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• pp.52-60
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• 2002

The purpose of this research is to study the vibration and acoustic pressure radiation from a thin isotropic flat plate stiffened by a rectangular array of beams, and excited by a time harmonic point force. These constructions on aircraft and ship structures are often subjected to fiequency dependent pressure fluctuations and forces. Forces from the these excitations induce structural vibrations in a wide range of fiequencies, which may cause such things as acoustic fatigue and internal cabin noise in the aircraft. It is thus important that the response characteristics and vibration modes of such periodic structures be horn. From this theoretical model, the sound pressure levels(SPL) in a semi-infinite fluid(water) bounded by the plate with the variation in the locations of an external time harmonic point farce on the plate can be calculated efficiently using three numerical tools such as the Gauss-jordan method the LU decomposition method md the IMSL numerical package.

• Restorative Dentistry and Endodontics
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• 제48권3호
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• pp.24.1-24.16
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• 2023

This review aimed to answer the following question "Does photobiomodulation treatment of the root surface decrease the occurrence of root resorption in reimplanted teeth?" Electronic searches were performed in the MEDLINE/PubMed, Cochrane Library, Scopus, Web of Science, Embase, and Grey Literature Report databases. Risk of bias was evaluated using SYRCLE Risk of Bias tool. The Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) tool was used to assess the certainty of evidence. In total, 6 studies were included. Five studies reported a reduced occurrence of root resorption in teeth that received photobiomodulation treatment of the root surface prior to replantation. Only 1 study reported contradictory results. The photobiomodulation parameters varied widely among studies. GRADE assessment showed a low certainty of evidence. It can be inferred that photobiomodulation treatment of the root surface prior to replantation of teeth can reduce the occurrence of root resorption. Nonetheless, further clinical studies are needed.

• Restorative Dentistry and Endodontics
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• 제49권2호
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• pp.22.1-22.12
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• 2024

Objectives: This systematic review addressed the question: "What is the prevalence of apical periodontitis in patients prior to hematopoietic cell transplantation?" Materials and Methods: A systematic search was conducted in MEDLINE/PubMed, Cochrane Library, Scopus, Web of Science, Embase, and Grey Literature Report. Eligibility criteria were based on the condition, content, and population strategy: the condition was the radiographic prevalence of apical periodontitis, the content comprised patients scheduled for hematopoietic stem cell transplantation, and the population consisted of adult and pediatric patients. The revised Risk of Bias in Nonrandomized Studies of Exposure tool was used to assess the quality of studies. The Grading Recommendations Assessments, Development, and Evaluation (GRADE) tool was used to assess the quality of evidence. Results: Eight studies were included in this review. The average number of patients with apical periodontitis was 15.65% (range, 2.1%-43.34%). One study was classified as having a very high risk of bias, 1 with a high risk of bias, and 6 with some concern for bias. GRADE analysis showed a very low certainty of evidence. Significant limitations concerning the absence of control over confounding variables were identified. Conclusions: With the caveat of the very low quality of evidence in the studies reviewed, there was a low to moderate prevalence of apical periodontitis in patients prior to undergoing hematopoietic cell transplantation.

• 한국생산제조학회지
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• 제26권3호
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• pp.344-349
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• 2017

In this study, we developed a process technology to fabricate RFID tag antennas using a one-sheet inlay micro-pattern forming process by press-molding RFID tag antennas on insulation sheet layers, such as polymer films, using ultrasonic longitudinal vibration. In addition, a fine pattern applicable for RFID tag antennas was manufactured using a $25{\mu}m$ thick thin-plate square wire; this is in contrast to the method that uses a conventional round wire. The developed ultrasonic indentation process can be used to fabricate fine pattern of the RFID antenna using one piece of equipment. The simplified manufacturing process technology has a shorter manufacturing time and is more economical. The developed RFID tag antenna forming technique involves pressing the $25{\mu}m$ square wire directly on the thin sheet insulation sheet of maximum thickness $200{\mu}m$, using a 60 kHz ultrasonic tool horn.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.250-253
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• 2002

The operation of surface and edge finishing is the last and essential process of parts machining, because a product is completed as an assembly. Therefore, the quality of the finished parts has a direct effect upon the performance of the product. Especially, the edge quality depending on the burr control process is very important. A number of deburring processes have been developed for macro burrs such as barreling, brushing, chemical methods, etc. However, micro burr removal when piercing a very thin plate is very difficult, because this badly deteriorates the surface quality of the processed part. When ultrasonic wave is propagated in liquids, it forms an infinitude of micro bubbles. These bubbles generate extremely strong force, which removes micro burrs. In ultrasonic micro deburring, the problem is that burrs are not removed completely, because only components of the explosive force directly act on the burrs, which is not enough. An attempt was made to remove the burrs using ultrasonic vibration in water with SiC as an abrasive agent. Because of the abrasive, smoother edges have been achieved. There are many control parameters in ultrasonic deburring such as abrasive size, ultrasonic frequency and amplitude, distance between tool and workpiece, tilt angle of workpiece etc. This study focuses on how distance and tilt angle influence deburring effect. A number of experiments for these parameters have been carried out, and then the effect of each parameter analyzed.

• 한국정밀공학회지
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• 제30권11호
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• pp.1121-1128
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• 2013

Ultrasonic grinding system is that the ultrasonic vibration by ultrasonic actuator is applied on conventional grinding system during grinding process. The Ultrasonic vibration with a frequency of over 20kHz can reduce grinding forces and increase surface quality, material removal rate (MRR) and grinding wheel life. In addition, ultrasonic vibration assisted grinding can be used for the materials that are difficult to cut. In this paper, methodology for ultrasonic tools is studied based on finite element method, and in turn the ultrasonic tools are designed and fabricated. It is found that the ultrasonic tool can vibrate with a frequency of 20kHz and amplitude of $25{\mu}m$. In order to verify the machining performance, the grinding experiment is performed on titanium alloy. By applying ultrasonic vibration, the grinding force and temperature are reduced and MRR is increased compared with the conventional grinding.