• Restorative Dentistry and Endodontics
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• v.22 no.2
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• pp.648-658
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• 1997

The purpose of this study was to compare the effects of various techniques on the quality and quantity of instrumentation in curved canals. Instrumentation time was evaluated too. Forty eight canals of resin blocks($35^{\circ}$) were divided into three groups and filed. In group A, 16 blocks were instrumented using a step-back technique with stainless steel(SS) K-file(Mani, Matsutani Seisakusho Co.,Japan). In group B, canals were prepared with SS K-files using the Endo-Angle (Nakanishi Dental MFG.CO.,LTD.,Japan). Group C was prepared using N i-Ti engine-driven instruments (Quantec Series $2000^{TM}$ system). Group A and B were filed from # 5 to # 25 at the apex followed by a 1 mm stepback technique, and the coronal half of the canals were flared with Gates Glidden burs(#2,3,4). Group C was instrumented from # 1 to # 8. After the instrumentation time was measured, canals were filled with India ink, and photographed, which to magnify the canal images 8 times. Using these photographs the apical portions were evaluated And scored from 1 to 4 according to the severity of ledging and zipping. On the same photographs, the area of the coronal two thirds of the canals were measured using a personal computer with the computer program Brain and Digitizer (SummaSketch III). The following results were obtained. 1. Instrumentation time was significantly shorter for group C, as opposed to group A and B(ANOVA, P<0.05). 2. The qualitative evaluation of the apical portions of the canals showed no significant difference between the groups(Kruscal-Wallis, p>0.05). 3. The area removed by group C was significantly smaller than group A and B(ANOVA, P<0.05).

• Journal of the Ergonomics Society of Korea
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• v.6 no.2
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• pp.19-28
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• 1987

If an error occurs in the automatic mode when the advanced teleoperator system performs a task in hostile environment, then the mode changes into the manual mode. The operation by program and the operation by hyman recover the error in the manual mode. The system resumew the automatic mode and continues the given task. In order to utilize the inverse kinematics as means of the operation by program in the manual mode, Lee and Nagamachi determined the end point of the robot trajectory planning which varied with the height of the task object recognized by a T.V monitor, solved the end point by the fuzzy set theory, and controlled the position of the robot hand by the inverse kinematics and the posture of the robot hand by the operation by human. But the operation by human did take a lot of task time because the position and the posture of the robot hand were separately controlled. To reduce the task time by human, this paper developes an error recovery expert system (ERES). The position of the robot hand is controlled by the inverse kinematics of the cartesian coordinate system to the end point which is deter- mined by the fuzzy set theory. The posture of the robot hand is controlled by the modulality of the robot hand's motion which is made by the posture of the task object. The knowledge base and the inference engine of the ERES is developed using the muLISP-86 language. The experimental results show that the average task time by human the ERES which was performed by the integration of the position and the posture control of the robot hand is shorter than that of the research, done by the preliminary experiment, which was performed by the separation of the position and the posture control of the robot hand. A further study is likely to research into an even more intelligent robot system control usint a superimposed display and digitizer which can present two-dimensional coordinate of the work space for the convenience of human interaction.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.05a
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• pp.602-607
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• 2002

In this paper, we proposed an approach to efficiently compress and transmit multiresoltion 3D lariat models for multimedia and very low bit rate applications. A personal facial model is obtained by a 3D laser digitizer, and further re-quantized at several resolutions according to different scope of applications, such as animation, video game, and video conference. By deforming 2D templates to match and re-quantize a 3D digitized facial model, we obtain its compressed model. In the present study, we create hierarchical 2D lariat wireframe templates are adapted according to facial feature points and the proposed piecewise chainlet affined transformation(PACT) method. The 3D digitized model after requantization are reduced significantly without perceptual loss. Moreover the proposed multiresoulation lariat models possessed of hierarchial data structure are apt to be progressively transmitted and displayed across internet.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.51 no.5
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• pp.213-221
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• 2002

In order to improve the reliability of XLPE cables, it is necessary to find the useful diagnostic parameter according to long term aging. This paper described the change of partial discharge(PD) phase Properties of XLPE cable insulation with branch type electrical tree degradation. for long term aging. To understand the PD Properties with $\phi$ -q-n distributed shape of XLPE insulation, specimens were prepared by 22.9㎸ distribution cable and made in a type of block(16${\times}$16${\times}$3[mm]). Ogura needles having tip radius of l0${\mu}{\textrm}{m}$ were inserted into each block pieces. The measuring system was consisted of PD detector, digitizer for digital conversion, VXI system for signal processing. The PD properties of the specimens were measured from initiation of tree to breakdown and their characteristics were analyzed. We analyzed the relationship between electrical properties(PD Quantity, PD initiation angle, PD extinction angle, PD occurrence angle : (PD extinction angle - PD initiation angle)) and the normalized aging rate. We found PD parameter, PD initiation angle and occurrence angle, which are a useful diagnostic parameter in estimating the branch type electrical tree for XLPE insulation condition.

• The Journal of Korean Academy of Prosthodontics
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• v.27 no.1
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• pp.55-81
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• 1989

Recently the instantaneous center concept has been to understand the biomechanics by which a tissue derangement causes a mechanical derangement in human joint. Therefore, to understand the biomechanics of temporomandibular joint (T.M.J.) as a part of human joint, it is necessary to clarify the instantaneous center of rotation (I.C.R.) in the mandibular movement. Twenty male subjects without T.M.J. disorder and mandibular deviation during the mandibular movement were selected for this study. The habitual opening and closing paths were recorded on the paper of the sagittal metal plate by two pencil markers connected to the resin open clutch attached on the lower teeth, which was designed for this study. The coordinates of the 33-target points and the 109-anatomical landmarks were obtained using a Summagraphic digitizer connected to a 18AT computer. The original raw data of the opening and closing paths were smoothed by B-spline curve fitting technique and then the I.C.R. pathways were determined mathematically by the computer using algorithm for finding the I.C.R. of a planer rigid body model. Also the opening and closing movements of the mandible were simulated according to the determined I.C.R. The results obtained from this study were as follows. 1. At the early opening and the last closing, I.C.R's were almost distributed around the mastoid process outside the mandibular body without the presence in the region of the mandibular condyle. 2. The I.C.R. pathway showed variable patterns to each subject at the opening and closing movements. 3. The K constant with uniform pattern was obtained by the rotation angle times the radius, which was assumed to the index of the mandibular movement. 4. The opening and closing movements of the mandible were simulated by the I.C.R. pathways at the habitual opening and closing movements. 5. The mandibular condyle was rotated or translated accordng to the relative rotation angle and radius of the determinant factors of K contant.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.6
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• pp.342-349
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• 2019

We describe and anlayzes the methodology and implementation results of H / W configuration and signal characteristics analysis algorithm for analyzing equipment for analyzing OFDMA physical layer based on 802.16e. Recently, demand for signal analysis of instruments that analyze these signals with the development of digital communication signals is rapidly increasing. Accordingly, it is necessary to develop signal analysis equipment capable of analyzing characteristics of a broadband communication signal using a wideband digital signal processing module. In this paper, we have studied the basic theory of OFDMA in order to devise a device capable of analyzing characterisitcs of broadband communication signals. Second, the structure of OFDMA transmitter/receiver was examined. Third, a wideband digitizer was implemented. we design Wimax signal analysis algorithm based on OFDMA among broadband communication methods and propose Wimax physical layer analysis S/W implementation through I, Q signals. The IF downconverter used the receiver module and the LO generation module of the spectrum analyzer. Quantitative analysis result is obtained through the algorithm of Wimax signal analysis by I, Q data.

• Radiation Oncology Journal
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• v.21 no.2
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• pp.167-173
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• 2003

Purpose: The purpose of this study was to evaluate whether a GafChromic film applied to stereotactic radiosurgery with a linear accelerator could provide information on the value for acceptance testing and quality control on the absolute dose and relative dose measurements and/or calculation of treatment planning system. Materials and methods: A spherical acrylic phantom, simulating a patient's head, was constructed from three points. The absolute and relative dose distributions could be measured by inserting a GafChromic film into the phantom. We tested the use of a calibrated GafChromic film (MD-55-2, Nuclear Associate, USA) for measuring the optical density. These measurements were achieved by irradiating the films with a dose of 0-112 Gy employing 6 MV photon. To verify the accuracy of the prescribed dose delivery to a target isocenter using a five arc beams (irradiated in 3 Gy per one beam) setup, calculated by the Linapel planning system the absolute dose and relative dose distribution using a GafChromic film were measured. All the irradiated films were digitized with a Lumiscan 75 laser digitizer and processed with the RIT113 film dosimetry system. Results: We verified the linearity of the Optical Density of a MD-55-2 GafChromic film, and measured the depth dose profile of the beam. The absolute dose delivered to the target was close to the prescribed dose of Linapel within an accuracy for the GafChromic film dosimetry (of $\pm$3$\%$), with a measurement uncertainty of $\pm$1 mm for the 50$\~$90$\%$ isodose lines. Conclusion: Our results have shown that the absolute dose and relative dose distribution curves obtained from a GafChromic film can provide information on the value for acceptance. To conclude the GafChromic flim is a convenient and useful dosimetry tool for linac based radiosurgery.

• The korean journal of orthodontics
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• v.28 no.5 s.70
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• pp.717-729
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• 1998

This study was done to estimate arch forms and dimensions at the bracket level where archwire was placed in Angle's Class I first premolars extraction cases. 60 post-treatment dental casts which had attained good orthodontic treatment results were used in this study Many landmarks and linear measurement items to describe arch forms and dimensions were determined and measured. With a computer system and digitizer, arch forms were described and linear measurement items were statistically analysed. The following results were obtained. 1. The average labial and lingual arch forms at the bracket level were obtained. 2. Arch forms were expressed by parabolic equations and coefficients of determination. 3. Arch widths were larger in male than in female. 4. There were statistical significances in upper intercanine width, upper interfirst molar width, upper intersecond molar height, lower intercanine width and lower interfirst molar width between both sexes (p<0.05, p<0.01). 5. Interfirst molar width differences between maxilla and mandible were 6.43mm in male and 6.05mm in female.

• The korean journal of orthodontics
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• v.33 no.3 s.98
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• pp.157-167
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• 2003

The purpose of this study was to find whether there is a correlation between tooth size and jaw size. Dental stone models and cephalometric radiographic films of 87 untreated individuals were evaluated. Repeated measurements of the maximum mesiodistal width of the teeth were taken by means of a digital vernier caliper. Linear measurements of jaw size were assessed by means of a digitizer and Visual C++ program. All measurements were taken separately according to the subject's gender. To determine the relationship between jaw and tooth size, the Pearson correlation was used. The results were as follows: 1. Male and female subjects showed a statistical difference in regard to tooth size and jaw size 2. In contrast to the results of the male subjects, there were no statistically significant correlations between maxillary size and maxillary teeth size in female subjects 3. In male subjects, the two maxillary sizes of PTM vert-ANS vert (FH plane) and PTM vert-A yen (palatal plane) were significantly correlated with themaxillary teeth size. Especially, the size of the upper central incisor showed significant correlation with all maxillary sizes. 4. In both male and female subjects, mandibular size B vert- Point J vert (mandibular plane) showed significant correlation with mandibular teeth size. As gleaned kom the results of this study, the relationship between jaw size and tooth size was fair or little in natural occurring good occlusion.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2002.02a
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• pp.479-485
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• 2002

본 연구는 초음파를 이용하여 한우도체의 연도를 비파괴적이며 객관적으로 측정할 수 있는 시스템을 개발하기 위해서 수행되었다. 한우도체 연도 측정 시스템은 크게 초음파 측정장치, 자동 탐촉자 수직이동장치, 데이터 획득 및 분석장치로 구성되었는데 초음파 측정장치는 초음파 pulser/receiver 및 탐촉자, 자동 탐촉자 이동장치는 상하운동부, 구동부, 제어부, 데이터 획득 및 분석장치는 digitizer, Labview 5.1을 사용하여 구성되었다. 통합된 시스템을 이용하여 획득된 도체의 초음파 신호를 분석하기 위해 1.0~1.1 MHz의 bandpass filtering을 거쳐 hilbert 변환을 이용, envelope를 구할 수 있었으며 탐촉자와 도체의 최적 접촉 위치를 결정하기 위하여 3단계로 나누어 신호분석을 실시하였다. 시료의 개수는 40개였으며 획득된 envelope를 FFT 변환 후 PLS, PCR 분석을 수행한 결과 7단계의 PCR 분석에서 $R^2$= 0.6474의 유의성 있는 결과를 나타내었으므로 최적 접촉 위치로 결정하였다. 최적 접촉 위치를 통해 시료 80개의 추가 실험을 실시한 결과 PCR 분석에서 $R^2$= 0.4304의 결과를 나타내었으며 이를 이용, 도체의 연도를 측정하는 프로그램을 개발하고 최종 통합 시스템을 구축하였다. 본 한우도체 연도 측정 시스템의 개발을 통해 한우도체의 전단력을 예측하여 연도를 객관적으로 판정 가능할 것으로 생각되며 또한 사이즈의 확대로 도축장에 설치하는 설비로서 가능할 것이라 사료된다. 그러나 추후 좀 더 세밀한 측정과 결과의 보완을 위한 분석방법의 개선에 관한 연구가 진행되어야 할 것이다. 사용해 설계된 장치를 사용자가 쉽게 제작할 수 있도록 하였다. 공정설계프로그램을 통해 설계된 공정은 데이터베이스에 저장이 되며 장치설계프로그램에서 쉽게 이전에 설계했던 공정을 이용할 수 있도록 하여 공정 설계와 장치설계를 연계하도록 하였다.동투하시간과 비용 -종자준비부터 통마늘선별까지의 일관기계화로 투입된 주요작업의 노력은 75∼76%가 절감되고, 재배규모 3ha기준시 비용은 44-53%절감되었음. the annealing texture. Observations by TEM and EBSD revealed the formation of very fine grains of ∼1.0$\mu\textrm{m}$ after CCSS.he dislocations form local defect arrangements at the grooves permitting the substantial reduction in defect density over the remainder of the interfacial area.한 최대의 감자 재배지역을 형성하였다. 제주도는 산지지형과 따뜻한 기온으로 2기작이 가능하고, 감자가공 공장설립과 교통발달에 따른 육지 시장과의 접근이 용이해졌기 때문에 남한에서 2번째로 큰 감자재배지역이 되었다.(요약 및 결론에서 발췌)그람양성균에서 효과적이었으며, 농도별 항균력시험 결과 농도가 증가할수록 비례하여 저해율도 증가함을 알 수 있었다. 첨가농도를 달리하여 미생물의 생육도를 측정한 결과, fraction II磎꼭\ulcorner경우 그람양성균에 대해 500 ppm 이상에서 뚜렷한 증식억제효과를 나타내었다.서 뚜렷한 증식억제효과를 나타내었다.min/+}$계