• Title/Summary/Keyword: geometrical characteristic

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Scan Manifestation and Trace-Dose Radiogold Clearance Rates in Obstructive Jaundice (폐쇄성(閉鎖性) 황달의 진단에 관한 핵의학적(核醫學的) 고찰)

  • Kim, Dong-Jip;Bahk, Yong-Whee;Shinn, Kyung-Sub
    • The Korean Journal of Nuclear Medicine
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    • v.3 no.2
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    • pp.49-54
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    • 1969
  • The present study has been undertaken to analyze scan manifestations in obstructive jaundice. Scan changes were cprrelated with the duration of jaundice. In addition, clearance rates of trace dose of colloidal radiogold were assessed in each case. The materials were consisted of 19 cases with surgically and/or histopathlogically verified obstructive jaundice from various causes including common duct stone, empyema of the gall bladder and carcinoma of the pancreas head etc. Blood clearance rates of colloidal $^{198}Au$ were determined after the injection of 8 uCi by simple geometrical drawing of recorded strip charts. Scan was performed following additional injection of the same radiogold. In 16 out of 19 cases, the scan revealed rather typical "arborifrom" mottlings around the porta hepatis. The intensity and appearance of such mottlings on the scan was related with the duration of jaundice and level of serum bilirubin and alkaline phosphatase. The blood clearance rates remained to be within normal range in 74 percent of the patients. In the remaining 26 percent, clearance rates ranged between 4.1 and 6 minutes. It is concluded that the association of "arboriform" mottlings and normal or mildly delayed clearance rates in the patients with jaundice is characteristic of obstructive changes in the biliary system.

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Hand Gesture Sequence Recognition using Morphological Chain Code Edge Vector (형태론적 체인코드 에지벡터를 이용한 핸드 제스처 시퀀스 인식)

  • Lee Kang-Ho;Choi Jong-Ho
    • Journal of the Korea Society of Computer and Information
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    • v.9 no.4 s.32
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    • pp.85-91
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    • 2004
  • The use of gestures provides an attractive alternate to cumbersome interface devices for human-computer interaction. This has motivated a very active research area concerned with computer vision-based analysis and interpretation of hand gestures The most important issues in gesture recognition are the simplification of algorithm and the reduction of processing time. The mathematical morphology based on geometrical set theory is best used to perform the processing. The key idea of proposed algorithm is to track a trajectory of center points in primitive elements extracted by morphological shape decomposition. The trajectory of morphological center points includes the information on shape orientation. Based on this characteristic we proposed the morphological gesture sequence recognition algorithm using feature vectors calculated to the trajectory of morphological center points. Through the experiment, we demonstrated the efficiency of proposed algorithm.

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A Study on Many Pleated Skirt of Miao Women's Guizhou Province in China (중국 귀주성 마이오족여성의 백습군에 관한 연구)

  • Kim, Young-Sin
    • Fashion & Textile Research Journal
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    • v.6 no.3
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    • pp.307-313
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    • 2004
  • The Purpose of this study is to investigated characteristics of many pleated skirt of Miao women's Guizhou province in China. The method of this study is referd to sundry recordes and demonstrated traditional clothing of several region in Guizhou province. The most important characteristic of the costume of the Miao is the many pleated skirt, worn by most but not all groups. Pleats are pulled into place with a sharp pointed instrument and sprinkled constantly with starch. The length of the pleated skirt depends on the group. The long skirts reach to the ankle, the medium-sized to the shank and the short ones not below the knee. The design of the pleated skirt is simple but most pleated skirt ornamented with fine, cross-stiched or batic designs of geometrical figures. The figures decorated on the pleated skirt has been handed down with little change from generation to generation and has become an important mark of Miao women's each area. Seeing the many pleated skirt of Miaos investigated in these several respects by the standard of contemporary beauty, it is thought that it has the infinite possibility of being used in contemporary fashion design on account of the characteristics of almost perfect costume.

Fire Resistance Characteristics of Polyolefin cable Insulating Materials for Flame Retardant (난연성 폴리 올레핀 케이블 절연재료의 내화특성)

  • Yoon, Hun-Ju;Hong, Jin-Woong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11b
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    • pp.251-254
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    • 2001
  • In this paper, we analyzed the properties change of electric wire when the thermal stress was applied to NFR-8 and FR-PVC 600[V] wire. Messurement is made of the attenuation of a light beam by smoke accumulating with in a closed chamber due to nonflaming pyrolytic decomposition and flaming combustion. Results are expressed in terms of specific optical density which is derived from a geometrical factor and the measured optical density a measurement characteristic of the concentration of smoke. Referenced documents were ASTM E662 standard test method for specific Ds genalated by solid materials. The furnace control system shall maintain the required irradiance level under steady-state condition with the chamber door closed of $2.5{\pm}0.04[w/cm^{2}]$ for 20 min. According to the results of the smoke density analysis of NFR-8 and FR-PVC the highest decomposition flaming smoke density range of NFR-8 and FR-PVC were 25.2 to 37.5 and 51.1 respectively. Nonflaming smoke density range of NFR-8 and FR-PVC were 100.4 to 112.2 and 126.5 to 398.8. The amount of carbon monoxide generated was found to be much higher in FR-PVC decomposition than in NFR-8 due to incomplete combustion of FR-PVC which has high content of carbon in compound.

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Characteristic Analysis of Planetary Gear Set of Hydromechanical Transmission System of Agricultural Tractors

  • Park, Young-Jun;Kim, Jeong-Gil;Lee, Geun-Ho
    • Journal of Biosystems Engineering
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    • v.41 no.3
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    • pp.145-152
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    • 2016
  • Purpose: This study aims to establish the effect of pinhole position errors in the planet carrier of a planetary gear set (PGS) on load sharing among the planet gears in the hydromechanical transmission (HMT) system of an agricultural tractor. Methods: A simulation model of a PGS with five planet gears was developed to analyze load sharing among the planet gears. The simulation model was verified by comparing i ts r esults w ith those of a model developed in a previous s tudy. The verified simulation model was used to analyze the load-sharing characteristics of the planet gears with respect to the pinhole position error and the input torque to the PGS. Results: Both simulation models had identical load magnitude sequences for the five planet gears. However, the load magnitudes on the corresponding planet gears differed between the models because of the different stiffnesses of the PGS components and the input torques to the PGS. The verified simulation model demonstrated that the evenness of load sharing among the planet gears increases with decreasing pinhole position error and increasing input torque. Conclusions: The geometrical tolerance of the pinhole position should be properly considered during the design of the planet carrier to improve the service life of the PGS and load sharing among the planet gears.

Prediction of Shape Accuracy in Elastomer-Forming of a Cylindrical Tube by a Response Surface Method (반응표면법을 이용한 실린더 튜브 고탄성체 성형의 형상 정확도 예측)

  • Kim, K.T.;Lee, G.A.;Choi, S.;Lee, H.W.;Lee, Y.S.
    • Transactions of Materials Processing
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    • v.17 no.3
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    • pp.218-224
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    • 2008
  • A recent trend in automotive parts has been an integration of sub-assemblies with unified shapes. Tube structures also have been integrated to one body structure by using a near net shape forming instead of adopting welding. A cylindrical elastomer-forming process can be utilized to form a steel tube compressed in a radial direction. This process has some advantages compared to a hydro-forming or a swaging process in the viewpoint of a lower investment and a higher productivity. In order to predict a feasible specification of products within a work capability of the elastomer-forming equipment developed previously, effects of geometrical parameters of a tube on its shape accuracy are examined. Two characteristic parameters to account for the shape accuracy are chosen. One is the curvature radius at the corner part and the other is the straight ratio of the formed region. Careful examination of two parameters has led that the shape accuracy can be easily predicted by the regression equation obtained from the response surface method.

Modeling of the Mechanical Drivetrain of an Electric Vehicle for Investigation of Torsional Oscillation Characteristics (전기자동차 기계적 구동계의 모델링 및 비틀림 진동특성 분석)

  • Kim, Ho-Gi;Oh, Joong-Seok;Kim, Sam-Kyun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.32 no.10
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    • pp.866-872
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    • 2008
  • Torsional oscillations of the mechanical drivetrain in electric vehicles are generated under rapid driving conditions. These lead to an uncomfortable jerking of the vehicle and to an increased stress of the mechanical components. To analyze this phenomenon, a drivetrain model is constructed with lumped parameters. The model parameters are identified by geometrical design data and experimental tests. The proposed model is validated by simulation and experimental tests in the time and the frequency domains. As a result, the torsional oscillations are observed at 7Hz of a low damped natural frequency. Also, the analysis of the effect of the parameter variations on the oscillations shows that the oscillation characteristic is mainly dependent on the rotor inertia, and the stiffness of the mounting of the drive aggregate and the driveshaft. The results will be utilized on the basis of the design of an electric drivetrain and an active control of drivetrain oscillations.

Effect of Combustors and Propellant Parameters on the L* Instability of Solid Rocket Motors (연소실 및 추진제 변화에 따른 고체로켓 모터의 L* 불안정에 관한 연구)

  • Lee, Donghee;Ryu, Seunghyun;Joo, Seongmin;Kim, Junseong;Moon, Heejang;Sung, Honggye;Yang, Juneseo
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.23 no.4
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    • pp.30-35
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    • 2015
  • In this paper, a theoretical study of low frequency non acoustic instability, the $L^*$ instability, of a solid rocket motor is investigated. The $L^*$ stability criterion is determined by analysing the $L^*$ stability curves of two very distinct propellants for five different geometrical combustors. The $L^*$ instability of two extreme fuels showed totally different behavior in terms of operating pressure of the combustor. A parametric study on the stability for different chamber volume and different throat area keeping constant $L^*$ is conducted and analyzed. It was found that one of the main parameters, the non-dimensional critical characteristic time, requires an enough margin from the critical $L^*$ stability curve.

Correction of Single Photon Emission CT Image Distorted by Collimator Characteristic (시준기의 특성으로 인한 SPECT 왜곡 화상의 보정)

  • 백승권
    • Journal of the Institute of Convergence Signal Processing
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    • v.5 no.1
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    • pp.18-24
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    • 2004
  • SPECT technology is used for the reconstructed image in the field of industry noncontact measurement system. One of the distortion problems in reconstructed image quality is a collimator characterictic. The image distortion is caused by a geometrical structure of the collimator. This paper indicated a correction method to remove the image distortion by the structure of the collimator, and compared with the existing correction method. The correction. method removed the image distortion to use deconvolution of projection data with the shift-variant blurring function in the frequency domain. In this pater, I simulated with the collimator angle and distance between the detector and the center of object. and verified with expeimental data. The validity and limitation of correction method is studied for actual industrial applications.

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A Numerical Study on the Heat Transfer Characteristics of the Multiple Slot Impinging Jet (다양한 노즐 수 변화에 따른 충돌 제트의 열전달 특성에 관한 수치적 연구)

  • Kim, Sang-Keun;Ha, Man-Yeong;Son, Chang-Min
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.23 no.11
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    • pp.754-761
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    • 2011
  • The present study numerically investigates two-dimensional flow and heat transfer in the multiple confined impinging slot jet. Numerical simulations are performed for the different Reynolds numbers(Re=100 and 200) in the range of nozzles from 1 to 9 and height ratios(H/D) from 2 to 5, where H/D is the ratio of the channel height to the slot width. The vector plots of velocity profile, stagnation and averaged Nusselt number distributions are presented in this paper. The dependency of thermal fields on the Reynolds number, nozzle number and height ratio can be clarified by observing the Nusselt number as heat transfer characteristic at the stagnation point and impingement surface. The Nusselt number at the stagnation point of the central slot shows unsteadiness at H/D=3 and Re=200. The value of Nusselt number at the stagnation point of the central slot decreases with higher Reynolds number and number of nozzle although overall area averaged Nusselt number increases. Hence careful selection of geometrical parameters and number of nozzle are necessary for optimization of the heat transfer performance of multiple slot impinging jet.