• Applied Science and Convergence Technology
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• 제24권5호
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• pp.136-141
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• 2015

We studied the compact anode design to develop 100 kW rotating anode X-ray tube with large focal spot 1.2 mm, small focal spot 0.6 mm and tube voltage 150 kV for large hospital digital radiography using computer thermal simulation. The larger thermal radiation effect in a high vacuum can reduce the temperature of anode so the method to increase the surface area of anode is investigated. The anode has the multi-tier shape at the back side of TZM body of anode and also bigger diameter of anode. The number of multi-tiers was varied from 6 to 15 and the diameter of anode was also varied from ${\Phi}74$ to ${\Phi}82$. From ANSYS transient thermal simulation result, we could obtain $1056.4^{\circ}C$ anode maximum temperature when applying 100 kW input power at 0.1 second on target focal track which is less than $1091^{\circ}C$ of the conventional 75 kW X-ray tube with reduced anode weight by 15.5% than the conventional anode. The compact anode of reduced anode weight is able to improve the unwanted noise when the rotor is rotating at high-speed and also reduce the rotational torque which the cost effective stator-coil is possible. It is believed that the anode with 15 ea multi-tiers using ${\Phi}82$ can satisfy with the specification of the anode heat capacity. From the results of this paper, it has been confirmed that the proposed compact anode can be used as the anode of 100 kW rotating anode X-ray tube for digital radiography.

• 제어로봇시스템학회논문지
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• 제10권12호
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• pp.1164-1171
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• 2004

A new multi-scale simulation model is proposed to analyze heart mechanics. Electrophysiology of a cardiac cell is numerically approximated using the previous model of human ventricular myocyte. The ion transports across cell membrane initiated by action potential induce an excitation-contraction mechanism in the cell via cross bridge dynamics. Negroni and Lascano model (NL model) is employed to calculate the tension of cross bridge which is closely related to the ion dynamics in cytoplasm. To convert the tension on cell level into contraction force of cardiac muscle, we introduce a simple geometric model of ventricle with a thin-walled hemispheric shape. It is assumed that cardiac tissue is composed of a set of cardiac myocytes and its orientation on the hemispheric surface of ventricle remains constant everywhere in the domain. Application of Laplace law to the ventricle model enables us to determine the ventricular pressure that induces blood circulation in a body. A lumped parameter model with 7 compartments is utilized to describe the systemic circulation interacting with the cardiac cell mechanism via NL model and Laplace law. Numerical simulation shows that the ion transports in cell level eventually generate blood hemodynamics on system level via cross bridge dynamics and Laplace law. Computational results using the present multi-scale model are well compared with the existing ones. Especially it is shown that the typical characteristics of heart mechanics, such as pressure volume relation, stroke volume and ejection fraction, can be generated by the present multi-scale cardiovascular model, covering from cardiac cells to circulation system.

• 대한치과교정학회지
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• 제19권1호
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• pp.187-200
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• 1989

The purpose of this study was to find out the craniofacial skeletal characteristics and to establish standards in facial patterns of Korean adolescences with normal occlusion. The subjects consisted of 54 males and 71 females ranging in age from 12 to 16 years. To classify facial patrons, number the clinical deviations from the normal five key measurements: the facial axis, facial angle, mandibular plane angle, lower face height, mandibular arc, are added and averaged with the proper sign to divide subjects into three groups ; brachyfacial, mesofacial dolichofacial groups. For the comparison of each group, a total of 43 morphologic variables were employed and the data were analyzed by statistical methods. The findings of this study can be summerized as follows; 1. The mesofacial group was $54.4\%$, the brachyfacial group was $29.6\%$ and the dolichofacial group was $16.0\%$ in this subjects. 2. There were no significant differences in size and shape of cranial base among each groups. 3. The brachyfacial group manifested the forward positioned maxilla and mandible to anterior cranial base, smaller cant of the mandibular plane, square shaped mandible, and prominent symphysis as compared with dolichofacial group. 4. There were no significant differences in the cant of the maxilla to the anterior cranial base among each groups. 5. Ramal height and madibular body length of brachyfacial group were larger than those of dolichofacial group. 6. Brachyfacial group indicated the smallest degree in divergency of maxilla and mandible while dolichofacial group showed the largest degree.

• 한국어병학회지
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• 제10권2호
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• pp.177-186
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• 1997

양식넙치에서 분리한 스쿠티카섬모충을 배양배지(P2Y1-DW배지)를 사용하여 순수분리한 후 배양온도에 의한 성장시험, 6종류 배양배지에서의 성장시험, 약제감수성시험을 하였다. 배양온도시험에서는 $25^{\circ}C$에서 $1.50{\times}10^3$충체/ml로 가장 좋았고, $15^{\circ}C$가 $1.03{\times}10^2$ 충체/ml로 가장 낮았다. 6종류의 배양배지에서의 성장시험에서는 3일째에 P1Y1-S배지가 $2.6{\times}10^4$ 충체/ml로 가장 좋았으며 DW배지에서가 $2.0{\times}10^2$ 충체/ml로 가장 낮았다. 5일째에는 배양배지 모두 감소하는 경향을 나타내었다. 스쿠티카섬모충의 분열방법은 앞부분을 밑으로 부착한 후 형태가 점점 서양배모양으로 변하고 시간이 경과함에 따라 2개의 세포로 분열하여 유영하다가 성충크기인 $40{\mu}m$로 되는데 부착개시부터 성충까지 소요되는 시간은 대략 3시간 전후였다.

• Tribology and Lubricants
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• 제32권2호
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• pp.50-55
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• 2016

Recently, a double-side machining process has been adopted in fabricating a sapphire glass to enhance the manufacturability. Double-side lap grinding (DLG) is one of the emerging processes that can reduce process steps in the fabrication of sapphire glasses. The DLG process uses two-body abrasion with fixed abrasives including pallet. This process is designed to have a low pressure and high rotational speed in order to obtain the required material removal rate. Thus, the temperature is distributed on the DLG platen during the process. This distribution affects the shape of the substrate after the DLG process. The coolant that is supplied into the cooling channel carved in the base platen can help to control the temperature distribution of the DLG platen. This paper presents the results of computational fluid dynamics with regard to the heat transfer in a DLG platen, which can be used for fabricating a sapphire glass. The simulation conditions were 200 rpm of rotational speed, 50℃ of frictional temperature on the pallet, and 20℃ of coolant temperature. The five cases of the coolant flow rate (20~36 l/min) were simulated with a tetrahedral mesh and prism mesh. The simulation results show that the capacity of the generated cooling system can be used for newly developed DLG machines. Moreover, the simulation results may provide a process parameter influencing the uniformity of the sapphire glass in the DLG process.

• 정보처리학회논문지B
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• 제11B권6호
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• pp.683-690
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• 2004

3차원 의상 모델링과 시뮬레이션은. 디지털 콘텐츠에서 중요한 요소가 되었다. 이를 위한 여러 도구들이 개발되었으나, 고유한 의복을 표현하는 가상 의상의 디자인은 그래픽 디자이너에게 어려운 작업이며 의상에 대한 전문지식을 필요로 한다. 특히, 한복의 경우는 옷감, 재단방식, 착용법 등에서 양복과는 구성학적 차이점을 지니므로 모델링이 더욱 어렵다. 본 연구에서는 한복 제작에 대한 전문성이 없이도 한복을 쉽게 모델링 할 수 있도록 하는 지식 기반 접근법을 제안한다. 특히, 실사 및 가상 옷감의 시각적 유사성 판단 방법에 의해 옷감 소재 특성 규칙베이스를 구축하고, 신체 특성이 다른 캐릭터들의 체형 특성을 반영한 한복 사이즈의 부분별 다단계 조정 방법을 지식베이스 화하였다. 제안된 지식 기반 모델링 방법은 마야의 플러그-인으로서 제작되었고 다양한 신체형에 대한 드레이핑(착용 시뮬레이션) 실험을 통해 적용 가능성을 보였다.

• 터널과지하공간
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• 제28권2호
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• pp.142-155
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• 2018

${\bigcirc}{\bigcirc}$광산은 광체주변에 미고결된 층서가 불규칙하게 발달되어 있다. 본 연구는 효율적인 루프볼트(roof bolt) 시공을 위하여 불규칙한 층서의 두께를 체계적으로 배열하고 이에 대응하는 지보시스템을 제시한 것이다. 층서별 두께를 조합한 81개의 경우의 수를 강건설계에 의하여 9개의 사례로 한정하여 지보설계를 하였다. 각 사례에 대하여 천반하중으로 작용할 수 있는 하중고를 층서의 특성과 RMR에 의하여 결정하였다. 하중고에 의한 하중범위를 블록형상과 아치형상으로 가정하여 계산하였다. 두 방법의 평균하중으로 루프볼트의 지보력을 감안한 지보설계를 하였다. 지보설계에 대한 수치해석 결과 케이블 볼트는 선단정착 방식보다 전면접착 방식이 천반유지에 더 효과적인 것으로 분석되었다. 시공결과 천반의 컨트롤은 가능하였으나 갱도측벽의 변형으로 천반 전체가 하부로 조금씩 침강하는 현상을 보였다.

• 복식
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• 제59권3호
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• pp.67-81
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• 2009

Body shape of a child in elementary school is distinguished by physical differences in the form of low weight, normal weight and obesity, which are influenced by various periodic environments. In particular, there are hardly any patterns for obese children in elementary school to choose. To this end, the purpose of this study is to supplement the problems with the production lines of the companies for children's patterns as well as an analysis on the physical characteristics of obese children and to suggest the patterns appropriate to obese children. This study employed obese children from the 3rd- to 5th-grade elementary school students whose number has been rapidly increasing and conducted a questionnaire regarding the draft of the patterns for obese children on their mothers and the makers of children's clothing. Based on the results, the study compared and analyzed ordinary children's patterns to the patterns in question by suggesting a dimension system for Korean obese children. The results are as follows. The obesity rate of the children in elementary school has been grown in significant numbers every year, whereas obese children's sense of self-identity and degree of satisfaction with their patterns appeared to be much lower than other ordinary children in the peer group; also, the satisfaction level their mothers with their children's patterns appeared to be low. In order to verify the degree of the children's satisfaction with their patterns, the study suggested a dimension system for the obese children and displayed appropriateness by comparing the children patterns from ordinary companies and the patterns in question.

• Parasites, Hosts and Diseases
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• 제46권2호
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• pp.87-90
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• 2008

Gynaecotyla squatarolae (Digenea: Microphallidae) adult flukes were recovered from experimental chicks at day 4-6 post-infection and their tegumental ultrastructure was observed with a scanning electron microscopy. They were pyriform in shape, and their anterior halves were concaved ventrally. The whole body surface was covered with tegumental spines, which were wide and 16-17 digitated between oral and ventral suckers. The density of spines and number of digits decreased posteriorly. The oral sucker was subterminal and the excretory pore was at the posterior end of the worm. Two ventral suckers were similar in appearance and protruded near midline of the worm. The genital atrium was dextral to the small ventral sucker. The dorsal surface was covered with tegumental spines, but the spines were sparser than on the ventral surface. On the middle portion of the dorsal surface, a small opening presumed to be the Laurer's canal was seen. From these findings, it has been confirmed that the adult G. squatarolae has unique characteristics in the surface ultrastructure.

• 한국콘텐츠학회논문지
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• 제10권10호
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• pp.172-179
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• 2010

물질에 대한 본질과 그 안에 내재된 시지각적 구조에 대한 관심으로부터 시작된 본 작품연구의 목적은 분자의 형태상 특징인 원, 선과 같은 단순기하형을 시공간에서 입체화시켜 이들 간의 결합이 갖은 조형적 연속성을 표현하는데 있다. 이와 같은 목적으로 현대미술에서의 기하형태는 무엇이며, 분자구조의 구조적 결합과 상징성이 어떠하였는가를 살펴보았으며, 이러한 고찰을 바탕으로 분자구조의 단순기하형태를 입체화시켜 단위체간의 반복적인 결합에서 오는 연속적인 조형성을 표출하였다. 작업의 유형은 분자모형과 전자현미경상에서 보이는 분자를 선을 매개체로 사용하여 단위체를 결합하는 방법과 단위체간을 직접 결합하는 방법으로 신체장신구와 금속조형물을 표현해 보았다. 결국은 단위체간의 직접결합을 통한 "분할과 복제의 연속성" 및 구와 곡선과 같은 분자이미지를 입체화 시킨 단순기하형들의 결합에서 오는 "순환적 연속성"이 공간적 구성에서 발생하는 조형화를 시도해 보았다.