• Title/Summary/Keyword: Cusp angle

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A Inclined Slot-excited Circular Plasma Source with a Cusp Magnetic Field

  • You, H.J.;Kim, D.W.;Koo, M.;Jang, S.W.;Jung, Y.H.;Lee, B.J.
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.02a
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    • pp.435-435
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    • 2010
  • A inclined slot-excited plasma source is newly designed and constructed for higher flux HNB(Hyperthermal Neutral Beam) generation. The present source is different from the vertical SLAN(SLot ANtenna) sources [1] in two aspects. One is that the slots are inclined, and the other is that the magnetic field is configured to a cusp type. These modifications are intended to make the source plasma operated in sub-milli-torr pressure regime and as thin as possible, both of which is to get higher HNB flux by decreasing the re-ionization rate of the reflected atoms from the neutralizer [2]. The plasma is generated in a quartz tube of internal diameter 170 mm enclosed in a aluminum application chamber of larger diameter 250 mm. The microwave power is fed to the plasma chamber by 8 inclined slots cut into the application chamber wall. The slots are coupled the chamber to a WR280 waveguide wound around it to form a ring resonator. In order to make two slots $\lambda_g/2$ apart in phase, the adjacent slots are rotated in opposite directions. The rotation angle of the slots are set to $60^{\circ}$ from the chamber axis. Between the quartz chamber and the aluminum cylindrical chamber 8 NdFeB magnets are equally spaced and fixed to form the cusp magnetic field confinement and ECR (Electron Cyclotron Resonance) field. In this presentation, the magnetic and electromagnetic simulations, and the measured plasma parameters are given for both the inclined and the vertical slot-excited plasma sources. We also discuss how the sources can be tailored to suit better-performing HNB sources.

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A Study on the Attrition of Maxillary Canine in Korea (상악 견치의 교모에 관한 연구)

  • Lim, Byung-Chul
    • Journal of Technologic Dentistry
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    • v.19 no.1
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    • pp.121-130
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    • 1997
  • This study was aimed to help the construction of naturally dental prosthesis by investigation of the factors affecting on the attrition position and attrition angle of maxillary canines. Therefore 163 complete cast of maxillary and mandibular extracted from the student of K. college were subjected for this study, and result through the study are as follows. 1. None attrite rate of the maxillary canine was 7%, of examined teeth. 2. Throughout mesiodistal attrition of 1) Throughout mesiodistal attrition area of the maxillary canines showed that mesial area and mid area of cusp was more frequence in attrition than distal area of it. 2) Sex, dental arch type, vertical overlap, horizontal overlap, did not affect significantly to throughtout mesiodistal attrition statistically 3. Througout labiolingual attrition area 1) Throughout labiolingual attrition area of the maxillary canines showed that attrition of the from lingual to labioncisal edge was more frequence than it of linguoincisal edge 2) It showed that attrition of the from lingual to labioincisal edge was more frequence when the length of horizontal overlap is shorter, by horizontal overlap 3) The attrition of the from lingual to labioincisal edge in maxillary left canines showed that male was more frequence in attrition than female. 4) Dental arch type, vertical overlap, did not affect signioficantly to labiolingual attrition, statistically. 4. Attrition angle 1) It showed that average attrition angle of the maxillary right canines were $19{\pm}11.02$ dagree, and it of left canines were $18{\pm}11.83$ degree. 2) It showed that famale have a bigger attrition angle than male, by sex. 3) It showed that attrition angle was bigger when the length of horizontal ovelap is bigger, by horizontal overlap.

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The Prevalence Study of TMD and the Associated Factors in Korean Malocclusion Patients (한국인 부정교합자의 측두하악장애(TMD) 유병율과 그 기여요인에 관한 연구)

  • Kim, Myung-Hee;Nahm, Dong-Seok
    • The korean journal of orthodontics
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    • v.27 no.4 s.63
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    • pp.523-538
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    • 1997
  • In order to investigate TMD prevalence in malocclusion patients and to study its relationship with occlusal factors, 205 malocclusion patients (M67, F138, 6Y1M-46Y8M) were examined. The following examinations were carried out, Questionnaire personal history, TMD symptoms, and the associated factors Clinical examination : TMJ sound and maximum mouth opening Orthopantomogram : condyle abnormalities, length of Co'-Inc' and Co'-Go', ratio Co'- Inc'/ Co'-Go', and depth of antegonial notch Transcranial view limitation of anterior movement of condyle Model Angle classification, overjet, overbite, midline discrepancy, missing of posterior teeth, posterior crossbite, attrition of palatal cusp of maxillary molars, crowding/spacing The results could be summarized as follows, 1. The prevalence of TMD showed that Helkimo Anamestic Inder(Ai) 0 was $46.8\%$, Ai I was $22.0\%$, Ai II was $31.2\%$ and subjective symptoms increased with aging (p<0.001) and were frequent in females (p<0.05). 2. Flattening ($4.4\%$) was the most frequent condyle abnormality on Orthopantomogram, and $8.3\%$ of subjects showed some abnormalities on Orthopantomogram. 3. The cases with neck and shoulder pain (p<0.001), clenching, lip biting (p<0.01), and headache (p<0.05) showed higher scores of Ai. 4. Angle class II showed high frequency of condylar abnormalities on Orthopantomogram, and subjects whose palatal cusp of maxillary molars had been attrided had the tendency to show high hi scores (p<0.05). The other occlusal factors had nothing to do with the symptoms of TMD. 5. In the cases that 1)the value of Co'-Inc', Co'-Go' or Co'-Inc'/Co'-Go' were low or 2)the differences of Co'-Go' or Co'-Inc'/Co'-Go' between the right and the left were large, condylar abnormalities were frequently obserbed on Orthopantomogram.

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Optimum Design on Lobe Shapes of Gerotor Oil Pump

  • Kim, J.H.;Kim, Chul;Chang, Y.J.
    • Journal of Mechanical Science and Technology
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    • v.20 no.9
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    • pp.1390-1398
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    • 2006
  • A gerotor pump is suitable for oil hydraulics of machine tools, automotive engines, compressors, constructions and other various applications. In particular the pump is an essential machine element that feeds lubricant oil in an automotive engine. The subject of this paper is the theoretical analysis of internal lobe pump whose the main components are the two rotors. Usually the outer one is characterized by lobes with a circular shape, while the inner rotor profile is determined as a conjugate to the other. For this reason the first topic presented here is the definition of the geometry of the rotors starting from the design parameters. The choice of these parameters is subject to some limitations in order to limit the pressure angle between the rotors. Now we will consider the design optimization. The first step is the determination of the instantaneous flow rate as a function of the design parameter. This allows us to calculate three performance indexes commonly used for the study of positive displacement pumps the flow rate irregularity, the specific flow rate, and the specific slipping. These indexes are used to optimize the design of the pump and to obtain the sets of optimum design parameter Results obtained from the analysis enable the designer and manufacturer of the oil pump to be more efficient in this field.

A RADIOGRAPHIC STUDY ON THE POSITIONAL RELATIONSHIP OF THE MANDIBLE TO THE HINGE AXIS (접번축에 대한 하악의 위치관계 및 변위에 관한 방사선학적 연구)

  • Kim Jae Duk;Kim Won Pyo
    • Journal of Korean Academy of Oral and Maxillofacial Radiology
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    • v.21 no.1
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    • pp.91-98
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    • 1991
  • This study was made to analyze the positional relationship of mandible to hinge axis in normal subject as the diagnostic criteria of T.M.J. dysfunction. The author has conducted the study using the Cephalometric P-A view, and dental of 53 males and 51 females. By measurement, the standard value of cranio-facial and occlusal asymmetry in normal subject obtained. The following results were obtained: 1. Although the degree of the difference between right and left width in each measured line was small, asymmetry in normal subject could be identified. 2. In male, measurement between genial tubercle and hinge axis is 127.20±6.06㎜ in left, 125.83±6.25㎜ in right, and angle between genial tubercle and hinge axis is 48.48±3.53° in left, 49.58±3.72° in right. In female, measurement is 119.32±5.81㎜ in left, 118.82±5.35㎜ in right and angle is 48.06±2.15° in left, 48.17±2.31° in left, 48.17±2.31° in right. 3. In male, difference between left and right canine cusp tip of maxilla about X-bar is 0.70±0.59㎜, and that of central pit of first molar of maxilla is 0.98±0.75㎜. In female, difference is 0.64±0.52㎜ in canine and 0.92±0.76㎜ in molar.

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Optimum design on the lobe shapes of Gerotor Oil Pump (제로터 오일 펌프 로버형상에 관한 최적설계)

  • Kim Jae-Hun;Kim Chang-Ho;Kim Chul
    • Journal of the Korean Society for Precision Engineering
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    • v.23 no.4 s.181
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    • pp.124-131
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    • 2006
  • A gerotor pump is suitable for oil hydraulics of machine tools, automotive engines, compressors, constructions and other various applications. Especially the pump is an essential machine element of an automotive engine to feed lubricant oil. The subject of this paper is the theoretical analysis of internal lobe pump whose the main components are the rotors: usually the outer one is characterized by lobes with circular shape, while the inner rotor profile is determined as conjugate to the other. For this reason the first topic presented here is the definition of the geometry of the rotors starting from the design parameters. The choice of these parameters is subject to some limitations in odor to limit the pressure angle between the rotors. Now we will consider the design optimization. The first step is the determination of the instantaneous flow rate as a function of the design parameter. This allows us to calculate three performance indexes commonly used far the study of positive displacement pumps: the flow rate irregularity, the specific flow rate, and the specific slipping. These indexes are used to optimize the design of the pump and to obtain the sets of optimum design parameter. Results obtained from the analysis enable the designer and manufacturer of oil pump to be more efficient in this field, and the system could serve as a valuable one for experts and as a dependable training aid for beginners.

A Comparative Study of Two Species of Viviparidae ( Mollusca : Prosobranchia ) : Cipangopaludina chinensis malleata and C. japonica in Korea (한국산 논우렁이 2종의 형태학적 비교연구)

  • Gab-Man Park;Kye-Heon Jeong;Younghun Jung
    • The Korean Journal of Malacology
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    • v.13 no.1
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    • pp.9-19
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    • 1997
  • 한국에 분포된 논우렁이과(family Viviparidae)에는 논우렁이(Cipangopaludina chinensis malleata)와 큰논우렁이(C. japonica) 두 종으로 알려져 있으나 그 형태적 차이점을 구별하기는 쉽지 않다. 형태학적 주요 차이점은 논우렁이에서 패각의 봉합이 깊어 나탑이 뚜렸하고 둥글며 spire angle이 약 62。- 66。인데 비해, 큰 논우렁이는 봉합이 깊지 않아 나탑이 뚜렷하지 못하고 밋밋하며 각 나층에 두개씩의 나륵이 있는 점과 spire angle이 약 58。- 61。인 점이다. 소화기관과 생식기관에서는 2종의 암, 수 모두에서 특이할만한 차이점을 찾아 볼 수 없으나 논우러이는 큰논우렁이에 비해 전반적으로 크고 긴 기관들을 갖고 있었다. 논우렁이와 큰노누렁이 모두에서 IM, IOL, ILL, IC, ILL, IOL, IM의 치설 배열을 보였으나 분치(cusp)배열이 다소 상이하였으며, 논우렁이 개체군 사이에도 분치 배열의 상이점이 관찰되었다. 그러나 위의 두 종은 형태적으로 유사성이 높기 때문에 $\beta$-분류 및 $\gamma$-분류로 그 체계를 확실히 구명하여야 할 필요성이 인정된다.

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Experimental Results of New Ion Source for Performance Test

  • Kim, Tae-Seong;Jeong, Seung-Ho;Jang, Du-Hui;Lee, Gwang-Won;In, Sang-Yeol
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.08a
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    • pp.269-269
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    • 2012
  • A new ion source has been designed, fabricated, and installed at the NBTS (Neutral Beam Test Stand) at the KAERI (Korea Atomic Energy Research Institute) site. The goalis to provide a 100 keV, 2MW deuterium neutral beam injection as an auxiliary heating of KSTAR (Korea Super Tokamak Advanced Research). To cope with power demand, an ion current of 50 A is required considering the beam power loss and neutralization efficiency. The new ion source consists of a magnetic cusp bucket plasma generator and a set of tetrode accelerators with circular copper apertures. The plasma generator for the new ion source has the same design concept as the modified JAEA multi-cusp plasma generator for the KSTAR prototype ion source. The dimensions of the plasma generator are a cross section of $59{\times}25cm^2$ with a 32.5 cm depth. The anode has azimuthal arrays of Nd-Fe permanent magnets (3.4 kG at surface) in the bucket and an electron dump, which makes 9 cusp lines including the electron dump. The discharge properties were investigated preliminarily to enhance the efficiency of the beam extraction. The discharge of the new ion source was mainly controlled by a constant power mode of operation. The discharge of the plasma generator was initiated by the support of primary electrons emitted from the cathode, consisting of 12 tungsten filaments with a hair-pin type (diameter = 2.0 mm). The arc discharge of the new ion source was achieved easily up to an arc power of 80 kW (80 V/1000 A) with hydrogen gas. The 80 kW capacity seems sufficient for the arc power supply to attain the goal of arc efficiency (beam extracted current/discharge input power = 0.8 A/kW). The accelerator of the new ion source consists of four grids: plasma grid (G1), gradient grid (G2), suppressor grid (G3), and ground grid (G4). Each grid has 280 EA circular apertures. The performance tests of the new ion source accelerator were also finished including accelerator conditioning. A hydrogen ion beam was successfully extracted up to 100 keV /60 A. The optimum perveance is defined where the beam divergence is at a minimum was also investigated experimentally. The optimum hydrogen beam perveance is over $2.3{\mu}P$ at 60 keV, and the beam divergence angle is below $1.0^{\circ}$. Thus, the new ion source is expected to be capable of extracting more than a 5 MW deuterium ion beam power at 100 keV. This ion source can deliver ~2 MW of neutral beam power to KSTAR tokamak plasma for the 2012 campaign.

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A STUDY OF INTRAORAL ANATOMIC LANDMARKS OF KOREAN ADULT-UPPER JAW (성인 유치악자 상악골의 악궁과 치열궁의 형태에 관한 조사)

  • Oh, Yu-Ree;Lee, Sung-Bok;Park, Nam-Soo;Choi, Dae-Gyun
    • The Journal of Korean Academy of Prosthodontics
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    • v.33 no.4
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    • pp.753-768
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    • 1995
  • For accurate impression taking of dental patient and esthetic denture treatment of ednetulous patient, measuring between intraoral anatomic landmarks is useful.In this study the subjects selected at a random were two-jundred forty persons with a mean age 22.5(range 21-24) and were taken impression of by irreversible hydrocolloid impression material(Alginate). On the study model made by dental stone, each individual tray was made and final impresion was taken by border moilding. On final model measurings were performed with 3-dimensional measuring device and the values were analyzed by t-test The results is following : ABOUT THE MEASURED VALUES. 1. The width between maxillary right and left canine cusp tip was average 36.44mm(s.d. 2.48), man 36.67mm, woman 35.83mm(p<0.05). 2. The width between labial height of contour of maxillary right and left canine was average 40.08mm(s.d. 2.42), man 40.29mm, woman 39.52mm(p<0.05). 3. The width between mesio-lingual cusps of maxillary first molar was average 43.14mm(s.d. 3.33), man 43.56mm, woman 42.05mm(p<0.05). 4. The width between buccal alveolar ridge on axis of mesiolingual cusp of right and left maxillary first molar was average 64.89mm(s.d. 3.88), man 65.58mm, woman 62.92mm(p<0.05). 5. The width between buccal alveolar ridge on axis of mesiolingual cusp of right and left maxillary second molar was average 68.58mm(s.d. 3.91), man 69.29mm, woman 66.30mm (p<0.05). 6. The width between right and left hamular notch was average 49.80mm(s.d. 3.96), man 50.70mm, woman 48.20mm(p<0.05). 7. The length from labial heigth of contour of maxillary central incisor to center of incisive papilla was average 9.52mm(s.d. 1.18), man 9.46mm, woman 9.63mm(p>0.05). 8. The length from labial heigth of contour of maxillary central incisor to palatine fovea was average 53.27mm(s.d. 2.93), man 53.93mm, woman 52.08mm(p<0.05). 9. The center of incisive papilla ws located posterior to intercanine line at 0.40mm(s.d. 1.16), man 0.51mm, woman 0.11mm(p<0.05). 10. The height from incisal edge of maxillary central incisor to the labial vestibule was average 21.84mm(s.d. 1.38), man 22.01mm, woman 21.00mm(p<0.05). 11. The height from mesiolingual cusp of maxillary first molar to buccalvestible was average 17.45mm(s.d. 1.42), man 17.56mm, woman 17.08mm(p>0.05). 12. The height from hamular notch to standard occlusal plane was average 6.84mm(s.d. 1.06), man 6.91mm, woman 6.70mm(p>0.05). 13. The height from the deepest point of palatal vault to standard occlsalplane was average 19.95 mm(s.d. 2.03), man 20.19mm, woman 19.12mm(p<0.05). ABOUT THE ARCH FORM 1. The arch form was able to classify into four typr by the rate of the measured values. Each arch form distribution was that the 1 group had 32.46% the 2 group 2.19%, the 3 group 52.83%, the 4 group 12.72%. The sexual composition was that in 1 group man had 73.5%, woman 26.5%, in 2 group man had 40.0%, woman 60.0%, in 3 group man had 83.3%, woman 16.7%, and in 4 group man had 55.17%, woman 44.83%. 2. When canine cusp tip was marked as point O, the intersection point between labial height of contour of maxillary central incisor and intermaxillary suture as point A, height of contour of maxillary second molar buccal alveolar ridge as B point, ${\angle}$AOB was measured $133.8^{\circ}$for the 1 group, $133.0^{\circ}$for the 2 group, $132.3^{\circ}$for the 3 group, $128.9^{\circ}$for the 4 group.

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A STUDY ON THE ANALYSIS OF THE CURVE OF SPEE ON THE GNATHOLOGICAL CAST AND THE CEPHALOMETRIC RADIOGRAPH (악태모형과 측모두부 계측 방사선 사진상 스피만곡 분석에 관한 연구)

  • Choi, Ah-Young;Kim, Jeong-Sun;Kay, Kee-Sung
    • The Journal of Korean Academy of Prosthodontics
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    • v.36 no.2
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    • pp.323-335
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    • 1998
  • Clinically, the curve of Spee is widely applied as a determined level of the occlusal curvature when the oral rehabilitation and the reconstruction of the prosthesis is needed at the malalignment dentition due to the missing, extrusion, and the inclination of the teeth. The purpose of this study was to analyze the curve of Spee of the occlusal curvature which influences to the occlusal form and the location three dimensionally, and then was to measure the radius and the degree of curvature of the curve of Spee and also was to investigate the influence to the cuspal inclination according to the change of the inclination of the curve of Spee which was analyzed by AutoCAD R.13 program at the gnathological cast and the cephalometric radiograph. The following results were obtained : 1. The radius of the curve of Spee was the mean of $11.74{\pm}3.64cm$ in the model, $12.75{\pm}4.63cm$ in the radiograph and there was no significant difference statistically between the model and the radiograph(P>0.001). 2. The radius and the degree of curvature of the curve of Spee showed negative correlation(r=-0.80), while the radius and the degree of curvature of the curve of Spee in relation to the length of the curve of Spee did not show correlation. 3. The case of the curve of Spee inclined to the posterior, that is. $Post.M{\theta}$ group showed the mean of $4.73{\pm}3.64$, positive correlation to the P2m, M1mm, M1dm, M2dm, and especially the greatest correlation coefficient to the mesial inclination angle of the mesio-buccal cusp tip of the first molar(r=0.70). 4. The case of the curve of Spee inclined to the anterior, that is, $Ant.M{\theta}$ group showed the mean of $3.28{\pm}3.59$, positive correlation to the P2m, M1mm, and also the greatest correlation coefficient to the mesial inclination angle of the mesio-buccal cusp tip of the first molar(r=0.78

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