• Title/Summary/Keyword: Base position

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Mandibular shape prediction using cephalometric analysis: applications in craniofacial analysis, forensic anthropology and archaeological reconstruction

  • Omran, Ahmed;Wertheim, David;Smith, Kathryn;Liu, Ching Yiu Jessica;Naini, Farhad B.
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.42
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    • pp.37.1-37.13
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    • 2020
  • Background: The human mandible is variable in shape, size and position and any deviation from normal can affect the facial appearance and dental occlusion. Objectives: The objectives of this study were to determine whether the Sassouni cephalometric analysis could help predict two-dimensional mandibular shape in humans using cephalometric planes and landmarks. Materials and methods: A retrospective computerised analysis of 100 lateral cephalometric radiographs taken at Kingston Hospital Orthodontic Department was carried out. Results: Results showed that the Euclidean straight-line mean difference between the estimated position of gonion and traced position of gonion was 7.89 mm and the Euclidean straight-line mean difference between the estimated position of pogonion and the traced position of pogonion was 11.15 mm. The length of the anterior cranial base as measured by sella-nasion was positively correlated with the length of the mandibular body gonion-menton, r = 0.381 and regression analysis showed the length of the anterior cranial base sella-nasion could be predictive of the length of the mandibular body gonion-menton by the equation 22.65 + 0.5426x, where x = length of the anterior cranial base (SN). There was a significant association with convex shaped palates and oblique shaped mandibles, p = 0.0004. Conclusions: The method described in this study can be used to help estimate the position of cephalometric points gonion and pogonion and thereby sagittal mandibular length. This method is more accurate in skeletal class I cases and therefore has potential applications in craniofacial anthropology and the 'missing mandible' problem in forensic and archaeological reconstruction.

ROENTGENOGRAPHIC CEPHALOMETRIC STUDY OF ANGLE'S CLASS II, DIVISION 1 MALOCCLUSION IN KOREAN CHILDREN (한국인 성장기 아동에서 Angle씨 2급 1류 부정교합자의 골격 특징)

  • Kim, Yoo-Kyung;Kyung, Hee-Moon;Kwon, Oh-Won;Sung, Jae-Hyun
    • The korean journal of orthodontics
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    • v.19 no.3
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    • pp.67-78
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    • 1989
  • This study was designed to investigate the difference of teeth and craniofacial complex between normal occlusion and Angle's Class II, div. 1 malocclusion in Korean children. The sample was divided into 2 groups, the 66 subjects with normal occlusion and 96 subjects with Angle's Class II, div. 1 malocclusion in both sexes. The results obtained were as follows: 1. No significant differences were observed in ant. cranial base length & cranial flexure (saddle) angle) between normal occlusion & Angle's Class II, div. 1 malocclusion group, but posterior cranial base length of Class II, div. 1 malocclusion group was larger than that of normal occlusion group. 2. No significant difference was observed in the anteroposterior position of Maxilla to cranial base between two groups, but mandibular position in Class II, Div. 1 malocclusion was posterior and interior to that of normal occlusion. 3. The length of maxilla (ANS-PSN) was larger in Class II, div. 1 malocclusion than normal occlusion. The length of mandibular body (Go-Me) was nor different between Class II, div. 1 malocclusion and normal occlusion. 4. Maxillary incisor position of Class II, div. 1 malocclusion to cranial base was more protrusive than that of normal occlusion, but there was no difference in mandibular incisor position between two groups.

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A COMPARATIVE STUDY ABOUT THE POSITION OF UPPER AND LOWER JAWS, AND FIRST MOLARS IN NORMAL OCCLUSION AND ANGLE'S CLASS $I{\cdot}II{\cdot}III$ MALOCCLUSIONS (정상교합과 부정교합에서의 상${\cdot}$하악골과 제 1 대구치 위치에 관한 비교연구)

  • Yun, Byoung-Mo;Ahn, Byoung-Keun;Rhee, Geon-Ju;Kim, Sun-Hae;Park, Young-Ju;Han, Ho-Jin
    • The korean journal of orthodontics
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    • v.23 no.4 s.43
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    • pp.633-644
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    • 1993
  • There has been so much controversies about the position of upper and lower jaws, and their first permanent molars in normal occlusion and Angle's class $I{\cdot}II{\cdot}III$ malocclusions. So, the purpose of this study is to compare the position of upper and lower jaws, and their first molars in normal occlusion and Angle's class $I{\cdot}II{\cdot}III$ malocclusions by lateral cephalometric analysis. The sample consisted of one hundred and twenty girls(thirty in each group) who had completed growth. The findings of this study were as follows : 1. In class I malocclusion, both maxilla and mandible were slightly posterior position than normal occlusion, but they showed harmonious relationship. 2. In class II malocclusion, the mandible was greatly retruded, and the maxilla was also slightly retruded to the cranial base as compared with normal occlusion. 3. In class III malocclusion, the maxilla was significantly retruded to the cranial base, but no significant difference was found in mandibular position as compared with normal occlusion. 4. The maxillary first molar was located at posterior position in class II malocclusion, and anterior position in class III malocclusion to the cranium, so that the rotation of mandible was influenced by that. 5. The mandibular first molar showed constant relationship to the mandible in all four groups, but different position to the cranial base in direct proportion to the mandibular position. 6. On the treatment planning of class III malocclusion, it seems to be better to promote the mandibular horizontal growth by inhibiting the vertical growth of maxillary molar area, and on the treatment planning of class III malocclusion, it seems to be better to promote the antero-inferior growth of maxilla mi to promote the mandibular vertical growth by inducing the vertical growth of maxillary molar area.

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An Propagation Path Analysis for Optimal Position Selection of Microcell Base Station in the Mobile Communication System (이동통신 마이크로셀 기지국의 최적 위치 선정을 위한 전파경로 해석)

  • 노순국;박창균
    • The Journal of the Acoustical Society of Korea
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    • v.18 no.7
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    • pp.92-100
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    • 1999
  • In the microcell mobile communication, we propose algorithms processing operational disposition to exactly analysis propagation environments from the base station to mobile stations. Algorithms are developed by the triangle analysis method can operate variable propagation paths and reflect numbers. For simulation, we suppose that mobile stations are located in the shadow region of the line of sight and the area of the non-line of sight sloping against the line of sight area at variable angles. By analyzing the results of simulation using proposed algorithms, we can be applied to the optimal position selection of the base station in the microcell mobile communication.

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Position Location of Mobile Terminal in Wireless MIMO Communication Systems

  • Li, Ji;Conan, Jean;Pierre, Samuel
    • Journal of Communications and Networks
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    • v.9 no.3
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    • pp.254-264
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    • 2007
  • A promising approach to improve the performance of mobile location system is the use of antenna arrays in both transmitter and receiver sides. Using advanced array signal processing techniques, such multiple-input multiple-output (MIMO) communication systems can offer more mobile location information by exploiting the spatial properties of the multipath channel. In this paper, we propose a novel approach to determine the position of mobile terminal based on estimated multipath signal parameters using only one base station in MIMO communication systems. This approach intends to minimize the error occurring from the estimation of multiple paths and gives an optimal estimation of the position of mobile terminal by simultaneously calculating a set of nonlinear location equations. This solution breaks the bottleneck of conventional mobile location systems which have to require multilateration of at least three base stations.

Development of Underwater Vehicle Position Tracking Algorithm by using a Gyro-Doppler Sensor and Ultra Short Base Line (자이로 도플러 센서와 USBL을 통한 수중체 위치추적 알고리즘개발)

  • Kim, Deok-Jin;Park, Dong-Won;Park, Yeon-Sic
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.10 no.11
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    • pp.1973-1977
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    • 2006
  • This paper reports the absolute position tracking algorithm of underwater vehicles such as ROV, AUV in global region by fusing sensor informations of IMU, DVL, USBL, DGPS etc. This algorithm is to be used in the position tracking of the 6,000m class deep-sea unmanned underwater vehicle, HEMIRE for scientific exploration.

Motion analysis of a Translating Flexible Beam Carrying a Moving Mass (이동부하를 가지고 병진운동하는 유연보의 운동 해석)

  • Park, Sang-Deok;Chung, Wan-Kyun;Youm, Young-Il
    • Journal of the Korean Society for Precision Engineering
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    • v.16 no.11
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    • pp.204-212
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    • 1999
  • In this paper, the vibrational motion of a flexible beam clamped on a translating base and carrying a moving mass is investigated. The equations of motion which describe the total dynamics of the beam-mass-cart system are derived and the coupled dynamic equations are solved by unconstrained modal analysis. In modal analysis, the exact normal mode solutions corresponding to the eigenfrequencies for the position of the moving mass and the ratios of the mass of the flexible beam, the moving mass and the base cart are used. Proper transformations of the time solutions between the normal modes for a position and those for the next position of the moving mass are also adopted. Numerical simulations are carried out to obtain the open-loop responses of the system in tracking the pre-designed path of the moving mass.

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ePosition Identification linked Model Based on ENC (전자해도 기반의 위치식별 ID 연계 모델)

  • Seo, Gi-Yeol;Lee, Sang-Ji;O, Se-Ung;Seo, Sang-Hyeon;Park, Gye-Gak
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2007.04a
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    • pp.201-205
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    • 2007
  • This paper proposes a link model that can provide the spacial position along the surface of the earth as an information or data using ePosition ID through the Internet. Moreover, to support the information service of maritime position, it needs the ENC linked technique based on S-57 that is an IHO transfer standard for digital hydrographic data. Therefore, it designs the linked model for applying and utilizing the ePosition technology with ENC data, as well as supplementing the base technology in applying them to marine related fields. As a study method, this paper first analyses ENC data model and structure, and converses for processing of ENC file to ePosition data. Finally, it derives the interconnection method with ePosition database and shows the ePosition service application based on the linked ENC data and its validity.

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Performance Analysis of Scanning Scheme Using ToF for the Localization of Optics-Based Sensor Node (광신호 기반 무선 센서 노드 위치 인식을 위한 ToF 기법의 성능 분석)

  • Jang, Woo Hyeop;Park, Chan Gook
    • Journal of Institute of Control, Robotics and Systems
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    • v.19 no.3
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    • pp.268-274
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    • 2013
  • In this paper, the performance analysis of optics-based sensor node localization using ToF (Time of Flight) scheme is conducted. Generally, the position of the sensor node is calculated on the base station. And the base station scans neighboring sensor nodes with a laser. The laser which is reflected from one sensor node, however, can be reached to the base station at different angles according to the scanning resolution. This means that the error of the reached angle can increase and one node may be recognized as different nodes. Also the power of laser can decrease because the laser signal spread. Thus the sensor node which is located at a long distance from the base station cannot be detected. In order to overcome these problems which can be occurred in localization using ToF, the beam spot, the scanning resolution, the size of reflector and the power of laser at the sensor node were analyzed. It can be expected that the consequence of analysis can be provided in acquisition of accurate position of sensor node and construction of optics-based sensor node localization system.

Why Are Sentential Subjects Not Allowed in Seem-type Verbs in English?

  • Jang, Youngjun
    • Journal of English Language & Literature
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    • v.55 no.6
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    • pp.1245-1261
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    • 2009
  • The purpose of this paper is to show the internal structure of the socalled sentential subject constructions in English. The constructions that we examine in this paper are such as It seems that John failed in the syntax exam vs. *That John failed in the syntax exam seems and It really stinks that the Giants lost the World Series vs. That the Giants lost the World Series really stinks. As seen above, the English verb seem does not tolerate the sentential subject. This is in sharp contrast to other English verbs such as suck, blow, bite, and stink, which do allow the sentential subject. There are several issues regarding these constructions. First, where is the sentential subject located? Second, is the sentential subject assigned structural Case? Third, is the sentential subject extraposed or does it remain in its base-generated complement position? Fourth, is the sentential subject a base-generated topic in the specifier position of CP, as Arlenga (2005) claims? In this paper, we argue that sentential subjects are base-generated in the specifier of the verbal phrase in case of stink-type verbs, while they are licensed as a complement to verbs like seem. We also argue that a sentential subject can be raised in the seem-type verbal constructions, if it were part of the complement small clause.