• Title/Summary/Keyword: First Position

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Detection of Absolute Position of Robot Joint Using Incremental Encoders (증분형 엔코더를 이용한 로봇 관절의 절대위치 검출)

  • Lim, Jae Sik;Lee, Young Jin
    • Journal of Institute of Control, Robotics and Systems
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    • v.21 no.6
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    • pp.577-582
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    • 2015
  • This paper proposes an efficient detection of absolute position of a robot joint using two incremental encoders. We considers a robot joint comprising a motor, a reducer, two encoders, and a motor drive. An incremental(first) encoder provides motor's rotor position or input position of reducer while another incremental(second) encoder does output position of the reducer. A table is made where the relationship between the first and the second encoder counts is recorded. The key point is placed where the table is constructed: when a pulse occurs in the second encoder, there exists a corresponding unique count value of the first encoder. The absolute position is detected using the table by searching the second encoder position corresponding to the first encoder count value when a pulse occurs in the second encoder. The proposed method needs a small rotation, as just one second encoder's pulse angle, for the initial absolute position detection.

Correlation between the Position of the Pituitary Stalk as Determined by Diffusion Tensor Imaging and Its Location as Determined at the Time of Surgical Resection of Pituitary Adenomas

  • Wang, Fu-yu;Wang, Peng;Yang, Chen-xuan;Zhou, Tao;Jiang, Jin-li;Meng, Xiang-hui
    • Journal of Korean Neurosurgical Society
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    • v.63 no.4
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    • pp.504-512
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    • 2020
  • Objective : An important factor during pituitary adenoma surgery is to preserve pituitary stalk (PS) as this plays a role in reduction of the risk of postoperative diabetes insipidus. The hypothalamic-hypophyseal tract (HHT) projects through the PS to the posterior pituitary gland. To reconstruct white matter fiber pathways, methods like diffusion tensor imaging (DTI) tractography have been widely used. In this report we attempted to predict the position of PS using DTI tractography and to assess its intraoperative correlation during surgery of pituitary adenomas. Methods : DTI tractography was used to tract the HHT in nine patients before craniotomy for pituitary adenomas. The DTI location of the HHT was compared with the PS position identified at the time of surgery. DTI fiber tracking was carried out in nine patients prior to the planned craniotomy for pituitary adenomas. In one patient, the PS could not be identified during the surgery. In the other eight patients, a comparison was made between the location of the HHT identified by DTI and the position of the PS visualized at the time of surgery. Results : The position of the HHT identified by DTI showed consistency with the intraoperative position of the PS in seven patients (88.9% concordance). Conclusion : This study shows that DTI can identify the position of the HHT and thus the position of the PS with a high degree of reliability.

Position of Source Leaf Affects Translocation and Distribution of $C^{14}$ Photo-Assimilates in Tomato

  • Lee Sang-Gyu;Lee Chiwon W.
    • Journal of Bio-Environment Control
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    • v.15 no.2
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    • pp.173-176
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    • 2006
  • The relationship between source leaf position and photo-assimilate translocation and distribution was characterized for tomato (Lycopersicon esculentum Mill) grown in the greenhouse. Three different positions of source leaf on the stem (first node above or below the first fruit cluster and $5^{th}$ node above the first fruit cluster) were tested for their influence on $^{14}CO_2$ assimilation and transfer to different parts of the plant. The leaves at the $5^{th}$ node above the first fruit cluster transferred the highest (57%) proportion of $C^{14}$ to other plant parts, followed by leaves home on the first node below the first fruit cluster (50%), and the first node above the first fruit cluster (39%). In all treatments, fruits served as the strongest sink for $C^{14}$, followed by stem, leaf, and root tissues. The leaf home on the $5^{th}$ node above the first fruit cluster transferred the largest amount of $C^{14}$ to the second fruit cluster.

Cone-beam computed tomographic evaluation of the temporomandibular joint and dental characteristics of patients with Class II subdivision malocclusion and asymmetry

  • Huang, Mingna;Hu, Yun;Yu, Jinfeng;Sun, Jicheng;Ming, Ye;Zheng, Leilei
    • The korean journal of orthodontics
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    • v.47 no.5
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    • pp.277-288
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    • 2017
  • Objective: Treating Class II subdivision malocclusion with asymmetry has been a challenge for orthodontists because of the complicated characteristics of asymmetry. This study aimed to explore the characteristics of dental and skeletal asymmetry in Class II subdivision malocclusion, and to assess the relationship between the condyle-glenoid fossa and first molar. Methods: Cone-beam computed tomographic images of 32 patients with Class II subdivision malocclusion were three-dimensionally reconstructed using the Mimics software. Forty-five anatomic landmarks on the reconstructed structures were selected and 27 linear and angular measurements were performed. Paired-samples t-tests were used to compare the average differences between the Class I and Class II sides; Pearson correlation coefficient (r) was used for analyzing the linear association. Results: The faciolingual crown angulation of the mandibular first molar (p < 0.05), sagittal position of the maxillary and mandibular first molars (p < 0.01), condylar head height (p < 0.01), condylar process height (p < 0.05), and angle of the posterior wall of the articular tubercle and coronal position of the glenoid fossa (p < 0.01) were significantly different between the two sides. The morphology and position of the condyle-glenoid fossa significantly correlated with the three-dimensional changes in the first molar. Conclusions: Asymmetry in the sagittal position of the maxillary and mandibular first molars between the two sides and significant lingual inclination of the mandibular first molar on the Class II side were the dental characteristics of Class II subdivision malocclusion. Condylar morphology and glenoid fossa position asymmetries were the major components of skeletal asymmetry and were well correlated with the three-dimensional position of the first molar.

Analysis of Parallel Mechanisms with Forward Position Closed-Form Solution with Application to Hybrid Manipulator (정위치 해석해를 가지는 병렬 메카니즘에 관한 분석과 혼합구조 매니퓰레이터로의 활용)

  • 김희국;이병주
    • Journal of Institute of Control, Robotics and Systems
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    • v.5 no.3
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    • pp.324-337
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    • 1999
  • In this work, a new 3-PSP type spatial 3-degree-of-freedom parallel mechanism is proposed. And a 6 DOF hybrid manipulator which consists of a 3-PPR type planar 3 DOF parallel mechanism and a new 3-PSP type spatial 3-degree-of-freedom parallel mechanism is proposed. Both 3 DOF mechanism modules have closed-form forward position solutions and particularly, 3-PSP spatial module has unique forward position solution. Firstly, the closed-form position analysis and first-order kinematic analysis for the proposed 3-PSP type module are carried out, and the first-order kinematic characteristics are examined via maximum singular value and the isotropic index of the mechanism. It is shown through these analyses that the mechanism has excellent isotrpic property throughout the workspace. Secondly, position and kinematic analysis of the 3-PPR planar module are briefly described. Thirdly, the forward position analysis for the 3-PPR 3-PSP type 6 degree-of-freedom hybrid mechanism consisting of a 3-PPR planar module and a 3-PSP spatial module is performed along with the analysis of the workspace size and first-order kinematic characteristics. The kinematic characteristics of the proposed hybrid manipulator are compared to those of geometrically similar Stewart manipulator.

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A Study on the Social Position and Status of the Dress Symbolism Described in the Traditional Korean Folktale (전통설화에 나타난 복식의 사회적 지위 및 신분 상징에 관한 연구)

  • 김애련;김진구
    • The Research Journal of the Costume Culture
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    • v.10 no.4
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    • pp.419-432
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    • 2002
  • This research analyzes how our people use the social position and status symbolism of the dress in focus of the Chosun Dynasty Period by analysis data of traditional folktale. This research material was analyzed social position and status symbolism of the dress with basis on Korean Oral Literature grand volumes of 82 published by The Academy of Korean Studies and whole volumes of 7 of Korean Literature Traditional , Folktale written by Kimhyunrwong. The methods of study is that first, selected part of describing social position and status of dress from the traditional Korean folktale. Second, summmarized things classified such as clothes, shape of hair and belt. Third, analyzed social position and status of dress with basis on symbol theory to be pre-studied. As a result, 1 can get the next conclusion. First, in case of the dress symbolism of social position and status, we classify as class. occupation, surreal person. Second, the changes of the social position and status showed upward position or downward position, and occupation change. Third, symbolization of position disguise was classified disguise of social position, sex, occupation.

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FFT-Based Position Estimation in Switched Reluctance Motor Drives

  • Ha, Keunsoo;Kim, Jaehyuck;Choi, Jang Young
    • Journal of Magnetics
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    • v.19 no.1
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    • pp.90-100
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    • 2014
  • Position estimation that uses only active phase voltage and current is presented, to perform high accuracy position sensorless control of a SRM drive. By extracting the amplitude of the first switching harmonic terms of phase voltage and current for a PWM period through Fast Fourier Transform (FFT), the flux-linkage and position are estimated without external hardware circuitry, such as a modulator and demodulator, which result in increased cost, as well as large position estimation error, produced when the motional back EMF is ignored near zero speed. A two-phase SRM drive system, consisting of an asymmetrical converter and a conventional closed-loop PI current controller, is utilized to validate the performance of the proposed position estimation scheme in comprehensive operating conditions. It is shown that the estimated values very closely track the actual values, in dynamic simulations and experiments.

A Study on the Competitive Position and Strategic Exportable Goods of Korea Focused on Korea-China-Japan Fisheries Products Class (한.중.일 수산물부문에 있어 한국의 경쟁력 수준과 수출전략품목 분석에 관한 연구)

  • Kim, Ki-Soo;Woo, Ji-Hyo
    • The Journal of Fisheries Business Administration
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    • v.38 no.3
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    • pp.1-24
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    • 2007
  • This study examines the relative competitive position of korean fisheries products market over period of 2001 to 2005 and selects strategic exported goods from its position provide against concluding FTA agreement with China and Japan. The portfolio approach is used to develope competitiveness-market share matrix. The position of each export countries on the competitiveness market share matrix will be in one of nine cells, with differing implications for their role in korean fisheries products market. Based the competitiveness market share matrix, each export countries are divided into first cell type, third cell type and ninth cell type and the items of ninth cell type are chosen as strategic exportable goods. The results of this study are summarized as follows: First, in the case of each country change aspect, China is trending to decrease quantity but shows number of item that increase gradually with high share still, and look trend that increase third cell type item too gradually, and in case of first cell type item is that competitive position is high more relatively than the Korea. In the case of Japan, ninth cell type item is falling gradually, and share does not show big change generally in case of first cell type item. Second, in the case of strategic exportable goods that analyze using domestic competitive position cell type and MCA with competitive position in domestic fisheries products market and export market, was appear by codfish(frozen), cuttle fish(frozen) etc. in case with China, and by mackerel(frozen), other sea bream(frozen), laver(dry), bathing(dry) etc. in case with Japan. And analyzed goods that have all export competitive advantages in both countries are roes of alaska pollack(frozen), other roes of fish(except frozen roes of alaska pollack), squid(frozen) etc.

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An Electromyographic Study on Mandibular Rest Position Induced by Several Methods (하악안정위 유도에 관한 근전도학적 연구)

  • Chang Jung;Kyung-Soo Han;Min Shin
    • Journal of Oral Medicine and Pain
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    • v.18 no.2
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    • pp.121-130
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    • 1993
  • Mandibular rest position is very essential position because in that position, masticatory muscularture can be reciprocally coordinative and unstrained. So obtaining a good ability to establish and maintain rest position in non-functioning state is mandatory for treatment of patient with craniomandibular disorders. In general, many types of mandibulr movement exercise start from rest position and use the sense of muscle relearning, that is, muscle smoothness and relaxation, throughout the exercise period. In this study, 44 normal subjects for control group and 37 patients with craniomandibular disorders for experimental group participated and they were classified into 3 subgroups, respectively. One method to guide mandibular rest position was used for one subgroup, so theree methods were used for this study, 1)self-guided rest position without any education, 2) guided by Rocabado's tongue rest position, 3) guided through swallowing after Dawson's centric relation. To record electromyographic activity, Bioelectric processor EM2 (Myotronics, U.S.A.) was used. The numbers of sessions from start to stable resting electromyographic level and muscle activities in stable state were recorded and two recordings which were first and second, 3 days after first recording, were done, The data were processed with SPSS/PC+package. The obtained results were as follows : 1. Mean number of sessions in second recording were fewer than those in first recording in both groups. In comparison among 3 subgroups, mean number of sessions of subgroup guided through Dawson's method were fewer than those of other groups though it is not statistically significant. 2. There was a difference of mean number of sessions between control and experimental group in first recording, but in second recording there was no difference in any cases. 3. Mean value of muscle activity were generally not different without regard to group and method if once come to stable resting position level. Mean value of muscle activity of guided subgroups showed a tendency of decreasing in second recording than in first recording. However, in self-guided subgroup there was a inconsistent pattern. 4. The amounts of change in session number from first to second recording in control group were fewer than those in experimental group.

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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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