• Title/Summary/Keyword: position analysis

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Indirect Detection of Rotor Position of Switched Reluctance Motor Based on Flux Linkage Analytic Model

  • Zhou, Yongqin;Hu, Bo;Wang, Hang;Jin, Ningzhi;Zhou, Meilan
    • Journal of Electrical Engineering and Technology
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    • v.13 no.2
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    • pp.829-837
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    • 2018
  • In this paper, a flux linkage model based on four magnetization curves fitting is proposed for three-phase 12/8 switched reluctance motor (SRM), with the analysis of the basic principle of flux detection method and function analysis method. In the model, the single value function mapping relationship between position angle and flux is established, which can achieve a direct estimation of rotor position. The realization scheme of SRM indirect position detection system is presented. It is proved by simulation and experiment that the proposed scheme is suitable for rotor position detection of SRM, and has high accuracy of position estimation.

Comparative Analysis of the Serratus Anterior Muscle Activity When Right and Left Knee Lift during Quadruped Position on Push Up Plus

  • Nam, KiSeok;Kim, JiWoong;Park, JiWon
    • The Journal of Korean Physical Therapy
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    • v.32 no.1
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    • pp.58-63
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    • 2020
  • Purpose: This study examined the effects of the right or left knee lift during push up plus in the quadruped position on the serratus anterior (SA) muscle activity. Methods: Twenty-one subjects (male 11, female 10) performed the quadruped position on push up plus. The muscle activities of the lower trapezius (LT), SA, and upper trapezius (UT) were measured by surface electromyography. Repeated measurements of one-way ANOVA were performed for statistical analysis of the data, and the criterion for statistical significance was set to p<0.05 and comparative analysis of the UT and SA ratio using a Paired t-test. Results: The right SA increased the muscle activity of the right knee lift during quadruped position push up plus (p<0.05). In particular, the right SA muscle activity was higher than the left. In addition, comparative analysis of the UT and SA ratio to the right knee lift during quadruped position push up plus was performed (p<0.05). The right was found to be a significant statistic compared to the left, but the left SA increased the muscle activity of the left knee lift during quadruped position push up plus (p<0.05). The left SA muscle activity was higher than right. In addition, comparative analysis of UT and SA ratio to the left knee lift during quadruped position push up plus was performed (p<0.05). The left was found to be a significance statistic than the right. In addition, the interaction effect between the groups showed significant differences (p<0.05). Conclusion: Knee lift during push up plus is recommended for the selective activation of a research exercise protocol of one side of the serratus anterior.

A CEPHALOMETRIC AND PANORAMIC ANALYSIS OF THE CHANGES OF THE CONDYLAR POSITION AFTER ORTHOGNATHIC SURGERY (하악전돌증 환자의 악교정 수술후 하악과두의 위치변화에 대한 연구)

  • Kang, Young-Ki;Kim, Jong-Ryoul;Yang, Dong-Kyu
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.22 no.4
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    • pp.411-419
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    • 2000
  • Purpose: This study was aimed at analysis of the changes in the condyle position in subjects with mandibular setback osteotomies Method: Twenty patients were evaluated retrospectively for their changes in the condyle position who underwent surgical mandibular setback using bilateral sagittal split osteotomies with a manual condyle repositioning technique and rigid fixation. The cephalometric and panoramic analysis was performed preoperatively, 1 week, 6 months, and 1 year postoperatively. And postoperative noise, temporomandibular joint pain, and mouth opening were clinically examined 2 months, 4 months, 6 months, 8 months, 10 months, and 12 months postoperatively. Result: The condyles rotated posteriorly and laterally immediately after surgery, and they returned to the preoperative position during follow-up period but it is not significant. The statistical analysis (Paired t-test) showed no significant effects in postsurgical stability. The changes in the condyle position didn't have a significant harmful influence on temporomandibular joint disorder. Conclusion: A careful surgical mandibular setback using manual condyle repositioning and fixation technique will move condyle minimally and that will decrease the relapse and temporomandibular joint disorder.

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A New Airbag Modeling Using a Sphere and a Torus and the Occupant Analysis in the Out-of-position (구와 원환체를 이용한 에어백의 모델링 및 비정상위치시의 승객 거동 해석)

  • 임재문;김창환;박경진
    • Transactions of the Korean Society of Automotive Engineers
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    • v.4 no.1
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    • pp.96-109
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    • 1996
  • The airbag system is known to be extremely efficient for the protection in an automobile crash. The performance of the airbag system is evaluated by real tests. However, the test is very difficult and expensive. Therefore, the computational simulations are carried out with low cost. The airbag analysis is included in the anlysis of the full-car crashworthiness. The behavior of the airbag can be predicted by a thermodynamic analysis. The contact force between the occupant and the airbag is calculated from the contact volume and the pressure in the airbag. The injury rate is evaluated from the contact force and the acceleration of dummies. So far, the contact is defined after the airgag is fully inflated. In many cases, the occupant is seated in the out-of-position and the contact can happen during the inflation process. A new algorithm has been developed for the out-of-position. To describe the inflation process precisely, the airbag is defined by a sphere and a torus. The injury is evaluated for the contact happened at any time. The developed algorithm is coded and interfaced with an existing software in the public domain. The full-car modeling is adopted from the previous study which is tuned for the regular position and real tests. Numerical experimentation have been carried out with a couple of dummies in the out-of-position and the injury processes are analyzed.

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Aspect-Based Sentiment Analysis with Position Embedding Interactive Attention Network

  • Xiang, Yan;Zhang, Jiqun;Zhang, Zhoubin;Yu, Zhengtao;Xian, Yantuan
    • Journal of Information Processing Systems
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    • v.18 no.5
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    • pp.614-627
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    • 2022
  • Aspect-based sentiment analysis is to discover the sentiment polarity towards an aspect from user-generated natural language. So far, most of the methods only use the implicit position information of the aspect in the context, instead of directly utilizing the position relationship between the aspect and the sentiment terms. In fact, neighboring words of the aspect terms should be given more attention than other words in the context. This paper studies the influence of different position embedding methods on the sentimental polarities of given aspects, and proposes a position embedding interactive attention network based on a long short-term memory network. Firstly, it uses the position information of the context simultaneously in the input layer and the attention layer. Secondly, it mines the importance of different context words for the aspect with the interactive attention mechanism. Finally, it generates a valid representation of the aspect and the context for sentiment classification. The model which has been posed was evaluated on the datasets of the Semantic Evaluation 2014. Compared with other baseline models, the accuracy of our model increases by about 2% on the restaurant dataset and 1% on the laptop dataset.

A Study on the Analysis of Multi-let Spread Mooring Systems (다점지지 계류시스템의 정적해석에 대한 연구)

  • Sin, Hyeon-Gyeong;Kim, Deok-Su
    • Journal of Ocean Engineering and Technology
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    • v.9 no.2
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    • pp.53-60
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    • 1995
  • A multi-leg spread mooring system for floating offshore structures is important, but the multi-leg static analysis is complicated due to the nonlinear behavior of each line and the effect of current which affects each line differently. The pretensioned position of the multi-leg mooring system obtained from the static equilibrium condition changes into a different position due to external loads and current. In this paper, the new position and the static tension at each line are caculated. The relation between the initial static equilibrium position and the new position due to the external loads is expressed in terms of the Taylor's series expansion. The Runge-Kutta $4^{th}$ method is employed in analyzing the 3-dimensional static cable nonlinear equations.

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Analysis on Position Estimation Performance according to Injection Frequency in Carrier-Based Sensorless Operation (반송파 기반 센서리스 운전에서 주입하는 신호의 주파수에 따른 위치 추정 성능 분석)

  • Hwang, Chae-Eun;Lee, Younggi;Sul, Seung-Ki
    • The Transactions of the Korean Institute of Power Electronics
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    • v.23 no.2
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    • pp.139-146
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    • 2018
  • This work puts forward a theoretical analysis on position estimation performance of interior permanent magnet synchronous motor (IPMSM) according to the injection frequency in carrier-based sensorless operation. The effects of spatial harmonics on inductance and voltage distortion due to the nonideal characteristics of IPMSM and inverter are examined as factors influencing the position estimation performance. Furthermore, the position estimation performance is analyzed by calculating the current at the switching instant in several operating conditions. In summary, the half switching frequency injection is more robust to the nonideal characteristics of IPMSM, especially with light load condition. The validity of the analysis is verified by the simulation and experimental results.

Analysis and Suggestions of the Librarians Public Servants in USA, UK and Korea (영미 및 한국의 사서직제 분석과 시사점)

  • Yoon Hee-Yoon
    • Journal of Korean Library and Information Science Society
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    • v.36 no.2
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    • pp.121-140
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    • 2005
  • The purpose of this paper is to analyze the public servant and librarian position in USA, UK, and Korea and to give suggestions to improve the position classification of librarianship in Korea. Professional librarian positions in USA and UK are very useful to understand the excellency of position classification system. On the other hand, librarian positions in Korea is useful to catch the present situation of librarianship and its backwardness. This paper can use for the grounds of an improvement of the librarian position in Korea. In order to improve current position classification of librarianship. we have to overcome a theoretical and actual weakness of the libraries and librarians and to act as the main stream for position reform.

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3-Dimensional Analysis of Magnetic Road and Vehicle Position Sensing System for Autonomous Driving (자율주행용 자계도로의 3차원 해석 및 차량위치검출시스템)

  • Ryoo Young-Jae
    • Journal of the Korean Institute of Intelligent Systems
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    • v.15 no.1
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    • pp.75-80
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    • 2005
  • In this paper, a 3-dimensional analysis of magnetic road and a position sensing system for an autonomous vehicle system is described. Especially, a new position sensing system, end of the important component of an autonomous vehicle, is proposed. In a magnet based autonomous vehicle system, to sense the vehicle position, the sensor measures the field of magnetic road. The field depends on the sensor position of the vehicle on the magnetic road. As the rotation between the magnetic field and the sensor position is highly complex, it is difficult that the relation is stored in memory. Thus, a neural network is used to learn the mapping from th field to the position. The autonomous vehicle system with the proposed position sensing system is tested in experimental setup.

POSITION RECOGNITION AND QUALITY EVALUATION OF TOBACCO LEAVES VIA COLOR COMPUTER VISION

  • Lee, C. H.;H. Hwang
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 2000.11c
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    • pp.569-577
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    • 2000
  • The position of tobacco leaves is affluence to the quality. To evaluate its quality, sample leaves was collected according to the position of attachment. In Korea, the position was divided into four classes such as high, middle, low and inside positioned leaves. Until now, the grade of standard sample was determined by human expert from korea ginseng and tobacco company. Many research were done by the chemical and spectrum analysis using NIR and computer vision. The grade of tobacco leaves mainly classified into 5 grades according to the attached position and its chemical composition. In high and low positioned leaves shows a low level grade under grade 3. Generally, inside and medium positioned leaf has a high level grade. This is the basic research to develop a real time tobacco leaves grading system combined with portable NIR spectrum analysis system. However, this research just deals with position recognition and grading using the color machine vision. The RGB color information was converted to HSI image format and the sample was all investigated using the bundle of tobacco leaves. Quality grade and position recognition was performed through well known general error back propagation neural network. Finally, the relationship about attached leaf position and its grade was analyzed.

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