• Title/Summary/Keyword: Space Convergence

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Performance Improvement in Alternate Mainbeam Nulling by Adaptive Estimation of Convergence Parameters in Linearly Constrained Adaptive Arrays

  • Chang, Byong-Kun;Jeon, Chang-Dae;Song, Dong-Hyuk
    • Journal of information and communication convergence engineering
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    • v.7 no.3
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    • pp.392-398
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    • 2009
  • A novel approach is presented to improve the array performance of the alternate mainbeam nulling in a linearly constrained adaptive array processor in coherent environment. The convergence parameters in the linearly constrained LMS algorithm with a unit gain constraint and a null constraint in the direction of the desired signal are adaptively estimated to reduce the error power between the desired signal and the array output in the 2-dimensional convergence parameter space. It is shown that the case for estimating the convergence parameter for the unit gain constraint with that for null constraint fixed performs best. Also, it is observed that the proposed method performs significantly better than conventional methods as the number of coherent interferences increases.

WEAK SUFFICIENT CONVERGENCE CONDITIONS AND APPLICATIONS FOR NEWTON METHODS

  • Argyros, Ioannis-K.
    • Journal of applied mathematics & informatics
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    • v.16 no.1_2
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    • pp.1-17
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    • 2004
  • The famous Newton-Kantorovich hypothesis has been used for a long time as a sufficient condition for the convergence of Newton method to a solution of an equation in connection with the Lipschitz continuity of the Frechet-derivative of the operator involved. Using Lipschitz and center-Lipschitz conditions we show that the Newton-Kantorovich hypothesis is weakened. The error bounds obtained under our semilocal convergence result are finer and the information on the location of the solution more precise than the corresponding ones given by the dominating Newton-Kantorovich theorem, and under the same hypotheses/computational cost, since the evaluation of the Lipschitz also requires the evaluation of the center-Lipschitz constant. In the case of local convergence we obtain a larger convergence radius than before. This observation is important in computational mathematics and can be used in connection to projection methods and in the construction of optimum mesh independence refinement strategies.

Using Magnetic Quadrupoles in Cathode-Ray Tubes

  • Sluyterman, A.A.S.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2002.08a
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    • pp.367-370
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    • 2002
  • CRTs can be improved by means of magnetic quadrupoles. Areas of improvement are convergence, spot shape, image-flatness and space charge compensation.

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Case Analysis of the performance contents using virtual reality technology (가상현실 기술을 활용한 공연콘텐츠의 사례분석연구)

  • YOO, YOUNGJAE
    • Journal of the Korea Convergence Society
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    • v.8 no.5
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    • pp.145-153
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    • 2017
  • As success stories of using virtual reality (VR) have become more prevalent, interest in performance-related technology has rapidly increased around the world. Performances such as, Cirque du Soleil had much success in using video technology, these VR applications have enabled experiences using digital image technology. However, critics have claimed that the completeness and diversity of visual content is reduced, due to insufficient storylines, spatial composition, and partial use of the entire visual field. Therefore, the design of a performance using digital image technology should consider the characteristics of the production stage to be different from real world performances. In this study, the visual space of the stage, the method of creating space for the stage, and the movement of the performer and utilization of the performance was analyzed. Through this, It transferred the limitation of the traditional stage into the space and time of the image and opened the possibilities of the tran­-media.

The Study on the Spatial Change in an Aging Society (고령화에 따른 공간변화 연구)

  • You, Seung-Hee;Kwon, Chang-Hee
    • Journal of Digital Convergence
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    • v.15 no.1
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    • pp.11-22
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    • 2017
  • The purpose of the study is to come up with counter plans to the spatial change caused by an aging society. To achieve the purpose of this study, research methods are conducted in the literature survey and the census data are compared. This study focuses on an aging society, the current status of space and related problems, based on political economic spatial concepts, and then presents five countermeasures as follows. First, the planning considering the aging populations. Second, increase in total fertility rate and increase population absorption. Third, increased economic vitality of the elderly due to increased participation in the production of senior citizens. Forth, establishment and implementation of regional development plan for the elderly. Fifth, needs to transform the spatial policies of the aged to prepare a large gap in space. The result of this paper proposes the need to change the living space policies and planning to avoid mismatching between them, reducing the aging speed simultaneously. The study is expected to contribute to the establishment of a space plan for areas where the aging population is rapidly increasing.

A Comparative Study on Teacher-Student Perception of Forest Function in Elementary School (초등학교 내 학교숲 기능에 관한 교사 - 학생간 인식 비교 연구)

  • Kim, Jeong-Ho;Lee, Sang-Hoon;Yoon, Yong-Han
    • Journal of Environmental Science International
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    • v.27 no.7
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    • pp.519-529
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    • 2018
  • With rapid economic growth, the urban environment has created a problem of human physical and mental illness. In order to solve these problems, urban forests have emerged as a way to mitigate the environmental risks through improving the polluted environment of the city and improve the quality of life. As the urban forests have expanded, the school forests movement has also been taking an important place recently. The study focused on the performance of school forests by comparing the perceptions among teachers and students about their functions. The questionnaire was composed of 4 questions concerning human matters, 10 questions for space recognition, 4 questions for thermal environment, 2 questions for health promotion, and 20 total questions for composition of survey items. The reliability of the school forest function, number of tree planting areas and quantities, the harmony of the planting, and the satisfaction of the school forest were analyzed in the questionnaire conducted by the school members. Although it does not recognize school forests, it has a positive response to the green space that is built outdoors. It is considered that outdoor education and environmental education are sufficient in school forests and green spaces. The results showed that the outdoor green space was more satisfactory when compared with the general school. Teachers and students' preferences were similar to 'seasonal changes' and' trees of various colors and shapes'. The reliability analysis between each item shows that the coefficient for cronbach's ${\alpha}$ was .700 to .834. The purpose of this study is to identify the perception of forest function among school forest members and to utilize them as a basic data in the future.

Indoor Path Recognition Based on Wi-Fi Fingerprints

  • Donggyu Lee;Jaehyun Yoo
    • Journal of Positioning, Navigation, and Timing
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    • v.12 no.2
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    • pp.91-100
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    • 2023
  • The existing indoor localization method using Wi-Fi fingerprinting has a high collection cost and relatively low accuracy, thus requiring integrated correction of convergence with other technologies. This paper proposes a new method that significantly reduces collection costs compared to existing methods using Wi-Fi fingerprinting. Furthermore, it does not require labeling of data at collection and can estimate pedestrian travel paths even in large indoor spaces. The proposed pedestrian movement path estimation process is as follows. Data collection is accomplished by setting up a feature area near an indoor space intersection, moving through the set feature areas, and then collecting data without labels. The collected data are processed using Kernel Linear Discriminant Analysis (KLDA) and the valley point of the Euclidean distance value between two data is obtained within the feature space of the data. We build learning data by labeling data corresponding to valley points and some nearby data by feature area numbers, and labeling data between valley points and other valley points as path data between each corresponding feature area. Finally, for testing, data are collected randomly through indoor space, KLDA is applied as previous data to build test data, the K-Nearest Neighbor (K-NN) algorithm is applied, and the path of movement of test data is estimated by applying a correction algorithm to estimate only routes that can be reached from the most recently estimated location. The estimation results verified the accuracy by comparing the true paths in indoor space with those estimated by the proposed method and achieved approximately 90.8% and 81.4% accuracy in two experimental spaces, respectively.