• Title/Summary/Keyword: global minimum

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Assesment of Protected Mt. Seorak Areas in Korea Applied by the Key Biodiversity Areas(KBAs) (중요생물다양성지역(KBAs) 기준 적용을 통한 설악산 보호구역 평가)

  • Sung, Jung-Won;Kang, Shin-Gu;Kim, Keun-Ho
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.23 no.1
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    • pp.37-48
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    • 2020
  • This study was aimed to design core areas applied by the global conservation criteria to promote the public awareness to the protected areas and the value cognition of the Key Biodiversity Areas (KBAs), targeting the Mt Seorak, according to the designation of globally important biodiversity areas. As a method for carrying out this study, the biota were cataloged through literature reviews and field trips. With applied by the Global Red List criteria of the International Union for Conservation of Nature (IUCN), only nine species were categorized in the studied area; plants were classified into six species as follows: Megaleranthis saniculifolia ohwi, Bupleurum euphorbioides Nakai, Hanabusaya asiatica Nakai, Thuja koraiensis Nakai, Leontopodium leiolepis Nakai, Androsace cortusaefolia Nakai, fish was classified one species as follow: Pungitius sinensis Tanaka, and the mammal was classified as two species as follows: Hydropotes inermis, Naemorhedus caudatus. According to the occupation area (EoO, Extent of Occurrence) and Minimum Viable Population(MVP), the size of protected area was 234.56㎢ for plants, 235.07㎢ for mammals, and 0.14㎢ for fish, and the Key Biodiversity Area (KBA) of Mt. Seolak suggested as 286.72㎢.

Korean Satellite Based Augmentations System (한국형 위성기반 항법보강시스템)

  • Park, Jae-U;Lee, Yong-Min
    • Journal of Satellite, Information and Communications
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    • v.1 no.1
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    • pp.48-53
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    • 2006
  • A K-SBAS (Korean Satellite Based Augmentation System) is proposed as one of the space infrastructure. The proposed system considers the existed elements to the utmost for the most economical SBAS construction. As reference system the current DGPS (differential global positioning system) network is investigated. Space segment is investigated based on the COMS-1 (Communications, Oceanographic, and Meteorological Satellite-1). While bus system of COMS-1 can be kept to minimum change, the communication payload of needed, crucial parts such as software, man power can be easily secured through the DGPS network operation heritage.

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Study of Tube Expansion to Produce Hair-Pin Type Heat Exchanger Tubes using the Finite Element Method (유한요소법을 이용한 헤어핀 형 열 교환기의 튜브 확관에 대한 연구)

  • Hong, S.;Hyun, H.;Hwang, J.
    • Transactions of Materials Processing
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    • v.23 no.3
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    • pp.164-170
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    • 2014
  • To predict the deformation and fracture during tube expansion using the finite element (FE) method, a material model is considered that incorporates the damage evolution due to the deformation. In the current study, a Rice-Tracey model was used as the damage model with inclusion of the hydrostatic stress term. Since OFHC Cu is not significantly affected by strain rate, a Hollomon flow stress model was used. The material parameters in each model were obtained by using an optimization method. The objective function was defined as the difference between the experimental measurements and FE simulation results. The parameters were determined by minimizing the objective function. To verify the validity of the FE modeling, cross-verification was conducted through a tube expansion test. The simulation results show reasonable agreement with the experiments. The design for a minimum diameter of expansion tube using the FE modeling was verified by a simplified tube expansion test and simulation results.

Path Planning of Mobile Robot using Weighted Potential Function with Obstacle Avoidance (가중화된 포텐셜 함수를 이용한 이동 로봇의 장애물 회피 경로 계획)

  • Kim, Jin-Hwan
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.58 no.1
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    • pp.15-19
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    • 2009
  • This paper presents the potential field for mobile robot path planning. The proposed repulsive potential has weighted parts, which consists of conventional repulsive potential and goals nonreachable with obstacles nearby repulsive potential. It ensures the global minimum of the total potential when the robot approaches goals near obstacle and the robot passes the adjacent obstacles. Simulation results shows that the proposed potential is better than conventional potentials.

XML Based Standard Protocol for Remote Control (확장성표기언어(XML) 기반의 원격제어규약 표준)

  • Choi, Jung-In
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.55 no.5
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    • pp.216-219
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    • 2006
  • This paper presents an XML based standard specification of remote control protocol for home appliances. In the framework level, the XML protocol provides a useful bridge between services and platforms. The proposed protocol has been implemented into a personal video recorder for remote recording service. The results imply the potential of global standards for remote control by its minimum overhead in network and processor. The proposed XML is designated RCXML in this paper.

SOME MORE COUNTEREXAMPLES FOR BOMBIERI'S CONJECTURE ON UNIVALENT FUNCTIONS

  • Efraimidis, Iason;Pastor, Carlos
    • Journal of the Korean Mathematical Society
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    • v.55 no.6
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    • pp.1485-1498
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    • 2018
  • We disprove a conjecture of Bombieri regarding univalent functions in the unit disk in some previously unknown cases. The key step in the argument is showing that the global minimum of the real function (n sin x - sin(nx))/(m sin x - sin(mx)) is attained at x = 0 for integers m > $n{\geq}2$ when m is odd and n is even, m is sufficiently big and $0.5{\leq}n/m{\leq}0.8194$.

4차 고다드 알고리즘의 몇 가지 수렴 성질: 2. 평균성능함수의 기하

  • 최진호;배진수;송익호;박래홍;이민수
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.9
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    • pp.2355-2361
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    • 1996
  • Convergence analysis on Godard's quartic(GQ) algorithm used for blind equalization is accomplished in this paper. First, we explain the local behavior of the GQ algoithm around the global minimum point of the average performance function. Then we consider the geometry of the average performance function. The main result is that a good initial parameter vector of the GQ algorithm can be chosen based on the information of the geometry of the average performance function.

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Comparison of the Dynamic Time Warping Algorithm for Spoken Korean Isolated Digits Recognition (한국어 단독 숫자음 인식을 위한 DTW 알고리즘의 비교)

  • 홍진우;김순협
    • The Journal of the Acoustical Society of Korea
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    • v.3 no.1
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    • pp.25-35
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    • 1984
  • This paper analysis the Dynamic Time Warping algorithms for time normalization of speech pattern and discusses the Dynamic Programming algorithm for spoken Korean isolated digits recognition. In the DP matching, feature vectors of the reference and test pattern are consisted of first three formant frequencies extracted by power spectrum density estimation algorithm of the ARMA model. The major differences in the various DTW algorithms include the global path constrains, the local continuity constraints on the path, and the distance weighting/normalization used to give the overall minimum distance. The performance criterias to evaluate these DP algorithms are memory requirement, speed of implementation, and recognition accuracy.

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A New Effective Learning Algorithm for a Neo Fuzzy Neuron Model

  • Yamakawa, Takeshi;Kusanagi, Hiroaki;Uchino, Eiji;Miki, Tsutomu
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1993.06a
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    • pp.1017-1020
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    • 1993
  • This paper describes a neo fuzzy neuron which was produced by a fusion of fuzzy logic and neuroscience. Some learning algorithms are presented. The guarantee for the global minimum on the error-weight space is proved by a reduction to absurdity. Enhanced is that the learning speed of the neo fuzzy neuron exceeds 100,000 times of that of conventional multi-layer neural networks.

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Study on GNSS Constellation Combination to Improve the Current and Future Multi-GNSS Navigation Performance

  • Seok, Hyojeong;Yoon, Donghwan;Lim, Cheol Soon;Park, Byungwoon;Seo, Seung-Woo;Park, Jun-Pyo
    • Journal of Positioning, Navigation, and Timing
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    • v.4 no.2
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    • pp.43-55
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    • 2015
  • In the case of satellite navigation positioning, the shielding of satellite signals is determined by the environment of the region at which a user is located, and the navigation performance is determined accordingly. The accuracy of user position determination varies depending on the dilution of precision (DOP) which is a measuring index for the geometric characteristics of visible satellites; and if the minimum visible satellites are not secured, position determination is impossible. Currently, the GLObal NAvigation Satellite system (GLONASS) of Russia is used to supplement the navigation performance of the Global Positioning System (GPS) in regions where GPS cannot be used. In addition, the European Satellite Navigation System (Galileo) of the European Union, the Chinese Satellite Navigation System (BeiDou) of China, the Quasi-Zenith Satellite System (QZSS) of Japan, and the Indian Regional Navigation Satellite System (IRNSS) of India are aimed to achieve the full operational capability (FOC) operation of the navigation system. Thus, the number of satellites available for navigation would rapidly increase, particularly in the Asian region; and when integrated navigation is performed, the improvement of navigation performance is expected to be much larger than that in other regions. To secure a stable and prompt position solution, GPS-GLONASS integrated navigation is generally performed at present. However, as available satellite navigation systems have been diversified, finding the minimum satellite constellation combination to obtain the best navigation performance has recently become an issue. For this purpose, it is necessary to examine and predict the navigation performance that could be obtained by the addition of the third satellite navigation system in addition to GPS-GLONASS. In this study, the current status of the integrated navigation performance for various satellite constellation combinations was analyzed based on 2014, and the navigation performance in 2020 was predicted based on the FOC plan of the satellite navigation system for each country. For this prediction, the orbital elements and nominal almanac data of satellite navigation systems that can be observed in the Korean Peninsula were organized, and the minimum elevation angle expecting signal shielding was established based on Matlab and the performance was predicted in terms of DOP. In the case of integrated navigation, a time offset determination algorithm needs to be considered in order to estimate the clock error between navigation systems, and it was analyzed using two kinds of methods: a satellite navigation message based estimation method and a receiver based method where a user directly performs estimation. This simulation is expected to be used as an index for the establishment of the minimum satellite constellation for obtaining the best navigation performance.