• Title/Summary/Keyword: collective coordinate

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Current-Induced Magnetic Domain-Wall Motion by Spin Transfer Torque: Collective Coordinate Approach with Domain-Wall Width Variation

  • Jung, Soon-Wook;Lee, Hyun-Woo
    • Journal of Magnetics
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    • v.12 no.1
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    • pp.1-6
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    • 2007
  • The spin transfer torque generated by a spin-polarized current can induce the shift of the magnetic domain-wall position. In this work, we study theoretically the current-induced domain-wall motion by using the collective coordinate approach [Gen Tatara and Hiroshi Kohno, Phys. Rev. Lett. 92, 86601 (2004)]. The approach is extended to include not only the domain-wall position and the polarization angle changes but also the domain-wall width variation. It is demonstrated that the width variation affects the critical current.

A study on village economic cooperative in the city of China

  • Chen, Lifeng;Jin, Shanyue
    • International Journal of Advanced Culture Technology
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    • v.8 no.3
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    • pp.1-9
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    • 2020
  • According to the 2012 social blue book released by the Chinese Academy of Social Sciences, China's urban population reached 50% in 2011. With the migration from marriage and new household registration, many urban collective assets have been formed in cities. Due to the unclear property rights and the emptiness of the main body, the distribution of collective assets mostly depends on the village cadres. The central government is preparing relevant laws and regulations to fill this legal gap, while the scheme of restructuring is decided by the villagers' vote, the local government coordinate the land acquisition and management. With the process of urbanization, a large number of second-generation of demolition studied abroad, which has attracted worldwide attention. In addition to the huge amount of compensation, due to the continuous rising of the land price, the value of the collective property and enterprises on the land also keep rising, the management agency of these assets is named village economic cooperative. This paper seeks to analyze the current status and future direction of these wealthy organizations, propose solutions to some existing problems.

A Study on the Meaning of 'Social Construction' in Mathematics Education (사회적 구성'의 수학교육적 의미에 관한 고찰)

  • 홍진곤
    • The Mathematical Education
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    • v.41 no.3
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    • pp.329-339
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    • 2002
  • This study analyzes the epistemological meaning of‘social construction’in mathematical instruction. The perspective that consider the cognition of mathematical concept as a social construction is explained by a cyclic scheme of an academic context and a school context. Both of the contexts require a public procedure, social conversation. However, there is a considerable difference that in the academic context it is Lakatos' ‘logic of mathematical discovery’In the school context, it is Vygotsky's‘instructional and learning interaction’. In the situation of mathematics education, the‘society’which has an influence on learner's cognition does not only mean‘collective members’, but‘form of life’which is constituted by the activity with purposes, language, discourse, etc. Teachers have to play a central role that guide and coordinate the educational process involving interactions with learners in this context. We can get useful suggestions to mathematics education through this consideration of the social contexts and levels to form didactical situations of mathematics.

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Mobile Robot Localization using Ubiquitous Vision System (시각기반 센서 네트워크를 이용한 이동로봇의 위치 추정)

  • Dao, Nguyen Xuan;Kim, Chi-Ho;You, Bum-Jae
    • Proceedings of the KIEE Conference
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    • 2005.07d
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    • pp.2780-2782
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    • 2005
  • In this paper, we present a mobile robot localization solution by using a Ubiquitous Vision System (UVS). The collective information gathered by multiple cameras that are strategically placed has many advantages. For example, aggregation of information from multiple viewpoints reduces the uncertainty about the robots' positions. We construct UVS as a multi-agent system by regarding each vision sensor as one vision agent (VA). Each VA performs target segmentation by color and motion information as well as visual tracking for multiple objects. Our modified identified contractnet (ICN) protocol is used for communication between VAs to coordinate multitask. This protocol raises scalability and modularity of thesystem because of independent number of VAs and needless calibration. Furthermore, the handover between VAs by using ICN is seamless. Experimental results show the robustness of the solution with respect to a widespread area. The performance in indoor environments shows the feasibility of the proposed solution in real-time.

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A Visualization Method for the Efficient Product Searching in Internet Shopping Mall (인터넷 쇼핑몰에서 효율적인 상품 검색을 위한 가시화방법)

  • Whangbo, Taeg-Keun;Lee, Soo-Jin
    • Journal of Internet Computing and Services
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    • v.6 no.5
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    • pp.111-121
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    • 2005
  • As the scale of e-commerce has been increasing, information about products and service become diversified, Most current internet shopping mall. however, provides product information to consumers in collective arrangement. thus they devote a lot of efforts and time to select the product they want, In this paper, as providing consumers convenient interfaces adapting feature inquirer and parallel coordinate, a method for selecting a right product through searching the wanted products easily and comparing their features efficiently has been proposed. To evaluate the efficiency of the method proposed in this paper, several experiments to measure the time spent and the number of clicks of mouse taken in finding the product they want have been conducted. The results verify the effectiveness of the proposed method.

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Non-Steady Group Combustion of Liquid Fuel Droplets (액체연료 액적군 의 비정상 집단연소)

  • 김호영
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.8 no.6
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    • pp.544-552
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    • 1984
  • A non-steady group combustion model of a spherical droplets cloud has been developed to access the non-steady effects of collective behavior of fuel droplets on combustion characteristics and cloud structure. A system of conservation equations of droplets cloud in axisymmetric spherical coordinate was solved by numerical methods for n-Butylbenzene(C$_{10}$ / $H_{14}$) It was found that the effect of initial droplet size on combustion characteristics is dominated compare with effects of cloud size and number density of droplets. For dense droplets cloud, external group combustion mode is established during main part of cloud life time, and internal and single droplet combustion modes are simultaneously established for the dilute droplets cloud. Radius of cloud and external envelope flame are slowly decreased during main part of cloud life time, and suddenly decreased at end of combustion period.d.

A reverse engineering system for reproducing a 3D human bust (인체 흉상 복제를 위한 역공학 시스템)

  • 최회련;전용태;장민호;노형민;박세형
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2001.04a
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    • pp.15-19
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    • 2001
  • A dedicated reverse engineering(RE) system for rapid manufacturing of human head in a 3D bust has been developed. The first step in the process is to capture the surface details of a human head and shoulder by three scanners based upon the digital moire fringe technique. Then the multiple scans captured from different angles are aligned and merged into a single polygonal mesh, and the aligned data set is refined by smoothing, subdividing or hole filling process. Finally, the refined data set is sent to a 4-axis computer numerically control(NC) machine to manufacture a replica. In this paper, we mainly describe on the algorithms and software for aligning multiple data sets. The method is based on the recently popular Iterative Closest Point(ICP) algorithm that aligns different polygonal meshes into one common coordinate system. The ICP algorithm finds the nearest positions on one scan to a collection of points on the other scan by minimizing the collective distance between different scans. We also integrate some heuristics into the ICP to enhance the aligning process. A typical example is presented to validate the system and further research work is also discussed.

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The Novel Configuration of Integrated Network for Building Energy System (빌딩 에너지시스템 통합네트워크 구축에 관한 연구)

  • Hong, Won-Pyo
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2008.10a
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    • pp.229-234
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    • 2008
  • The new millennium has started with several innovations driven by fast evolution of the technologies in energy sector. A strong impulse towards the diffusion of new economical efficient technologies regulatory incentives related to energy production from renewable source and a small scale building trigeneration and to promotion of more sustainable environmental-friendly generation solutions, the evolution of electricity markets, more and more binding local emission constraints, and the need for improving the security of supply to reduce the energy system vulnerability. The 24 percentage energy quantify of total energy consumption consumes in commercial buildings and residential houses and the 30% portion of total $CO_2$ emissions covers also in the commercial buildings and residential houses sector. To cope with efficiently this energy sinuation in building sector, Building microgrid or building tooling, heating & power(BCHP) system has been interested in recent day due to meeting thermal and electric energy requirements efficiently and with appropriate energy quality. A multi agent system is a collective of intelligent agents that communicate with each other and work cooperatively to achieve common goals. Also, it is to medicate and coordinate communication between Control Areas and Security Coordinators for teal-time control of the BCHP system and the power pid. In this new circumstance, it is very important to integrate the power and energy delivery system and the information system(communication, networks, and intelligent equipment) that controls it. Therefore, development of smart control modules with open communication protocol and seamlessly interchange the data and information between control network and data network including extranet and intranet give a great meanings. We designed and developed the TCP/IP-CAN IED agent modules and ModBus./LonTalk/(TCP/IP) IED agent ones to configure the multi-agent system based smart energy network of commercial buildings and also intelligent algorithms for inverter fault diagnostics which ran be operated in control level or agent level network.

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