• 제목/요약/키워드: new bounds

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Rare Earth Dispute and Trend in Development of NdFeB Anisotropic Bonded Magnets (희토류 자원분쟁과 NdFeB계 이방성 본드자석 개발동향)

  • Kim, H.J.;Kim, S.M.
    • Journal of the Korean Magnetics Society
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    • v.22 no.3
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    • pp.109-115
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    • 2012
  • NeFeB anisotropy bonded magnet has proposed a new paradigm of weight reduction of small motors by replacing the conventional ferrite permanent magnets with its high magnetic property of 25 MGOe during last five years. It has also advanced by leaps and bounds in the field of motor industry for automobiles and electric power tools. And it has led a new innovation of fifty percent weight lightening compared to its current motors by correctly focusing on fuel performance improvement through weight lightening that automobile industry chased. There was, however, another price skyrocketing in 2011 after China had announced its export regulation in rare earth materials in July, 2010. And this price change has an extensive impact on the industries that consume rare earth magnets. This environmental change has caused technical challenge to improve the performance by using least amount of rare earth elements in NdFeB anisotropy bonded magnets, and led to make a new technical approach to a new applied field. In this article, we will show how each nation deals with this industrial issue, and introduce development trend and application of anisotropic NdFeB bonded magnets, so-called MAGFINE made by Aichi Steel Corp.

A Exploratory Study on Big-data based Election Campaign Strategy Model in South Korea (빅데이터 기반 선거캠페인 전략에 관한 탐색적 연구)

  • Noh, Kyoo-Sung
    • Journal of Digital Convergence
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    • v.11 no.12
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    • pp.113-120
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    • 2013
  • The victory of Barack Obama in the presidential reelection, in which he got closer to voters by scientific election strategy based on data, is making a new paradigm of this scientific election mechanism. But it is within bounds to say that Korean election has developed based on emotional confrontation, rather than on the confrontation of policy or personal qualification. This study suggests a Big data-based election campaign strategy in an effort to reduce the harmful consequences of Korean election and to settle down a desirable campaign culture. To do so, this study examines the actual status and problems of Korean politics and election campaign. And then it designs a Korean election strategy model using Big data as an alternative to break through the problems. Last, it discusses the plan to utilize Big data.

A Study on Abstract Synesthesia for Visual Music (비쥬얼 뮤직에 나타난 추상적 공감각에 관한 연구)

  • Kim, Ho
    • The Journal of the Korea Contents Association
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    • v.16 no.8
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    • pp.484-492
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    • 2016
  • Role of music in an image can be divided into a supplementary function to express narrative of image and an independent function to become the subject of music and to lead the image. To perceive sound through hearing and then, to make it visualized is called visual music. Since the 19th century, image synchronization of music through colored hearing has been continuously attempted by artists in their works. Also in the 20th century, many artists could attempt time-wise concept of movement passing the bounds of three-dimensional expression due to development of cinema. In such a process, artists with strong experimental spirits inferred correlation between sound and image and then, pioneered new genre of visual music. As a result, the times are being changed from those of listening to those of watching, and various works are being produced by experimental attempt of various music and images. This thesis aims to investigate aesthetic characteristics of modern visual music and then, to conduct comparative analysis on how visual music using colors are utilized in diversified fields such as movie, animation, music video and media art.

A Study on Adolf Loos's thought about Modernity and his Works of Houses (근대성과 관련한 Adolf Loos의 사상과 주거건축에 관한 연구)

  • Kim, Kyung-Ho
    • Korean Institute of Interior Design Journal
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    • v.15 no.5 s.58
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    • pp.36-43
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    • 2006
  • Architecture is the product of a way of thinking. If the problems of architecture are to be traced to their roots, then attention needs to be focused on the thinking and considerations that inform its production. Adolf Loos occupies a truly exceptional place in the history of architecture. Adolf Loos's ideas and attitudes disagree with the notion that modernity is possible to develop a harmonious culture within the bounds of a modernizing society. Loos chronologically precedes the modern movement, but his ideas contain the seeds of what will be worked out later as a complex critique of the movement's notions about architecture and modernity. Loos holds the view that modernity provokes an inevitable rupture with tradition that has as a consequence the disintegration of one's experience of life. This evolution, he think, obliges architecture to display a number of languages corresponding to a multitude of different experiences. Through the discussion of Loos's opinions on dwelling and architecture, it explores the true features of position of Loos in modern architecture. Loos thinks that the rejection of the deliberate creation of a new style was a correct response to the diagnosis of life as being rootless and fragmented. Ornament is that which people use to attempt to relate different aspects of life and to join inner and outer worlds in a coherent whole. By getting rid of ornament the illusion is destroyed that a harmonious unity of this sort is still possible. One can only remain true to tradition if one acknowledges that its continuity is not an unbroken one. Dwelling can only be saved by separating it from other aspects of life.

A Study on the Balancing of the Demand and Supply of Radio Operators (通信人力의 需給均衡化에 關한 硏究 - 地域 및 海域別 無線通信을 중심으로 -)

  • 나경식;김정부;이영철;김기문
    • Journal of the Korean Institute of Navigation
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    • v.16 no.2
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    • pp.53-78
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    • 1992
  • GMDSS-the Global Maritime Distress and Safety system which is utilizing the new technologies such as satellite communication system, DSC and NBCP-is effectuated not only by the amendment of SOLAS but also by the conference of RR and IMO's MSC, and will be the major factor of the variation of the demand and supply of Radio Operators. To cope with the GMDSS voluntarily, regulations relating to the radio installation, the posting of Radio Operators, the bounds of duty, etc. must be established and the demand and supply of Radio Operators which take charge of the system must be accomplished pertinently. In this study, the authors suggested some practical schemes to improve the effect of policy as follow. 1. The Ministry of Communication must supervise strictly the arrangement of Radio Operators, especially relating tot he legally qualified complement of Radio Station, and must review the official certification system to upgrade the quality of Radio Operators. 2. The Ministry of Communication must take overall charge of the qualitifications and technical standards of Radio Operators, the extent of their engagement, etc. which are provided by International Regulations. 3. Relating Administrations must cooperate with Shipping Companies in onboard-training to foster and ensure the manpower of Radio Operators. 4. Institutional devices to drive the resolute investment in education and training for mariners, especially for the ship's officers, must be prepared. 5. The Communication Administration and the Korea Maritime and Port Adminstration(KMPA) must cooperate mutually in the balance of the demand and supply of Radio Operators and use make their best to realize more harmonious policies on the demand and supply of manpower.

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A Study on the Scope of the Development of Ship Communication in the GMDSS (GMDSS도입에 따른 선박통신의 발전방향에 관한 연구)

  • 신현식;김기문
    • Journal of the Korean Institute of Navigation
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    • v.18 no.1
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    • pp.39-61
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    • 1994
  • GMDSS(the Global Maritime Distress and Safety System), which is utilizing recently developed systems such as satellite communications and positioning system, digital communication system, computer and microelectronics technology, etc., has been adopted by International Maritime Orgnization(IMO) and coordina-ted with such organization as the International Telecommunication Union(ITU), World Meteorological Organizatoion(WMO), etc. This system took effect partly on February 1st 1992 according to the 1988 SOLAS Amemdments and, after some more complementary measures, will be fully operational by February 1st 1999. Comparing with the existing communication system, the new system is mainly based on the latest scientific technologies, and therefore overall countermeasure will be necessary to accept the system reasonably. GMDSS will transform the current communication system basically and be the major factor to change the demand and supply of personnel for radio communication. To cope with the system assertively, regulations relating to the radio installation, the posting of radio operators, the bounds of their duty, etc. must be established and the demand and supply of radio operators to meet the system must be accomplished pertinently. Moreover, the technique and quality of the person-nel responsible for the system must be upgraded to carry out the obligations by international regulations as well as to ensure the safety of life and property at sea. Looking into the actual situations of our country, every regulation relating to the GMDSS has been improved, but the concerned educational institutions and administrations have not yet prepared the rational and concrete schemes on the educational methods and adquate procedures for the system. Therefore, in this thesis, the author intends to propose directions for improving the courses and contents of education of the relating educational institutions and to suggest rational schemes for balancing the demand and supply of personnel to the administrative anthorty concerned.

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A Jitter Analysis for Improved Schedulability of Distributed Real-Time Tasks (분산 실시간 태스크의 스케쥴가능성 개선을 위한 지터 분석)

  • Kim, Tae-Woong;Shin, Heon-Shik;Chang, Nae-Hyuck
    • Journal of KIISE:Computer Systems and Theory
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    • v.27 no.5
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    • pp.506-517
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    • 2000
  • In distributed real-time system, a task activated by the completion of its preceding task can be modeled as a periodic task with activation jitter. An activation jitter of a task is defined asthe difference between the worst case and the best case response time of its preceding task. Becausethe existing approaches assume that the best case response time is much smaller than the actual one,the activation jitter and the worst case response time of lower priority tasks are overestimated. Thispaper proposes a new analysis technique to calculate the best case response time more precisely andto reduce the activation jitter bounds. The proposed technique obtains the best case response time byconsidering the relative phase between tasks. The precise analysis of the activation jitters can reducethe worst case response time of other tasks and increase the schedulability. The simulation resultsshow that the proposed analysis technique improves the accuracy of the best case and the worst caseresponse time up to 40% and 6%, respectively.

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A Study on the Improvement of Real-Time Traffic QoS using the Delay Guarantee Queue Service Discipline of End-to-End (종단간 지연 큐 서비스 방식을 이용한 실시간 트래픽 QoS 개선에 관한 연구)

  • 김광준;나상동
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.6 no.2
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    • pp.236-247
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    • 2002
  • We propose a cell-multiplexing scheme for the real-time communication service in ATM network and a new service discipline guarantee end-to-end delay based on pseudo-isochronous cell switching. The proposed scheme consists of two level frame hierarchy, upper and lower frame, which is used to assign the bandwidth and to guarantee the requested delay bound, respectively. Since the Proposed algorithm employs two level frame hierarchy, it can overcome the coupling problem which is inherent to the framing strategy It can be comparatively reduce the complexity, and still guarantee the diverse delay bounds of end-to-end. Besides, it consists of two components, traffic controller and scheduller, as the imput traffic description model and regulates the input traffic specification. The function of the traffic controller is to shape real -time traffic to have the same input pattern at every switch along the path. The end-to-end delay is bounded by the scheduller which can limit the delay variation without using per-session jitter controllers, and therefore it can decrease the required buffer size. The proposed algorithm can support the QoS's of non-real time traffic as well as those of real time traffic.

A Die-matching Method for 3D Memory Yield Enhancement considering Additional Faults during Bonding (3차원 메모리의 수율 증진을 위해 접합 공정에서 발생하는 추가 고장을 고려한 다이 매칭 방법)

  • Lee, Joo-Hwan;Park, Ki-Hyun;Kang, Sung-Ho
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.48 no.7
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    • pp.30-36
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    • 2011
  • Three-dimensional (3D) memories using through-silicon vias (TSVs) as vertical bus across memory layers are implemented by many semiconductor companies. 3D memories are composed of known-good-dies (KGDs). If additional faults are arisen during bonding, they should be repaired. In order to enhance the yield of 3D memories with inter-die redundancies, a die-matching method is needed to effectively stack memory dies in a 3D memory. In this paper, a new die-matching method is proposed for 3D memory yield enhancement with inter-die redundancies considering additional faults arisen during bonding. Three boundary-limited conditions are used in the proposed die-matching method; they set bounds to the search spaces for selecting memory dies to manufacture a 3D memory. Simulation results show that the proposed die-matching method can greatly enhance the 3D memory yield.

Study on Wear of Journal Bearings during Start-up and Coast-down Cycles of a Motoring Engine - II. Analysis Results (모터링 엔진의 시동 사이클 및 시동 정지 사이클에서 저어널베어링의 마모 연구 - II. 해석 결과)

  • Chun, Sang Myung
    • Tribology and Lubricants
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    • v.31 no.3
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    • pp.125-140
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    • 2015
  • In this paper, we present the results of the wear analysis of journal bearings on a stripped-down single-cylinder engine during start-up and coast-down by motoring. We calculate journal bearing wear by using a modified specific wear rate considering the fractional film defect coefficient and load-sharing ratio for the asperity portion of a mixed elastohydrodynamic lubrication (EHL) regime coupled with previously presented graphical data of experimental lifetime linear wear in radial journal bearings. Based on the calculated wear depth, we obtain a new oil film thickness for every crank angle. By examination of the oil film thickness, we determine whether the oil film thickness at the wear scar region is in a mixed lubrication regime by comparing dimensionless oil film thickness, h/σ, to 3.0 at every crank angle. We present the lift-off speed and the crank angles involved with the wear calculation for bearings #1 and #2. The dimensionless oil film thickness, h/σ, illustrates whether the lubrication region between the two surfaces is still within the bounds of the mixed lubrication regime after scarring of the surface by wear. In addition, we present in tables the asperity contact pressure, the real minimum film thickness at the wear scar region, the modified specific wear rate, and the wear angle, α, for bearings #1 & #2. To show the real shape of the oil film at wear scar region, we depict the actual oil film thickness in graphs. We also tabulated the ranges of bearing angles related with wear scar. We present the wear volume for bearings #1 and #2 after one turn-on and turn-off of the engine ignition switch for five kinds of equivalent surface roughness. We show that the accumulated wear volume after a single turn-on and turn-off of an ignition switch normally increases with increasing surface roughness, with a few exceptions.