• 제목/요약/키워드: Boundaries

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An Effective Frequency Allocation Plan for Symmetric 10MDSL Systems (양방향 10MDSL을 위한 VDSL 시스템의 주파수할당 계획)

  • Kil, Jung-Su;Kwon, Ho-Yeol
    • Journal of Industrial Technology
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    • v.22 no.B
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    • pp.169-173
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    • 2002
  • In this paper, we discussed an effective VDSL frequency plan for symmetric 10MDSL service. The frequency plan 998 and plan 997 for asymmetric VDSL services have been not optimally designed for 10MDSL services. To obtain the reaches and data rates of 10MDSL, we proposed two frequency allocation schemes : Static method and dynamic method. We can select frequency bands with their fixed boundaries in static method while with their variable boundaries in dynamic method. To show the effectiveness of our proposed methods, we performed some simulations about plan 997 and plan 998, new static method, and new dynamic method. According to the simulation results, the proposed dynamic method can provide the best data rates and reaches for 10 Mbps symmetric VDSL services.

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Design Elements Related to Territoriality for Apartment Community Design (영역성 측면에서 공동주택 커뮤니티 계획요소에 관한 연구)

  • Cho, Sung-Heui;Choi, In-Young
    • Journal of the Korean housing association
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    • v.22 no.1
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    • pp.57-64
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    • 2011
  • The purpose of this study is to investigate design elements to strengthen apartment communities in territoriality perspectives. To this end, the study first identified the functions of territoriality to communities, and examined precedent studies on community planning. Then, looking into actual apartment, the study analyzed design elements of the apartments by territoriality functions, and found significant community-building and community-strengthening elements. The results of case studies are as follows: Specific design elements are 1) both individual and shared places from the perspective of possession, 2) both physical boundaries including visible mark and physical demarcation, and emotional boundaries including space arrangement and visual expansion from the perspective of boundary-regulation, 3) both physical proximity, such as providing space for physical encounter and easy access, and emotional proximity such as homogeneity and intimacy from the perspective of proximity 4) design differentiation and adoption of the design concept to express the identity of the community from the perspective of proximity personalization.

Levitation force and trapped magnetic field of top-seeded melt growth processed YBCO superconductors (종자결정성장법으로 제조한 YBCO 초전도체의 자기 부상력과 포획자력 특성)

  • 김찬중;홍계원
    • Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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    • 2001.02a
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    • pp.139-141
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    • 2001
  • YBCO superconductors were prepared by top-seeded melt growth process using various numbers of seeds. The levitation forces and trapped magnetic fields of the top surfaces of the samples were measured using Nd-B-Fe permanent magnets It was found that the processing time was greatly reduced by multiple seeding, but the properties were decreased as the number of seeds was increased. The degradation of the properties is attributed to the presence of the nonsuperconducting phases at the grain boundaries as result of the entrapment of a residual melt at grain boundaries during melt processing.

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A Study on General Management of Multi-family Housing Manager (공동주택 관리자의 일반적 관리업무 실태 -경기도 광명시 지역 아파트 관리소장을 중심으로-)

  • 은난순;홍형옥
    • Journal of the Korean housing association
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    • v.11 no.2
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    • pp.139-148
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    • 2000
  • The purpose of this paper was to find the apartment manager's general work, problems and opinion. 35 managers of multi-family housing which located in Kwangmyung city were interviewed during July, 1999. Questionnaire was consisted of questions which manager's opinion about their job boundaries. At the managerial standpoint, there was a perceived gap in expectation level about the manager's role between the manager and residents in multi-family housing complexes. The fact that the lack of interpersonal communication caused this gap was founded. Managerial rules and guidelines should be described in detail and be known by all residents. Specified guideline should be suggested regarding the boundaries of the manager's job, responsibilities and rights, and extra work beyond the management job in order to prevent conflicts or problems between the managing body and the residents. There guidelines also play an important role in solving the conflicts and problems in multi-family housing.

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Analysis of Temperature Distribution in EHV GIS Three-Phase Busbar Using Analytic Technique (해석적 기법을 이용한 초고압 GIS용 삼상모선의 온도분포 해석)

  • Hahn, Sung-Chin;Kim, Joong-Kyoung
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.55 no.4
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    • pp.196-202
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    • 2006
  • This paper presents a new magneto-thermal finite element analysis for predicting the temperature rise of the EHV GIS busbar. Joule's heat due to current flowing in the main conductor and the heat due to the induced eddy current in the tank are calculated by the magnetic field analysis. And these heats are used as the input data to predict the temperature rise for the thermal analysis. However, it is not easy to apply the heat-transfer coefficients on the boundaries for the thermal analysis. In this paper, the heat-transfer coefficients on the boundaries are analytically calculated by applying the Nusselt number considering material constant and model geometry for the natural convection. The temperature distribution in the busbar by coupled magneto-thermal finite element analysis shows good agreement with the experimental data.

The Role of Prosodic Boundary Cues in Word Segmentation in Korean

  • Kim, Sa-Hyang
    • Speech Sciences
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    • v.13 no.1
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    • pp.29-41
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    • 2006
  • This study investigates the degree to which various prosodic cues at the boundaries of prosodic phrases in Korean contribute to word segmentation. Since most phonological words in Korean are produced as one Accentual Phrase (AP), it was hypothesized that the detection of acoustic cues at AP boundaries would facilitate word segmentation. The prosodic characteristics of Korean APs include initial strengthening at the beginning of the phrase and pitch rise and final lengthening at the end. A perception experiment utilizing an artificial language learning paradigm revealed that cues conforming to the aforementioned prosodic characteristics of Korean facilitated listeners' word segmentation. Results also indicated that duration and amplitude cues were more helpful in segmentation than pitch. Nevertheless, results did show that a pitch cue that did not conform to the Korean AP interfered with segmentation.

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Electromagnetic scattering characteristics of a hyperbolic reflector antenna accounting for the UTD higher order diffraction (UTD 고차회절을 고려한 쌍곡면 반사판 아테나의 전자파 산란 특성)

  • 최재훈;이병우;이상설
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.33A no.5
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    • pp.85-93
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    • 1996
  • The far-zone scattered field patterns of a hyperbolic reflector antenna are analyzed by using uniform geometrical theory of diffraction(UTD). The main objective of this paper is to obtain the higher order diffraction contributions which provide the continuity over the shadow boundaries of the first order solution. to obtain the scattered magnetic field characteristics, the scattered field components of the secodn-order diffraction, diffraction-reflection, diffraction-reflection-diffraction terms are added to the result of the previous research. The results of the present research are compared to those of the first order solution and the method of moments. One can observe the improvemtn of the current approach over the first order solution. also, the results of the present method agree very well with those of the moment methods especially in the transition regions near the first order diffraction shadow boundaries.

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An efficient recognition of round objects using the curve segment grouping (곡선 조각의 군집화에 의한 둥근 물체의 효과적인 인식)

  • 성효경;최흥문
    • Journal of the Korean Institute of Telematics and Electronics C
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    • v.34C no.9
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    • pp.77-83
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    • 1997
  • Based on the curve segment grouping, an efficient recognition of round objects form partially occuluded round boundaries is proposed. Curve segments are extracted from an image using a criterion based on the intra-segment curvature and local contrast. During the curve segment extraction the boundaries of pratially occluding and occuluded objects are segmented to different curve segments. The extracted segments of constant intra-segment curvature are grouped to different curve segments. The extracted segments of constant intra-segment curvature are grouped nto a round boundary by the proposed grouping algorithm using inter-segment curvature which gives the relatinships among the curve segments of the same round boundary. The 1st and the 2nd order moments are used for the parameter estimation of the best fitted ellipse with round boundary, and then recognition is perfomed based on the estimated parameters. The proposed scheme processes in segment unit and is more efficient in computational complexity and memory requirements those that of the conventional scheme which processed in pixel units. Experimental results show that the proposed technique is very efficient in recognizing the round object sfrom the real images with apples and pumpkins.

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Center estimation of the n-fold engineering parts using self organizing neural networks with generating and merge learning (뉴런의 생성 및 병합 학습 기능을 갖는 자기 조직화 신경망을 이용한 n-각형 공업용 부품의 중심추정)

  • 성효경;최흥문
    • Journal of the Korean Institute of Telematics and Electronics C
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    • v.34C no.11
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    • pp.95-103
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    • 1997
  • A robust center estimation tecnique of n-fold engineering parts is presented, which use self-organizing neural networks with generating and merging learning for training neural units. To estimate the center of the n-fold engineering parts using neural networks, the segmented boundaries of the interested part are approximated to strainght lines, and the temporal estimated centers by thecosine theorem which formed between the approximaged straight line and the reference point, , are indexed as (.sigma.-.theta.) parameteric vecstors. Then the entries of parametric vectors are fed into self-organizing nerual network. Finally, the center of the n-fold part is extracted by mean of generating and merging learning of the neurons. To accelerate the learning process, neural network uses an adaptive learning rate function to the merging process and a self-adjusting activation to generating process. Simulation results show that the centers of n-fold engineering parts are effectively estimated by proposed technique, though not knowing the error distribution of estimated centers and having less information of boundaries.

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A Study of Accuracy Improvement of an Analysis of Flow around Arbitrary Bodies by Using an Eulerian-Lagrangian Method (Eulerian-Lagrangian 방법을 사용한 임의 물체주위 유동해석의 정도 향상을 위한 연구)

  • Park I. R.;Chun H. H.
    • Journal of computational fluids engineering
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    • v.6 no.3
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    • pp.19-26
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    • 2001
  • An Eulerian-Lagrangian method, so called immersed boundary method, is used for analysing viscous flow around arbitrary bodies, where governing equations are discretized on a regular grid by using a finite volume method. To improve the accuracy of flow near body boundaries, a second-order accurate interpolation scheme is used and a level-set based grid deformation method is presented to construct the adaptive grids around body boundaries. The present scheme is used to simulate steady flow around a semicircular cylinder mounted on the bottom of flow domain and calculated results are validated by results of a body fitted grid method. Finally, present method is applied to a complex flow around multi body and the usefulness is checked by investigating calculated results.

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