• 한국정보통신학회논문지
• /
• 제3권3호
• /
• pp.687-694
• /
• 1999

본 논문에서는 ADSL용 칩 설계를 위한 동기화 파라미터 값을 도출하기 위하여 컴퓨터 모의수행으로 STR과 프레임동기의 성능을 분석한다. ADSL에 적합한 PLL루프를 분석하고 설계를 하며, 이러한 결과를 통하여 ADSL칩 설계를 위한 STR의 최적 파라미터 값을 얻는다. 또한 여러 가지 알고리즘으로 프레임동기를 수행할 때, 컴퓨터 모의수행으로 FER(Frame Error Rate)의 성능을 분석했고, 프레임 offset의 효과를 분석했다.

• Steel and Composite Structures
• /
• 제22권2호
• /
• pp.235-255
• /
• 2016

This paper experimentally investigated the behavior of steel frame structures of traditional-style buildings subjected to combined constant axial load and reversed lateral cyclic loading conditions. The low cyclic reversed loading test was carried out on a 1/2 model of a traditional-style steel frame. The failure process and failure mode of the structure were observed. The mechanical behaviors of the steel frame, including hysteretic behaviors, order of plastic hinges, load-displacement curve, characteristic loads and corresponding displacements, ductility, energy dissipation capacity, and stiffness degradation were analyzed. Test results showed that the Dou-Gong component (a special construct in traditional-style buildings) in steel frame structures acted as the first seismic line under the action of horizontal loads, the plastic hinges at the beam end developed sufficiently and satisfied the Chinese Seismic Design Principle of "strong columns-weak beams, strong joints-weak members". The pinching phenomenon of hysteretic loops occurred and it changed into Z-shape, indicating shear-slip property. The stiffness degradation of the structure was significant at the early stage of the loading. When failure, the ultimate elastic-plastic interlayer displacement angle was 1/20, which indicated high collapse resistance capacity of the steel frame. Furthermore, the finite element analysis was conducted to simulate the behavior of traditional-style frame structure. Test results agreed well with the results of the finite element analysis.

• 대한전자공학회논문지SD
• /
• 제46권9호
• /
• pp.14-24
• /
• 2009

System on panel 프레임 버퍼를 위한 메모리 셀 어레이와 주변회로가 설계되었다. 또한, system on panel 공정의 낮은 yield를 극복하기 위해, 블럭 단위의 parallel test 방안이 제안되었다. 기존의 메모리 테스트 보다 빠르게 fault detection이 가능하며, 다양한 embedded memory나 일반 SRAM 테스트 분야에도 적용 가능하다. 또한 기존의 다양한 test vector pattern이 그대로 적용될 수 있어 fault coverage가 높고, 최근의 추세인 hierarchical bit line과 divided word line 구조에도 적용될 수 있다.

• 조명전기설비학회논문지
• /
• 제29권12호
• /
• pp.83-87
• /
• 2015

This paper presents a simple notch filter, which is so suitable for three-phase unbalanced and distorted power line. In the d-q synchronous transformation, three-phase unbalanced and distorted voltages generate lots of ripple voltages on d-q axes. The ripples make disturbances on controllers such as PLL of phase tracking. Unbalanced state makes ripple of double the frequency of power line. Odd harmonics 5th and 7th on the line make even 4th and 6th ripples on d-q axes due to the rotating reference frame, respectively. Cascaded two comb filters, delay lines 1/4T and 1/8T, are adopted for the ripple rejection. The filter rejects harmonics 2nd, 4th, 6th, 10th and so on. They are very effective to remove the ripples of both unbalance and distortion. The filter, implemented by two FIFOs on an experimental system, is adopted on a PLL controller of power line phase tracking. Through the simulation and experimental results, performance of the proposed comb filter has been validated.

• 한국지능시스템학회논문지
• /
• 제15권6호
• /
• pp.709-713
• /
• 2005

고해상도의 항공영상으로부터 3차원 와이어프레임(wire-frame) 구성을 위한 새로운 선소 추출 알고리듬을 제안하였다. 본 연구의 목적은 기존의 방식들의 문제점인 라인 불일치 문제, 에지부분의 Blurring 문제 등을 고려하여 보다 정밀하고 효과적인 선소를 추출하는데 있다. 먼저 항공영상으로부터 에지맵을 추출한 후, 에지 점들의 체인 코드 추적을 수행하고 에지강도와 방향성분을 고려한 선소의 추출을 행하였다. 에지맵의 추출은 Smith가 제안한 SUSAN(Smallest Univalue Segment Assimilating Nucleus) 알고리듬을 이용하였다. 제안한 알고리듬은 다음의 4 단계로 구성된다. 에지 맵의 체인코드 추적 결과에 기반하여 비선소 후보점을 감소시키기 위한 수평/수직/대각 성분 제거, 인접점 제거, 각도 일치점 제거, 선소를 이루는 시작점 및 끝점 검출 등의 과정을 통하여 선소추출을 행하였다. 제안한 알고리듬과 기존의 Boldt 알고리듬을 비교한 결과 제안한 알고리듬이 건물을 이루고 있는 주요 선소를 더욱 충실히 찾아냈고 불필요한 선소는 적게 찾아냄을 확인하였다.

• Structural Engineering and Mechanics
• /
• 제46권5호
• /
• pp.645-672
• /
• 2013

The differential settlements and rotations among footings cannot be avoided when the frame-footing-soil system is subjected to seismic/dynamic loading. Also, there may be a situation where column(s) of a building are located near adjoining property line causes eccentric loading on foundation system. The strap beams may be provided to control the rotation of the footings within permissible limits caused due to such eccentric loading. In the present work, the seismic interaction analysis of a three-bay three-storey, space frame-footing-strap beam-soil system is carried out to investigate the interaction behavior using finite element software (ANSYS). The RCC structure and their foundation are assumed to behave in linear manner while the supporting soil mass is treated as nonlinear elastic material. The seismic interaction analyses of space frame-isolated footing-soil and space frame-strap footing-soil systems are carried out to evaluate the forces in the columns. The results indicate that the bending moments of very high magnitude are induced at column bases resting on eccentric footing of frame-isolated footing-soil interaction system. However, use of strap beams controls these moments quite effectively. The soil-structure interaction effect causes significant redistribution of column forces compared to non-interaction analysis. The axial forces in the columns are distributed more uniformly when the interaction effects are considered in the analysis.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 1999년도 전력전자학술대회 논문집
• /
• pp.333-337
• /
• 1999

This paper presents the DQ transfomation space space vector modulation method to devel control algorithm of distribu STATCON(STATic CONdenser) for line volt regulation, dc link voltage regulation harmonics compensation. The Performance an of a PI with ramp comparision and synchro reference frame current controller is carried Based on these analysis, the control perform are desirable to compensate the harmonics a regulate dc link and line voltage of Distrib line.

• 전기전자학회논문지
• /
• 제24권1호
• /
• pp.154-160
• /
• 2020

본 논문에서는 계통연계인버터용 정지좌표기반 전류제어알고리즘을 제안한다. PI 제어기는 계통 연결 인버터의 전류 제어기로 사용되고 있다. 정지좌표기반 PI 제어기를 사용할 경우, AC 신호 제어로 인하여 정상 상태 오류와 위상지연현상이 발생한다. 본 논문에서는 전향보상기를 추가하여 명령 추적 성능을 높이고 과도 응답을 개선하는 방법을 제안한다. 또한 계통 전압을 외란으로 사용하여 계통 오류 발생 시 시스템을 보호하기 위해 외란을 측정 및 제거하는 제어 방법을 제안한다. 제안된 제어 방법은 수학적으로 유도하고 전달 함수로 표현하였으며 시뮬레이션을 통하여 검증하였다.

• 한국지구과학회지
• /
• 제40권4호
• /
• pp.353-381
• /
• 2019

The general world model for homogeneous and isotropic universe has been proposed. For this purpose, we introduce a global and fiducial system of reference (world reference frame) constructed on a (4+1)-dimensional space-time, and assume that the universe is spatially a 3-dimensional hypersurface embedded in the 4-dimensional space. The simultaneity for the entire universe has been specified by the global time coordinate. We define the line element as the separation between two neighboring events on the expanding universe that are distinct in space and time, as viewed in the world reference frame. The information that determines the kinematics of the geometry of the universe such as size and expansion rate has been included in the new metric. The Einstein's field equations with the new metric imply that closed, flat, and open universes are filled with positive, zero, and negative energy, respectively. The curvature of the universe is determined by the sign of mean energy density. We have demonstrated that the flat universe is empty and stationary, equivalent to the Minkowski space-time, and that the universe with positive energy density is always spatially closed and finite. In the closed universe, the proper time of a comoving observer does not elapse uniformly as judged in the world reference frame, in which both cosmic expansion and time-varying light speeds cannot exceed the limiting speed of the special relativity. We have also reconstructed cosmic evolution histories of the closed world models that are consistent with recent astronomical observations, and derived useful formulas such as energy-momentum relation of particles, redshift, total energy in the universe, cosmic distance and time scales, and so forth. The notable feature of the spatially closed universe is that the universe started from a non-singular point in the sense that physical quantities have finite values at the initial time as judged in the world reference frame. It has also been shown that the inflation with positive acceleration at the earliest epoch is improbable.

• 대한전자공학회논문지SP
• /
• 제48권6호
• /
• pp.61-67
• /
• 2011

3D TV를 위한 스테레오 영상은 기존의 디지털 TV와 호환성을 유지하기 위하여 프레임 호환 패킹 포맷으로 전송될 수 있다. 이 경우 수신단은 해상도가 절반으로 줄어든 스테레오 영상으로부터 원래 크기의 좌우 영상을 확대하여 복원할 필요가 있다. 이 논문은 삭제된 영상 라인의 픽셀값을 적응적으로 내삽하는 기법을 제안한다. 삭제되지 않은 주변 영상 라인의 정보로부터 수평라인 기반 선형 필터와 NEDI6를 선택적으로 적용함으로써 기존의 Bilinear 내삽 기법에 비해 0.6dB 정도의 화질 향상을 달성할 수 있었다.