Stator Current Processing –Based Technique for Bearing Damage Detection in Induction Motors

Won ?Pyo Hong,Chung-Sup Yoon,Dong-Hwa Kim 제어로봇시스템학회 2005 제어로봇시스템학회 국제학술대회 논문집 Vol.2005 No.6

버팀보로 지지된 흙막이벽의 거동에 관한 연구

홍원표,여규권,윤중만,조용상 중앙대학교 기술과학연구소 1997 기술과학연구소 논문집 Vol.27 No.-

버팀보 축력으로부터 산정된 측방토압은 지표면에서 굴착깊이의 17%에 해당되는 깊이까지 선형적으로 증가하다가 그 깊이 아래로부터는 일정토압분포를 보이는 사다리꼴모양의 분포를 보였다. 이 일정토압 분포부분의 토압 크기는 평균적으로 최종굴착깊이에서의 Rankine 주동토압의 58%에 해당하거나 연직상재압의 17%에 해당하였다. 또한 흙막이벽의 수평변위와 굴착깊이와의 관계로부터 흙막이구조물의 안정성을 판단할 수 있는 시공관리기준을 설정하였다. 흙막이벽의 수평변위량이 굴착깊이의 0.20%보다 작으면 흙막이벽과 굴착배면지반은 안정된 상태에 있다. 그러나 벽체의 수평변위가 굴착깊이의 0.20%보다 크게 발생하면 굴착공사의 안정성을 주의깊게 관찰해야만 하며, 필요하다면 흙막이 구조물을 보강해야만 한다. The lateral earth pressures on braced earth retaining walls, which are estimated form the measured strut force, shows a trapezoidal distribution that the earth pressure increases linearly with depth from the ground surface to 17% of the final excavation depth, and then keeps constant value. The maximum lateral earth pressure was same to 58% of Rankine's active earth pressure or 17% of the vertical overburden pressure at the final excavation depth. Also, empirical criterion is established for construction management to monitor and ensure the stability of deep excavation from the relationship between horizontal displacement of wall and excavated depth. If the horizontal displacement of wall measured from inclinometer shows less than 0.20 percent of the excavated depth, the retention wall and surrounding ground exist under stable state. When the horizontal displacement is developed more than 0.20 percent of the excavated depth, excavation works should be carefully observed and reinforced the earth retention wall, if necessary.

초전도고장전류제한기가 포함된 전력시스템에서 고장전류계산방법과 고장전류억제효과 분석

홍원표 大田産業大學校 1998 한밭대학교 논문집 Vol.15 No.1

Design & Operation of power system for meeting increase of electric power demand is becoming more difficult and complex. One of reasons is increase of fault current. As one of the most effective methods for suppressing the fault current, installation of SFCL is expected. This paper describes a method of fault analyses of power system with SFCLs, and also discusses determination of specification two-bus electric power system with single transmission lines

연약지반상 교대의 측방이동에 대한 대책공법

홍원표,이재호,송영석 중앙대학교 기술과학연구소 2003 기술과학연구소 논문집 Vol.33 No.-

한 도로교량의 교대를 시공한 후 상부거더가 교대 흉백으로 밀려들어가는 현상이 발생 되었다. 이 교량교대를 대상으로 기초연약지반의 특성을 분석하고, 사면안정해석을 실시하여 교대의 측방이동 여부를 판정하여 보았다. 판정결과 교대의 측방이동은 계속적으로 발생될 것으로 예측되어, 합리적인 대책공법을 고찰한다. 여러 가지 대책공법을 분류 · 분석 한 후 본 현장에 적합한 대책공법으로서 성토지지말뚝공법으로 분류되는 파일슬래브 공법이 선정된다. 본 공법은 교대 배면에 말쪽을 설치하여 성토하중을 지지층으로 전달함으로써 연약지반의 측방유동을 억제하는 공법이다. 또한 대책공법 적용 후 교대의 안정성을 확인할 수 있는 현장계측시스템을 도입한다. After construction of bridge abutment of a bridge for roads, steel box girder of bridge was moved into the parapet wall of abutment. Based on analysis of geotechnical characteristics and slope stability, the judgement of lateral movement of bridge abutment on soft ground is performed. As a result of judgement. various countermeasures are analyzed to prevent against the lateral movement of bridge abutment. The pill slab method among the various countermeasures is based on embankment pile which is installed in soft ground to decrease the overburden due to embankments Also, field instrumentation system is installed to observe reinforced effect of the countermeasures and stability of bridge abutment.

진공용 나노스테이지 개발

홍원표,강은구,이석우,최헌종 한국공작기계학회 2004 한국공작기계학회 춘계학술대회논문집 Vol.2004 No.-

Miniaturization is the central theme in modem fabrication technology. Many of the components used in modern products are becoming smaller and smaller. The direct write FIB technology has several advantages over contemporary micromachining technology, including better feature resolution with low lateral scattering and capability of maskless fabrication. Therefore, the application of focused ion beam(FIB) technology in micro fabricaton has beome increasingly popular. In recent model of FIB, however the feeding system has been a very coarse resolution of about a few μm. It is not unsuitable to the sputtering and the deposition to make the high-precision structure in micro or macro scale. Our research is the development of nano stage of 200mm strokes and 10nm resolutions. Also, this stage should be effectively operating in ultra high vacuum of about 1×10^(-5)pa. This paper presents the concept of nano stages and the discussion of the material treatment for ultra high vacuum.

Carbon Black이 시멘트 Paste 및 Mortar의 물리적 특성에 미치는 영향

홍원표,황의환,조헌영 忠南大學校 産業技術硏究所 1986 산업기술연구논문집 Vol.1 No.2

This study was performed to determine the most desirable carbon black and it's content in ordinary porland cement for the increase of physical properties of the cement and mortar. The various contents of carbon black were used for this study such as 0.2wt%, 0.5wt%, 1.0wt% and 3.0wt%. The different particle size and structure of carbon black were used. The physical properties of the cement paste and mortar were tested by KS methods. The experimental results are as follow; 1) The contents of 0.5-1.0wt% carbon blacks in cement increased most apparently the setting time of cement paste, flow value, compressive and flexural strengths of mortar, whereas decreased the water absorption ratio of mortar by about 10%. 2) SNP and D company's carbon black which have smaller numbers of I₂adsorption and DBP absorption and heavier pour density than those of others showed to be the most effective carbon blacks. 3) The soundness of cements remained unchanged regardless to the different kinds and contents of carbon blacks.

리비아 대수로공사 지역의 지반특성

홍원표,남정만,김시현,이재호 중앙대학교 기술과학연구소 1996 기술과학연구소 논문집 Vol.26 No.-

리비아 사막지역의 지반특성을 연구하기 위하여 리비아 1단계 대수로공사가 실시된 지역의 지반특성을 검토하였다. 본 연구에서는 Sarir 취수원에서 Ajdabiya 저수조를 경유하여 Sirt 저수조까지의 대수로 공사지역을 따라 실시된 실내시험과 현장시험결과를 포함하고 있다. 이 지역은 내륙지역(Sarir 취수원에서 Ajdabiya 저수조까지)과 해안지역(Ajdabiya 저수조에서 Sirt 저수조까지)으로 구분하여 연구된다. 본 연구결과, 지표면 부근에 있는 모암(Cap rock)은 주로 Caliche나 석회사암(Calcarenite) 성분을 많이 띠고 있고, 이들의 깊이에 따른 강도변화는 발견할 수 없었다. 또한 모래에 대한 Ncl도 깊이에 대한 변화를 발견할 수 없었으나 이들을 종류별로 분류하였을 경우, N치가 약간 증가하는 추세를 보였다. 끝으로 해안지역의 점토에서는 지표면부근에서 조금 과압밀된 경향을 볼 수 있었으며, 내륙지역의 점토에서는 대단히 높은 팽윤포텐셜이 관찰되었다. To study geotechnical properties on Sahara desert of Libya, geotechnical characteristics in the region of the Great Man-made River Project were reviewed. A series of field and laboratory tests were carried out along the route of the conveyance lines from Sarir well field to Sirt end reservoir through Ajdabiya holding reservoir. In the view of geotechnical aspect, the research subject area can be divided into two areas ; one is the inland area(from Ajdabiya holding reservoir to Sirt reservoir). The results of this study showed that the cap rocks nearby ground surface were generally composed of caliche or calcarenite and variation of its strength according to depth could not find. Also, N value in sand did not show a trend of variation with depth however, the N value in the classified soil reveals tendency to increased. The clay of ground surface in the coastal area was slightly overconsolidated due to the desiccation of the surface soils. The clay in the inland area had high swelling potential.

근대성의 한국적 변용에 대한 정치공동체론적 비판

홍원표 한국외국어대학교 사회과학연구소 2001 社會科學論集 Vol.18 No.2

부력저항용 영구앵커의 거동

홍원표,송영식,고광태 중앙대학교 기술과학연구소 2002 기술과학연구소 논문집 Vol.32 No.-

본 연구에서는 부력저항용 영구앵커의 거동을 시공단계별로 구분하여 분석한다. 즉, 앵커의 두부에 하중계를 설치하여 앵커축력을 계측하였으며, 이 계측결과를 토대로, 앵커축력의 손실, 건물자중의 증가 및 외적조건 변화에 따른 앵커의 거동을 분석하였다. 영구앵커는 초기인장력에 비하여 Jacking Free시 인장력이 약 7% 정도 감소하며, 최종인장력은 약 15%정도 감소한다. 한편, 앵커의 초기인장력은 외력이 작용하지 않아도 PC 강선의 relaxation, 주입재 및 지반의 creep 등의 내적요인에 의하여 비선형적으로 감소되어 1차 수렴치에 도달하게 된다. 1차 흙되메우기 작업 기간동안 앵커축력은 흙되메우기에 따른 횡방향 토압이 증가 및 상부구조물의 자중증가로 인하여 감소된다. 그러나, 흙되메우기 작업이 중단된 기간동안 되메우기한 흙의 이완현상으로 횡방향 토압이 감소되며 이로 인하여 앵커축력이 증가하게 된다. 그리고, 되메우기한 흙속으로 지하수가 유입되어 부력이 증가하게 되므로 앵커축력은 증가하게 된다. 이때 앵커축력은 1차 수렴치까지 회복하게 된다. The behavior of permanent anchors for buoyant resistance is investigated at each construction stage. The prestressed anchor forces were measured by load cells which were attached to anchor head. On the basis of instrumentation, the loss of anchor force and the behavior of anchor by increment of structure weight and change of external condition were investigated. Prestressed anchor force at jacking free is decreased by about 7% than initial prestressed anchor force and decreased by about 15% finally. Although external forces does not act on the substructure, initial anchor force is decreased nonlinearly due to relaxation of PC strand and creep of grouting materials and soils. Also, anchor force was converged at the first convergent value. When first backfill was performed, anchor force was decreased due to increment of lateral earth pressure and superstructure weight. But, anchor force grew gradually during the period of breaking backfill by lowering of lateral earth pressure due to relaxation of soils. When groundwater inflowed into backfill soils, anchor force is slowly increased by uplift force below mat foundation. At that time, anchor force is recovered by the first convergent value.

전력계통에서의 초전도전력기기의 제어 및 운전

홍원표 大田産業大學校 1996 한밭대학교 논문집 Vol.13 No.0201

An image of future power system which has introduced superconducting generator, cable, transformer, fault current limiter, SMES and so on is presented. Conceptual designs of each SC Machines and devices are carried out. The SC cable and SFCL utilize the high Tc superconductor(HTS) cooled by liquid N_2-. Other devices use low temperature superconducting cooled by liquid He. The SC power system models are proposed detailedly. In viewpoint of the operation and control SC power system, the concrete design direction and effective role of each SC apparatus are investigated. In this paper, superconducting fault limiters(SFCLS) should play an important part of the quenching current level coordination to prevent the other SC devices from quenching. Finially, SFCL are also expected to be very effective to introduce flexibility of power system planning and operation due to their possibility to enhance transient stability and reduce short circuit current.