• 제목/요약/키워드: Power quality improvement

검색결과 582건 처리시간 0.023초

혼합형 감각조절장애 아동에 대한 단기집중 감각통합치료 프로그램의 효과-사례보고 (The Effect of Short-Term Intensive Sensory Integration Therapy Program on a Child with Sensory Modulation Disorder(Mixed Pattern) : Case Study)

  • 김은영;지석연
    • 대한감각통합치료학회지
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    • 제4권1호
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    • pp.37-46
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    • 2006
  • Objective : This single-subject study explored the effect of short-term intensive sensory integration therapy program which was provided in a 2006 sensory integration treatment course on adaptive response of a four-year-girl with sensory modulation disorder(mixed pattern). Method : Based on results of the assessment to the child, her therapist offers an organized sensory integration program during four days. Results : Improvement of child's movement quality and variety in physical environment in therapy rooms and interaction with her therapist were observed. Conclusions : This report of the case will be helpful for occupational therapists who plan to intervent with a short-term intensive sensory integration therapy program. In addition, the need for consideration of consultation with the child's parents is discussed.

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금형의 고정도ㆍ고능률 가공기술 (Advanced Machining Technology for Die Manufacturing)

  • 김정석;이득우;정융호;강명창;이기용;김경균;김석원
    • 한국정밀공학회지
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    • 제17권4호
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    • pp.48-68
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    • 2000
  • The high-speed machining technology of difficult-to-cut material is needed to achieve the high-efficiency of die manufacturing. The high-speed machining is applied in automobile, airplane and electricityㆍelectro industry etc, because it can improve machining efficiency and productivity with high speed, high power and high rotation. In this study, high speed machinability, tool wear characteristics and its monitoring, characteristics of damaged layer, machinability of difficult-to-cut material, characteristics of a free curved surface and method of CAD/CAM system were introduced to acquire the shortening of machining time, the improvement of machining efficiency and the high quality of machined surface. Therefore, we establish the stabilization condition of difficult-to-cut material machining and present the optimal cutting condition for high-efficiency cutting.

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마이크로그리드의 단독 운전시 전력품질 향상에 관한 연구 (Improvement of the quality of power in Microgrid system which is operating in islanding mode)

  • 정태영;백영식
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2008년도 추계학술대회 논문집 전력기술부문
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    • pp.479-481
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    • 2008
  • 마이크로그리드 시스템은 계통측에 문제가 발생하게 되면 계통과 분리되어 독립운전 모드로 동작하게 된다. 이때 마이크로소스들은 계통운전원의 제어신호없이 빠르게 마이크로그리드 내 부하들의 전력수요를 담당하여야 하며, 전력품질을 유지하면서 운전되어야 한다. 이 논문은 마이크로그리드가 독립운전 모드로 전환하여 운전되거나 독립운전 모드에서 부하 변동이 발생될 경우, 주파수를 일정하게 유지하면서 마이크로소스와 부하와의 전력수급 균형을 맞추기 위한 제어 방법을 제시하였다. 그리고 마이크로그리드에의 적용가능성을 알아보기 위하여 전력계통 과도현상 분석용 수치해석 프로그램인 EMTP/RV를 이용하여 모델링하고 시뮬레이션 하였다.

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공 회전시 자동변속기 차량의 실내소음 음질 개선에 관한 연구 (A Study on the Improvement of the Sound Quality of the Interior Noise of A/T Vehicle in Idle State)

  • 이상권;최병욱;여승동
    • 한국자동차공학회논문집
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    • 제1권1호
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    • pp.110-119
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    • 1993
  • 본 논문은 자동변속기를 탑재한 차량에서 에어콘(air condition)을 작동시키고, 공 회전시 기어의 변속을 "D"단에 두었을 때 실내에서 발생하는 이상음의 원인규명 및 해결 방 법에 관한 연구 결과를 논하고자 한다. 이 이상한 소음의 원인을 규명하기 위하여 실린더 내부의 연소압력, 메인 베어링캡(main bearing cap)의 진동, 엔진 마운팅 보스의 진동 및 차 량의 실내소음을 동시에 측정하여 분석하였으며 이 결과에 의하면 이상음의 원인은 크랭크 샤프트(crank shaft)의 굽힘진동이 파워플랜트(power plant)를 가진하여 진동을 증가시키고, 이 진동이 마운팅 보스를 통하여 차량의 차체에 전달되며, 차체의 진동에 의해서 발생하는 고체 전달음(structure-borne noise)이었다. 또한 이상음의 주기는 주파수 성분은 200-400Hz 이었다. 이 이상음은 크랭크 샤프트의 댐퍼 풀리의 질량을 저감하여 크랭크 샤프트의 동특 성을 개선함으로서 해결가능하고, 혹은 점화시기를 지연하여 연소 압력을 낮춤으로서 해결 가능하다.

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주택건설공사 감리의 고객만족도에 관한 연구 -대구·경북지역을 중심으로- (A Study on the Satisfaction Degree of Clients on the Supervision in the House Construction Work - Focusing in Taegu, Kyungbuk Province -)

  • 이호;이택운
    • 한국산업융합학회 논문집
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    • 제10권4호
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    • pp.291-298
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    • 2007
  • In 1994, the house construction work was separated from design part to prevent incomplete work and to improve quality. During that time, the supervision in the house construction work has made a great development in the quantity phase, but there is no study case about the satisfaction degree of clients on the supervision job. This study presents the improvement schemes of the supervision job rationality, the revision of supervision system and supervisor's improved construction management ability. also, This paper aims at advancing our construction field and enhancing competitive power by seeking for solutions to problems and improving current system to a reasonable supervision in the house construction work comparing and analyzing by questionnaire in Taegu, Kyungbuk area. The further study will be needed about the whole Korean construction market.

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도시철도 전동차 유지보수체계의 개선에 관한 연구 (A Study on the Improvement for EMU Maintenance System of Urban Transit)

  • 김규중;이근오
    • 한국안전학회지
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    • 제25권1호
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    • pp.87-92
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    • 2010
  • Urban transit system must secure fast, safe and reliable transportation capacity as a metropolitan mass transit. For this purpose, it is important to make all the sub-systems (which consist of EMU, power feeding, signaling & telecommunication, railway, platform facility, and control system and so on) work well. To operate all the systems effectively and reliably, a maintenance measure optimal to each system's characteristics is needed to be established and executed. So, highly reliable maintenance should be performed. But, EMU maintenance methods suitable to its own model and EMU lines are not yet introduced. This study examined few examples mainly to secure reliability on a maintenance quality in operating method and the features of train maintenance system based on travel distance.

이중센서 위너필터를 이용한 디지탈 라디오 그라피 영상 복원 (Image Restoration in Digital Radiography Using Dual Sensor Wiener Filer)

  • Lee, Tae-Soo;Park, Kwang-Suk;Min, Byoumg-Goo;Lim, Jeong-Gee;Han, Man-Chung
    • 대한의용생체공학회:의공학회지
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    • 제10권3호
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    • pp.293-302
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    • 1989
  • A Dual Sensor Wiener Filter technique was used to improve the image quality of the scanning type digital radiographic system (resolution and SNR). In this method, two images were acquried simultaneously using two sensors with high and low resolution and SNR values. Using the cross Power spectrum between dual sensor outputs of the same chest radiographic image. we design a new type of Wiener Filter and implement it with fast algorithm. We compared the performance of this new dual sensor filter with conventional single sensor filters (Wiener Filter and Parametric Projec- tion Filter) . In simulation studies, it is shown that this new method has SNR improvement of 1-3 dB better than conventional filters.

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Low Phase Noise LC-VCO with Active Source Degeneration

  • Nguyen, D.B. Yen;Ko, Young-Hun;Yun, Seok-Ju;Han, Seok-Kyun;Lee, Sang-Gug
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제13권3호
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    • pp.207-212
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    • 2013
  • A new CMOS voltage-bias differential LC voltage-controlled oscillator (LC-VCO) with active source degeneration is proposed. The proposed degeneration technique preserves the quality factor of the LC-tank which leads to improvement in phase noise of VCO oscillators. The proposed VCO shows the high figure of merit (FOM) with large tuning range, low power, and small chip size compared to those of conventional voltage-bias differential LC-VCO. The proposed VCO implemented in 0.18-${\mu}m$ CMOS shows the phase noise of -118 dBc/Hz at 1 MHz offset oscillating at 5.03 GHz, tuning range of 12%, occupies 0.15 $mm^2$ of chip area while dissipating 1.44 mW from 0.8 V supply.

다중채널 해양탄성파탐사 시스템개발과 응용 (Development of Multichannel Marine Seismic Data Acquisition System and its Application)

  • 신성렬;김찬수;여은민;김영준
    • 한국마린엔지니어링학회:학술대회논문집
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    • 한국마린엔지니어링학회 2005년도 후기학술대회논문집
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    • pp.144-145
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    • 2005
  • In this study, we have developed the high resolution multichannel seismic data acquisition system and shallow marine seismic source. It is easy to operate our source system which utilizes piezoelectric transducer of high electrical power. According to water depth, survey condition and purpose, transducer number of source system can be easily changed in order to maximize field applicability. In the recording part, we used 24 bits and 8 channel high speed A/D board in order to achieve the improvement of data quality and the efficiency of data acquisition. The developed system was tested and varied with the data acquisition parameters such as source-receiver offset, and transducer number versus water depth for the field application.

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$SF_6$와 제조공기의 절연특성 비교 연구 (The Breakdown Characteristics of $SF_6$ and Imitation-Air)

  • 최은혁;박혜리;도영회;최영길;이광식
    • 한국조명전기설비학회:학술대회논문집
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    • 한국조명전기설비학회 2008년도 춘계학술대회 논문집
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    • pp.335-338
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    • 2008
  • With the improvement of industrial society, the high quality electrical energy, simplification of operation and maintenance, ensuring reliability are being required Also we request urgently change a $SF_6$ for an environment friendly gas insulation material. In this paper the experiments of breakdown characteristics by pressure and gap change of Imitation-Air in model GIS(Gas Insulated Switchgear) were described. Also assess of breakdown characteristics about Imitation-Air and $SF_6$. It is considered in this paper that the results are fundamental data for electric insulation design of Distribution Power Facilities which will be studied and developed in the future.

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