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검색결과 973건 처리시간 0.033초

공진형 전압형 인버터의 전동기구동 시스템 응용 (Application of Motor Drive System Using Resonant Voltage-Type Inverter)

  • 김용주;마영호;김한성;최규하;김병주
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1991년도 추계학술대회 논문집 학회본부
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    • pp.164-166
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    • 1991
  • This paper achieved by Pulse-Withed Modulation of the inverter switchs. But Conventional PWM inverter is employed hard switching by means a switching device. Moreover, this paper presents resonant DC link Voltage type inverter thet it was not necessary snubber circuit and dead time and modeling of motor drive control system and simulating analysis are discussed.

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관성센서를 이용한 도립진자의 제어를 위한 상보필터 설계 및 성능평가 (Design and Performance Evaluation of a Complementary Filter for Inverted Pendulum Control with Inertial Sensors)

  • 나카시마토시타카;장문제;홍석교
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
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    • pp.544-546
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    • 2004
  • This paper designs and evaluates a complementary filter for fusion of inertial sensor signals. Specifically, the designed filter is applied to inverted pendulum control where the pendulum's angle information is obtained from low-cost tilt and gyroscope sensors instead of an optical encoder. The complementary filter under consideration is a conventional one which consists of low- and high-pass filters. However, to improve the performance of the filter on the gyroscope, we use an integrator in the filter's outer loop. Frequency responses are obtained with both tilt and gyroscope sensors. Based on the frequency response results, we determine appropriate parameter values for the filter. The performance of the designed complementary filter is evaluated by applying the filter to inverted pendulum control. Experiments show that the performance of the designed filter is comparable to that of an optical encoder and low-cost inertial sensors can be used for inverted pendulum control with the heir of sensor fusion.

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연속회분식 반응기에서 생물학적 인 제거에 대한 pH의 영향

  • 전체옥;박종문
    • 한국생물공학회:학술대회논문집
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    • 한국생물공학회 2000년도 춘계학술발표대회
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    • pp.105-108
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    • 2000
  • Enhanced biological phosphorus removal (EBPR) is not always successfully achieved by anaerobic/aerobic operation. It has been reported that the EBPR deterioration was caused by the outgrowth of glycogen-accumulating organisms (GAO) over polyphosphate-accumulating organisms (PAO). It was found that pHcould be a tool which might induce the success of EBPR in a sequencing batch reactor (SBR) supplied with acetate. When the pH of anaerobic phase was controlled at 7.0, the operation resulted in failure of EBPR. However, when the pH of anaerobic phase increased up to 8.4, complete EBPR was achieved. We explained the mechanism of pH effect on the competition between GAO and PAO with experimental results and previously proposed biochemical models.

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문장패턴을 이용한 자연어 질의 시스템에 대한 연구 (A Study on the Natural Language Query System Using Sentence-Pattern)

  • 우근신;송재관;홍성웅;연제용;박찬곤
    • 한국정보과학회 언어공학연구회:학술대회논문집(한글 및 한국어 정보처리)
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    • 한국정보과학회언어공학연구회 2003년도 제15회 한글 및 한국어 정보처리 학술대회
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    • pp.214-218
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    • 2003
  • 질의응답 시스템은 인터넷과 같은 실용적 환경에서 사용될 경우, 실제 사용자의 질의는 다양한 유형으로 나타나게 된다. 따라서 실용적인 시스템에서 사용되는 질의는 문장의 형태나 단어의 쓰임에 관계없이 같은 의도를 가진 질의를 같은 유형으로 분류할 수 있는 의문형 문장패턴을 태깅하여 다양한 형태의 자연어로 기술된 문서에서 원하는 응답으로 처리할 수 있는 질의 응답 시스템은 정보 검색 시스템으로서의 가능성을 보여준다.

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한국 성인에 있어서의 'Wits' 수치에 관한 연구 (A STUDY OF THE 'WITS' APPRAISAL OF THE KOREAN ADULTS)

  • 유영규;조봉제
    • 대한치과교정학회지
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    • 제10권1호
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    • pp.65-70
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    • 1980
  • The purpose of this study was giving some helpful datas in analysing the degree of anteroposterior jaw disharmony with the 'Wits' appraisal. The cephalograms of 105 Korean adults with normal occlusion ranging from 17 to 20 years of age and 76 Koreans with various malocclusion ranging from 12 to 24 years of age were studied and analyzed statistically. The results were as follows; 1. The mean value of 'Wits' appraisal in normal occlusion group was -0.82mm in males and -0.17mm in females. 2. There was no significant difference between the males and females in normal occlusion group. 3, The mean value of 'Wits' appraisal in Angles class II malocclusion group was 2.67mm and higher than normal group. 4. The mean value of 'Wits' appraisal in Angles class III malocclusion group was -8.11 mm and lower than normal group.

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Analysis of Electromagnetic Wave Scattering from a Sea Surface Using a Monte-Carlo FDTD Technique

  • Choi Dong-Muk;Kim Che-Young;Kim Dong-Il;Jeon Joong-Sung
    • Journal of electromagnetic engineering and science
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    • 제5권2호
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    • pp.87-91
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    • 2005
  • This paper presents a Monte-Carlo FDTD technique to determine the scattered field from a perfectly conducting surface like a sea surface, from which the useful information on the incoherent pattern tendency could be observed. A one-dimensional sea surface used to analysis scattering was generated using the Pierson-Moskowitz model. In order to verify the numerical results by this technique, these results are compared with those of the small perturbation method, which show a good match between them. To investigate the incoherent pattern tendency involved, the dependence of the back scattering coefficients on the different wind speed(U) is discussed for the back scattering case.

Analysis of Radio Interference through Ducting for 2.5 GHz WiMAX Service

  • Son, Ho-Kyung;Kim, Jong-Ho;Kim, Che-Young
    • Journal of electromagnetic engineering and science
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    • 제12권1호
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    • pp.94-100
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    • 2012
  • Radio interference has been occurring in mobile communication services on the southern seashore in Korea. Monitoring the radio interference signal revealed that the main reason for the radio interference was a radio ducting signal coming from the seaside of Japan. In this paper, we have analyzed the effect of interference on WiMAX service using a 2.5 GHz frequency band between Korea and Japan. We focus on the interference scenario from base station to base station and we use the Minimum Coupling Loss (MCL) method for interference analysis and the Advanced Propagation Model (APM) for calculating the propagation loss in ducts. The propagation model is also compared with experimental measurement data. We confirm that the interfering signal strength depends on the antenna height and this result can be applied to deployment planning for each system with an interference impact acceptable to both parties.

양문여닫이 냉장고에서 도아의 단차영향 연구 (A Study on the Door Height Difference of the SBS Refrigerator)

  • 신광철;채수원
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 추계학술대회
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    • pp.528-533
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    • 2004
  • This paper deals with the issue of door height difference (DHD) which occurs for SBS refrigerator necessarily. In order to identify the cause of DHD, analysis of refrigerator structure and entire process from door manufacturing to usage have been investigated. From diverse experiments, it was found that the flatness of the floor was a main causing factor. In order to decrease the DHD , the effects of 6 design parameters to control of cabinet deformation have been investigated by using DOE(design of experiment) and finite element analysis. Based on the correlation equation, it was possible to estimate the DHD for new refrigerator design.

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Relationship between SOA Adoption and Performance of IT Organizations

  • Niknejad, Naghmeh;Ghani, Imran;Hussin, Ab Razak Che;Jeong, Seung Ryul
    • 인터넷정보학회논문지
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    • 제17권4호
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    • pp.173-180
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    • 2016
  • SOA has been adopted by enormous number of organizations world-wide. This study has investigated significant factors which affect SOA adoption in positive and negative manner. Unlike the previous similar studies, where they focused on qualitative analysis for SOA adoption, this study conducted a quantitative analysis to investigate the relationship between the adoption of SOA and the performance of IT organizations. In order to conduct the research, an online questionnaire was created and distributed among SOA experts through the social networking platform of professionals, LinkedIn. Total one hundred and four (104) respondents from thirty (30) different countries participated in this study. The results of this study indicate that there are both positive and negative influences upon SOA adoption. The positive influences includes: governance, strategy, culture and communication, business and IT alignment and ROI; whereas complexity, security concerns, and costs have negatively affected SOA adoption.

조선통신사(朝鮮通信使) 및 일본사신(日本使臣)을 통해서 한(韓).일(日)간의 음식문화(飮食文化)의 비교와 , 대마도에서의 연회(宴會)를 통해서 본 조선왕조(朝鮮王朝)의 수배상(壽杯床).과반(果盤).아가상(阿架床) 고(考) (The Comparison of Food Culture between Korea and Japan through Korean Communication Facilities and Japanese Envoys, Agasang.Subaesang.Kwaban of the Choson Dynasty through the Dinner Party in Thusima Island)

  • 김상보
    • 한국식생활문화학회지
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    • 제14권2호
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    • pp.115-129
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    • 1999
  • The following demonstrates similarities between Japanese and Korean food culture. The facts have been discovered through the examination of records kept by Korean Communication Facilities and Japanese Envoys. Both countries used the numbers 7, 5, 3, in food treats. Both demonstrated Da do(茶道) style during banquet. Japanese Na-ra-dae(奈良臺) is similar to Korean Sue-bae-sang(壽杯床). Both countries had a Kan-ban(decorative table, 看盤) and Mi-soo(wine and someatables, 味數) during banquet. The composition of the table may be the same for both Korean Geo-sick-oh-kwa-sang and Japanese 3Jeup(soups) 15Che(dishes). Agasang is a Kan-ban(decorative table) of Choson's Da-do(茶道) style.

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