에타놀 - 석유 혼합연료의 농용석유엔진에의 이용에 관한 연구

배영환,류관희 ( Yeong Hwan Bae,Kwan Hee Ryu ) 한국농업기계학회 1982 바이오시스템공학 Vol.7 No.1

CIFER ^® 를 이용한 무인 헬리콥터의 동특성 분석 (III) - 전달함수 해석 -

배영환,구영모,Bae, Yeong-Hwan,Koo, Young-Mo 한국농업기계학회 2012 바이오시스템공학 Vol.37 No.3

Purpose: Aerial application of chemicals with an agricultural helicopter allows for precise and timely spraying and reduces working labor and pollution. An attitude controller for an agricultural helicopter would be helpful to aerial application operator. The objectives of this paper are to determine the transfer function models and to estimate the handling qualities of a bare-airframe model helicopter. Methods: Transfer functions of a model unmanned helicopter were estimated by using NAVFIT and DERIVID modules of the $CIFER^{(R)}$ program to the time history data of frequency sweep flight tests. Control inputs of the transfer functions were elevator, aileron, rudder and collective pitch stick positions and the outputs were resulting on-axis movements of the fuselage. Results: Minimum realization of the transfer functions for pitch rate output to elevator control input and roll rate output to aileron control input produced second order transfer functions with undamped natural frequencies around 3.0 Hz and damping ratios of 0.139 and 0.530, respectively. The equivalent time delays of the transfer functions ranged from 0.16 to 0.44 second. Sensitivity analysis of the proposed parameters allowed derivation of minimal realization of the transfer functions. Conclusions: Handling quality of the model helicopter was addressed based on the eigenvalues of the transfer functions, corresponding undamped natural frequencies with damping ratios. The equivalent time delays of the lateral-directional motion ranged from 0.16 to 0.44 second, longer than the 0.1 to 0.15 second requirement for well-controlled typical manned aerial vehicles.

CIFER(R)를 이용한 무인 헬리콥터의 동특성 분석 (3) -전달함수 해석-

배영환 ( Yeong Hwan Bae ),구영모 ( Young Mo Koo ) 한국농업기계학회 2012 바이오시스템공학 Vol.37 No.3

Purpose: Aerial application of chemicals with an agricultural helicopter allows for precise and timely spraying and reduces working labor and pollution. An attitude controller for an agricultural helicopter would be helpful to aerial application operator. The objectives of this paper are to determine the transfer function models and to estimate the handling qualities of a bare-airframe model helicopter. Methods: Transfer functions of a model unmanned helicopter were estimated by using NAVFIT and DERIVID modules of the CIFER? program to the time history data of frequency sweep flight tests. Control inputs of the transfer functions were elevator, aileron, rudder and collective pitch stick positions and the outputs were resulting on-axis movements of the fuselage. Results: Minimum realization of the transfer functions for pitch rate output to elevator control input and roll rate output to aileron control input produced second order transfer functions with undamped natural frequencies around 3.0 Hz and damping ratios of 0.139 and 0.530, respectively. The equivalent time delays of the transfer functions ranged from 0.16 to 0.44 second. Sensitivity analysis of the proposed parameters allowed derivation of minimal realization of the transfer functions. Conclusions: Handling quality of the model helicopter was addressed based on the eigenvalues of the transfer functions, corresponding undamped natural frequencies with damping ratios. The equivalent time delays of the lateral-directional motion ranged from 0.16 to 0.44 second, longer than the 0.1 to 0.15 second requirement for well-controlled typical manned aerial vehicles.

〈진성이씨 이동표가 언간〉의 국어학적 연구

배영환(Bae, Yeong-hwan),신성철(Shin, Seong-cheol),이래호(Lee, Rae-ho) 한국학중앙연구원 2013 장서각 Vol.0 No.30

이 글은 17세기의 인물인 이동표와 그의 숙질인 이명익이 남긴 언간의 특징을 서지적 특징과 국어학적 특징으로 나누어 고찰한 것이다. 전체 언간은 39건이고, 그중 37건은 이동표가 발신자로 판단되며 2건은 이명익이 발신자이다. 수신자는 어머니, 딸, 그리고 서모, 첩 등이다. 편지의 작성 시기는 대체로 17세기 중후반으로 볼 수 있다. 그러므로 이 자료는 전기 근대국어의 실상을 확인할 수 있고, 동남방언의 모습도 일부 확인할 수 있어 국어사 자료로서 중요한 가치를 가진다. 음운론적인 특징으로는 구개음화 현상이 상당히 진행되었지만 <진주하씨묘 출토 언간>보다는 상대적으로 덜 진행되었는데 이것은 지역적 차이에 의한 것으로 추정된다. 문법적 특징으로는 무엇보다도 친모와 서모, 부인, 첩에 대한 상대경어법 사용에 있어서 확연한 차이를 두고 있다는 점이 특징적이고, ‘-게하-’ 구성이 ‘겠’과 비슷한 용법을 보이기도 한다. 어휘적 특징으로는 <진주하씨묘 출토 언간>과 비교해 볼 때 ‘곻-’, 지명접미사 ‘-이’ 등과 같이 몇 가지 방언적 요소가 확인된다. 그 밖에 이 자료에는 당시 과거 제도 등에 관한 자세한 내용을 담고 있어 기존의 일반 사료에서는 확인할 수 없는 구체적 생활사 자료로서도 가치가 있다. This study investigated the Korean linguistic characteristics of the letters written in hangeul (eongan) by Yi Dongpyo and his uncle Yi Myeongik in the 17th century in the bibliographic aspect. There are total 39 letters written in hangeul, and 37 of them appear to be sent by Yi Dongpyo and 2, by Yi Myeongik. Letters were sent to their mother, daughter, and father’s concubine. Letters appear to be written around the mid and late 17th century and hold important values as the source for studying the history of Korean language for it shows the actual use of early modern Korean and also partially shows south-east dialect. Considering phonological characteristics, the palatalization has progressed considerably, however, relatively less than the ‘Letters Excavated from the Tomb of the Has of Jinju’, and this is estimated to be attributed to regional differences. Grammatically, the Yi’s letters are characterized by the clear difference in the use of honorific system for hearer toward the real mother, father’s concubine, wife, and concubine above all, and they also show the use of ‘-ge ha-’ which is similar to ‘-get-.’ Compared with the ‘Letters Excavated from the Tomb of the Has of Jinju’, Yi’s letters also show lexical characteristics show a few dialectic elements such as ‘goh-" and suffix ‘-i’ of place name. Furthermore, the letters contain details about the state examination system of the time, valuable as the details source for the life history that cannot be examined with existing general historical sources.

논문 : 정보처리 및 복합기술 ; CIFER(R)를 이용한 무인 헬리콥터의 동특성 분석 (2) -주파수 응답 해석-

배영환 ( Yeong Hwan Bae ),구영모 ( Young Mo Koo ) 한국농업기계학회 2011 바이오시스템공학 Vol.36 No.6

The aerial application using an unmanned helicopter has been already utilized and an attitude controller would be developed to enhance the operational convenience and safety of the operator. For a preliminary study of designing flight controller, a state space model for an RC helicopter would be identified. Frequency sweep flight tests were performed and time history data were acquired in the previous study. In this study, frequency response of the flight test data of a small unmanned helicopter was analyzed by using the CIFER software. The time history flight data consisted of three replications each for collective pitch, aileron, elevator and rudder sweep inputs. A total of 36 frequency responses were obtained for the four control stick inputs and nine outputs including linear velocities and accelerations and angular velocities in 3-axis. The results showed coherence values higher than 0.6 for every primary control inputs and corresponding on-axis outputs for the frequency range from 0.07 to 4 Hz. Also the analysis of conditioned frequency response showed its effectiveness in evaluating cross coupling effects. Based on the results, the dynamic characteristics of the model helicopter can further be analyzed in terms of transfer functions and the undamped natural frequency and damping ratio of each critical mode.

농용 디이젤 엔진 연료로서의 에타놀 이용에 관한 연구

류관희,배영환,유수남 ( Kwan Hee Ryu,Yeong Hwan Bae,Soo Nam Yoo ) 한국농업기계학회 1981 바이오시스템공학 Vol.6 No.2

농용(農用) 디이젤 엔진 연료(燃料)로서의 에타놀 이용(利用)에 관(關)한 연구(硏究)

유관희,배영환,유수남,Ryu, Kwan Hee,Bae, Yeong Hwan,Yoo, Soo Nam 한국농업기계학회 1982 바이오시스템공학 Vol.6 No.2

The objective of this study was to find out the technical feasibility of ethanol-diesel fuel blends as a diesel engine fuel. Fuel properties essential to the proper operation of a diesel engine were determined for blends containing several concentrations of ethanol in No. 2 diesel fuel. A single-cylinder diesel engine for a power tiller was used for the engine tests, in which load, speed and fuel consumption rate were measured. The fuels used in tests were No. 2 diesel fuel and a blend containing 10-percent ethanol and 90-percent No. 2 diesel fuel. The results of the study are summarized as follows. 1. It was not possible to blend ethanol and No. 2 diesel fuel as a homogeneous solution even though anhydrous ethanol was used. The problem of blending ethanol in No. 2 diesel fuel could be solved by adding butanol about 5% of the amount of ethanol in the blends. 2. Because ethanol had a much lower boiling point ($78.3^{\circ}C$ under atmospheric pressure) than a diesel fuel, it was necessary to store ethanol-diesel fuel blends airtight in order to prevent them from evaporation losses of ethanol. 3. The addition of ethanol to No. 2 diesel fuel lowered the fuel viscosity and the cetane rating, but a blend of 10% ethanol and 90% diesel fuel had a viscosity and a cetane rating well above the KS minimum values for No. 2 diesel fuel. 4. At the rated speed, the specific fuel consumption of No.2 diesel fuel was lower than that of the 10% ethanol blend for the almost entire range of load. However, under the overload condition the specific fuel consumption was lower for the 10% ethanol blend. 5. Under the variable-speed full-load tests, both fuels produced approximately the same torque and power. At the speeds of 1600rpm or below, the specific fuel consumption of No. 2 diesel fuel was lower than that of the 10% ethanol blend. At the speeds of 1600rpm or above, however, the specific fuel consumption was lower for the 10% ethanol blend. 6. At the ambient temperature above $15^{\circ}C$, the use of the 10% ethanol blend in the engine created a vapor lock in the fuel injection pump and stalled the engine. The vapor locking problem was overcome by chilling the surroundings of the fuel injection pump and the cylinder head with water.

VLSI 설계를 위한 CAD 기술동향-상위 수준 합성에 대하여

박성범,배영환,장영조,이철동,Park, Seong-Beom,Bae, Yeong-Hwan,Chang, Yeong-Jo,Lee, Chul-Dong 한국전자통신연구원 1990 전자통신동향분석 Vol.5 No.2

본 기술동향에서는 시스템에서 요구되는 동작에 관한 기술을 레지스터 전송 수준의 구조에 관한 기술로 바꾸는 상위 수준 합성에 대하여 그 현황을 분석하였다. 현황 분석은 스케줄링과 할당으로 나누어 진행하였으며, 상위 수준 합성의 필요성, 내용, 기법 분석 및 시스템 분석을 행하였다. 현재의 연구가 갖는 문제점을 검토하였으며, 앞으로의 전망을 예측하였다.

SoC Platform기반 Design Methodology

장준영,한진호,배영환,조한진,Jang, Jun-Yeong,Han, Jin-Ho,Bae, Yeong-Hwan,Jo, Han-Jin IT-SOC협회 2004 IT SOC magazine Vol.2 No.-

실리콘 처리 기술의 고속화 요구와 유무선 환경에서 동영상 통신이 가능한 비디오 폰, 영상 회의 시스템, 이동 통신용 단말기 등의 전자 제품 사용자의 급증은 시스템을 하나의 칩에 집적화하는 SoC(System-On-a-Chip) 설계 기술을 요구하고 있다. 칩의 복잡도와 SoC 제품의 생산성 차이가 계속적으로 증가함에 따라 현재의 IC 설계 방법으로는 SoC 제품의 성능과 요구의 변화를 만족시킬 수 없다. 칩의 면적을 최소화하고 성능을 최대화하며 게이트 수준의 최적화를 통한 기존의 셀 기반 설계 방법으로는 설계의 생산성 문제를 해결할 수 없다. 이러한 문제를 해결 위한 새로운 설계 방법인 IP 재사용을 기반으로 한 플랫폼 기반 설계가 제시되었다. 플랫폼 기반 설계는 SoC 제품을 빠르게 개발하기 위한 응용 기반 통합 플랫폼과 재사용이 가능한 IP(Intellectual Property) 이용한 플랫폼 기반 설계(Platform-Based Design) 방법이다. 새로운 설계 방법은 90% 이상의 IP 재사용을 통해서 설계 시간을 단축하며, 시스템 수준에서의 최적화를 통해서 제품의 시장 경쟁력(Time-to-Market)의 문제를 해결하기 위한 방법이다.

상용 CAE 워크스테이션의 동향 및 비교분석

김욱현,강인,배영환,이철동,Kim, Uk-Hyeon,Gang, In,Bae, Yeong-Hwan,Lee, Cheol-Dong 한국전자통신연구원 1989 전자통신동향분석 Vol.4 No.1

최근 성능 및 시장규모에 있어서 급성장하고 있는 워크스테이션에 대해서 이의 발생기원과 발전과정 및 기술동향에 대해서 알아보고, 이들중에서 현재 널리 사용되고 있는 외국의 5개 회사의 상용 CAE 워크스테이션과 당 연구실에서 개발한 CAE 워크스테이션 EDAS(Electronic Design Automation System)와의 기능 및 특징을 비교분석하였다. 외국의 5개 CAE 소프트웨어 회사는 Mentor Graphics, Daisy Systems, Valid Logic Systems, VLSI Technology Inc., Phase Three Logic Inc. 이다.