도파관 내의 음파산란 해석에 있어서 Helmhortz 방정식의 정적 한계에 관한 연구

정현교,최경 江原大學校 産業技術硏究所 1989 産業技術硏究 Vol.9 No.-

In this paper, the static limit of Helmhortz equation is discussed in the analysis of acoustic wave scattering in a waveguide. Boundary integral equation method is used to formulate the scattering process in the exerior of the scatterer and finite element method in the interior of the scatterer. And hybrid Ray-Mode Method is used the provide the Green's function of the waveguide. The proposed algorithm is applied to a sample poblem with arbitrary scatterer in a waveguide. The results are compared with those of Laplace's equation which is the governing equation in the static problems.

온실재배와 노지재배한 금산 깻잎의 품질 특성과 향기성분

현광욱,구교철,장정호,이재곤,김미리,이종수 한국식품저장유통학회 ( 구 한국농산물저장유통학회 ) 2004 한국식품저장유통학회지 Vol.11 No.1

깻잎을 이용한 건강 식품을 개발하고자 먼저 깻잎의 주산지인 금산에서 5월 온실재배한 깻잎과 8월 노지재배한 깻잎들의 품질특성과 향기성분을 조사하였다. 시료깻잎 모두 4.0%의 조단백질과 0.8%의 조지방을 함유하고 있었고, 플라보노이드의 함량은 온실재배 깻잎 25.2%, 노지재배 깻잎 26.5%로 시료깻잎간에 큰 차이는 나타나지 않았으며 조사포닌 함량도 2,7%와 2,8%로 비슷하였다. 시료깻잎의 효소 활성은 오직 알칼리성 단백질 분해효소 활성만이 8월 노지재배 깻잎에서만 물 추출물 7.1 unit, 에탄올 추출불 11.8 unit을 보였고 기타 효소 활성은 없었다. 8월 노지재배 깻잎의 조직감 특성으로 먼저 견고성과 탄력성 등은 잎의 상층부와 중층부 보다 잎받침을 포함하는 하층부에서 높았고 응집성은 하층부가 약간 약하였으며 5월 온실재배 깻잎은 씹힘성이 다서 낮았을 뿐 노지재배 깻잎과 비슷하였다. 5월 온실재배와 8월 노지재배 깻잎에는 1-octen-3-ol, linalool, β-caryorhyllene, α-caryophyllene, α-famesene, perilla ketone, nerolidol, eugenol. α-cadinol 등 14종∼15종의 향기성분을 함유하고 있었고 주요한 향기성분은 perilla ketone 이었다. Quality and flavor compounds of perilla leaves cultivated in greenhouse(May) and field (August) in Geumsan province were investigated and compared. All perilla leaves contained 4.0% crude protein and 0.8% crude lipid. C겨de flavonoid contents of perilla leaves cultivated in greenhouse and field showed 25.2% and 26.5%, respectively and each crude saponin content was cultivated in field. Hardness and chewness of bottom parts of field-perilla leaves were higher than those of top and middle part, whereas the cohesiveness of top parts and middle parts of perilla leaves were higher than that of bottom part. Furthermore, texture properties of greenhouse-perilla leaves were similar with those of field-perilla leaves except chewness. Nine kind of flavor compounds such as 1-octen-3-ol, linalool, β-caryophyllene, α-caryophylene, α-franesene, perilla ketone, nerolidol, eugennl, α-cadinol were identified in greenhouse-perilla and field-perilla leaves, showing that main flavor compound was perilla ketone.

고층건축공사의 리프트 양중계획 합리화 방안

정용찬,구교진,현창택 대한건축학회 2004 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.24 No.1

Recently, as the building height goes up, the construction period of finishing materials has become one of the most important key issues in the tall building construction. For the reason, one of the vertical transportation equipment, the lift car is more important than before. So. this study reviews properties and problems of the lift car planning in the tall building construction field, and systemizes the process of how many lift cars are suitable in the field. Also, this study suggests the lift car selecting model to calculate exact figures of finishing materials and workers.

민간부문 건설사업관리 활성화방안

이정희,장홍진,구교진,김옥규,현창택,김양현 대한건축학회 2004 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.24 No.1

Since, korean government introduced Construction Management system by the law in 1997, only a few public construction projects have been adopted the system Nevertheless there are many laws which are related in public construction projects, Construction Management is positively carried out by non-government. About the activation plan of Construction Management questionnaire was inquired by experts in construction. The purpose of this study is to give a solution by finding out the problem of the laws, reconstructions remodelings.

공간벡터변조에 의한 반송용 편측식 선형유도전동기의 센서리스 속도제어

우정인,노태균,신동률,고성현 東亞大學校 附設 情報通信硏究所 1997 情報通信硏究所論文誌 Vol.5 No.1

Space Vector control of linear induction motor without speed sensor is one of the most up-to-date researching subjects to the engineers in the fields of power electronics and control theory. A conveyance SLIM(Single-sided Linear Induction Motor) has required a stable speed and a soft start/atop when the goods convey. So, the close loop control method to use a speed sensor have been adopted and as the speed sensor, a linear encorder has been used. But when the speed sensor used, the application boundary is limited and the confidence of system is diminished because it is sensitive to external environment variations and its cost is very expensive. So to solve these problems, this paper deals with speed control of the conveyance SLIM using space vector without speed sensorless.

이젝터 구동관로의 유동특성 연구

설재림,오정교,고현선,장현준 朝鮮大學校 機械技術硏究所 2007 機械技術硏究 Vol.10 No.1

이젝터(Ejector)의 원리는 노즐에서 높은 유속을 갖고 분출하는 유체의 운동에너지에 의하여 저에너지 유체를 흡입하는 펌프의 일종이다. 이젝터는 생산현장의 열기관이나 유체기계발전소의 대류열전달 및 공기조화 덕트시스템에는 필연적으로 관로망이 연결되며 이들 관로망의 설계는 플렌트 전체의 효율뿐만 아니라 안정성과도 밀접한 관계를 갖고 있다. An ejector IS a fluid-transportation device, which spouts high-pressure fluid from driving pipes using kinetic energy of spouted fluid and raises pressure through exchange of momentum with surrounding gases of lower pressure. It can be manufactured with a simple structure irregardless of size of system, installed and used easily at places where fluid is flowing.

동종 조혈모세포이식 후 발생한 치명적 홍역 폐렴 1예

백창렬,이동건,최정현,정현화,조유경,박훈준,이승훈,박윤희,이교영,민우성,김춘추,신완식 대한감염학회 2001 감염 Vol.33 No.4

As a result of the enlarging pool of unvaccinated children and young adults, there has been an increase in measles in our countries. In these situation, it has been reported that measles associated pneumoinia is easily complicated with fatal respiratory failure, espycially in immunocompromised patients. Herein we report the case of lethal measles pneumonia after allogenic hematopoietic stem cell transplantation in adults proven by autopsy. Recently, one case of measles was encountered in 39-year-old female patients after allogenic bone marrow transplanted case (chronic myelogenous leukemia), who progressed into interstitial pneumonia pattern, despite treatment including antibiotics, immunoglobulin. The patient died of giant cell pneumonia compatible with that of measles which was comfirmed in the section of necropsy lung specimen. (Korean J Infect Dis 33:301∼309, 2001)

자기회귀 모델을 이용한 팔운동 근전신호의 기능분리

南文鉉,金正鉉,金洛敎 建國大學校 附設 産業技術硏究所 1992 논문집 Vol.17 No.-

본 연구에서는 AR 모델을 이용한 인간의 팔운동 근전신호의 기능분리에 관한 방법을 제시하였다. 4가지 기능의 팔운동 시에 근전신호의 특성을 잘 나타낼수 있는 매개변수를 공분산범과 연속적 최소제곱 알고리즘을 이용하여 각 기능에 대한 모델의 매개변수와 적정차수를 결정하였다. 또한 팔 기능을 분류하기 위한 신뢰구간은 총합제곱오차의 평균과 표준차로 결정하였다. AR 모델의 오차를 이용하여 각 운동에 대한 기능분리를 실행한 결과 차수가 4차일 때 가장 높은 인식률을 얻을 수 있었으며, 차수가 증가할수록 인식률은 감소하였다. 따라서 본 연구의 결과는 의용생체공학이나 재활공학에 응용할 수 있으리라 기대한다. In this thesis, general method using autoregressive model in the functional separation of the myoelectric signal of human arm movements are suggested. Covariance method and sequential least squares algorithm were used to determine the model parameters and the order of signal model to describe four arm movement patterns; the forearm flexion and extension, the wrist pronation and supination. The confidence interval to classify the functions of arm movement was defined by the mean and standard deviation of total squares error. With the error signals of autoregressive(AR) model, the result showed that the highest success tate was obtained in the case of 4th order, and success rate was decreased with increase of order. This technique might be applied to biomedical-and rehabilitation-engineering.

Design and Analysis of Slotless Brushless DC Motor

Jung-Moo Seo,Joo-Han Kim,In-Soung Jung,Hyun-Kyo Jung IEEE 2011 IEEE transactions on industry applications Vol.47 No.2

<P>This paper presents a design method for a small-sized slotless brushless dc motor. Distributed hexagonal windings are employed for achieving a high torque density and for ease of manufacture. Numerical approaches with an analytic model are used to analyze the magnetic and output characteristics of the motor. The proposed motor is manufactured, and the empirical results are compared with the results of the simulation.</P>

Analysis of Overhang Effect for a Surface-Mounted Permanent Magnet Machine Using a Lumped Magnetic Circuit Model

Jung-Moo Seo,In-Soung Jung,Hyun-Kyo Jung,Jong-Suk Ro IEEE 2014 IEEE transactions on magnetics Vol.50 No.5

<P>This paper presents a magnetic field analysis of a surface-mounted permanent magnet machine with an overhang structure wherein the rotor axial length exceeds that of the stator. A 2-D analytic method using a lumped magnetic circuit model (LMCM) is proposed for more rapid computation of the overhang effect compared with a conventional 3-D or quasi-3-D finite element analysis (FEA). In the LMCM, the effective overhang length is calculated, and a leakage flux generated in the overhang region is estimated. The accuracy and usefulness of the proposed analytic method is confirmed through the 3-D FEA and the experimental results according to the diverse overhang length, the number of slot/pole, and stator core length.</P>