동적 귀환 신경망에 의한 비선형 시스템의 동정

심귀보,이상환,전효병 중앙대학교 생산공학연구소 1997 생산공학연구소 논문집 Vol.6 No.2

최근들어 비선형 동적 시스템의 동정을 위한 동적 귀환 신경망에 대한 연구가 활발히 이루어 지고 있다. 일반적으로, 신경망의 연결강도를 학습시키기 위해서는 역전파 학습규칙이 사용되고 있다. 그러나, 이 방법은 많은 복잡한 계산과정을 필요로 하게 되고, 지역 최소값에 빠질 가능성이 매우 높다. 따라서 본 논문에서는 동적 귀환 신경망을 이용하여 비선형 동적 시스템을 동정하기 위한 새로운 방법을 제안한다. 뉴런의 연결강도를 학습시키기 위해서 본 논문에서는 진화전략을 사용한다. 주 연산자로서 돌연변이를 갖는 진화전략에 의해 학습된 동적 귀환 신경망은 플랜트 에뮬레이터로서 역할할 수 있게 된다. 또한 진화전략의 적합도 평가 함수는 플랜트의 출력과 신경망의 출력간의 오차에 기반을 둔다. 비선형 동적 시스템을 동정하는 새로운 방법은 2축 로봇 메니퓰레이터의 시뮬레이션에 적용하여 그 가능성과 유효성을 검토한다. Recently, dynamic recurrent neural networks(DRNN) for identification of nonlinear dynamic systems have been researched extensively. In general, dynamic backpropagation was used to adjust the weights of neural networks. But, this method requires many complex calculations and has the possibility of falling into a local minimum. So, we propose a new approach to identify nonlinear dynamic systems using DRNN. In order to adjust the weights of nonlinear dynamic systems using DRNN. In order to adjust the weights of neurons, we use evolution strategies, which is a method used to solve and optimal problem having many local minimums. DRNN trained by evolution strategies with mutation as the main operator can act as a plant emulator. And the fitness function of evolution strategies is based on the difference of the plant's output and DRNN's outputs. Thus, this new approach at identifying nonlinear dynamic system, when applied to the simulation of a tow-link robot manipulator, demonstrates the performance and efficiency of this proposed approach.

전방향 신경망에 의한 비선형 동적 시스템의 동정

심귀보,전효병,이상환 중앙대학교 생산공학연구소 1998 생산공학연구소 논문집 Vol.7 No.1

최근에 신경망을 이용한 비선형 동적 시스템의 동정에 관한 연구가 활발히 진행되고 있다. 그러나 일반적인 비선형 동적 시스템의 동정에 있어서는 신경망의 동적 특성을 높이기 위해 과거 데이터를 저장하는 과도한 메모리의 사용이 요구되며, 역전파 알고리즘의 수행에 많은 복잡한 계산이 수행된다. 따라서, 본 논문에서는 단순한 전방향 신경망을 이용한 새로운 비선형 동적 시스템의 동정 방법을 제시한다. 제안된 방법에서는 전방향 신경망의 출력을 현재의 상태변수값에 얼마만큼 증감할 것인가 하는 증감량으로 사용한다. 연결강도의 조정을 위해서 많은 국소해가 존재하는 문제에서 보다 쉽고 간단하게 최적해를 구할 수 있는 진화전략을 사용한다. 제안된 방법의 유효성은 2축 로봇 메니퓰레이터의 시뮬레이션을 통해 검증된다. Recently, the identification of nonlinear dynamic systems using neural networks has been researched extensively. For the identification of nonlinear dynamic systems, generally, excessive memories storing past data set are required to give dynamic property to neural networks and lots of complex calculations are executed for the backpropagation algorithm. So, we propose a new approach to identify nonlinear dynamic systems using simple feedforward neural networks. We use the outputs of feedforward neural networks as the value of what is added to or subtracted from the current states. In order to adjust the weights of neurons, we use evolution strategies, which makes it easier and simpler to solve an optimal problem having many local minima. Simulation results using two-link robot manipulator data reveal the performance and efficiency of this proposed approach.

超硬合金 Gun drill에 의한 CNC 深孔加工 特性에 관한 硏究

全泰玉,沈成輔 동아대학교 공과대학 부설 한국자원개발연구소 1994 硏究報告 Vol.18 No.2

The techiques of gundrilling and gun boring began developing in the late 18th century with the need for more accurate bores in rifle and cannon. Gun drilling developed first for correcting errors in long holes and was later modified to bore through solid stock. Gun drilling is performed with the rotating drill and stationary workpiece in this study. The work material is SM45C carbon steel. Empirical data thave been obtained for work materials SM45C under pepresentative drilling conditions. The several features of gun drilling are obtained in this study.

싱글 튜브 시스템 BTA 工具를 使用한 SM55C 鋼의 深孔 加工 特性에 관한 硏究

全泰玉,全彦燦,沈成輔,張性圭 동아대학교 공과대학 부설 한국자원개발연구소 1994 硏究報告 Vol.18 No.2

The BTA deep hole machining has an increasing demand because of its wide applications and its good productivity. The main feature of the BTA drill is that the tool cutting edges are unsymmetrically located on the boring head. This provides a stabilizing cutting force resultant necessary for self guidance of the boring head. The BTA drills are capable of machining for having large length to diameter ratio in single pass. The study of the accuracy and surface finish of holes produced would reveal quite useful information regarding the process. This thesis deals with the experimental results obtained during single tube system BTA machining on SM55C steel for different machining conditions.

Caerulein과 총담췌장관 결찰에 의한 급성췌장염 모델의 특징

심상수,김현준,이윤혜,박진형,이승준,김창종 중앙대학교 약학연구소 2000 약학 논총 Vol.14 No.-

To investigate the difference in acute pancreatitis experimentally induced by common bile-pancreatic duct (CBPD) ligation and caerulein iv infusion, we measured amylase activity, pancreatic edema and phospholipase A_2 activity in pancreatic tissue and serum. In acute pancreatitis induced by CBPD ligation and caerulein infusion, tissue edema and tissue phospholipase A_2 activity significantly increased as compared with normal group. Also experimental acute pancreatitis significantly increased the levels of serum protein, serum amylase activity and serum phospholipase A_2 activity. In the comparison of two experimental models, the symptom of acute pancreatitis induced by CBPD ligation was more severe than that induced by caerulein infusion. These results indicate that the increase of phospholipase A_2 activity in pancreatic tissue and serum may be one of the parameters for the diagnosis of acute pancreatitis.

중국 광동성 한국전통정원 조성사업 기본계획

서주환,이준근,심성보,전영임 경희대학교 디자인연구원 2004 예술· 디자인학연구 Vol.7 No.1

The cultural interchanges have been dramatically increased between Korea and China since the diplomatic agreement on the 24th of August, 1992, Among the several discussions between the two countries, particularly building up Korea traditional garden will take concrete shape in Kwan-dong in China. These followings are the basic plans. First, the project approaches the garden as a place for the interchange and the cooperation between the counties, and where people can experience Korea traditional garden. Secondly, it is plotted to express the distinct character and originality of Korea traditional garden. Third, it applies the same materials, subject matters and the same construction method of Korea traditional garden. We can use the most similar materials if it is not possible. Fourth, the project is plotted to make the efficient use of the land form to decrease the damage of natural environment.

악성 위궤양의 형태를 보인 원발성 위결핵 1예

한종대,이동욱,심성준,류운석,안현택,박찬욱,김배영,이미선 大韓消化器內視鏡學會 1999 Clinical Endoscopy Vol.19 No.부록2

자동차용 실리콘 가속도센서의 개발(Ⅱ)

이종현,신장규,이상룡,천희곤,조찬섭,심준환,류인식,박석홍,허정준,박기열 경북대학교 센서기술연구소 1994 연차보고서 Vol.1994 No.-

자동차의 air-bag 장치에 실용될 수 있는 압저항형 단결정 실리콘 가속도센서 칩을 개발하기 위하여 결정 실리콘 미세구조의 제조방법을 확립하고, 단위공정의 검증을 통하여 일괄공정에 의한 PROTO-TYPE 칩을 만드는 기술을 연구하였다. 단결정 실리콘 미세구조는 선택확산법을 이용하여 정확히 선택된 영역에만 air-gap을 형성하여 미세구조의 측면식각을 방지하는 선택확산법에 의한 실리콘 마이크로머시닝 기술로 제조하였다. 일괄공정을 위한 단위공정확립을 위하여 PROTY-TYPE 8빔 브릿지형 가속도 센서를 제조하였다. 제조된 칩의 가속도에 따른 출력전압은 선형성을 나타내고 있으며, 감도는 약 50 ㎶/V·g로 나타났다. 이 감도는 50G용 가속도센서의 사양을 만족하지 못했다. 이는 공정에 의한 문제라기 보다는 가속도센서의 시뮬레이션에 의해 설계한 구조가 이미 원하는 감도에 못 미친다는 것으로 생각된다. 따라서 2차 공정으로 제조될 가속도센서의 파라미터를 SuperSAP 유한요소 패키지를 이용하여 실리콘 미세구조부의 파라미터에 따른 특성을 시뮬레이션하였다. 설계된 50G용 가속도센서의 mass Pad의 반경 및 빔 길이, 빔 폭, 빔 두께, 그리고 mass의 각 파라미터 값은 700 ㎛, 120 ㎛, 5 ㎛, 1.0 ㎎ 이었다. 반도체 공정기술, 관성질량 제조법 및 선택확산을 이용한 마이크로머시닝을 사용하여 일괄공정으로 8빔 브린지형 가속도센서를 제조하였다. We researched the establishment of the silicon microstructure fabrication technique to develop a piezoresistive type silicon acceleration sensor chip and the technique to make a proto-type chip by the verification of the unit-process. Silicon microstructure is fabricated silicon micro-machining by selective diffusion method. This method prevent a side-etching of microstructure because selective diffused region is only formed an air-gap. We fabricated a proto-type 8-beam bridge-type acceleration sensor to establish the unit-process for the batch-process. The output voltage of the chip represented linearity with acceleration, and the sensitivity was about 50 ㎶/V·g. But this sensitivity dosen't satisfy the requirements of a practical acceleration sensor. The cause of this result is assumed not process problem, but the structure designed by simulation isn't suitable already. Threfore, the characteristics of parameters of the acceleration sensor that will be fabricated by 2nd-process is simulated by SuperSAP finite-element package. The determined parameter values of beam length, beam width, beam thickness, mass, and mass radius are 120 ㎛, 5 ㎛, 1.0 ㎎, and 700 ㎛, respectively. We fabricated 8-beam bridge-type acceleration sensor by batch-process using a semiconductor process technique, proof-mass fabrication method, and micromachinig using selective diffusion.

Microlalgal removal of CO₂ in a photobioreactor

Sang Jun SIM 한국생물공학회 2010 한국생물공학회 학술대회 Vol.2010 No.4

Removal of Natural Organic Matter (NOM) by Ozone Oxidation and Biological filtration Using a Rope-Type Biofilter

Sim, Sang Jun,Kang, Youn Seok,Kim, Woo Sik 한국공업화학회 2004 Journal of Industrial and Engineering Chemistry Vol.10 No.3

As raw water quality gets worse, a great number of advanced techniques have been developed and adapted for water treatment to provide safe and high-quality drinking water. One of various water treatment processes is biological treatment, which is suitable for advanced water treatment, followed by conventional treatment processes. In this paper, we propose ozonation and biofiltration by a rope-type biofiltration contactor for the effective removal of natural organic matter (NOM) from the source of drinking water. The removal efficiencies of NOM were evaluated under various experimental conditions, such as ozone contact time, empty bed contact time (EBCT), media density of the sedimentation tank, and turbidity of the raw water. The combination of pre-ozonation and bio-filtration was found to be very effective for removing biodegradable organic matter as well as the turbidity of raw water. We expect that the biological rope media biofiltration contactor, with pre-ozonation, may be complimentary units for NOM removal when employed in a conventional water treatment process. This process can be easily introduced in small-and medium-scale water purification units.