Time-Dependent Optimal Heater Control Using Analytic and Numerical Methods

Yun-De Shen,Zhen-Zhe Li,Dong-Ji Xuan,Kwang-Su Heo,Seoung-Yun Seol 한국정밀공학회 2010 International Journal of Precision Engineering and Vol.11 No.1

Thermoforming is one of the most versatile and economical processes to produce polymer products. The drawback of thermoforming is difficult to control thickness of final products. Temperature distribution affects the thickness distribution of final products, but temperature difference between surface and center of the sheet is difficult to be decreased because of low thermal conductivity of ABS material. In the first step, it was found out that timedependent variation of heat affects to the temperature difference between surface and center. An analytic solution was studied because the optimization time is remarkably large when optimal design is directly carried out using the analysis code developed in a previous study. Duhamel’s Theorem was used in order to solve a one-dimensional heat conduction with a time-dependent boundary condition when neglecting the effect of natural convection, but the analytic solution was difficult to be applied when the boundary condition is complicate or noncontinuous. In the following step, an optimal heating profile expressed by exponential function was recommended from 8 simple optimal cases using Duhamel’s Theorem, but the analysis results show that the effect of natural convection must be considered under the condition of setting the heat fluxes as suitable values. In order to consider the effect of natural convection with suitable heat inputs, Finite Difference Method was used. Through investigation, the optimal results using Finite Difference Method show that the temperature difference between surface and center of the sheet can be remarkably minimized with satisfying Temperature of Forming Window.

Suppression of the Epidermal Growth Factor-like Domain 7 and Inhibition of Migration and Epithelial-Mesenchymal Transition in Human Pancreatic Cancer PANC-1 Cells

Wang, Yun-Liang,Dong, Feng-Lin,Yang, Jian,Li, Zhi,Zhi, Qiao-Ming,Zhao, Xin,Yang, Yong,Li, De-Chun,Shen, Xiao-Chun,Zhou, Jin Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.9

Background: Epidermal growth factor-like domain multiple 7 (EGFL7), a secreted protein specifically expressed by endothelial cells during embryogenesis, recently was identified as a critical gene in tumor metastasis. Epithelial-mesenchymal transition (EMT) was found to be closely related with tumor progression. Accordingly, it is important to investigate the migration and EMT change after knock-down of EGFL7 gene expression in human pancreatic cancer cells. Materials and Methods: EGFL7 expression was firstly testified in 4 pancreatic cancer cell lines by real-time polymerase chain reaction (Real-time PCR) and western blot, and the highest expression of EGFL7 was found in PANC-1 cell line. Then, PANC-1 cells transfected with small interference RNA (siRNA) of EGFL7 using plasmid vector were named si-PANC-1, while transfected with negative control plasmid vector were called NC-PANC-1. Transwell assay was used to analyze the migration of PANC-1 cells. Real-time PCR and western blotting were used to detect the expression change of EGFL7 gene, EMT markers like E-Cadherin, N-Cadherin, Vimentin, Fibronectin and transcription factors like snail, slug in PANC-1, NCPANC-1, and si-PANC-1 cells, respectively. Results: After successful plasmid transfection, EGFL7 gene were dramatically knock-down by RNA interference in si-PANC-1 group. Meanwhile, migration ability decreased significantly, compared with PANC-1 and NC-PANC-1 group. Meanwhile, the expression of epithelial phenotype marker E-Cadherin increased and that of mesenchymal phenotype markers N-Cadherin, Vimentin, Fibronectin dramatically decreased in si-PANC-1 group, indicating a reversion of EMT. Also, transcription factors snail and slug decreased significantly after RNA interference. Conclusions: Current study suggested that highly-expressed EGFL7 promotes migration of PANC-1 cells and acts through transcription factors snail and slug to induce EMT, and further study is needed to confirm this issue.

Optimal design of high temperature vacuum furnace using response surface method

이진철,Yun-De Shen,Hui-Lan Xu,이재우,호광수,설승윤 대한기계학회 2008 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.22 No.11

A new method using the response surface method and optimization technique has been developed instead of the original method based on trial and error. In order to construct a response surface, thermal analysis was performed under the condition of using the calculated thermal conductivity of the insulator in a previous study. In order to set up the response surface, the D-Optimal method was used in the process of selecting experimental points. Using a weighting factor, an optimization study was carried out under the condition of satisfying user requirements. Finally, the merits and drawbacks of the new method were described by comparing with the optimal design method based on the thermal analysis database which was developed in a previous study. The optimal results show that the developed method can be used to design an energy efficient, low manufacturing cost, high temperature vacuum furnace with avoiding unnecessary iterative manufacturing, and anticipating the performance before manufacturing.

환경변수를 고려한 박막 랩 와인딩 기계의 제어기 설계

임대윤(Dae Yun Lim),김주영(Ju Young Kim),신윤덕(Yun De Shen),황인철(In Choul Whang),양성모(Sung Mo Yang),기창두(Chang Doo Kee) 대한기계학회 2006 대한기계학회 춘추학술대회 Vol.2006 No.11

The bio-wrap used in our experiments has many good properties including high tensile strength and ductility than widely used polyethylene wrap. However, the cost of the wrap material is very expensive and it requires very precise control to get uniform-thin film. In general, PID control does work for this kind of wrap machine, but very thin film is very sensitive to the environmental changes of temperature and humidity, etc, and has highly nonlinear characteristics. This paper suggests Hybrid-fuzzy controller which controls the system in the every possible case and make a database to the temperature and humidity of the wrap.

Optimal Design for Cooling System of Batteries Using DOE and RSM

Zhen-Zhe Li,Yun-De Shen,Tai-Hong Cheng,Dong-Ji Xuan,Ming Ren,Gui-Ying Shen 한국정밀공학회 2012 International Journal of Precision Engineering and Vol. No.

A hybrid power composed of fuel cell and batteries has become the good strategy for HEV. On the contrary, the produced heat of batteries can affect to the total performance of HEV significantly. In this study, simulation methods with optimization were developed for obtaining the high performance cooling system of batteries. At first, a numerical method for obtaining the temperature distribution of batteries was developed by using CFD. In the following step, several parameters were investigated for selecting design variables with the important effect on the performance of the cooling system of batteries. Finally, an optimization method based on DOE and RSM was obtained through a real optimal design. There was 21.1% reduction on the view of the root mean square temperature between batteries as shown in the optimization result. The developed analysis with optimization can be used to improve the performance of the cooling system of batteries, and these works have made the theoretical basis for simulation and optimization of the cooling system of batteries.

휴머노이드 타입의 이족 보행 로봇 제작과 Path-Finding에 관한 연구

김정기(Jung Kee Kim),신윤덕(Yun De Shen),기창두(Chang Doo Kee) 대한전기학회 2004 대한전기학회 학술대회 논문집 Vol.2004 No.11

빅 데이터(Big Data)를 이용한 용접품질에 연구

김일수(Ill Soo Kim),신윤덕(Yun-De Shen) 제어로봇시스템학회 2021 제어·로봇·시스템학회 논문지 Vol.27 No.12

Generally, in welding technology, big data refers to data that is too large, fast, or complex for processing using traditional methods. For the past years, the act of accessing and storing large amounts of information for welding has been utilized. Welding technology is a central component of numerous value creation chains and plays an important role in this development. In this study, gas metal arc (GMA) welding experiments were conducted to develop an algorithm for predicting welding defects in the GMA melting process of flat plates on SS400 materials using big data technology. The correlation between various welding parameters was analyzed using the real-time measured current and voltage data during welding. In addition, the welding quality related to the weld bead was analyzed using a 3D scanner. The optimal welding parameters were predicted using a CHMM model for the welShen Yun Deding current signal in the normal welding section, which is one of the machine learning technologies. By learning this, the similarity between the normal welding current signal and the weld defect was expressed as a probability, and the changed pattern of the Log-pdf value was used to predict the welding quality.

모델기반 신경망 제어기를 이용한 열린 박스 구조물의 진동제어

장승익(Seung Ik Jang),신윤덕(Yun De Shen),기창두(Chang Doo Kee) 대한기계학회 2003 대한기계학회 춘추학술대회 Vol.2003 No.11

Vibration causes noise and sometimes makes structure unstable. Especially, due to the efforts of lightening,<br/> deformation of flexible structure is increased in its shape. Just a little disturbance can cause vibration and low<br/> damping ratio makes residual vibration last long time. This research is concerned with the model reference<br/> neuro-controller design for the vibration suppression of smart structures. By using a model reference neurocontroller,<br/> which is one of the algorithms of adaptive control, we performed an adaptive control of flexible<br/> cantilever plate and opened box structure with piezoelectric materials. The proposed adaptive vibration<br/> control algorithm, a model reference neuro-controller, was proved in its effectiveness by applying to an<br/> opened box structure. The model reference neuro-controller is implemented with DSP, and the real-time<br/> adaptive vibration control experiment results confirm that the model reference neuro-controller is reliable.

Optimization for Cooling System of Batteries Having Porous Material Using Design of Experiments

Zhen-Zhe Li,Dong-Ji Xuan,Yong Li,Yun-De Shen 한국정밀공학회 2015 International Journal of Precision Engineering and Vol. No.

A hybrid power composed of fuel cell and batteries has become the reasonable strategy for hybrid electric vehicles. On the contrary,the produced heat by batteries can affect the total performance of hybrid electric vehicles significantly. In this paper, analysis methodsand optimization strategy were constructed for obtaining the high performance cooling system for batteries having porous material. At first, a numerical method for obtaining the temperature distribution of battery pack including porous material was developed byusing CFD technique. In the following step, the cooling systems for batteries with porous material or not were compared for showingthe merit of the cooling system for batteries having porous material. Ultimately, an optimization strategy based on D-optimal DOEmethod was obtained through a real optimal design process. There was 13.3% reduction on the view of the root mean squaretemperature between batteries compared with the original cooling system for batteries as shown in the optimization result. Theconstructed analysis method and optimization strategy can be used to improve the performance of the cooling system for batteries,and these works have made the theoretical basis for simulation and optimization of the cooling system for batteries.

HMA를 이용한 이족로봇의 이동물체 추적에 관한 연구

조동수(Dong Soo Cho),김동일(Dong Iel Kim),신윤덕(Yun De Shen),기창두(Chang Doo Kee) 대한기계학회 2005 대한기계학회 춘추학술대회 Vol.2005 No.11

In this paper, the visual tracking system for a moving target is proposed in the biped robot of which the movement of the camera is irregular. Hexagonal Matching Algorithm is used to measure the changes of size, location, and rotation angle for a moving object from its image frame. Also, for enhancing the efficiency of the tracking, we can adaptively adjust the starting point and the size of search area from the image information obtained. Finally, using Affine Transform and Kalman Filter, the position estimation of the moving target is refined against the swing of the camera. Experiments of the moving target tracking were implemented with 20-DOF biped robot using mono vision sensor to prove the reliability of the proposed method.