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A Review on Robust Control of Robot Manipulators for Future Manufacturing
Jeongwoo Son,Hyunah Kang,Sang Hoon Kang 한국정밀공학회 2023 International Journal of Precision Engineering and Vol.24 No.6
Robots are used for many manufacturing tasks, and its prevalence in manufacturing is ever-increasing. Robots in future manufacturing are expected to be valuable and essential tools. It is difficult to control a robot to achieve assigned tasks because of the nonlinear time-varying coupled multi-input multi-output dynamics, nonlinear joint friction being difficult to estimate and compensate for, and variations in payload and in environmental dynamics. Further, from the manufacturing engineers’ point of view, the controller needs to be simple and intuitive to understand and implement in practice. One such controller is Time Delay Control, which has been used for more than three decades with many advances. The time-delay estimation allows us to estimate the unknown/uncertain robot dynamics and disturbances by just using the most recent past control torque and acceleration, alleviating the need to identify robot dynamics and/or its parameters for the design of the controller. Time Delay Control can be implemented in industrial controllers allowing only proportional-integral-derivative control thanks to the gain relationship between Time Delay Control and proportional-integral-derivative control; has built-in first-order low-pass filter reducing noise; can be equipped with a simple anti-windup scheme for increasing its stability. A brief comparison of Time Delay Control and Disturbance Observer is also provided for readers who are interested in various robust control. With the introduction and review of the Time Delay Control for a robot, it is expected that the readers’ understanding of this robust control is increased and the use of the Time Delay Control in manufacturing becomes prevalent.
Kang, JeongWoo,Park, Su-Jeong,Park, Hae-Chul,Gedi, Vinayakumar,So, ByungJae,Lee, Kwang-Jick Humana Press 2014 Applied biochemistry and biotechnology Vol.174 No.1
<P>Nonsteroidal anti-inflammatory drugs (NSAIDs) are the group of drugs having the therapeutic efficacy of analgesic and antipyretic. To detect health-threatening residues of NSAIDs, a fast and easy multiresidue method based on liquid chromatography tandem mass spectrometry (LC-MS/MS) was described. Ten NSAIDs were extracted from the tissues using 2 mL of acetonitrile and 0.1 mL of 2 mM ammonium formate in distilled water. After clean-up using C18 sorbent, it was evaporated under nitrogen, reconstituted with 1 mL distilled water and analyzed by LC-MS/MS. The method was validated based on guideline for residue testing laboratory. Furthermore, the method has also been applied successfully to detect ten NSAIDs from bovine, porcine, and chicken liver tissues. In a total of 315 liver samples tested, acetylic salicylic acid was detected from 28 porcine and 2 chicken liver tissues at levels of 13 576 and 50 53 ng/g, respectively. Subsequently, paracetamol was detected in 15 porcine liver tissues with a detection levels of 28 381 ng/g. Phenylbutazone and its metabolite, oxyphenylbutazone, were detected at 247 and 15 ng/g range in one of the bovine liver tissue, respectively.</P>
Dynamical mean-field theory study of a ferromagnetic CrI3 monolayer
Kang Chang-Jong,Hong Jeonghoon,Kim Jeongwoo 한국물리학회 2022 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.80 No.12
We have employed one of the well-known many-body techniques, density functional theory plus dynamical mean-feld theory (DFT+DMFT), to investigate the electronic structure of ferromagnetic monolayer CrI3 as a function of temperature and hole-doping concentration. The computed magnetic susceptibility follows Curie’s law, indicating that the ferromagnetism of monolayer CrI3 originates from localized magnetic moments of Cr atoms rather than Stoner-type itinerant ones. The DFT+DMFT calculations show a diferent coherent temperature for each spin component, demonstrating apparent strong spin-dependent electronic correlation efects in monolayer CrI3. Furthermore, we have explored the doping-dependent electronic structure of monolayer CrI3 and found that its electronic and magnetic properties is easily tunable by the hole-doping.
Kang, Jaegu,Chu, Sanghyun,Lee, Jeongwoo,Kim, Gyujin,Min, Kyoungdoug The Korean Society of Automotive Engineers 2018 International journal of automotive technology Vol.19 No.1
In this research, the effects of three operating parameters (Diesel injection timing, propane ratio, and exhaust gas recirculation (EGR) rates) in a diesel-propane dual fuel combustion were investigated. The characteristics of dual-fuel combustion were analyzed by engine parameters, such as emission levels (Nitrogen oxides (<TEX>$NO_x$</TEX>) and particulate matter (PM)), gross indicated thermal efficiency (GIE) and gross IMEP Coefficient of Variance (CoV). Based on the results, improving operating strategies of the four main operating points were conducted for dual-fuel PCCI combustion with restrictions on the emissions and the maximum pressure rise rate. The <TEX>$NO_x$</TEX> emission was restricted to below 0.21 g/kWh in terms of the indicated specific <TEX>$NO_x$</TEX> (<TEX>$ISNO_x$</TEX>), PM was restricted to under 0.2 FSN, and the maximum pressure rise rate (MPRR) was restricted to 10 bar/deg. Dual-fuel PCI combustion can be available with low <TEX>$NO_x$</TEX>, PM emission and the maximum pressure rise rate in relatively low load condition. However, exceeding of PM and MPRR regulation was occurred in high load condition, therefore, design of optimal piston shape for early diesel injection and modification of hardware optimizing for dual-fuel combustion should be taken into consideration.
Experimental Method for Durability Evaluation of a Chisel Mounted on a Composite Working Implement
( Jeongwoo Han ),( Sanggon Moon ),( Geunho Lee ),( Daesik Kang ) 한국농업기계학회 2017 바이오시스템공학 Vol.42 No.4
Purpose: A chisel mounted on working implement, such as agricultural machinery used in irregular farming conditions, is subjected to highly variable fatigue loading during work. To ensure the safety of the chisel on a working implement for the duration of its service life, fatigue testing must be performed with the proper fatigue test load conditions. In this study, working loads for a chisel were developed by reconstructing loads from strain gage data collected during field tests and used to conduct fatigue tests on the chisel component. Methods: FE analysis with nCode software was utilized to select the proper quantity and locations of strain gages for load measurements. A fatigue test was performed to experimentally verify the fatigue strength of the chisel and to evaluate the validity of the load history developed with the load reconstruction technique. Results: A strain history for the chisel was obtained from data collected during field tests. The data was filtered for the 14-16 km/h speed range, connected, and merged. The chisel load history was developed using the load reconstruction technique. The resulting load history was expressed as a load spectrum using the rain-flow counting method. Conclusions: A fatigue test was conducted on a chisel under a constant load condition with an equivalent load amplitude and number of cycles, as calculated by Miner’s Rule for linear damage accumulation. During the fatigue test, there were no cracks at any position. It is concluded that the fatigue test method proposed in this study can be utilized successfully as a durability evaluation method for the chisel.
폐플라스틱 열분해시설 에너지회수효율 산정을 위한 방열손실 산정 연구
최정우(Jeongwoo Choi),김장영(Jangyeong Kim),김수향(Suhyang Kim),박찬(Chan Park),손준익(Junik Son),김영란(Younglan Kim),강준구(Jun-gu Kang),전태완(Tae-wan Jeon) 한국환경에너지공학회 2023 한국열환경공학회 학술대회지 Vol.2023 No.2
Korea is promoting a policy to switch from landfill and incineration to pyrolysis in order to complete a circular economy through recycling, and has revised subordinate laws of the Waste Management Act and established a new inspection method for pyrolysis facilities. However, in the case of pyrolysis facilities, unlike incineration and incineration heat recovery facilities, policies related to subsidies such as tax reductions for energy recovery have not been activated. Therefore, we conducted a study to prepare an incentive payment plan that reflects the effect of replacing fossil fuels. In addition, we secured basic data for the calculation of recovery efficiency by energy source for waste energy production and utilization facilities, and proposed a method for measuring and calculating heat loss, which is one of the methods for calculating the heat balance of pyrolysis facilities.