http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
마찰교반용접의 하중에 따른 구조적 편향 저감에 관한 연구
차운용,임세빈,김재원 한국기계기술학회 2023 한국기계기술학회지 Vol.25 No.6
Power converter devices require a high level of quality because they have a high direct connection with vehicle operation. Therefore, structural bonding was carried out by friction stir welding with excellent mechanical properties. Friction stir welding can cause structural deflection depending on the load of the welding tool, so it is important to control this for high quality flatness. In this study, pre-welding was performed before welding to minimize deflection generated during welding. And deflection reduction data according to the location of pre-welding were analyzed through dynamic analysis. As a result, based on computerized data rather than experimental data an optimized position of pre-welding was secured to minimize the deflection that occurs during friction stir welding. Through this, a process guide that enables high quality structural bonding was presented.
착륙 안전 보조장치에 대한 국산 고등훈련기 T-50의 동적 특성에 관한 연구
차운용,전종균,이현섭 한국CDE학회 2022 한국CDE학회 논문집 Vol.27 No.1
Fighter planes should be helped by landing safety assistance device when landing requires a lot of deceleration on the runway. Landing safety assistance device are divided into primary and secondary systems. The primary system rapidly decelerates the fighter with the tension of the wire as the wire of the safety device is caught in the hook structure connected to the rear of the fighter. If the fighter’s landing speed is fast, the hook structure may not be caught on the wire in the primary safety device, and the fighter may leave the runway and cause safety problems. In preparation for such a case, a secondary safety device is installed behind the primary safety device, and the secondary safety device is a system in which a wire is caught on the landing gear. Landing safety assistance device are designed to meet the specifications of foreign fight- ers, and what dynamic characteristics they have when applying the domestic advanced trainer T- 50 are confirmed through simulation. Through this, it is possible to check the applicability of the landing safety assistance device without actual driving a fighter.
고속도로 진입 곡선도로에서 세미-트레일러의 운전 안정성에 대한 연구
차운용,권영철 한국기계기술학회 2021 한국기계기술학회지 Vol.23 No.5
Driving safety of a semi-trailer is greatly reduced when driving in a section with a narrow turning radius, so a dynamic study of driving and road conditions is required. In this study, the driving stability of the semi-trailer was investigated using the RecurDyn program in consideration of the velocity and weight of the semi-trailer in the entrance curve section of the highway, and the turning angle and radius of the curved road. In order to select the model and analysis conditions according to the road type, the sloping curved road was modeled by selecting the curvature, entry length, height difference, and entrance angle of the curved section. From the analysis results, the higher the semi-trailer's entrance velocity, the heavier the weight, the narrower the entrance angle of the curved road, and the smaller the curvature, the greater the semi-trailer's maximum running angular speed which had an effect on driving stability.
발파작업으로 인한 인접 구조물에서의 생활진동에 관한 연구
차운용(Woon-Yong Cha),전종균(Chong-Keun Chun) (사)한국CDE학회 2021 한국CDE학회 논문집 Vol.26 No.1
One of the important factors to consider during blasting work is the problem of living vibration that occurs in the surrounding area. In Korea, due to topographical characteristics, there are many cases where construction work is carried out in mountainous areas, and blasting work is necessary for the work. Therefore, the location and separation distance of blasting must be calculated to satisfy the defined life vibration reference value, but it is not easy to calculate the vibration value due to blasting in the case of mountainous areas with various topographical shapes. In this study, in order to solve this problem, the blasting load by FEM analysis was calculated and the vibration value in the target area was measured. This makes it possible to calculate the location and separation distance of the blasting that meets the standard value for life vibration. And the vibration effect can also be checked in advance.
컨베이어 롤러에 의한 평판 디스플레이용 글라스의 편향과 거동에 관한 연구
차운용(Woon-Yong Cha),전종균(Chong-Keun Chun),이현섭(Hyeon-Seop Lee) (사)한국CDE학회 2021 한국CDE학회 논문집 Vol.26 No.3
Flat displays are transported by various transport devices in each production line, where the conveyor system is a representative transport device. A flat display is made of glass. By making direct contact with the glass, the rollers in the conveyor system use the roller’s rotational force to transport the display. In this process, a roller’s flatness or design error can cause deflection problems in the transported display or cracks in the glass, which is vulnerable to impact due to its nature. Because a roller’s speed and acceleration can also cause damage, it is important to consider design errors and the particular characteristics of a roller’s rotational force. We conducted this study with a CAE program(Recurdyn) specialized in dynamics. In this study, we analyzed simulation results of various cases. Based on these findings, we secured a technical template that optimizes the design of the conveyor system.
의료용 로봇의 미진동제어를 위한 가변감쇠형 동조질량감쇠기 기술 개발
차운용(WoonYong Cha),전종균(ChongKeun Chun),박상곤(SangGon Park),한현희(HyunHee Han) 한국소음진동공학회 2014 한국소음진동공학회 논문집 Vol.24 No.9
Recently, the medical community has been enthusiastically welcoming robots that are able to provide high-quality medical services across the board, including assisting the surgeons during surgeries. In response, many higher education institutions and research facilities started to conduct various experiments and studies about these robots. During such research, it was discovered that the arm of one particular robot type that is being developed to assist surgeries are prone to vibrate even from the weakest impact, in addition to other residual vibration problems. We attempted to reduce such dynamic response by using a MF-TMD that is produced by adding magnetic fluid to ECD. We verified the MF-TMD’s performance by testing it within various frequency bands and attenuations. We then designed a cantilever that was structurally similar to the robot’s arm. We attached the MF-TMD to this cantilever and conducted a pilot experiment, which validated our hypothesis that MF-TMD will reduce the robot arm’s vibrations through its optimal damping ratio. Henceforth, we attached the MF-TMD to the robot arm in question and conducted a performance experiment in which we tuned the MF-TMD’s frequency and damping factor to its optimal level and measured the vibrations of the arm. The experiment demonstrated that the vibrations that occurred whenever the arms rotated were significantly reduced.
심다솔,차운용 한국기계기술학회 2022 한국기계기술학회지 Vol.24 No.6
Screw jet equipment has been developed based on the existing accumulated experimental indicators in the semiconductor industry, and for specific performance development, it is necessary to visually check a process in which a high viscosity solution is discharged to a nozzle through a screw. Since the transparency of the exterior is not guaranteed after design and production due to the characteristics of the equipment, simulation must be performed to confirm the performance data according to the internal shape. Therefore, in this study, the screw jet equipment was simulated using the moving particle system, and through this, all processes of the screw jet internal solution flow were visually checked and computerized data capable of predicting the performance of the equipment was secured.
초고압 및 초음파 추출공정을 이용한 매자나무 수피의 향장활성 증진
하지혜,최운용,서용창,김지선,김영옥,차선우,김진철,이현용 한국약용작물학회 2011 한국약용작물학회지 Vol.19 No.1
This study was performed to investigate the enhancement of cosmeceutical activities of Berberis koreana bark by different extraction processes. The extracts are WE (water extract at 100℃, control), USE (ultrasonification for 1 hours at 60℃ with water), HPE (high pressure for 5 minutes at 60℃ with water) and USE + HPE (ultrasonification process for 1 hours after high pressure for 5 minutes at 60℃ with water), respectively. The cytotoxicity of the extracts was in the range of 24.02~26.94% at 1.0 mg/ml concentration. The USE + HPE showed the lowest cytotoxicity. Compared to the WE, total phenolic and flavonoid contents in the USE + HPE increased to 121.5% and 154.2%. The USE + HPE showed the highest activity at 1.0 mg/ml concentration in 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging, inhibition activity of xanthine oxidase and superoxide dismutase (SOD)-like test, respectively. Tyrosinase inhibition of WE, USE, HPE and USE + HPE at 1.0 mg/ml concentration was measured as 17.72, 19.62, 22.83 and 24.16%, respectively. Hyaluronidase inhibition activities of the USE + HPE were higher than 20.8%~29.5% of the WE. Our results suggested that the extracts from ultrasonification process after high pressure extraction has relatively high cosmeceutical activities, and that the bark of Berberis koreana could be considered as a candidate of new functional cosmetic agents.