• 전자공학회논문지B
• /
• 제32B권3호
• /
• pp.38-47
• /
• 1995

A new automatic cardiac output control algorithm for the motor-driven electromechanical total artificial heart(TAH) was developed based on the motor current waveform analysis without using any extra transducer. The basic control requirements of artificial heart can be described in terms of three features : preload sensitivity, afterload insensitivity, and balanced ventricular outputs. In the previous studies, many transducers were utilized to obtain informations of hemodynamic states for the automatic cardiac output control, But such automatic control systems with sensors have had reliability problems. We proposed a new sensorless automatic cardiac output control algorithm providing adequate cardiac output to the time-varying physiological demand without causing right atrial collapse, which is one of the critical problem in an active-filling type device. In-vitro tests were performed on a mock circulation system to evaluate the performance of the developed algorithm and the results show that the new algorithm satisfied the basic control requirements on the cardiac output response and the possibility of application of the developed algorithm to in vivo experiments.

• 대한기계학회논문집
• /
• 제19권3호
• /
• pp.605-614
• /
• 1995

In the automatic transmission using planetary gear there exists nonlinearities due to the finite difference between gear ratios, which yield torque hole during shift and influence on the ride quality and life of clutch. Based on the reaction carrier and converter turbine speed sliding functions are defined. Nonlinear closed-loop control laws are derived using them. Computer simulation shows that the closed loop design is better than the open loop design and semi-closed loop design.

• 한국공작기계학회:학술대회논문집
• /
• 한국공작기계학회 2004년도 춘계학술대회 논문집
• /
• pp.258-262
• /
• 2004

This study has been focused on the development of automatic bottle air rinser. It is designed to rinse clean empty bottles prior to filling. The bottles are automatically indexed beneath an air nozzle that has both a clean airjet and vacuum source. The bottle is first given a burst of clean air to loosen any particles from the wall of the bottle. A vacuum sequence follows which removes all particulates into a self contained filter unit. In order to the provide the desired function, analysis is carried out by FEM simulation using FLUENT and CATIA software. The final results of analysis are applied to the design of automatic bottle rinser and the machine is successfully developed.

• 한국정밀공학회지
• /
• 제22권8호
• /
• pp.71-75
• /
• 2005

This study has been focused on the development of automatic bottle air rinser. It is designed to rinse clean empty bottles prior to filling. The bottles are automatically indexed beneath an air nozzle that has both a clean airjet and vacuum source. The bottle is first given a burst of clean air to loosen any particles from the wall of the bottle. A vacuum sequence follows which removes all particulates into a self contained filter unit. In order to the provide the desired function, analysis is carried out by FEM simulation using FLUENT and CATIA software. The final results of analysis are applied to the design of automatic bottle rinser and the machine is successfully developed.

• 소성∙가공
• /
• 제13권7호
• /
• pp.614-622
• /
• 2004

A new approach for the automatic elimination of free edges in the finite element model for the analysis of sheet metal forming processes is presented. In general, the raw finite element model constructed from an automatic mesh generator is not well suited for the direct use in the downstream forming analysis due to the many free edges which requires tedious time consuming interactive graphic operations of the users. In the present study, a general method for the automatic elimination of free edges is proposed by introducing a CAD/CAE hybrid method. In the method a trimmed parametric surface is generated to fill the holes which are orginated from the free edges by using the one step elastic finite element analysis. In addition, mesh generation algorithm is suggested which can be used in the general trimmed surface. In order to verify the validity of the proposed method, various examples including actual automobile sheet metal parts are given and discussed.

• 한국산업융합학회 논문집
• /
• 제23권3호
• /
• pp.507-513
• /
• 2020

Liquid filling machines are frequently used in packaging fields; however, there exists a problem in precisely measuring the quantity of the liquid. In the case where the liquid filling machine is not properly metered, there may be issues, such as the fluid exceeding the capacity or chemicals being exposed outside. In this paper, we propose a smart injection nozzle device that can solve the issues stated above. The proposed smart injection nozzle can raise the nozzle according to the water level to remove bubbles and inject the accurate amount of fluid. In addition, the efficiency of the logistics process is enhanced by the smart QR code. Through experiments using the developed smart injection nozzle device, we have noticed that the accuracy of injection capacity, nozzle position, reaction time and building data exceeded the target value. Therefore, it expected that this machine will give more production and save a lot of manpower for packaging industry.

• 한국정보통신학회:학술대회논문집
• /
• 한국해양정보통신학회 2001년도 춘계종합학술대회
• /
• pp.414-417
• /
• 2001

본 논문은 버스회사의 각 버스를 자동인식하고 그 버스에 주입된 주유량을 자동 계측하여 본사 메인 컴퓨터로 LAN을 통해 데이터를 전송함으로써 본사에서 일괄 처리한 수 있는 시스템으로 버스 자동인식장치, IBM-PC, 주유기 제어 시스템 및 처리 프로그램으로 크게 나뉘어진다. 본 시스템 도입으로 버스회사의 모든 차량 주유상태를 통합관리 할 수 있어 각 버스별, 노선별, 전체의 기름소모량을 일률적으로 화인 관리할 수 있다. 이렇게 함으로써 운전자의 운전습관, 노후정도 및 정비 스케줄의 판단정보로 활용할 수 있고, 경영혁신과 월가분석을 통한 에너지 절감효과가 있다.

• 한국정밀공학회지
• /
• 제18권12호
• /
• pp.124-129
• /
• 2001

Recently, life cycle and lead-time of products have been shortened with the demand of customers. Therefore, it is important to reduce time and cost at the step of manufacturing trial molds. High speed machining can be applied for this kind of purpose with a lot of practical advantages. In our research, several fundamental experiments are carried out to obtain machining parameters such as cutting force, machining time and surface characteristics for tool paths that are appropriate to high-speed machining. Moreover, a trial mold for an automatic transmission knob is fabricated with aluminum-7075 material. Using automatic set-up equipments, an ABS rapid prototype of a trial product of an AT knob is also manufactured with a filling process.

• Journal of Biosystems Engineering
• /
• 제12권4호
• /
• pp.31-43
• /
• 1987

This study was performed to develop a hot water boiler system with small scale automatic rice hull furnace for the multi-purpose use in the farm. For the experiment a prototype hot water boiler system with rice hull furnace was fabricated, which was equipped with automatic hull feeder, igniter and ash removal device. Optimum operational conditions of the prototype: system were analyzed. The results arc summarized as follows. 1. The temperature measured right above the burning surface should be higher than $500^{\circ}C$ combustion. 2. The top zone of the combustion chamber was the most suitable location of the thermocouple to pick up the control temperature for the automatic operation of the rice hull furnace. 3. The content of carbon monoxide in the flue gas was increased with the filling height of burning material but it was less than 0.3 percent in volume in this experiment. When the filling height was expressed as the ratio of rice hull feed rate to the volume of the combustion chamber above the burning surface, the optimum ratio was about $150kg/m^3-h$. 4. The combustion efficiency of the prototype was higher than 95 percent when the feed rate was 1.1 to 2.3 kg/h and moisture content of rice hull was 22.4 percent (w.b.) or less. 5. It was estimated that the optimum operational conditions of the system were 1.3 to 2.0 kg/h in feed rate, 70 to 100 percent in excess air and 500 to $510^{\circ}C$ in control temperature. 6. The efficiency of coil heal exchanger increased with a decrease in feed rate of rice hull. When the rice hull feed rates were 1.1, 1.7 and 2.3 kg/h, the efficiencies of coil heat exchanger were about 34, 30 and 25 percent and heat transfer rates were 5.7, 7.6 and 8.8 MJ/h, respectively. When the flat plate heat exchanger was used in addition to the coil heat exchanger, the efficiency of the heat exchanger system increased to 48 percent.

• Journal of Pharmaceutical Investigation
• /
• 제41권2호
• /
• pp.75-82
• /
• 2011

LB71350 is an HIV protease inhibitor with poor aqueous solubility and extensive first pass effect. The purpose of the present study was to test the feasibility of solid dosage form of LB71350 with improved bioavailability utilizing solid dispersion. Three different compositions with varying ratio of (LB71350: Gelucire 44/14: Tween 20) were studied. Capsule filling of these solid dispersion compositions was tested using a semi-automatic capsule filling system. Oral bioavailability in dog was tested. Chemical and physical stability at 4, 25 and $40^{\circ}C$ was monitored by HPLC assay, dissolution test, powder XRD and microscopy. The capsule filling system yielded uniform products of drug loading up to 10%. Oral bioavailability in dog was improved compared to the aqueous suspension of crystalline LB71350. Capsules were chemically stable for up to 6 months at $40^{\circ}C$. However, there were temperature and composition dependent physical changes. Decrease in dissolution rates after storage at $40^{\circ}C$ was due to the polymorphic change. In conclusion, manufacturing process, bioavailability, and physico-chemical stability have been considered to propose a solid dispersion capsule formulation for the HIV protease inhibitor with poor physico-chemical properties. A new less soluble crystalline form identified during the physical stability test warrants further study.