• Journal of the Korean Society of Industry Convergence
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• v.13 no.1
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• pp.15-22
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• 2010

This paper was originated to set up a test equipment and to obtain the proper installation condition of the plastic damper for the hydraulic clutch control system. Performance tests with different specifications have been applied to the damper to investigate the workability and the vibration characteristics of each case, and the result was utilized into the system simulation for the optimal condition for the damper. The procedure has been developed to set up a damper test system to analyze the dynamic properties and the operation of the system, and further to setup a simulation program for the realistic situations. The result can also be applied to the dampers and the clutch systems to be developed in the future for the property tests and the optimization of the installation conditions.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.53 no.2
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• pp.70-76
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• 2004

The purpose of interlocking system in railway is to prevent the route for a train being set up and its protecting signal cleared if there were already another, conflicting route set up and the protecting signal for that route cleared. Recently, conventional relays circuitry in industrial field is replaced to computer-based control systems according to the advance of computer and communication technology. Therefore, interlocking systems in railway field are rapidly changing from existing relay-based interlocking system to computer-based electronic ones that executes the vital interlocking logic to assure the safety train routes at trackside signaling equipment room using electronic circuits. So it is very important to verify the performance of developed electronic interlocking system by plentiful laboratory testing before actually application in the railway system. However the laboratory testing in the present state of railway signaling is preformed individually by manual, so very much test time and cost are required. To solve these problems, we are developed the simulator for automatic interlocking inspection in this research. This simulator is able to operate on general personal computer and has following beneficial functions : automatic test sheet generation for inspection, automatic inspection execution and et al. The experiments are executed to test the feasibility of the developed simulator the experimental results have good agreements with the anticipated ones.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.12
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• pp.124-129
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• 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.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.633-637
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• 1995

Numerical calculation tool for forging of gear-like components based on kinematically admissible velocity fields for upper bound method applicable to various deformation features of workpiece in forging processes were suggested. Each one of them deals with unidirectional flow of metal on dies, such as external involute spur gear, sequare spline, internal serrations. A complex calcuation tool of gear-like component forging process was built up by combining these kinematically velocity fields. In this paper, the workpiece with both external and internal teeth is divided into two parts. The deformation of each part is analyzed simultaneously using numerical calculation tool form combined kinematically admissible velocity field. The experimental set-up was installed in a 200 ton hydraulic press. As a result, each kinematically admissible velocity field could be combined with other and the calculated solution are useful to predict the capacity of forging equipment.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.2
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• pp.81-89
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• 1998

Numerical calculation tools for forging of gear-like components based on kinematically admissible velocity fields for upper bound method applicable to various deformation features of workpiece in forging processes were suggested. Each one of them deals with unidirectional flow of metal on dies, such as external involute spur gear. square spline, internal serrations. A complex calculation tool of gear-like component forging process was built up by combining these kinematically velocity fields. In this paper the workpiece with 110th external and internal teeth is divided into two parts. The deformation of each part is analyzed simultaneously using numerical calculation tool from combined kinematically admissible velocity field. The experimental set-up was installed in a 200 ton hydraulic press. As a result, each kinematically admissible velocity field could be combined with others and the calculated solution are useful to predict the capacity of forging equipment.

• Journal of Aerospace System Engineering
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• v.4 no.4
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• pp.44-48
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• 2010

This paper is used the commercial magneto-rheological(MR) damper for landing gear. The damping characteristics of Commercial MR damper by changing the intensity of the magnetic field are investigated and the dynamic responses of the landing gear. it is set up tset equipment, the landing gear drop test system. The landing gear involved drop testing the gear. The landing gear is tested by implementing sky-hook control algorithm and its performance is evaluated comparing to the result.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2002.11a
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• pp.115-116
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• 2002

This study aimed to investigate flow measurement by using a 'bucket and stop-watch' method of flow measurement. Most flow measurement systems measure pressure or other fluid properties to infer flow rate, though time is a variable which can be easily and very accurately measured. The main principle behind the method was to fill up a reservoir until a set pressure had been reached. This reservoir would then be emptied and the cycle would repeat itself. The prototype was designed to control flow rate using the method. It made use of computer control with an analogue digital converter and fast acting solenoid valves which controlled the flow into a reservoir. Reservoirs were available with internal diameter of 1mm up to 5.5mm to cope with a range of flow rate.

• Proceedings of the KIEE Conference
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• 1994.11a
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• pp.314-316
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• 1994

The operation of RC(Rod Consolidation) technology carry out highly radiation environment. It requires remote operation and automation for efficient handling and for minimizing radiation exposure to the operator. So we investigated up and down position control of shock absorber device in RC system. To verify the research experimentally, a RC system was set up and PI control method was applied. Fuzzy control method was also tested to further improve control behavior.

• Journal of The Korean Digital Architecture Interior Association
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• v.11 no.4
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• pp.5-11
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• 2011

The present study investigated the actual conditions of physical therapy rooms at long-term hospitals in Korea and conducted a comparative analysis to develop an efficient floor plan and facility improvement measures. 1. At hospitals surveyed, physical therapy services were used at a high frequency but they did not have enough space for rehab treatment and long paths of patient flow were found to make patient management inconvenient. Therefore, physical therapy units should be conveniently located both in terms of distance and direction so as to be accessible from patient rooms or wards. The space should be organized in a concentrated layout for efficiency of physical therapy, and floor planning for therapy units should ensure the best possible viewing angle to therapists. 2. With regard to the disease characteristics of patients, many physical therapy rooms were in difficult circumstances because of poor facilities, so they need to secure skilled personnel, supplement apparatuses and equipment and have rooms for functional recovery, hydrotherapy and operation treatment. In addition, each of the curtained or partitioned areas for treatment should be set up with consideration for the amount of space taken up by medical equipment. The area under each bed should be designed for patient convenience so that it can be used as storage space for patient's belongings and shoes. 3. Patients complained about the lack of physical therapy space, resting places or exercise areas and demanded the expansion of rehab programs and facilities. Physical therapy facilities need to be improved for patient privacy and effective natural ventilation. 4. At most of the long-term hospitals surveyed, physical therapy units were found to have small areas and treatment equipment and devices were insufficient compared to the number of patients. Therefore, it is required to secure more space (at least 138.24 sq. meters per 100 beds) and improve facilities for better physical therapy services.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.46 no.2
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• pp.133-142
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• 2023

The large process plant is currently implementing predictive maintenance technology to transition from the traditional Time-Based Maintenance (TBM) approach to the Condition-Based Maintenance (CBM) approach in order to improve equipment maintenance and productivity. The traditional techniques for predictive maintenance involved managing upper/lower thresholds (Set-Point) of equipment signals or identifying anomalies through control charts. Recently, with the development of techniques for big analysis, machine learning-based AAKR (Auto-Associative Kernel Regression) and deep learning-based VAE (Variation Auto-Encoder) techniques are being actively applied for predictive maintenance. However, this predictive maintenance techniques is only effective during steady-state operation of plant equipment, and it is difficult to apply them during start-up and shutdown periods when rises or falls. In addition, unlike processes such as nuclear and thermal power plants, which operate for hundreds of days after a single start-up, because the pumped power plant involves repeated start-ups and shutdowns 4-5 times a day, it is needed the prediction and alarm algorithm suitable for its characteristics. In this study, we aim to propose an approach to apply the optimal predictive alarm algorithm that is suitable for the characteristics of Pumped Storage Power Plant(PSPP) facilities to the system by analyzing the predictive maintenance techniques used in existing nuclear and coal power plants.