• Food Engineering Progress
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• v.14 no.2
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• pp.85-91
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• 2010

In the food process, twist screen is widely used to divide particles on the basis of size. As screen equipped in the twist screen perfoms an important part in the particle size distribution mechanism, the contact area of screen and particles, retention time of particles on the screen, mesh and string thickness of screen and the flow pattern of particles on the screen are major points of the separation efficiency. To improve the separation efficiency, increase the retention time and control the flow pattern of particles, screen frame dam and spiral blockage are installed on the sieve of twist screen ${\emptyset}$ 1200 and ${\emptyset}$ 1500. Twist screen ${\emptyset}$ 1500 with frame dam treated similar separation capacity, 37% higher separation ratio and less non-separated particles of product output 1 than general twist screen. Twist screens with frame dam and spiral blockage showed less treatment capacity, three times higher division ratio and entire separation than general twist screen.

• The Journal of the Korea Contents Association
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• v.9 no.12
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• pp.1-9
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• 2009

A doll created by various materials is a miniature based on human model, and it has been one of components in a puppet show to take some responsibility for human's culture activity. However, demand and supply keeps on the decrease in the puppet show industry, since professional puppeteer has been reduced rapidly, and also it is difficult to initiate into the skill. Therefore, many studies related Robotic Marionette for automation of puppet show have been internationally accompanied, and more efficient structure design and process development are required for better movement and express of puppet with motor based controller. In this research, we suggest the effective way to enable to express the marionette's motion using motion data based on motion capture and 3D graphic program, and through applying of 3D motion data and proposal of simulation process, it will be useful to save time and expenses when the Robotic Marionette System is practically built.

• The Transactions of the Korean Institute of Power Electronics
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• v.4 no.5
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• pp.433-441
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• 1999

This paper presents a S-FES(Superconducting magnetic becuing Flywheel Energy Storage System) for the p purpose of replacing battery used to store the energy. Especially, the design elements of FES, such as the b beming, wheel mateηaI, and power converter, etc., are described. The design and manufacturing techniques of t the controllable IXlwer converter are proposed to generate the sinusoidal output current in the high speed operation and to get the const빠synchronous motor with halbach cuTay of high coesive I\d-Fe-B permanent magnet is used as the driver of F FES. The proposed S-FES system shows the stable rotation characteristics at high speed range about l 10,000[rpm]. To verify the validity of proposed system, the comparative study with the conventional ball b beming s~rstem is proceeded and it is well confirmed with the result of the lower friction losses of S-FES S system.

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.3
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• pp.407-412
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• 2014

Purpose: It is investigated whether the time division system can extend the field without diplopia for people with homonymous hemianopia. Methods: The time division system was manufactured by a modified mini fan and a black cardboard. In order to verify the effectiveness of the equipment, subjects with and without the equipment took part in the experiment to bisect the space and to recognize letters. Results: Subjects with and without the equipment showed +8.91 and +18.14 degrees in the experiment to bisect the space. In the experiment reading the letters and numbers with the equipment, there were 9 percentage point increase in $4{\times}4$ charts and 15 percentage point increase in $6{\times}6$ charts. It turned out that there was a remarkable improvement for the worst group for reading the charts. Conclusions: The time division system is effective in the mobility and orientation for people with homonymous hemianopia.

• The KIPS Transactions:PartB
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• v.16B no.5
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• pp.347-358
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• 2009

In this thesis, we develop a vision based hand motion recognition system using a camera with two rotational motors. Existing systems were implemented using a range camera or multiple cameras and have a limited working area. In contrast, we use an uncalibrated camera and get more wide working area by pan-tilt motion. Given an image sequence provided by the pan-tilt camera, color and pattern information are integrated into a tracking system in order to find the 2D position and direction of the hand. With these pose information, we estimate 3D motion plane on which the gesture motion trajectory from approximately forms. The 3D trajectory of the moving finger tip is projected into the motion plane, so that the resolving power of the linear gesture patterns is enhanced. We have tested the proposed approach in terms of the accuracy of trace angle and the dimension of the working volume.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.11
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• pp.988-995
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• 2014

Two axis gimbal type X-band antenna system has been widely used to effectively transmit the real time image data from the observation satellite to the ground station. The micro-vibration generated by stepping motor actuation and imperfect intermeshed gear configuration of the antenna is one of the sources to degrade the image quality. To guarantee a high quality image of high resolution observation satellite, micro-vibration isolation of X-band antenna is required. In this paper, the X-band antenna vibration isolation system using pseudoelastic SMA(Shape Memory Alloy) mesh washer has been newly suggested. The basic characteristics of the SMA mesh washer isolator proposed in this study has been measured through static load tests and its effectiveness has been demonstrated by the micro-vibration isolation test of the X-band antenna.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.886-887
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• 2015

There is a growing interest in and demand for power industry acceleration and energy efficiency due to the increased energy consumption, environmental issues. Electronic power IT convergence industries such as intelligent power system has attract attention as new growth engine industry. A large number of sensors and motors are being installed following unmanned, automated in existing incoming panel management system. Observe the operating conditions and rapid response is essential. Despite the need for immediate action to be taken in the event of various later failed to recognize the emergency power can lead to accidents. In this paper, we propose a new architecture of the implementation of incoming panel monitoring system for power monitoring, fault detection, maintenance and system control using open source hardware platform and Wi-Fi networks.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.1
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• pp.85-92
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• 2017

Recently, electric propulsion systems are used for unmanned surface vehicle, fish finder boat, etc. Some of these propulsion systems can be constructed of two electric motors and propellers for advanced impellent force. In this case, the speed difference generated between two propellers, namely, the synchronous error has a bad influence on the energy efficiency and course error. In this study, a synchronous control system is designed to restrain synchronous error caused by disturbance and mismatched dynamic characteristics. The control system is composed of the reference model, pre-filters, speed controllers, and synchronous controllers. The reference model is used for calculating the decoupled synchronous error and control input for each propulsion system. The pre-filters and speed controllers are designed in order that the propulsion system may follow the reference signal without overshoot and input saturation. And the synchronous controllers are designed from the viewpoint of stable and quick synchronization through root locus mothed approach. Finally, the simulation results show that the designed control system is effective for the disturbance.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.11
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• pp.2021-2032
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• 1992

A redundant sensor system, which consists of two incremental encoders and a gyro sensor, has been proposed for the estimation of the posture of mobile robots. A hardware system was built for estimating the heading angle change of the mobile robot from outputs of the gyro sensor. The proposed hardware system of the gyro sensor produced an accurate estimate for the heading angle change of the robot. A sensor data fusion algorithm has been developed to find the optimal estimates of the heading angle change based on the stochastic measurement equations of our readundant sensor system. The maximum likelihood estimation method is applied to combine the noisy measurement data from both encoders and gyro sensor. The proposed fusion algorithm demonstrated a satisfactory performance, showing significantly reduced estimation error compared to the conventional method, in various navigation experiments.

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.4
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• pp.430-436
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• 2012

This study was conducted to measure battery's voltage drop in a compact electric vehicle to get driving performance in various driving situations. In the experiment, to evaluate the energy consumption and milage, system performance have measured with changing of the driving speed and the reduction of driving distance when the heater was operating. The battery of the car in this study is lead type storage battery. The driving velocity was changed from 10km/h to 50 km/h with 20km/h intervals and the operating step of the heating device. As results, the electronic consumption rate was maximum at 35 km/h of vehicle speed and if the driver turning the heater at maximum, capacity will lead to 35% of energy consumption increment.