• Journal of the Ergonomics Society of Korea
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• v.19 no.1
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• pp.49-61
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• 2000

An experiment was designed to evaluate Fitts' law for the three-dimensional virtual pointing task and to compare the three input devices; Spaceball, Spacemouse, and 3D-Mouse. The result showed that Fitts law fitted poorly for the three-dimensional pointing tasks with relatively low coefficients of determinant. Three reasons, high degree-of-freedom, dynamic egocentric viewpoint change, and clutching problem were discussed to explain the poor fitness of Fitts' law. In terms of device comparison, the 3D-Mouse was superior to the other input devices. Also, the stereoscopic display significantly increased the performance. The results of this study can be used for the design of virtual control tasks and the selection of suitable input devices.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1565-1570
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• 2003

Passive Haptic Devices have more benefit than the active in Stability. But Apart from benefits, it shows poor performance in haptic display. The author proposed the passive FME(Force Manipulability Ellipsoid) which can graphically show force generating ability of a passive haptic device. In this paper, performance indexes for the force approximation and pseudo friction cone are obtained with the passive FME and an optimized planar device with the indexes is proposed. Based on the above theory, experiment is conducted.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1753-1758
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• 2005

Human Adaptive Mechatronics (HAM), which is a system concept to adapt human characteristics, has been proposed. As the HAM application, this paper addresses an information emphasis scheme to alert some hazards which are undetectable by a human operator. The emphasis scheme employs cognitive psychological approach to human discrimination characteristics because excess or deficient emphasis may disturb the operation. One of advantages of teleoperation system is able to include human valuable abilities as global environment recognition, planning, prediction and so on. To implement these abilities to mechanical system is difficult because of not enough intelligence. Proposed teleoperation system is designed to progress the human abilities, and moreover, to not disturb the abilities. In this paper, we consider that the discrimination characteristics depend on window positions on GUI display and operator's individuality. Finally, the efficiency of the alert scheme is verified by some experiments.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.589-590
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• 2006

Recently, research for the micro printing technology has begun to get into the spotlight. It is due to the superior price competitiveness to existent semi-conductor process for manufacturing some parts of display unit, electronic paper, RF-ID information device, and so on. This paper present screen printing process not for paper publication but for parts of electronics such as PDP wall, LCD CF, and so on. There are two major issues. The first one is how to get a fine and even line pattern. The other one is how to get the same patterns in large area. In this research, we present the design, equipment, and process control of screen printing in order to overcome these issues.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2003.05a
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• pp.80-87
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• 2003

On this study, an End-Effector for the 300mm wafer transfer robot System is newly suggested. It is a mechanical type with $180^{\circ}$ rotating ranges and is composed of 3-point arms, two plate springs and single-axis DC motor. It is controlled by microchip for the DC motor control. To design, relationships on the gripping force and the wafer deformation is analyzed by FEM analysis. Criterion on gripping force of a suggested End-Effector is confirmed as $255 ~ 274g_f$ from experimental results. From experimented results on repeatable position accuracy, gripping force and gripping cycle times in a wafer cleaning system, we confirmed that the suggested End-Effector is well satisfied on the required performance for 300mm wafer transfer robot system.

• The Journal of Korean Academy of Prosthodontics
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• v.49 no.4
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• pp.316-323
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• 2011

Purpose: The purpose of this study was to investigate the effect of different thread designs on the marginal bone stresses around dental implant. Materials and methods: Standard ITI implant(ITI Dental Implant System; Straumann AG, Waldenburg, Switzerland), 4.1 mm in diameter and 10 mm in length, was selected as control. Test implants of four different thread patterns were created based on control implant, i.e. maintaining all geometrical design of control implant except thread pattern. Four thread designs used in test implants include (1) small V-shape screw (model A), (2) large V-shape screw (model B), (3) buttress screw (model C), and (4) trapezoid screw (model D). Surface area for unit length of implant was 14.4 $mm^2$ (control), 21.7 (small V-shape screw), 20.6 (large V-shape screw), 17.0 (buttress screw) and 28.7 $mm^2$ (trapezoid screw). Finite element models of implant/bone complex were created using an axisymmetric scheme with the use of NISA II/DISPLAY III (Engineering Mechanics Research Corporation, Troy, MI, USA). A load of 100 N applied to the central node on the crown top either in parallel direction or at 30 degree to the implant axis (in order to apply non-axial load to the implant NKTP type 34 element was employed). Quantification and comparison of the peak stress in the marginal bone of each implant model was made using a series of regression analyses based on the stress data calculated at the 5 reference points which were set at 0.2, 0.4, 0.6, 0.8 and 1.0 mm from implant wall on the marginal bone surface. Results: Results showed that although severe stress concentration on the marginal bone cannot be avoided a substantial reduction in the peak stress is achievable using different thread design. The peak marginal bone stresses under vertical loading condition were 7.84, 6.45, 5.96, 6.85, 5.39 MPa for control and model A, B, C and D, respectively. And 29.18, 26.45, 25.12, 27.37, 23.58 MPa when subject to inclined loading. Conclusion: It was concluded that the thread design is an important influential factor to the marginal bone stresses.

• Journal of Biosystems Engineering
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• v.28 no.1
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• pp.53-58
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• 2003

This study was carried out to design, construct, and test a greenhouse monitoring system fur the environment and status of control devices in a greenhouse from a remote site using internet. The measuring items selected out of many environmental factors were temperature, humidity, solar radiation, CO$_2$, SOx, NOx concentration, EC, pH of nutrient solution, the state of control devices, and the image of greenhouse. The developed greenhouse monitoring system was composed of the network system and the measuring module. The network system consists of the three kinds of monitors named the Croup Monitor. the Client Monitor and the Server Monitor. The results of the study are summarized as follows. 1. The measuring module named the House Monitor. which is used to watch the state of the control device and the environment of the greenhouse, was developed to a embedded monitoring module using one chip microprocessor 2. For all measuring items. the House Monitor showed a satisfactory accuracy within the range of ${\pm}$0.3%FS. The House Monitors were connected to the Croup Monitor by communication method of RS-485 type and could operate under power and communication fault condition within 10 hours. The Croup Monitor was developed to receive and display measurement data received from the House Monitors and to control the greenhouse environmental devices. 3. The images of the plants inside greenhouse were captured by PC camera and sent to the Group Monitor. The greenhouse manager was able to monitor the growth state of plants inside greenhouse without visiting individual greenhouses. 4. Remote monitoring the greenhouse environment and status of control devices was implemented in a client/server environment. The client monitor of the greenhouse manager at a remote site or other greenhouse manager was able to monitor the greenhouse environment and the state of control devices from the Server Monitor using internet.

• Journal of Advanced Navigation Technology
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• v.11 no.3
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• pp.319-328
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• 2007

In this paper we implemented the Real Time Contrast Enhancer for image quality enhancement of moving picture. Also we proposed adaptive contrast control method that use mean and variance of input video signal. The Designed the contrast Enhancer is measured in comparison with conventional pictures and interfaced to 30inch TFT LCD TV.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.1297-1300
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• 2005

We propose a new pixel design for active matrix organic light emitting diode (AM-OLED) displays using hydrogenated amorphous silicon thin-film transistors (a-Si:H TFTs). The pixel circuit is composed of five TFTs and one capacitor, and employs only one additional control signal line. It is verified by SPICE simulation results that the proposed pixel compensates the threshold voltage shift of the a-Si:H TFTs and OLED.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2007.04a
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• pp.74-77
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• 2007

In this paper, we propose a system which can display panoramic-stereopic image for tele-operating excavator. the system was implemented by using center-viewpoint corresponding algorithm and image mosaic process. We could obtain remarkable result from the survey among the ex-pert of excavator. We also design a control station with RF transfer module, H.264 codec module and suggested algorithm. Especially, our system shows a superb performance on cubic effect and presence sense of a field of excavating work.