• 제어로봇시스템학회:학술대회논문집
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• 1990.10b
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• pp.1135-1138
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• 1990

In this paper, we study the pole assignment problem for three-dimensional systems. We transform the denominator of transfer functions of the closed-loop system into the product of three stable one-dimensional polynomials, by performing two-dimensional dynamical feedback and input transformation on the given three-dimensional systems. In the next, we consider the possibility that these two-dimensional dynamic compensators are realizable, thoroughly, and propose the counter-measure in case that they are not realizable. And, we obtain the conditions so that the closed-loop three-dimensional systems are stable. Moreover, we calculate the dynamical dimension which is necessary for the pole assigntmnt, and suggest the pole assignmnt method with the lowest dynamical dimnsion.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2747-2752
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• 2003

This paper has develops a new framework to understand the human’s driving maneuver based on the expression as HDS focusing on the driver’s stopping maneuver. The driving data has been collected by using the three-dimensional driving simulator based on CAVE, which provides three-dimensional visual information. In our modeling, the relationship between the measured information such as distance to the stop line, its first and second derivatives and the braking amount has been expressed by the PWPS model, which is a class of HDS. The key idea to solve the identification problem was to formulate the problem as the MILP with replacing the switching conditions by binary variables. From the obtained results, it is found that the driver appropriately switches the ‘control law’ according to the following scenario: At the beginning of the stopping behavior (just after finding the stopping point), the driver decelerate the vehicle based on the acceleration information, and then switch to the control law based on the distance to the stop line.

• Journal of information and communication convergence engineering
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• v.16 no.3
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• pp.153-159
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• 2018

In this paper, we present a three-dimensional (3D) optical encryption technique for quick response (QR) code using computational synthesized integral imaging, computational volumetric reconstruction, and double random phase encryption. Two-dimensional (2D) QR code has many advantages, such as enormous storage capacity and high reading speed. However, it does not protect primary information. Therefore, we present 3D optical encryption of QR code using double random phase encryption (DRPE) and an integral imaging technique for security enhancement. We divide 2D QR code into four parts with different depths. Then, 2D elemental images for each part of 2D QR code are generated by computer synthesized integral imaging. Generated 2D elemental images are encrypted using DRPE, and our method increases the level of security. To validate our method, we report simulations of 3D optical encryption of QR code. In addition, we calculated the peak side-lobe ratio (PSR) for performance evaluation.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.15 no.4
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• pp.74-82
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• 2006

This paper describes the steady flow characteristics due to PDA and tumble control valve in combustion chamber. We also investigated the flow inclination angle defined as the inverse tangent of non-dimensional rig tumble(NRT) devided by non-dimensional rig swirl(NRS) to find dominant flow direction. So we adapted two different types of PDA valve(port deactivation valve) to strengthen a swirl flow. The in-cylinder swirl flow different tendency between with/without PDA valve. It might be thought to be affected by swirl flow. We could find that tumble ratio and swirl ratio is different by PDA valve. The comparison are taked account of the swirl, the tumble ratio comparison in same mass flow rate. As a result, PDA valve is better than tumble control valve both in steady flow condition and swirl, tumble ratio. The data from present study are available for design of engine as the basic data.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.94.5-94
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• 2001

Unrestricted measurement method of three-dimensional walking distance utilizing body acceleration and terrestrial magnetism is discussed. The three-dimensional walking distance is derived by the integration of the three dimensional acceleration of foot during swing phase. Since the sensor system attached on the foot rotates during swing phase, the acceleration data measured on the foot include acceleration of gravity which causes inaccurate calculation of the velocity and the distance. Three gyros are used to compensate the rotation of the sensor system. Moreover, one geomagnetic sensor is employed to derive the heading direction of the subject Healthy volunteers performed ...

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.704-706
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• 1991

In CAD/CAM system, many efforts are made to automate the converting process from drawling information to manufacturing Information. The most difficult step In this procedure is utilizing 2 dimensional drawing information In order to formulate 3 dimensional w&ling information. This paper emphasizes to mWe automatically series of convertirg steps which provide 3 dimensional wire frame, surface and solid modeling using feature recognition rules. With the standardization of design process and the recognition rule as preceding steps, it shows a good application tool to interface the design and manufacturing procedures in PC-Level CAD/CAM system.

• 제어로봇시스템학회:학술대회논문집
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• 1995.10a
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• pp.295-298
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• 1995

In this paper, one simple technique to calibrate the system setting of the three-dimensional measuring system is presented. Due to this technique, the three-dimensional shape of the huge structures and the buildings can be readily obtained. This technique is applied to the three-dimensional landscape simulation. Two examples are shown in this paper.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.407-408
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• 2006

Dimensional precision is a critical parameter in net shape processing of ferrous PM components. Sinter-hardening alloys undergo a transformation from austenite to martensite. Martensite formation expands the sintered compact, while tempering hardened steels results in shrinkage. In addition, martensitic regions with high Cu and C contents may contain large amounts of retained austenite. The presence of martensite and retained austenite, in addition to the tempering step, all play a role in the final dimensions of a component. This paper investigates the dimensional and microstructural changes to two sinter-hardening grades through different post-sintering thermal treatments.

• The Journal of Korean Academy of Prosthodontics
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• v.36 no.3
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• pp.496-505
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• 1998

The purpose of this study was to evalute the effect of immersion disinfection on the dimensional stability of rubber impression materials. The metallic master model was made in order to simulate the intraoral arch form. Impressions were made from four impression materials (Exaflex, Extrude, Reprosil, Impregum-F) and immersed in three disinfectant solutions (Wydex, Vi-Pon, Potadine). Casts from the impressions were measured according to the interpreparation distance. The A-B and The B-D abutment distance were compared with the control group and disinfected groups. The results were as follows; 1. The measurements of the stone cast increased relative to the master model and there was a significant difference (P<0.05). 2. The relative dimensional change of the stone cast as compared with master model ranged from 0.10% to 0.56% in the A-B distance and ranged from 0.04% to 0.27% in the B-D distance. 3. The dimensional change of the disinfected groups as compared with the control group was significantly different in the three impression materials except for Impregum-F (P<0.05). 4. The relative dimensional change of the disinfected groups compared with the control group ranged from 0% to 0.20% in the A-B distance and ranged from -0.09% to 0.11% in the B-D distance. These results suggest that immersion disinfection of rubber impression materials by chemical disinfectants causes very small dimensional change and the change is clinically acceptable for prothesis fabrication

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.1
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• pp.21-27
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• 2002

Inspection and shape measurement of three-dimensional objects are widely needed in industries for quality monitoring and control. A number of visual or optical technologies have been successfully applied to measure three-dimensional surfaces. However, those conventional visual or optical methods have inherent shortcomings such as occlusion and variant surface reflection. X-ray vision system can be a good solution to these conventional problems, since we can extract the volume information including both the surface geometry and the inner structure of any objects. In the x-ray system, the surface condition of an object, whether it is lambertian or specular, does not affect the inherent characteristics of its x-ray images. In this paper, we propose a three-dimensional x-ray imaging method to reconstruct a three dimensional structure of an object out of two dimensional x-ray image sets. To achieve this by the proposed method, two or more x-ray images projected from different views are needed. Once these images are acquired, the simultaneous algebraic reconstruction technique(SART) is usually utilized. Since the existing SART algorithms have several shortcomings such as low performance in convergence and different convergence within the reconstruction volume of interest, an advanced SART algorithm named as USART(uniform SART) is proposed to avoid such shortcomings and improve the reconstruction performance. Because, each voxel within the volume is equally weighted to update instantaneous value of its internal density, it can achieve uniform convergence property of the reconstructed volume. The algorithm is simulated on various shapes of objects such as a pyramid, a hemisphere and a BGA model. Based on simulation results the performance of the proposed method is compared with that of the conventional SART method.