• The KIPS Transactions:PartD
• /
• v.10D no.2
• /
• pp.301-308
• /
• 2003

In this paper, we propose a prototype system of digital data broadcasting system based on the ATSC data broadcasting standard. This prototype system uses data piping as a mechanism for delivery of arbitrary user-defined data inserted directly into the payload part of the MPEG-2 Transport Stream packets. This data type includes URL or HTML content. After the contents are inserted into the MPEG-2 Transport Stream, they can be delivered through the broadcasting to the DTV set-top receiver. The 75 packets received in real-time during the TV broadcast are used to start display or switch content. This prototype system describes how to achieve common design goals and integrating digital TV and web pages based on the ATSC data broadcasting standard. The prototype system can be used to display digital data contents - HTML, images-on existing TV or digital TV set-tops.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1996.04a
• /
• pp.472-477
• /
• 1996

This paper presents a new approachtothe design of adaptive control system using DSPs(TMS320C30) for robotic manipulators to achieve trajectory tracking by the joint angles. Digital signal processors are used in implementing real time adaptive control algorithms to provide an enhanced motion control for robotic manipulators. In the proposed control scheme, adaptation laws are derived from the improved Lyapunov second stability analysis method based on the adaptive model reference control theory. The adaptive controller consists of an adaaptive feedforward controller, feedback controller, and PID type time-varying auxillary control elements. The prpposed adaptive control scheme is simple in structure, fast in computation, and suitable for implementation of real-time control. Moreover, this scheme does not require an accurate dynamic modeling, nor values of manipulator parameters and payload. Performance of the adaptive controller is illustrated by simulation and experimental results for a SCARA robot.

• Journal of Mechanical Science and Technology
• /
• v.15 no.3
• /
• pp.339-350
• /
• 2001

To overcome problems in tracking error related to the unmodeled dynamics in the high speed operation of industrial robots, many researchers have used sliding mode control, which is robust against parameter variations and payload changes. However, these algorithms cannot reduce the inherent chattering which is caused by excessive switching inputs around the sliding surface. This study proposes a fuzzy-sliding mode control algorithm to reduce the chattering of the sliding mode control by fuzzy rules within a pre-determined dead zone. Trajectory tracking simulations and experiments show that chattering can be reduced prominently by the fuzzy-sliding mode control algorithm compared to a sliding mode control with two dead zones, and the proposed control algorithm is robust to changes in payload. The proposed control algorithm is implemented to the SCARA (selected compliance articulated robot assembly) robot using a DSP (digital signal processor) for high speed calculations.

• International Journal of Computer Science & Network Security
• /
• v.23 no.7
• /
• pp.141-148
• /
• 2023

During the medical data transmissions, the protection of the patient information is vital. Hence this work proposes a spatial domain watermarking algorithm that enhances the data payload (capacity) while maintaining the authentication and data hiding. The code is distributed at every pixel of the digital image and not only in the regions of non-interest pixels. But the image details are still preserved. The performance of the proposed algorithm is evaluated using several performance measures such as the mean square error (MSE), the mean absolute error (MAE), and the peak signal to noise Ratio (PSNR), the universal image quality index (UIQI) and the structural similarity index (SSIM).

• Journal of Satellite, Information and Communications
• /
• v.11 no.3
• /
• pp.104-109
• /
• 2016

A technology of GEO satellite communications starts from Koreasat program in Korea. Payload equipment of EQM Ku and Ka band transponders had been developed and space-qualified Ka band payload in COMS was successfully launched in June, 2010. For the purpose of military communications, Dehop-Rehop transponder was developed in Koreasat5 as ANASIS system and DAT(Digital Active Transponder) and DCAMP(Digital Channel AMPlifier) transponders are now under development. In this paper, from the study of military satellite communications trend, a direction of military communication satellite is suggested based on the current GEO SATCOM technologies in Korea. Considering the limit of frequency resources, a technology of battlefield adaptive transponder with medium capacity against high moveable jamming tactics would be efficient for the future military SATCOM system. Mid-sized military satellites with frequency hopping and mid-capacity transponders can be a solution of vitalizing the GEO satellite programs.

• Proceedings of the KSRS Conference
• /
• 1999.11a
• /
• pp.349-354
• /
• 1999

Electro-Optical Camera (EOC) is the main payload of the KOMPSAT-1 satellite to perform the mission of cartography that builds up a digital map of Korean territory including a digital terrain elevation map. This paper discusses the issues of the digital image simulation of EOC for the generation of EOC simulated scene as taken by EOC at 685km altitude on orbit. For the purpose, simulation work has been performed with the sensor models of EOC and the satellite platform motions models through image chain analysis from the illumination source (Sun) to a simulated image output in digital number. MODTRAN fur radiance calculation, MTF models of optics, detector and motions of EOC for system point spread function (PSF), and signal chain equations for digital number output are described. Several noise models of EOC are also considered. The final output is the EOC simulated image in digital number. The simulation technique can be used in several phase of a spaceborne electro-optical system development project, feasibility study phase, design, manufacturing, test phases, ground image processing phases, and so on.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.13 no.3
• /
• pp.503-508
• /
• 2018

This study describes the design and implementation of EGSE for Digital Satellite Communication. The EGSE is a equipment that evaluates digital satellite communication and requires precise and accurate measurement. EGSE consists of a PLDIU and IIU(Instrument Interface Unit), Up/Down converter for SHF band, Modems to verify the Digital Satellite Communication. The EGSE was used for performance verification and space environment test such as thermal vacuum after developing digital satellite communication.

• Journal of Internet Computing and Services
• /
• v.17 no.4
• /
• pp.43-50
• /
• 2016

In this paper, we propose the protocol of Ethernet that will receive a popular interesting in the automotive intelligent network, it also attempts to implementation and verification through simulation and experiments to propose a fault tolerance algorithm when the data transfer on it. It has proven the usefulness of the system in order to apply toward an existing automotive communication system. In the case of actual real-time data for automotive industry, we generated a randomly-generated data which is the set of payload into a standard format to complete the experiment. Among the implemented existing algorithms performance, we confirmed the effectiveness of all range from a single data to mixed (Hybrid-type) data, to verify the proposed algorithm.

• 제어로봇시스템학회:학술대회논문집
• /
• 2004.08a
• /
• pp.741-746
• /
• 2004

We propose a new technique to the design and real-time implementation of an adaptive controller for robotic manipulator based on digital signal processors in this paper. The Texas Instruments DSPs(TMS320C80) chips are used in implementing real-time adaptive control algorithms to provide enhanced motion control performance for dual-arm robotic manipulators. In the proposed scheme, adaptation laws are derived from model reference adaptive control principle based on the improved direct Lyapunov method. The proposed adaptive controller consists of an adaptive feed-forward and feedback controller and time-varying auxiliary controller elements. The proposed control scheme is simple in structure, fast in computation, and suitable for real-time control. Moreover, this scheme does not require any accurate dynamic modeling, nor values of manipulator parameters and payload. Performance of the proposed adaptive controller is illustrated by simulation and experimental results for a dual arm robot consisting of two 4-d.o.f. robots at the joint space and cartesian space.

• 제어로봇시스템학회:학술대회논문집
• /
• 1996.10b
• /
• pp.65-68
• /
• 1996

Robotic manipulators have become increasingly important in the field of flexible automation. High speed and high-precision trajectory tracking are indispensable capabilities for their versatile application. The need to meet demanding control requirement in increasingly complex dynamical control systems under significant uncertainties, leads toward design of intelligent manipulation robots. This paper presents a new approach to the design of neural control system using digital signal processors in order to improve the precision and robustness. The TMS32OC31 is used in implementing real time neural control to provide an enhanced motion control for robotic manipulators. In this control scheme, the networks introduced are neural nets with dynamic neurons, whose dynamics are distributed over all the, network nodes. The nets are trained by the distributed dynamic back propagation algorithm. The proposed neural network control scheme is simple in structure, fast in computation, and suitable for implementation of real-time, control. Performance of the neural controller is illustrated by simulation and experimental results for a SCARA robot.