• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.5
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• pp.927-934
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• 2019

Recently, mobile devices have evolved into small computers with various functions according to user requirements. Careful attention must be paid to the design of the power supply network for the stable operation of the application processor (AP), the wireless communication modem, the high performance camera, and the various interfaces of the mobile device to implement various functions of the mobile device. In this paper, we analyzed and verified the method of optimizing the design parameters such as the position, capacity, and number of decoupling capacitors to meet the target impedance required by the driver IC chip to ensure the stability of the power supply network of mobile devices that should be designed as wiring type due to mounting density limitation. The proposed wired power supply network design method can be applied to various applications including high-speed signal transmission line in addition to mobile applications.

• Journal of Korea Society of Digital Industry and Information Management
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• v.5 no.4
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• pp.77-85
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• 2009

In this paper, the implementation of creative engineering robot with MCU platform is described. This robot, as a platform of robot system to be used as creative engineering education, has to satisfy restrictions in many aspects in order to study algorithm and apply for the processor based function and pattern recognition application. Considering many restrictions of the mobile platform for creative robot system, we made this robot autonomous by using efficiently the LINUX embedded system. And we choose Marvell Monahan processor(PXA320) as MCU flatform, and used CentOS5.2 as an embedded OS that has the function of robustness and optimality. For flexibility and modularity, the platform has expansion ports. The results of experiment are described to show the pattern matching of creative engineering mobile robot with LINUX programming environments.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.4
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• pp.706-714
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• 2008

In this paper, we suggest a practical and flexible system architecture for JTAG(Joint Test Action Group) protection of application processors. From the view point of security, the debugging function through JTAG port can be abused by malicious users, so the internal structures and important information of application processors, and the sensitive information of devices connected to an application processor can be leak. This paper suggests a system architecture that disables computing power of computers used to attack processors to reveal important information. For this, a user authentication method is used to improve security strength by checking the integrity of boot code that is stored at boot memory, on booting time. Moreover for user authorization, we share hard wired secret key cryptography modules designed for functional operation instead of hardwired public key cryptography modules designed for only JTAG protection; this methodology allows developers to design application processors in a cost and power effective way. Our experiment shows that the security strength can be improved up to $2^{160}{\times}0.6$second when using 160-bit secure hash algorithm.

• The Journal of Korea Robotics Society
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• v.14 no.4
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• pp.293-300
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• 2019

In this paper, an Embedded solution for fast navigation and precise positioning of mobile robots by floor features is introduced. Most of navigation systems tend to require high-performance computing unit and high quality sensor data. They can produce high accuracy navigation systems but have limited application due to their high cost. The introduced navigation system is designed to be a low cost solution for a wide range of applications such as toys, mobile service robots and education. The key design idea of the system is a simple localization approach using line features of the floor and delayed localization strategy using topological map. It differs from typical navigation approaches which usually use Simultaneous Localization and Mapping (SLAM) technique with high latency localization. This navigation system is implemented on single board Raspberry Pi B+ computer which has 1.4 GHz processor and Redone mobile robot which has maximum speed of 1.1 m/s.

• Journal of Korea Society of Industrial Information Systems
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• v.13 no.5
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• pp.117-123
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• 2008

In this paper, we develop MPEG-4 AAC streaming player on embedded Linux processor such as mobile terminals. Moreover we show the experimental results that the player preforms the decoding processes of MPEG-4 AAC data effectively. MPEG-4 AAC technology supports a wide range encoding rates and high sound quality so it is appropriate to adopt various applications. In particular, the need in the development of the application of audio data increases according to significantly increase in devices used in mobile environments, such as cell phones and PDAs. In this environment, it is necessary to optimize the decoding processes to the ability of the terminal hardware in order to play audio data without delays. We also implement the decoding module to optimize the processor capabilities and make the player to decode and play streaming audio data from streaming server.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.4
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• pp.63-72
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• 2007

In this paper, we propose a novel reconfigurable coprocessor for multimedia mobile terminals. Because most of multimedia operations require fast operations of large amount of data in the limited clock frequency, it is necessary to enhance the performance of the embedded processor that is widely used in current multimedia mobile terminals. Therefore, we proposed and have designed the coprocessor which had the ability of fast operations of multimedia data. The proposed coprocessor was not only reconfigurable, but also flexible and expandable. The proposed coprocessor has been designed by using VHDL and compared with previous reconfigurable coprocessors and a commercial embedded processor in architecture and speed. As a result of the architectural comparison, the proposed coprocessor had better structure in terms of hardware size and flexibility. Also, the simulation results of DCT application showed that the proposed coprocessor was 26 times faster than a commercial ARM processor and 11 times faster than the ARM processor with fast DCT core.

• The KIPS Transactions:PartD
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• v.11D no.1
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• pp.1-10
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• 2004

According to the evolution of the Internet and wireless mobile communication technology, techniques for mobile databases and wireless web services are issued for them. Recently, these changes of geographic application environment increase the needs for development of new GIS database system for the web services and embedded system. In this paper, we proposed a Jana-based web database systems that can be used in the web-based GIS and mobile databases. This proposed system has been implemented using the Java to be displayed easily into the portable computing devices and Java-based web application servers and using OpenGIS for web data interoperability. Also, it can efficiently process web-based spatial queries by developing a spatial query processor including schema manager and a spatial object storage module.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.5
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• pp.1058-1067
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• 2004

Java virtual machine provides code compactness, simple execution engines, and platform-independence which are important features for small devices such as mobile or embedded device, but it has a big problem, such as low throughput due to stack-oriented operation. In this paper hardware lava accelerator targeted for mobile or embedded application is designed to eliminate the slow speed problem of lava virtual machine. The designed lava accelerator can execute 81 instructions of Java virtual machine(JVM)'s opcodes and be used as Java coprocessor of conventional 32-bit RISC processor with efficient coprocessor interface and instruction buffer. It consists of about 14,300 gates and its maximum operating frequency is about 50 Mhz under 0.35um CMOS technology.

• The Journal of the Korea Contents Association
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• v.8 no.12
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• pp.63-71
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• 2008

Recently, together with a new advent of embedded processor developed to support specific application area, and it evolution, a new study of software development to support the embedded processor and its commercial use has been revitalized. Specially, In a mobile device that is built-in embedded processor, software management is as important as hardware management for the limited power/energy. In this paper, we suggest that the code generation technique considering the energy dissipation through the verified retargetable compiler backend tool, EXPRESSION. For this goals, we describes the efficient code generation patterns and showed the variable performance results.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.2
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• pp.391-394
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• 2006

The paper deals with the experimental GNSS receiver built at the Czech Technical University for experiments with the real GNSS signal. The receiver is based on software defined radio architecture. Receiver consists of the RF front end and a digital processor based on programmable logic. Receiver RF front end supports GPS L1, L2, L5, WAAS/EGNOS, GALILEO L1, E5A, E5B signals as well as GLONASS L1 and L2 signals. The digital processor is based on Field Programmable Gate Array (FPGA) which supports embedded processor. The receiver is used for various experiments with the GNSS signals like GPS L1/EGNOS receiver, GLONASS receiver and investigation of the EGNOS signal availability for a land mobile user. On the base of experimental GNSS receiver the GPS L1, L2, EGNOS receiver for railway application was designed. The experimental receiver is also used in GNSS monitoring station, which is independent monitoring facility providing also raw monitoring data of the GPS, EGNOS and Galileo systems via internet.