• Journal of the Korea Computer Industry Society
• /
• v.4 no.4
• /
• pp.547-552
• /
• 2003

In this thesis, interference phenomena of bluetooth networks requiring Security were minimized; strengthened security of piconet by assigning an identical PIN code to bluetooth devices, which was establishing a specific piconet during authentication stage. To establish a bluetooth piconet system. an unique ID was assigned to each bluetooth device, communication algorithms having different data formats between devices was designed, and an embedded hardware module using ARM processor and uCOS-II RTOS was implemented. About 30% of CPU efficiency in the module was increased by modifying functions including block parameters to work as nonblocking; by the increased efficiency of total piconet, the module could be used as an access point. The module could transmit maximum 10 frames of image and also audio signal by switching the packet effectively according to channel condition. By above-mentioned process, video, audio, and data could be well transmitted by the bluetooth managing program and the possibility of a commercial remote control system using bluetooth technology was suggested.

• Journal of Korea Multimedia Society
• /
• v.8 no.1
• /
• pp.79-87
• /
• 2005

In e-commerce applications, a public key cryptosystem is an important and indispensible element for the basic security operations such as authentication, digital signaturing, and key distribution. In wired network environments, the public key infrastructure certificate, which is based on X.509 specification, has been widely used. On the other hand, it still remains difficult to use the certificate information in wireless network environments due to the inherent limitations of the hand-held devices such as low computational power and short battery life. In this paper, we facilitate a codesign approach by implementing a software public-key cryptosystem and classifying its internal computation overheads quantitatively using a software profiling technique. Moreover, we propose a method to analyze the profiled data and apply it to the problem of software/hardware partitioning in a codesign approach. As an illustrative example, we analyze the computational overheads of an EC-Elfagamal application and examine a critical computational path.

• Journal of KIISE:Computing Practices and Letters
• /
• v.13 no.3
• /
• pp.141-152
• /
• 2007

In this paper, we present a network-oriented lightweight real-time system, which is composed of an event-driven operating system called the Embedded Lightweight Operating System (ELOS) and a generic multi hop ad hoc routing protocol suite. In the ELOS, a conditional preemptive FCFS scheduling method with a guaranteed time slot is designed for efficient real-time processing. For more elaborate configurations, we reinforce fault tolerance by supplementing semi-auto configuration using wireless agent nodes. The developed hardware platform is also introduced, which is a scalable prototype constructed using off-the-shelf components. In addition, in order to evaluate the performance of the proposed system, we developed a ubiquitous network test-bed on which several experiments with respect to various environments are conducted. The results show that the ELOS is considerably favorable for tiny ubiquitous networked systems with real-time constraints.

• The Journal of the Korea Contents Association
• /
• v.13 no.8
• /
• pp.458-465
• /
• 2013

The purpose of this research is possible to reduce cost of management and maintenance to realization of smartphone and using data server network technology instead of GPS. Former wireless bus information system was focused on supply side management structure and national spread thus it needs to establish GPS terminal, Windows CE, Window XP embedded and LCD panels which provide only one way communication of information of public traffic information. Therefore, former system management and maintenance cost are very expansive. This research is not use GPS terminal and other hardware equipment but design and realization using smartphone and data network server. This system also provides low cost of management and maintenance. It is not only service downtown area but also out of town and small and medium-sized cities. This system functionally gets a satisfying result user convenience and satisfaction using function of set-up route map, real-time display, and running statically analysis.

• Journal of Satellite, Information and Communications
• /
• v.11 no.3
• /
• pp.58-64
• /
• 2016

This paper proposes the efficient transmit antenna selection (TAS) scheme considering trade-off between the performance and the complexity in massive MIMO system. The massive MIMO system is a core technology to achieve performance objectives for 5 generation wireless communication. It achieve high spectral efficiency, a reliability, and a diversity gain. However many RF chains required by massive transmit antennas equipped in a base station create the problem such as high hardware cost and complexity. Therefor we investigates the transmit antenna selection scheme, in which the number of RF chains of BS is reduced, and the trade-off between the performance and the complexity is considered for proposed scheme. And, the spectral efficiency and complexity are analysed by transmit antenna selection schemes.

• The Journal of the Korea Contents Association
• /
• v.7 no.2
• /
• pp.92-99
• /
• 2007

This paper presented a low power design of a 32bit block cypher processor reduced from the original 128bit architecture. The primary purpose of this research is to evaluate physical implementation results rather than theoretical aspects. The data path and diffusion function of the processor were reduced to accommodate the smaller hardware size. As a running example demonstrating the design approach, we employed a modified ARIA algorithm having four S-boxes. The proposed 32bit ARIA processor comprises 13,893 gates which is 68.25% smaller than the original 128bit structure. The design was synthesized and verified based on the standard cell library of the MagnaChip's 0.35um CMOS Process. A transistor level power simulation shows that the power consumption of the proposed processor reduced to 61.4mW, which is 9.7% of the original 128bit design. The low power design of the block cypher Processor would be essential for improving security of battery-less wireless sensor networks or RFID.

• Journal of Multimedia Information System
• /
• v.4 no.4
• /
• pp.195-204
• /
• 2017

Mobile robots are used for years as a valuable research and educational tool in form of available open-platform designs and Do-It-Yourself kits. Rapid development and costs reduction of Unmanned Air Vehicles (UAV) and ground based mobile robots in recent years allowed researchers to utilize them as an affordable research platform. Despite of recent developments in the area of ground and airborne robotics, only few examples of Unmanned Surface Vehicle (USV) platforms targeted for research purposes can be found. Aim of this paper is to present the development of open-design USV drone with integrated multi-level control hardware architecture. Proposed catamaran - type water surface drone enables direct control over wireless radio link, separate development of algorithms for optimal propulsion control, navigation and communication with the ground-based control station. Whole design is highly modular, where each component can be replaced or modified according to desired task, payload or environmental conditions. Developed USV is planned to be utilized as a part of the system for detection and identification of marine and lake waste. Cameras mounted to the USV would record sea or lake surfaces, and recorded video sequences and images would be processed by state-of-the-art computer vision and machine learning algorithms in order to identify and classify marine and lake waste.

• Journal of Advanced Navigation Technology
• /
• v.24 no.2
• /
• pp.134-141
• /
• 2020

Telemetry system is a communication system that measures and transmits various signals in the aircraft to the ground for collecting and monitoring flight data during the development of unmanned air vehicle and satellite launch vehicles. With the recent development of wireless communication technology, it is becoming important to apply encryption of telemetry system to prepare with security threats that may occur during flight data transmission. In this paper, we suggested and implemented the application method of ARIA-256, Korean standard encryption algorithm, to apply encryption to telemetry system. In consideration of the block error propagation and the telemetry frame characteristics, frame is encrypted using the CTR mode and can apply the Reed-solomon codes recommended by CCSDS. ARIA algorithm and cipher frame are implemented in FPGA, and simulation and hardware verification system confirmed continuous frames encryption.

• Journal of Satellite, Information and Communications
• /
• v.11 no.4
• /
• pp.102-106
• /
• 2016

With the popularity of smart phones and the help of high-speed wireless communication technology, high-quality multimedia contents have become common in mobile devices. Especially, the release of Oculus Rift opens a new era of virtual reality technology in consumer market. At the same time, 3D audio technology which is currently used to make computer games more realistic will soon be applied to the next generation of mobile phone and expected to offer a more expansive experience than its visual counterpart. This paper surveys concepts, algorithms, and systems for modeling 3D sound virtual environment applications. To do this, we first introduce an important design principle for audio rendering based on physics-based geometric algorithms and multichannel technologies, and introduce an audio rendering pipeline to a scene graph-based virtual reality system and a hardware architecture to model sound propagation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2007.06a
• /
• pp.347-350
• /
• 2007

An ECG analysis with activity monitoring for the home care of elderly persons or patients, using wireless sensors technology was design and implemented. The changes in heart rate occur before, during, or following behavior such as posture changes, walking and running. Therefore, it is often very important to record heart rate along with posture and behavior, for continuously monitoring a patient's cardiovascular regulatory system during their daily life activity. The ECG and accelerometer data are continuously recorded with a built-in automatic alarm detection system, for giving early alarm signals even if the patient is unconscious or unaware of cardiac arrhythmias. The hardware allows data to be transmitted wirelessly from on-body sensors to a base station attached to server PC using IEEE802.15.4. If any abnormality un at server then the alarm condition sends to the doctor' PDA (Personal Digital Assistant).