• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.13 no.4
• /
• pp.727-736
• /
• 2009

In this paper, the $arccos(cos^{-1})$ arithmetic unit for mobile graphics accelerator is designed. The mobile vector graphics applications need tight area, execution time, power dissipation, and accuracy constraints compared to desktop PC applications. The designed processor adopts 2nd-order polynomial approximation scheme based on IEEE floating point data format to satisfy speed and accuracy conditions and reduces area via hardware sharing structure. The arccosine processor consists of 15,280 gates and its estimated operating frequency is about 125Mhz at operating condition of $0.35{\mu}m$ CMOS technology. Because the processor can execute arccosine function within 7 clock cycles, it has about 17 MOPS(million arccos operations per second) execution rate and can be applicable to mobile OpenVG processor. And because of its flexible architecture, it can be applicable to the various transcendental functions such as exponential, trigonometric and logarithmic functions via replacement of ROM and minor hardware modification.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.42 no.2
• /
• pp.307-315
• /
• 2017

Random number generator(RNG) is essential in cryptographic applications. As recently a system using small devices such as IoT, Sensor Network, SmartHome appears, the lightweight cryptography suitable for this system is being developed. However due to resource limitations and difficulties in collecting the entropy, RNG designed for the desktop computer are hardly applicable to lightweight environment. In this paper, we propose a lightweight RNG to produce cryptographically strong random number using sensors. Our design uses a Hankel matrix, block cipher as the structure and sensors values as noise source. Futhermore, we implement the lightweight RNG in Arduino that is one of the most popular lightweight devices and estimate the entropy values of sensors and random number to demonstrate the effectiveness and the security of our design.

• Journal of the Korea Computer Graphics Society
• /
• v.13 no.2
• /
• pp.55-60
• /
• 2007

Diminished reality (DR) is a technique that provide a visual convenience by virtually hiding an object. Most of existing DR systems have been implemented based on HMDs or desktop displays. However, Here has been no report on the development of DR system based on projection displays due to technical difficulty in spite of its superiority in the aspect of human factor to conventional displays. Rapid advances of projection displays and projection-based vision technologies motivated us to develop a projection-based DR system. As the first attempt, this paper proposes a projection-based diminished reality system using an image completion technique. Its usefulness is demonstrated through experiments and its potential applications are discussed.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.41 no.6
• /
• pp.91-98
• /
• 2004

This paper proposes a PCB plane model for generic SPICE circuit simulators. The proposed model reflects two frequency-dependent losses, namely skin and dielectric losses. After power/ground plane pair is divided into arrays of unit-cells, each unit-cell is modeled using a transmission line and two loss models. The loss model is composed of a resistor for DC loss, series HL ladder circuit for skin loss and series RC ladder circuit for dielectric loss. To verify the validity of the proposed model, it is compared with SPICE ac analysis using frequency-dependent resistors. Also, we show that the estimation results using the proposed model have a good correlation with that of VNA measurement for the typical PCB stack-up structure of general desktop PCs. With the proposed model, not only ac analysis but also transient analysis can be easily done for circuits including various non-linear/linear devices since the model consists of passive elements onl.

• Proceedings of the Korean Society of Medical Physics Conference
• /
• 2002.09a
• /
• pp.68-73
• /
• 2002

In standard teletherapy, a treatment plan is generated with the aid of a treatment planning system, but it is common to perform an independent monitor unit verification calculation (MUVC). In exact analogy, we propose and demonstrate that a simple and accurate MUVC in Intensity Modulated Radiotherapy (IMRT) is possible. We introduce a concept of Modified Clarkson Integration (MCI). In MCI, we exploit the rotational symmetry of scattering to simplify the dose calculation. For dose calculation along a central axis (CAX), we first replace the incident IMRT fluence by an azimuthally averaged fluence. Second, the Clarkson Integration is carried over annular sectors instead of over pie sectors. We wrote a computer code, implementing the MCI technique, in order to perform a MUVC for IMRT purposes. We applied the code to IMRT plans generated by CORVUS. The input to the code consists of CORVUS plan data (e.g., DMLC files, jaw settings, MU for each IMRT field, depth to isocenter for each IMRT field), and the output is dose contribution by individual IMRT field to the isocenter. The code uses measured beam data for Sc, Sp, TPR, (D/Mu)$\_$ref/ and includes effects from MLC transmission, and radiation field offset. On a 266 MHZ desktop computer, the code takes less than 15 sec to calculate a dose. The doses calculated with MCI algorithm agreed within +/- 3% with the doses calculated by CORVUS, which uses a 1cm x 1cm pencil beam in dose calculation. In the present version of MCI, skin contour variations and inhomogeneities were neglected.

• The Journal of Korean Association of Computer Education
• /
• v.17 no.6
• /
• pp.9-20
• /
• 2014

With the change of global awareness of Computing education and introspection about Computer education focused on ICT literacy, efforts are being made to reflect computational thinking in the new curriculum. But if computational thinking would be possible at school, it require tremendous cost to prepare computers for school. In this study, we investigate potentiality and constraints of the one board computer to teach computational thinking in school. We study fundamental performance, application of physical computing and programming education, maintenance of the computers, power consumption of the one board computers which is raspberry pi, beagle bone black, and pcduino3. The result of the study show that one board computer can substitute desktop of the school unless tasks related to require massive data storage and processing. We draw a conclusion that Pcduino3 is well-suited for computational thinking education.

• Journal of Digital Convergence
• /
• v.12 no.2
• /
• pp.277-283
• /
• 2014

Recently, various cloud service has been being provided on mobile devices as well as desktop pc and server computer. Also, Smartphone users are very rapidly increasing, and they are using it for enjoying various services(cloud service, game, banking service, mobile office, etc.). So, research to utilize resources on mobile device has been conducted. In this paper, We have suggested efficient method of cloud resource management by using information of available physical resources(CPU, memory, storage, etc.) between mobile devices, and information of physical resource in mobile device. Suggested technology is possible to guarantee real-time process and efficiently manage resources.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.52 no.3
• /
• pp.136-144
• /
• 2015

The EEG system can be classified as a wired or wireless device. Each device used for the medical or entertainment purposes. The collected EEG signals from sensor are analyzed using feature extractions. A wireless EEG system provides good portability and convenience, however, it requires a mobile system that has heavy computing power. In this paper a single board system is proposed to handle EEG signal processing for BCI applications. Unfortunately, the computing power of a single board system is limited unlike general desktop systems. Thus, parallel approach using multiple single board systems is investigated. The parallel EEG signal processing system that we built demonstrates superlinear speedup for an EEG signal processing algorithm.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.27 no.9
• /
• pp.844-853
• /
• 2016

Generally, the compromising electromagnetic emanations are generated from LCD(Liquid Crystal Display) monitor which is typical output component of computer. Because display information transmitted to LCD monitor is included in these emanations, there are risks about information leakage of monitor by eavesdropping of leaked signal. So, analysis about possibility of information leakage is necessary because electromagnetic security through the electromagnetic emanations is being at issue. In this paper, the possibility of display information leakage are demonstrated by analyzing the electromagnetic emanations from desktop and laptop monitors. The characteristics of leaked signal from LCD monitor is verified by analyzing display mechanism and the electromagnetic emanations are measured in the long distance by eavesdropping experiment. Also, threat of information leakage is confirmed by recovering display information with several signal processing technique and comprising with target display.

• Journal of Korea Multimedia Society
• /
• v.9 no.10
• /
• pp.1361-1370
• /
• 2006

Recently fast innovation of Internet technology causes lot of application to change into web application and requirement for the inter-operable communication among various systems are increased rapidly. These trends are part of changes which is caused by ubiquitous world and it is just beginning of huge waves that is required to fit and change under the ubiquitous environments. This thesis is focused on the Design and Implementation of Layer Structured Components which can be interfaced effectively for the Material Management System under the Heterogeneous Client Server Environments. The key points to do that kinds of affairs are using XML web services that can communicate thru systems and also using independent layered components for the enforcement of reusability and inter-operability. For the various type of testing of implementation, we used RFID System, PDA, Desktop Systems and confirmed the normal operation without concerning the type of client system and platforms. The Components proposed in this thesis could be reused effectively in case of developing similar applications.