• Journal of KIISE:Computing Practices and Letters
• /
• v.7 no.6
• /
• pp.696-702
• /
• 2001

In this paper, we design IDEA cipher algorithm which is cryptographically superior to DES. To improve the encryption throughput, we propose an efficient design methodology for high-speed implementation of multiplicative inverse modulo $2^{15}$+1 which requires the most computing powers in IDEA. The efficient hardware architecture for the multiplicative inverse in derived from applying of Fermat's Theorem. The computing powers for multiplicative inverse in our proposal is a decrease 50% compared with the existing method based on Extended Euclid Algorithm. We implement IDEA by applying a single iterative round method and our proposal for multiplicative inverse. With a system clock frequency 20MGz, the designed hardware permits a data conversion rate of more than 116 Mbit/s. This result show that the designed device operates about 2 times than the result of the paper by H. Bonnenberg et al. From a speed point of view, out proposal for multiplicative inverse is proved to be efficient.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.46 no.2
• /
• pp.141-146
• /
• 2009

In this paper, a novel harmonic control circuit has been proposed for the design of high-efficiency power amplifier with Si LDMOSFET. The proposed harmonic control circuit haying the short impedances for the second- and third-harmonic components has been used to design the in/output matching network. The efficiency enhancement effect of the proposed harmonic control circuit is superior to the class-F or inverse class-F harmonic control circuit. Also, when the proposed harmonic control circuit has been adapted to the input matching network as well as the output matching network, the of ficiency enhancement effect of the proposed power amplifier has increased all the more. The measured maximum power added efficiency (PAE) of the proposed power amplifier is 82.68% at 1.71GHz band. Compared with class-F and inverse class-F amplifiers, the measured maximum PAE of the proposed power amplifier has increased in $5.08{\sim}9.91%$.

• Proceedings of the IEEK Conference
• /
• 2001.06b
• /
• pp.305-308
• /
• 2001

This paper describes the design of elliptic curve cryptographic (ECC) coprocessor over binary fields for the If card. This coprocessor is implemented by the shift-and-add algorithm for the field multiplication algorithm. And the modified almost inverse algorithm(MAIA) is selected for the inverse multiplication algorithm. These two algorithms is merged to minimize the hardware size. Scalar multiplication is performed by the binary Non Adjacent Format(NAF) method. The ECC we have implemented is defined over the field GF(2$^{163}$), which is a SEC-2 recommendation［7］..

• Proceedings of the IEEK Conference
• /
• 1999.06a
• /
• pp.938-941
• /
• 1999

In this paper, we designed a pipeline (15,9) Reed-solomon decoder. To compute the error locator polynomials, we used the Euclidean algorithm. This algorithm includes computation of inverse element. We avoided the inverse element calculation in this RS decoder by using ROMs. We designed this decoder using VHDL. Simulation results show that the designed decoder corrects three error symbols. We implemented this design through an Altera FPGA chip.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2001.05a
• /
• pp.967-972
• /
• 2001

An axial fan design code, called iDesignFan$^{TM}$, was developed. In this code, three major loss models were used to predicted the aerodynamic performance of a fan. The overall sound pressure level, predicted from steady blade loading, is also used as an input parameter from the third loop of the designing process to acquire most silent fan for the given aerodynamic performance parameters. With this kind of inverse design concept used in this code, the period of designing a fan, which has given aerodynamic performance with minimal acoustic noise, is significantly shortened. The experimental results of a prototype fan, designed by this code, showed that aerodynamic and acoustic performance of an axial fan is reasonably well predicted. Thus, one can design/develop an axial fan in a short time by using the code.e.

• Journal of Magnetics
• /
• v.19 no.3
• /
• pp.266-272
• /
• 2014

In this paper, we suggest reliability as a metric to evaluate the robustness of a design for the optimal design of electromagnetic devices, with respect to constraints under the uncertainties in design variables. For fast numerical efficiency, we applied the sensitivity-assisted Monte Carlo simulation (S-MCS) method to perform reliability calculation. Furthermore, we incorporated the S-MCS with single-objective and multi-objective particle swarm optimization algorithms to achieve reliability-based optimal designs, undertaking probabilistic constraint and multi-objective optimization approaches, respectively. We validated the performance of the developed optimization algorithms through application to the optimal design of a superconducting magnetic energy storage system.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2012.05a
• /
• pp.733-734
• /
• 2012

• Journal of Korean Society for Quality Management
• /
• v.39 no.3
• /
• pp.365-376
• /
• 2011

Robust design (RD) has emerged as a key feature in process design and development for more than twenty years. Many researchers and industrial engineers around the world have invested their intensive efforts to develop and apply RD in many fields in order to improve quality of output products. However, there is also room for improvement. The primary objective of this research is to determine "robust formulation" of a medicine by checking its gelation index. In order to achieve this target, based on the nature of problem, at first, a customized experimental format is designed for obtaining data. Second, time-depended responses based models are developed by the proposed inverse problem (IP) methodology. Third, an RD model based on mean square error (MSE) concept is introduced for time-depended responses. Finally, the proposed approach is illustrated by a case study while comparing obtained results to the response surface methodology (RSM) approach.

• Korean Journal of Computational Design and Engineering
• /
• v.16 no.6
• /
• pp.437-448
• /
• 2011

A robotic spatial augmented reality (RSAR) system combines a robotics technology with a spatial augmented reality system (SAR) where cameras are used to recognize real objects and projectors augment information and user interface directly on the surface of the recognized objects, rather than relying on handheld display devices. Moreover, a robotic module is actively used to discover and utilize the context of users and environments. The control of a RSAR system involves several issues from different technical fields such as classical inverse kinematics of motors where projector-camera pairs are mounted, inverse projection problems to find appropriate internal/external parameters of projectors and cameras, and image warping in graphics pipeline to compensate the kinematic constraints. In this paper, we investigate various control issues related to a RSAR system and propose basic approaches to handle them, specially focused on the prototype RSAR system developed in ETRI.

• Proceedings of the KIEE Conference
• /
• 1999.07b
• /
• pp.537-539
• /
• 1999

When dealing with a controller design in the two parameter configuration, there are some situations when neither a known pseudo inverse technique nor the inverse method can be applicable. In this case, we propose two methods of designing a controller by the gradient algorithm and the new pseudo inverse method such that the designed closed loop polynomial may be equal to or nearly equal to the desired closed loop polynomial. We compare the proposed methods with the known methods. We use the Manabe standard form as a desired closed loop characteristic polynomial.