• Journal of the Korean Institute of Telematics and Electronics
• /
• v.25 no.12
• /
• pp.1633-1638
• /
• 1988

This paper proposes the lattice-structured space subdivision method using bounding volume to reduce a great number of ray-surface intersection calculations in ray tracing algorithm for the computer graphics. We show that this method reduced 50%-70% calculations compard to pre-exist method by experiments.

• 제어로봇시스템학회:학술대회논문집
• /
• 1989.10a
• /
• pp.1035-1040
• /
• 1989

This paper describes first Boxes algorithm as a good method to generate the pulse patterns for a pulse width modulated inverter which has a good characteristics and simple to excute. Second we present the motor analysis fed by P.W.M. inverter in steady-state operation. In this analysis we improve the MRF ( Multiple Reference Frames ) to can be easy apply to analyse all the induction motor parameters. Finally we presented all the results obtained for a 3-phase induction motor.

• Journal of IKEEE
• /
• v.22 no.1
• /
• pp.168-173
• /
• 2018

To overcome the problems of the existing black box which is exposed to the risk of blind spots in the imaging of a fixed front and rear views of an object, this paper suggests a new intelligent black box that can detect and shoot side views of an object. This paper proposes an algorithm of the intelligent black box with a rotating function in order to compensate for the side blind spot of the vehicle. This intelligent black box with rotating screen adopts the infrared distance sensor to sense an object which approaches to the vehicle and rotates automatically towards the object.

• ETRI Journal
• /
• v.37 no.5
• /
• pp.1012-1022
• /
• 2015

Conventional cryptographic algorithms are not sufficient to protect secret keys and data in white-box environments, where an attacker has full visibility and control over an executing software code. For this reason, cryptographic algorithms have been redesigned to be resistant to white-box attacks. The first white-box AES (WB-AES) implementation was thought to provide reliable security in that all brute force attacks are infeasible even in white-box environments; however, this proved not to be the case. In particular, Billet and others presented a cryptanalysis of WB-AES with 230 time complexity, and Michiels and others generalized it for all substitution-linear transformation ciphers. Recently, a collision-based cryptanalysis was also reported. In this paper, we revisit Chow and others's first WB-AES implementation and present a conditional re-encoding method for cryptanalysis protection. The experimental results show that there is approximately a 57% increase in the memory requirement and a 20% increase in execution speed.

• Proceedings of the KIEE Conference
• /
• 1996.07a
• /
• pp.406-408
• /
• 1996

This paper describes the BLDC motor which is applicated for a top front loading domestic washing machine. This motor is adopted direct drive washing machine without gear-belt-pulley system. Because gear box is removed, machine volume and noise are reduced. Moreover mechanical troubles in gear box are removed. Realization of variable speed region through of PWM control and high speed is able to efficient washing and spinning.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.15 no.1
• /
• pp.475-481
• /
• 2014

Recently, it is used to apply various improved methods to determine the cause of traffic accidents. However, most of vehicle black box usually start to store the video information by an event trigger in case that the impact value at that time exceeds the threshold impact value as compared the threshold impact value saved in advance with the current impact value. there are problems with above method that a lot video information should be saved in the memory card of the vehicle black box, and the user should delete the unwanted video information every time because of unclassified video store. In this paper, we propose the ontology-based context aware algorithm that the vehicle black box recognize the situation, and then remove the video data with a low weighting factor by itself for efficient memory management.

• Proceedings of the IEEK Conference
• /
• 1999.11a
• /
• pp.1041-1044
• /
• 1999

This paper propose a solution to resolve data overflow or leakage when a subscriber receive data to service provider. The set-top box can communicate with a service provider and can inform the service provider its data overflow or leakage. When service provider received this control signal, it changes data transmit rate and transmits data with changed rate. The buffer of set-top box is important because incoming data from a service provider are stored by it.

• Proceedings of the IEEK Conference
• /
• 2003.07e
• /
• pp.2279-2282
• /
• 2003

This paper is research to control method between wireless LCD TV and Set-Top-Box. Audio and Video signal control of wireless LCD TV through Set-Top-Box, usually two systems fairly be away, there is weakness that must go to set-top-box for operation. In this paper design and manufacture to solve this weakness.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.33A no.12
• /
• pp.16-24
• /
• 1996

In this paper, the radiation pattern of the monopole antenna mounted on the portable phone is analyzed. The analyzed model consists of a rectangular conductor box and a monopole antenna. Even though the radiation pattern of the monopole has been well known, the monopole antenna mounted on the portable phone has not been fully studied. Because of the conductor box, portable phone acts as an unbalanced dipole antenna whoe radiation patterns deviate fro those of th econventional isolated monopole antenna. Therefore, the analysis of the radiation patterns of unbalanced dopole antenna is necessary. Using the moment method, its radiation patterns are analyzed and the numerical results are verified through the measurements. In addition, the radiation patterns depending on various length of the conductor box and the monopole antenna are also presented and the dimension of the portable phone which gives excellent radiation characteristics are derived from the analyzed results.

• ETRI Journal
• /
• v.42 no.4
• /
• pp.619-632
• /
• 2020

Highly dispersive S-boxes are desirable in cryptosystems as nonlinear confusion sublayers for resisting modern attacks. For a near optimal cryptosystem resistant to modern cryptanalysis, a highly nonlinear and low differential probability (DP) value is required. We propose a method based on a piecewise linear chaotic map (PWLCM) with optimization conditions. Thus, the linear propagation of information in a cryptosystem appearing as a high DP during differential cryptanalysis of an S-box is minimized. While mapping from the chaotic trajectory to integer domain, a randomness test is performed that justifies the nonlinear behavior of the highly dispersive and nonlinear chaotic S-box. The proposed scheme is vetted using well-established cryptographic performance criteria. The proposed S-box meets the cryptographic performance criteria and further minimizes the differential propagation justified by the low DP value. The suitability of the proposed S-box is also tested using an image encryption algorithm. Results show that the proposed S-box as a confusion component entails a high level of security and improves resistance against all known attacks.