• The Transactions of the Korea Information Processing Society
• /
• v.7 no.2S
• /
• pp.701-710
• /
• 2000

This paper presents a new method for an efficient coding of very low bit-rate color video based on adaptive wavelet transform. Our approach reveals that the coding process works more efficiently if the quantized wavelet coefficients are preprocessed by a mechanism exploiting the redundancies in the wavelet subband structure. Thus, we focuses optimized activity of coding part, and exhaustive overlapped block motion compensation is utilized to ensure coherency in motion compensated error frames, and raised cosine window is applied. The horizontal and vertical components of motion vectors are encoded separately using adaptive arithmetic coding while significant wavelet coefficients are encoded in bit-plane order using adaptive arithmetic coding. On average the proposed codec exceeds H.263 and ZTE in peak signal-to-noise ratio by as much as 2.07 and 1.38dB at 28 kbits, respectively. Fore entire sequence coding, 3DWCVC method is superior to H.263 and ZTE by 0.35 and 0.71dB on average, respectively.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.12 no.3
• /
• pp.218-223
• /
• 2019

To prevent the low heating effect of heating system caused by the high sheet resistance of CVD graphene, multi-layered graphene was laminated to implement a Transparent plane heating system with good optical properties of low-resistance. Low-resistance plane heating system implemented by $300{\times}400{\times}5mm$ heating plane laminated multi-layered CVD graphene film and PWM control system to drive efficient power. A plane resistance value of $85.5{\Omega}/sq$ was measured on average for 4-layer CVD graphene film used as a heating plane. Thus, the transfer by thermal film as the method of implementing low-resistance CVD graphene is reasonable. The experimental results of heat test show that an average heat-rise rate in low-resistance, transperent plane heating system using CVD graphene is $10^{\circ}C/min$ and has an optical transmittance rate of 86.44%. Therefore, the proposed heating system is applicable to large window glass and vehicle heating window-shild-glass.

• Journal of the Korean Solar Energy Society
• /
• v.31 no.4
• /
• pp.136-141
• /
• 2011

The lightshelf system reduces intense illumination levels of indoor from direct sun light and reflect to lead diffused light into indoor deeply. This study aims to design acurved-lightshelf by a ray tracing method and evaluate the daylighting performance of window integrated with the curved-lightshelf by computer simulations. For this purpose, evaluation test model was designed for the experiments to validate the simulation model, and the curved-lightshelf was designed by the ray tracing method using Ecotect. After the office model was designed using 3D simulation, the average indoor illuminance, luminance and distribution of illuminance were evaluated by simulation which has a algorithm of Radiosity and Ray-Tracing method under four different cases(case1;no lightshelf, case2; Flat board, case3; tilted at $30^{\circ}$ angle, case4; the curved-lightshelf). As results, it turns out that case1 showed higher average illuminance and case4 was more uniformly distributed than case2 and case3, In addition average luminance of case1 was also lower. indicating that the curved-lightshelf would reduce the possibility of the glare, while maintaining the sufficient daylight level.

• 대한공업교육학회지
• /
• v.32 no.2
• /
• pp.199-216
• /
• 2007

Stream Control Transmission Protocol(SCTP) is a transport layer protocol to support the data transmission. SCTP is similar to Transmission Control Protocol(TCP) in a variety of aspects. However, several features of SCTP including multi-homing and multi-streaming incur the performance difference from TCP. This paper highlights the data transfer during the initial slow start phase in SCTP congestion control composed of slow start phase and congestion avoidance phase. In order to compare the mean transfer time between SCTP and TCP, we experiment with different performance parameters including bandwidth, round trip time, and data length. By varying data length, we also measure the corresponding initial window size, which is one of factors affecting the mean transfer time. For the experiment, we have written server and client applications by C language using SCTP socket API and have measured the transfer time by ethereal program. We transferred data between client and server using round-robin method. Analysis of these experimental results from the testbed implementation shows that larger initial window size of SCTP than that of TCP brings the reduction in the mean transfer time of SCTP compared with TCP by 15 % on average during the initial slow start phase.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.52 no.1
• /
• pp.61-68
• /
• 2015

In recent times, the median filtering (MF) detector as a forensic tool for the recovery of forgery images' processing history has concerned broad interest. For the classification of MF image, MF detector should be designed with smaller feature set and higher detection ratio. This paper presents a novel method for the detection of MF in altered images. It is transformed from BMP to several kinds of MF image by the median window size. The difference distribution values are computed according to the window sizes and then the values construct the feature set same as the MF window size. For the MF detector, the feature set transformed to the model specification which is computed using latent growth modeling (LGM). Through experiments, the test image is classified by the discriminant into two classes: the true positive (TP) and the false negative (FN). It confirms that the proposed algorithm is to be outstanding performance when the minimum distance average is 0.119 in the confusion of TP and FN for the effectivity of classification.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2005.05a
• /
• pp.437-442
• /
• 2005

In this paper, we proposed the 2-dimensional inspection algorithm for micro-BGA(Ball Grid Array) device using a vision system. The proposed method uses the subpixel algorithm for high precision. The proposed algorithm preferentially extracts the package area of device in the input image. After the extraction of package area, each ball areas are extracted by ball search window method. The parameters for inspection are calculated for the extracted ball area. In the simulation results, we have the average error within $17{\mu}m$.

• Journal of Practical Engineering Education
• /
• v.6 no.2
• /
• pp.127-134
• /
• 2014

Analyzing test data of a vehicle for evaluating its emission performance is an essential process in automotive development field, yet it is intricate and tedious task. In addition, clear understanding and care are required when the analysis process is carried out. Computer software solutions significantly reduce the time and the effort for such analysis. Developing a computer routine to analyze the emission data in a vehicle test demands a complete understanding of the emissions analysis and its related details. In this paper, the principals to develop a LabVIEW analysis routine (VI) are introduced helping automotive engineers comprehend the emission analysis process of a vehicle test data and instruct them to develop similar routines for such analysis.

• Journal of Electrical Engineering and information Science
• /
• v.1 no.2
• /
• pp.45-51
• /
• 1996

This paper presents a neural network approach for on-line estimation of partial discharge(PD) location using advanced correlation technique in power transformer. Ultrasonic sensors detect ultrasonic signals generated by a PD and the proposed method calculates time difference between the ultrasonic signals at each sensor pair using the cross-correlation technique applied by moving average and the Hamming window. The neural network takes distance difference as inputs converted from time difference, and estimates the PD location. Case studies showed that the proposed method using advanced correlation technique and a neural network estimated the PD location better than conventional methods.

• Journal of Broadcast Engineering
• /
• v.14 no.3
• /
• pp.342-356
• /
• 2009

This paper presents a vote decision-based deinterlacing scheme for false directional error correction(VDD) to convert interlaced signal into non-interlaced signal using only one fields. The VDD using the vote decision goes through four steps process. The first step extracts regions having doubt of false edge using MM-ELA method. In these regions, the edge direction is decided by the majority vote using upper adjacent pixels's information through the second step. But, we still have undecided directions, which will be decided by the majority vote and the directional average decision at the third step. This step preserves the edge directions and minimizes visual degradation. Finally, the last step interpolates undecided pixels using DOI method which can consider the fine edge direction. Although the VDD with hierarchical structure has a high complexity, it can extract delicate edge compared to other pixel-by-pixel or window-by-window deinterlacing algorithms. Simulation results show that it has significantly improved both the subjective and objective qualities of the reconstructed images.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.16 no.9
• /
• pp.2021-2030
• /
• 2012

Premature ventricular contraction(PVC) is the most common disease among arrhythmia and it may cause serious situations such as ventricular fibrillation and ventricular tachycardia. Particularly, in the healthcare system that must continuously monitor patient's situation, it is necessary to process ECG (Electrocardiography) signal in realtime. In other words, the design of algorithm that exactly detects R wave using minimal computation and classifies PVC by analyzing the persons's physical condition and/or environment is needed. Thus, the patient adaptive pattern matching algorithm for the classification of PVC is presented in this paper. For this purpose, we detected R wave through the preprocessing method, adaptive threshold and window. Also, we applied pattern matching method to classify each patient's normal cardiac behavior through the Hash function. The performance of R wave detection and abnormal beat classification is evaluated by using MIT-BIH arrhythmia database. The achieved scores indicate the average of 99.33% in R wave detection and the rate of 0.32% in abnormal beat classification error.