• Journal of the korean Society of Automotive Engineers
• /
• v.14 no.5
• /
• pp.61-68
• /
• 1992

Knock phenomenon is an abnormal combustion originated from autoignition of unburned gas in the end-gas region during the later stage of combustion process and it accompanys a high pitched metallic noise. Engine Knock is accompanied with a vibration of engine cylinder and when it is severe, it can cause major engine demage. Engine Knock is characterized in terms of knock crank angle, knock pressure, pressure jump and knock intensity. In this study, a 4-cylinder spark ignition engine was used for experiment and eighty consecutive cycles were analyzed statistically. The purpose of this study is to characterize spark ignition engine knock as a function of ignition timing and fuel research octane number. The result of this study can be summerized as follows. Knock occurrence angle approached TDC as ignition timing is advanced. Pressure and knock intensity gradually increased as spark timing is advanced. Mean knock occurence angle gradually approached TDC as fuel research octane number is decreased for identical spark timing. Knock intensity increased linearly as RON is decreased.

• Proceedings of the Korean Society of Agricultural Engineers Conference
• /
• 2003.10a
• /
• pp.283-286
• /
• 2003

In order to examine effects of sampling frequency during rainfall-runoff process from paddy field on the estimation of pollution load, EMCs of several water sampling frequencies were examined. It was found that the difference of EMCs between one time sampling and two hours consecutive sampling during storm event showed $34.1{\sim}-19.1%$ for T-N, $55.4{\sim}-27.3%$ for T-P, $68.5{\sim}-41.0%$ for the SS, respectively. Five times sampling reduced difference of EMCs compared to those two hours interval sampling to $15.2{\sim}-15.2%$ for T-N, $20.0{\sim}-26.2%$ for T-P, $28.6{\sim}-35.7%$ for the SS, respectively.

• ETRI Journal
• /
• v.34 no.1
• /
• pp.110-113
• /
• 2012

We propose a very-low-complexity lattice-reduction (LR) algorithm for multi-input multi-output detection in time-varying channels. The proposed scheme reduces the complexity by performing LR in a block-wise manner. The proposed scheme takes advantage of the temporal correlation of the channel matrices in a block and its impact on the lattice transformation matrices during the LR process. From this, the proposed scheme can skip a number of redundant LR processes for consecutive channel matrices and performs a single LR in a block. As the Doppler frequency decreases, the complexity reduction efficiency becomes more significant.

• 제어로봇시스템학회:학술대회논문집
• /
• 1996.10b
• /
• pp.499-502
• /
• 1996

In this paper, we propose a fuzzy iterative learning controller(FILC). It can control fully unknown dynamic plants through iterative learning. To design learning controllers based on the steepest descent method, it is one of the difficult problems to identify the change of plant output with respect to the change of control input(.part.e/.part.u). To solve this problem, we propose a method as follows: first, calculate .part.e/.part.u using a similarity measure and information in consecutive time steps, then adjust the fuzzy logic controller(FLC) using the sign of .part.e/.part..u. As learning process is iterated, the value of .part.e/.part.u is reinforced. Proposed FILC has the simple architecture compared with previous other controllers. Computer simulations for an inverted pendulum system were conducted to verify the performance of the proposed FILC.

• 제어로봇시스템학회:학술대회논문집
• /
• 1996.10b
• /
• pp.1004-1007
• /
• 1996

Various auto-tuning methods using relay feedback are presented recently. They are composed of the consecutive procedures identifying Nyquist critical point using relay feedback and designing PID controller by one point of Nyquist plot mapping. This paper suggests a strategy to get the knowledges of Nyquist critical point and the neighborhood point of it using relay feedback. The parameters of PID controller are established by dominant pole approximation based on these knowledges. Designers can make use of the damping ratio as a time domain specification. So design flexibilities are taken in view of stability and performance of the system response considering practical system condition.

• Proceedings of the KIEE Conference
• /
• 2005.10b
• /
• pp.322-324
• /
• 2005

In this paper, we introduce the advanced Self-Organizing Fuzzy Polynomial Neural Network based on optimized FPN by evolutionary algorithm and discuss its comprehensive design methodology involving mechanisms of genetic optimization, especially genetic algorithms (GAs). The proposed model gives rise to a structurally and parametrically optimized network through an optimal parameters design available within Fuzzy Polynomial Neuron(FPN) by means of GA. Through the consecutive process of such structural and parametric optimization, an optimized and flexible the proposed model is generated in a dynamic fashion. The performance of the proposed model is quantified through experimentation that exploits standard data already used in fuzzy modeling. These results reveal superiority of the proposed networks over the existing fuzzy and neural models.

• IEIE Transactions on Smart Processing and Computing
• /
• v.6 no.4
• /
• pp.292-298
• /
• 2017

The complexity of image compression algorithms has increased in order to improve image compression efficiency. One way to resolve high computational complexity is parallel processing. However, entropy coding, which is lossless compression, does not fit into the parallel processing form because of the correlation between consecutive symbols. This paper proposes a new application-specific instruction set processor (ASIP) platform by adding new context-adaptive binary arithmetic coding (CABAC) instructions to the existing platform to quickly process a variety of entropy coding. The newly added instructions work without conflicts with all other existing instructions of the platform, providing the flexibility to handle many coding standards with fast processing speeds. CABAC software is implemented for High Efficiency Video Coding (HEVC) and the performance of the proposed ASIP platform was verified with a field programmable gate array simulation.

• Proceedings of the IEEK Conference
• /
• 2003.11a
• /
• pp.505-508
• /
• 2003

The current paper proposes a new vertex selection scheme for polygon-based contour ceding. To efficiently characterize the shape of an object, we incorporate the curvature information in addition to the conventional maximum distance criterion in vertex selection process. The proposed method consists of “two-step procedure.” At first, contour pixels of high curvature value are selected as key vertices based on the curvature scale space (CSS), thereby dividing an overall contour into several contour-segments. Each segment is considered as an open contour whose end points are two consecutive key vertices and is processed independently. In the second step, vertices for each contour segment are selected using progressive vertex selection (PVS) method in order to obtain minimum number of vertices under the given maximum distance criterion ( $D_{MAX}$). Experimental results are presented to compare the approximation performances of the proposed and conventional methods.s.

• Proceedings of the KSME Conference
• /
• 2000.11b
• /
• pp.381-384
• /
• 2000

Relationships between biochemical phenomena and hemodynamics on human endothelial cells are very important to study the mechanism of atherosclerotic formation and development. The objective of this study is to investigate the flow phenomena around the endothelial cell model by the PIV experiment. The microscopic images of endothelial cells were acquired by a CCD camera to fabricate the shape of endothelial cell. The cell models were fabricated by using a photoforming process. Two consecutive particle images were captured by the CCD camera for the image processing. Conifer powder as the tracing particles was added to water to visualize the flow field. The cross-correlation method was applied fer the image processing of the flow visualization. Pressure and wall shear stress variations on the surfaces of the endothelial cells were calculated to investigate the effects of hemodynamic forces on the morphological changes.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.25 no.7
• /
• pp.807-818
• /
• 1988

This paper proposes new algorithms for the estimation of displacement vector and moving object extraction using difference picture. First, the relations between the boundary of moving objects in two consecutive image and the boundary of difference picture regions are analyzed, then displacement vector estimation algorithm is proposed. Using the estimated displacement vector, moving objects are directly extracted from difference picture. Since the proposed algorithms do not process gray-valued image, they have a short processing time and are suitable to real time processing. From the experimental results, we observed that, if difference picture is wel extracted, the proposecd algorithms work well even in the circumstances of complex background, fast or slow motion, rotation etc., including occlusion where is not moving area.