• Proceedings of the KSME Conference
• /
• 2004.11a
• /
• pp.840-845
• /
• 2004

The reliability analysis for nonnormal distributions using the three level DOE(design of experiments) method was developed by Seo and Kwak in 2002. Although this method estimates only up to the first four moments(mean, standard deviation, skewness, and kurtosis) of the system response function, the result and the type of probability distribution determined by using the Pearson system are shown very good. However the accuracy is low in case of nonlinear performance function and sometimes, the level calculated is outside of the region in which the random variable is defined. In this article we suggest a modified three level DOE method to overcome these weaknesses and to obtain optimum choice for 3 levels and weights to handle nonnormal distributions. Furthermore we extend it to finding the optimum choice for 5 levels and weights to increase the accuracy in case of nonlinear performance function. A systematic procedure for reliability analysis is then proposed by using the Pearson system.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.9 no.1
• /
• pp.190-207
• /
• 2015

In the combustion engineering, to decrease pollution and increase production efficiency, and to optimally keep solid burning material amount constant in a burner online, it needs a smart method to detect the amount variation of the burning materials in a high temperature environment. This paper presents an online machine vision system for automatically measuring and detecting the burning material amount inside a burner or a boiler. In the camera-protecting box of the system, a sub-system for cooling is constructed by using the cooling water circulation techqique. In addition, the key and intelligent step in the system is to detect the pile profile of the variable burning material, and the algorithm for the pile profile tracing was studied based on the combination of the gey level (color) discontinuity and similarity based image segmentation methods, the discontinuity based sub-algorithm is made on the quaternion convolution, and the similarity based sub-algorithm is designed according to the region growing with multi-scale clustering. The results of the two sub-algoritms are fused to delineate the final pile profile, and the algorithm has been tested and applied in different industrial burners and boilers. The experiements show that the proposed algorithm works satisfactorily.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.27 no.7A
• /
• pp.659-667
• /
• 2002

In this dissertation, in the Turbo Code used for error correction coding of the recent digital communication systems, we propose a new S-R interleaver that has the better performance than the existing block interleaver, and the Turbo Decoder that has the parallel concatenated New structure using the MAP algorithm. For real-time voice and video services over the third generation mobile communications, the performance of two proposed methods is analyzed by the reduced decoding delay using the variable decoding method by computer simulation over multipath channels of DS-CDMA system. Also, a Modified NCMA based on conventional NCMA is proposed to improve the channel efficiency in the mobile communication system, and is investigated over the multi-user environment of DS-CDMA system through computer simulation.

• Journal of Korean Society of Transportation
• /
• v.19 no.6
• /
• pp.7-17
• /
• 2001

The purpose of this paper is to develop automatic incident detection algorithm using image based detector in freeway management system. This algorithm was developed by using neutral network for high speed roadway and by using speed and occupancy variable for low speed roadway. The image detector system with the developed automatic incident detection algorithm can detect multi-lane as well as several detect areas for each lane. To evaluate this system, field tests to measure the detecting rate of incidents were performed with other systems which have APID and DES algorithm at high speed roadway(freeway) and low speed roadway(national arterial). As the results of field test, it found that the detect rate of this system was highest rate comparing to other two systems.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 1999.05a
• /
• pp.266-271
• /
• 1999

The purpose in this study has to development the system on increasing operation of old-typed transceiver for solve the question that limited allocation frequencies and continuesly icreasment of traffic. Therefore, we are desigened the remote control system that has the function for variable channels, PTT and monitoring of transmission power and frequencies. Exchange of control data is to hold in common the twist two-wire or telephone line for the voice transmission. The H/W is consist of FSK and MCS-51 processor which are up-down control of channel, n control and monitoring display by serial data transmission. According to the simplex traffic operation is designed the algorithm of serial data transmission by sequential transmission sequence and protocol. The S/W of sequential transmission sequence is designed to usefully the intergrated communications system which is able to connection between the multi-transceiver and multi-terminal by master processor.

• Horticultural Science & Technology
• /
• v.31 no.3
• /
• pp.259-268
• /
• 2013

This study was carried out to evaluate the visual turfgrass's color quality, winter color, and spring green-up under three different soil systems and to make a practical use for sports turf design and construction. Several turfgrasses were evaluated in multi-layer, USGA and mono-layer systems. Turfgrass entries in the study comprised of 3 cultivars from Korean lawngrass (Zoysia japonica Steud.) of typical warm-season grass (WSG) and 3 blends and 3 mixtures from Kentucky bluegrass (KB, Poa pratensis L.), perennial ryegrass (PR, Lolium perenne L.), and tall fescue (TF, Festuca arundinacea Schreb.) of cool-season grass (CSG). Significant differences were observed in the turfgrass's color quality, winter color, and spring green-up in the study. Seasonal variation of visual turf color greatly occurred according to soil systems and turfgrasses. Multi-layer and USGA systems were highly associated with better visual color ratings, as compared with mono-layer system. Regardless of soil system, visual turf color in all entries was better from spring to fall than in winter. Great color differences were observed during a period of early December to early spring. CSG produced a better color quality over WSG in any soil system. Overall color ratings for CSG were KB > PR > Mixtures > TF. As for a winter color, its ranking was USGA > multi-layer > mono-layer system. No difference was found in winter among cultivars of Korean lawngrass, being completely brown, but great differences among CSG. Rated best for winter color was PR, followed by CSG mixtures, KB and finally TF in order. It was generally conceded that fast green-up in spring was greatly related with multi-layer over mono-layer system and also CSG over WSG. Among CSG, TF had a fastest green-up. PR was also fast in green-up, but poor in color uniformity. KB, however, was the slowest due to shallow rooting system, when compared with other CSGs. These results demonstrate color differences were greatly variable according to soil systems and also among turfgrass species. A precise decision should be made in selecting turfgrass species and soil system. Multi-layer and USGA systems were considered as the suitable one for turfgrass color quality, winter color and spring green-up. It is a great necessity to combine proper soil system, right turfgrass species, and appropriate mixing rates by a concept-oriented approach, when establishing garden, parks, soccer field, and golf courses and so on.

• Proceedings of the IEEK Conference
• /
• 2005.11a
• /
• pp.959-962
• /
• 2005

Efficient video data storage and search techniques are essential for DVR-based security systems. We have designed appropriate data structures and search techniques for efficient image storage and search, in this study. The date and time can be saved and searched as a folder form. The overall system is designed for MPEG4 CODEC. It can handle variable sizes of frames (100bytes $^{\sim}$ 6Kbytes) produced by MPEG4 CODEC without errors. We also have developed image transmission techniques through inter-net networking.

• Proceedings of the KIPE Conference
• /
• 2016.07a
• /
• pp.519-520
• /
• 2016

BLSRM is a nonlinear, strong coupling and multi-variable system. The conventional control method is vulnerable to uncertain factors such as the load disturbance and satellite parameters change. It is difficult to obtain satisfactory control effect. Basing on a 8/10 BLSRM, whose suspending force control is separated with the torque control, this paper presents adaptive fuzzy PID controller for levitation control, which apply the fuzzy logic control to the conventional PID controller for parameters self-tuning. Both fuzzy and parameters of PID controller are self-tuning on-line, which improve the performance of controller. Finally, simulation and experimental results show the performance of the proposed method.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.6 no.4
• /
• pp.118-123
• /
• 1997

The study suggests a method to analyze the vibration of the multi-stepped beam having the different circular cross-sections. The rotatory inertia, the shear deformation and the torque applied at both ends of the beam are considered in the governing equation. The complex displacement and the variable separation are introduced to derive the solution of the equation of each uniform beam element having constant cross-section. Then boundary conditions are applied to solve the total system. This method uses the mathematically exact solutions unlike numerical method such as the finite element method in solving the problem having the simultaneous differential equations of Timoshenko beam theory. the natural frequencies and the corresponding mode shapes are precise, especially the mode shapes are continuous.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.20 no.4
• /
• pp.39-44
• /
• 2012

This paper propose a transmission method for "Transportation system" that can decide precise position under wide area road traffic environment. For precise position detecting, central station collect multiple receiver station's satellite navigation data and generate correction information. In this process, we need efficient real time transmission method for satellite navigation message that has variable data size. We propose real time data transmission method. This real time transmission method offer efficient processing structure for multiple receiver station's satellite navigation message. This paper explains proposed real time transmission method and proofs this transmission method.