• Journal of Mechanical Science and Technology
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• v.15 no.12
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• pp.1762-1767
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• 2001

The Posuk-Chung Pavilion if a defunct irregular stone water channel in Kyongju, Korea, once used for the meandering stream feast'by kings of Silla Dynasty during the first millennium. The poets were seated around this stone water channel who composed the Chinese poems, overlooking the streams. They load to take the punishment drinks unless they finished the poem before the drifting cup filled with the rice wine arrived at their seats on the meandering stream. In this paper, we have made computer simulation as well as well as model experiment on the ancient meandering stream of the Posuk-Chung Pavilion. The computational results are compared with the experiment and the channel flow characteristics are delineated here. It is discussed how the present Posuk-Chung channel is morphologically distinguished from the Chinese and Japanese meandering streams.

• Journal of Mechanical Science and Technology
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• v.15 no.12
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• pp.1829-1834
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• 2001

The choking of dual subsonic streams flowing through a convergent duct in contact has been investigated experimentally and theoretically. The experiment was conducted by using blow-down wind tunnel. The condition, when the dual stream flow chocking (compound choking) occurs at the nozzle exit, was explained by one-dimensional analysis of compound sound wave propagation. The experimental results for the condition of compound choking were compared with the prediction from theoretical analysis, and the schlieren optical method using the spark light source has been used to visualize the flowfield.

• Journal of Mechanical Science and Technology
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• v.14 no.4
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• pp.466-476
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• 2000

This paper presents atomization characteristics of a double impinging F -0-0- F type injector with four streams. A phase Doppler particle analyzer was employed to measure the droplet-size and water was used as the inert simulant liquid instead of reactive propellant liquids. The droplet mean diameter (SMD) and size distribution were measured to investigate the effects of the momentum ratio and pressure drop variations. This experimental results can be used during the preliminary design stage of a impinging stream type injector for liquid rockets.

• Journal of Environmental Impact Assessment
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• v.15 no.2
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• pp.129-138
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• 2006

The measurements of nutrient and runoff in 4 streams have been performed before and after the rainfall in order to estimate nutrient loads in the Yongdam reservoir. The equations for the relationship between the flow and the loads in each stream could be estimated by the regression analysis. R2 of TN showed the range from 0.95 to 0.99 and the range of R2 for TP was 0.90~0.95 based on the results of the regression analyses. In 2002, total loadings from the upstream to the Yongdam reservoir were TN 1,175 ton/year, TP 69 ton/year. There were 64.9% of TN and 72.3% of TP during 4 months as the flood season. Due to the rainfall, the load of TP was higher than one of TN in Yongdam reservoir.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.31A no.4
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• pp.1-10
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• 1994

In the real-time delivery of multimedia data streams over networks, the interruption of continuity in a single media stream and the mismatching of the data within the same time interval in multimedia data streams transfered in paralled on different channels are considered as the most serious synchronization problems. There are several mechanisms proposed to handle these problems. In this paper, these mechanisms are analyzed and compared in various point of view by the computer simulation. According to the simulation results, it has been shown that the method which uses the segmentation and the method which uses the seperate synchronization channel are superior to the method which uses the synchronization marks in view of the real-time transmission and quality of sevice. On the other hand, it can be seen that the method which uses the segmentation is superior to the method which uses the seperate synchronization channel from a channel utilization's point of view.

• Journal of Computing Science and Engineering
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• v.5 no.1
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• pp.85-110
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• 2011

Achieving situation awareness is especially challenging for real-time data stream applications because they i) operate on continuous unbounded streams of data, and ii) have inherent realtime requirements. In this paper we showed how formal data stream modeling and analysis can be used to better understand stream behavior, evaluate query costs, and improve application performance. We used MEDAL, a formal specification language based on Petri nets, to model the data stream queries and the quality-of-service management mechanisms of RT-STREAM, a prototype system for data stream management. MEDAL's ability to combine query logic and data admission control in one model allows us to design a single comprehensive model of the system. This model can be used to perform a large set of analyses to help improve the application's performance and quality of service.

• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.536-537
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• 2010

If DC voltage adjustment can be controlled very easily, it is much more effective rather than AC in transmission efficiency. The main reason why DC is more effective than AC, DC has the same role as the 70[%] of AC whenever the same power send. In addition, AC streams the surface of electrical wire, but DC streams overall of electrical wire. Digital load, which is operated by DC, has increased in modern times. The step of convert of AC-DC has to be reduced. When we turn the dispersed AC-DC converters into the concentrated AC-DC converter, it can improve the effective of the whole system. Further more, if digital society develops more than now and the time of electric vehicle comes, the need of DC will increase much more than these days. This paper suggests that DC output of distributed power source and high efficient 3 phase PWM converter can control the adjustment of output voltage, harmonic restraint, power factor improvement and dump power.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.13 no.3
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• pp.164-170
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• 2013

Recent years have been higher demands for automatic speech recognition (ASR) systems that are able to operate robustly in an acoustically noisy environment. This paper proposes an improved product hidden markov model (HMM) used for bimodal speech recognition. A two-dimensional training model is built based on dependently trained audio-HMM and visual-HMM, reflecting the asynchronous characteristics of the audio and video streams. A weight coefficient is introduced to adjust the weight of the video and audio streams automatically according to differences in the noise environment. Experimental results show that compared with other bimodal speech recognition approaches, this approach obtains better speech recognition performance.

• Journal of environmental and Sanitary engineering
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• v.16 no.1
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• pp.40-46
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• 2001

Conventional membrane systems was difficult to treatment for pulp and paper mills waste warter. Technological advances in membrane filtration systems have created opportunity for pulp and paper mills to treat effluent streams in order to meet stricter environmental constraints. "Vibratory Shear Enhanced Processing(VSEP)" developed by new logic international makes if possible to filter effluent streams without the fouling problems exhibited by conventional membrane systems. Various kinds of waste water occurred to and paper mills experiment with "VSEP" set up conventional membrane. The results were as followes : Excepting ultra filter($0.1{\mu}\textrm{m}$ Teflon, C-100, G-50), Nano filter(NTR-7450, DS-5, PVD-1) and reverse osmosis(ACM-4) was treated with very excellent weight of treatment, electric conductivity, removal COD, TDS, turbidity.

• Journal of the Semiconductor & Display Technology
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• v.8 no.1
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• pp.19-25
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• 2009

Abstract JPEG2000 achieve quality scalability through the rate control method used in the encoding process, which embeds quality layers to the code-stream. This architecture might raise two drawbacks. First, when the coding process finishes, the number and bit-rates of quality layers are fixed, causing a lack of quality scalability to code-stream encoded with a single or few quality layers. Second, in Post compression rate distortion (PCRD) the bit streams after the truncation points discarded. Therefore, computational power for the discarded bit streams is wasted. For solving of problem, through bit rate control, there are many researches. Each proposed algorithms have specially target feature that is improved performance like reducing computational power. Research results have strength and weakness. For the mean time, research contents are reviewed and compared, so we proposed research direction in the future.