• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.9 no.1
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• pp.114-119
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• 2016

The necessity of IoT(Internet of Things) and Multimedia CSCW is described, and error control for multimedia CSCW(Computer Supported Cooperated Works) based on CoAP stack is suggested. This paper describes an error synchronization running on gateway software stack based CoAP. This system consists of an CS_EDA, and CS_ESA. CS_EDA is an agent that detects an error for multimedia distance system based on gateway software stack based CoAP environment. CS_ESA is an agent that is an error synchronization system for multimedia distance control based on gateway software stack based CoAP environment. From the perspective of multimedia collaborative environment of gateway software stack based CoAP, an error application becomes another interactive presentation error is synchronized with participants engaged in a cooperative work.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.8 no.1
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• pp.12-17
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• 2015

This paper describes an error synchronization running on IP-USN gateway software stack for transportation safety service. This system consists of an TS_EDA, and TS_ESA. TS_EDA is an agent that detects an error for multimedia distance system based on IP-USN gateway software stack environment. TS_ESA is an agent that is an error synchronization system for multimedia distance control based on IP-USN gateway software stack environment. From the perspective of multimedia collaborative environment of IP-USN gateway software stack for transportation safety service, an error application becomes another interactive presentation error is synchronized with participants engaged in a cooperative work.

• Journal of Environmental Science International
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• v.9 no.1
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• pp.57-64
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• 2000

The sensitivity analysis of two short-term models (ISCST3, INPUFF2.5) is performed to improve the model accuracy. It appears that the sensitivities on the changes of wind speed, stack height and stack inner diameter in the near distance from source, stability and mixing height in the remote distance form source, are significant. Also the gas exit velocity, stack inner diameter, gas temperature and air temperature which affect the plume rise have some effects on the concentration values of each model within the downwind distance where final plume rise is determined. And in modeling for the atmospheric dispersion of point pollutant source INPUFF2.5 can calculate amount, trajectory of puff and concentration versus time at each receptors. So, it is compatible to analyze distribution of point pollutants concentration at modeling area.

• Journal of Korean Society for Atmospheric Environment
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• v.9 no.2
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• pp.168-173
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• 1993

Air quality impacts of point and area sources were analyzed by using ISCST2 with wind speed and stability class combinations of SCREEN. Stack height was important in determining the impact of point sources. With the stack height reduced to 21m from 75m, the concentration in the vicinity increased several times in spite of decreasing the emission rate by half. When the emission rates were same, concentrations from an area source of 10m release height were slightly lower than those from a point source of 21m stack height at the plume centerline. Bur the area source resulted in larger area of high concentration. Concentration from the point source was high in neutral to slightly unstable conditions with strong winds in a short distance, and in stable conditions with weak winds in a long distance. Concentration from the area source decreased with distance from the source, and was high in stable conditions with weak winds.

• Journal of Korea Multimedia Society
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• v.25 no.1
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• pp.61-71
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• 2022

When communication such as light, radio wave, or magnetic field is used underwater, the communication distance is very short, so sound waves are mainly used. However, by combining the strengths of each medium and communicating, stable communication may be possible. Underwater multi-media communication requires a protocol stack that supports it, which is very complex. To this end, this paper proposes a standard protocol stack and modeling technique to enable easy protocol stack modeling for the purpose. In fact, in this paper, a random model was created and analyzed through the proposal of modeling elements and similarity measurement methods, and as a result, it was analyzed that it was very helpful in creating a new model based on a standard model.

• Journal of Computing Science and Engineering
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• v.3 no.4
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• pp.195-215
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• 2009

Worst-case execution time (WCET) analysis is critical for hard real-time systems to ensure that different tasks can meet their respective deadlines. While significant progress has been made for WCET analysis of instruction caches, the data cache timing analysis, especially for set-associative data caches, is rather limited. This paper proposes an approach to safely and tightly bounding data cache performance by computing the worst-case stack distance of data cache accesses. Our approach can not only be applied to direct-mapped caches, but also be used for set-associative or even fully-associative caches without increasing the complexity of analysis. Moreover, the proposed approach can statically categorize worst-case data cache misses into cold, conflict, and capacity misses, which can provide useful insights for designers to enhance the worst-case data cache performance. Our evaluation shows that the proposed data cache timing analysis technique can safely and accurately estimate the worst-case data cache performance, and the overestimation as compared to the observed worst-case data cache misses is within 1% on average.

• Particle and aerosol research
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• v.8 no.4
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• pp.161-172
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• 2012

Three-dimensional numerical simulation using a computational fluid dynamics (CFD) was carried out in order to investigate the formation and dispersion of the plume discharged from the stack of a thermal power station. The simulation was based on the standard ${\kappa}{\sim}{\varepsilon}$ turbulence model and a finite-volume method. Warm and moist exhaust from a power plant stack forms a visible plume as entering the cold ambient air. In the simulation, moisture content, emission velocity and temperature of the flue gas, air temperature and wind speed were dealt with the main parameters to analyze the properties of the plume composed mainly of water vapor. As a result of the simulation, the plume could be more apparent in cold winter due to a big difference of latent heat capacity. At no wind condition, the white plume rises 120 m upward from the top of the stack, and expands to 40 m around from the stack in cold winter after flue gas heat recovery. The influencing distance of relative humidity will be about 100 m to 400 m downstream from the stack with a cross wind effect. The decrease of flue gas temperature by heat recovery of thermal energy facilitates the formation of the plume and restrains its dispersion. Wind speed with vertical distribution affects the plume dispersion as well as the density.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2003.02a
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• pp.254-256
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• 2003

AC loss is one of the important superconducting power machine that we have to consider deeply using the stack wires with the HTS. AC magnetic field is occurred around the wires when the electric current is conducted to the stack wires. It also brings electric field to the wires and occurs self field loss, whose quantity is appeared differently by distance of the stack wires. In this paper, transport current losses of a stack short sample of HTS were compared with Norris equation and measured value.

• Journal of electromagnetic engineering and science
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• v.19 no.1
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• pp.37-41
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• 2019

A stack-ring configuration is proposed for designing a dual-band circularly polarized (CP) antenna. Each ring generates different resonant frequencies. A good CP performance at both resonant frequencies is achieved by adjusting the relative distance between the two rings. The two operating bands are separated with a small frequency ratio of 1.07. Measured results show that radiation patterns with good CP characteristics are obtained at the two resonant frequencies.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.3 no.1
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• pp.53-56
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• 2010

This paper explains a system that is suitable for detecting software error running on multimedia distance control for transportation safety environment. This system consists of an ED, and ES. ED is an agent that detects an error by hooking techniques for multimedia distance education based on IP-USN gateway software stack environment. ES is an agent that is an error sharing system for multimedia distance control based on IP-USN gateway software stack environment. From the perspective of multimedia collaborative environment, an error application becomes another interactive presentation error is shared with participants engaged in a cooperative work.