• Journal of the Korean Society of Industry Convergence
• /
• v.7 no.1
• /
• pp.25-31
• /
• 2004

The heat transfer characteristics of a plasma display panel has been investigated for cooling an electronic module. Hence, a two dimensional $\kappa-{\varepsilon}$ turbulent model was developed to predict the temperatures of the panel and module. The heat conduction was solve for the material region. To consider the mixed convection at the solid-fluid interfaces between the air and the panel and module, the energy equation was solved simultaneously. When the electronic module stands face to face with the panel, the temperatures of panel and module are lower than other arrangement due to the chimney effect. However the gap between the panel and module does not affect significantly the maximum temperature when the aspect ratio is less than 0.1. To maintain the maximum temperature of the module under a certain limit, the passage of air should be well designed by the optimal layout of electronic modules which have different heat emission.

• The Journal of Natural Sciences
• /
• v.8 no.1
• /
• pp.5-15
• /
• 1995

The equation error formulation in the adaptive IIR filtering provides convergence to a global minimum regardless a local minimum with a large stability margin. However, the equation error formulation suffers from the bias in the coefficient estimates. In this paper, a new algorithm, which does not require a prespecification of the noise variance, is proposed for the equation error formulation. This algorithm is based on the equation error smoothing and provides an unbiased parameter estimate in the presence of white noise. Through simulations, it is demonstrated that the algorithm eliminates the bias in the parameter estimate while retaining good properties of the equation error formulation such as fast convergence speed and the large stability margin.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.3 no.4
• /
• pp.83-90
• /
• 2010

The demands of analysis for the physical errors of systems and prediction system using this has increased steadily with computing environment growth linking real system just like IT Convergence. The physical errors are unpredictable because of relations of various elements such as natural phenomenon and mechanical errors. Especially, the elevator system occurs various problems because of the complexity of system so that we need to efficient approach for this. In this paper, we propose the analysis and management system for elevator based on data minining that predict the error to gather information about physical or natural phenomenon. This helps actively responding in early stage and saving lives through prediction of error and an early warning for just such an eventuality.

• Journal of the Korean Society of Industry Convergence
• /
• v.23 no.4_2
• /
• pp.653-659
• /
• 2020

In this study, seismic verification of the bellows used in the plant field was conducted. The pressure used in the analysis was analyzed by applying the design pressure of 15.7bar. For the seismic analysis, the natural frequency of the bellows system was obtained and the stability of the system was evaluated by static seismic analysis comparing the lowest order natural frequency with the dominant frequency of 33 Hz. The material of the bellows system is STS304, and the safety factor is obtained in comparison with the allowable stress. For the seismic analysis, the design response spectrum was prepared and the maximum acceleration was applied to the static seismic analysis and the stability of the entire system was confirmed. Compared to the structural analysis results, the maximum stress of the bellows system increased by about 16.4% and the maximum strain increased by about 3 times when seismic analysis was performed.

• Journal of the Korean Society of Industry Convergence
• /
• v.23 no.4_2
• /
• pp.569-581
• /
• 2020

Since the dehydration packages of offshore plant deal directly with oil & gas, there is a great risk of fire and explosion during operation. Therefore, this study performed risk assessment through HAZard & OPerability (HAZOP) for solid desiccant dehydration package that can remove water component of natural gas in offshore floating liquefied natural gas (LNG) production facilities below 0.1 ppmv. The risk matrix was determined by dividing the likelihood and the severity into five levels separately by asset, life, environment and reputation. The piping & instrumentation diagram (P&ID) of the dehydration package was divided into 9 nodes. Total 22 deviations were assessed in consideration of the adsorption and desorption conversion cycle. A risk assessment based on deviations revealed 14 major hazards. Three representative types of hazards were open/close failure of the control valve, control failure of the heater, and abnormal operation of the regeneration gas cooler. Finally, we proposed the installation of additional safety devices to improve safety against these major hazards, such as safety instrumented functions, alarms, etc.

• Journal of the Korean Society of Industry Convergence
• /
• v.24 no.1
• /
• pp.53-59
• /
• 2021

The purpose of this study is to develop a damper that protects against the dangers of tidal waves since there's no function to block the inflow of large amounts of water into the inside When natural disasters such as tidal waves occur. Therefore, it intended to derive the design data by simulating through flow analysis in order to predict the pressure that a damper configured to open and close manually or automatically receives. It examined the preceding researches first and conducted the flow analysis, to predict the force of the damper installed on the bottom of the building's outside to prevent the inflow of seawater into the inside when natural disaster occurring. As a result, it showed that, in the event of a tsunami, it moved about 170m and the time impacting the damper occurred within about eight seconds, and, at the moment, the damper door was pressured about 17bar. Also, it could identify that the load was approximately 900kN and the force by the fluid was applied to the damper door.

• The Korean Journal of Food & Health Convergence
• /
• v.8 no.3
• /
• pp.11-23
• /
• 2022

Processed meat products are prone to oxidation and spoilage due to prolonged storage. By using natural spices that are harmless to the human body and have antioxidant and antibacterial effects to replace synthetic preservatives in consideration of consumers' qualitative consumption patterns that pursue nutrition and safety, and stimulate appetite with taste, aroma, and color of food. The purpose of this study was to study the effect on the quality characteristics of processed meat products. The spice group had a low crude fat for both the loin and sirloin cuts. Brightness, redness, and yellowness in the chromaticity of beef jerky and PYUNYUK added with spices were different from those of the control group and increased. In terms of texture, all the beef jerky groups increased firmness and friability, and there was a difference between refrigeration and room temperature storage. The elasticity and stickiness decreased with the lapse of storage period. In the PYUNYUK, the flavor of the spice group was low and the meat quality was soft. It was found that the addition of natural spices to replace synthetic preservatives had different effects on processed meat products and had a positive effect on general ingredients, mechanical properties, physicochemical properties, and sensory quality properties.

• Journal of the Korean Society of Industry Convergence
• /
• v.25 no.6_3
• /
• pp.1155-1163
• /
• 2022

This study proposes a technology to ensure the seismic stability of a 1,000 kW diesel engine-type emergency generator by applying a seismic isolated bed system. The technology allows the static analysis by making the first natural frequency of the installed entire emergency generator larger than the earthquake cutoff frequency of 33 Hz. First a three dimensional model for the generator was made with simplification for mode analysis. A new bed system with springs, shock absorbers, stoppers was then devised. Next, The mode analysis for the finite element model equipped by the bed system was performed. the 1^st natural frequency above 33 Hz, the seismic safety cutoff frequency, was calculated to be 152.92 Hz. Finally, based on the seismic stability theory, the von-Mises equivalent stresses derived by structural analysis under the Upset and Faulted conditions were 0.01603 Mpa, and 32.06 Mpa, respectively. so seismic stability was confirmed.

• Journal of the Institute of Convergence Signal Processing
• /
• v.23 no.3
• /
• pp.123-128
• /
• 2022

A lot of research is being done to develop a high-efficiency heat pump to save energy, and research to reduce or eliminate the phenomenon of frost occurring in the outdoor unit coil is also being conducted at the same time. In order to conduct a study that does not cause frost on the outdoor unit of the heat pump regardless of the season, a constant temperature chamber like a general room that can be tested under the same conditions as in the natural state was built. The experiment was conducted by providing an environment similar to the natural state to the outdoor unit of the heat pump installed in the constant temperature chamber. As a result, the lower the outdoor temperature, the lower the efficiency of the heat pump. It wat confirmed that the lower the value, the longer it is.

• Journal of the Institute of Convergence Signal Processing
• /
• v.24 no.3
• /
• pp.140-146
• /
• 2023

A lot of research is being done to develop a high-efficiency heat pump to save energy. Among them, research to reduce or eliminate the phenomenon of frost occurring in the outdoor unit coil are being conducted at the same time. A constant temperature chamber that can be tested under the same conditions as natural conditions was constructed to conduct research that does not cause frost on the outdoor unit of the heat pump regardless of the season. The outdoor unit of the heat pump installed in the constant temperature chamber was simulated under the same natural conditions. As a result, it was confirmed that the mass flow rate of the refrigerant decreased as the outdoor temperature decreased, and the dryness of the refrigerant also increased linearly with the outdoor temperature.