• Journal of the Korea Safety Management & Science
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• v.3 no.3
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• pp.213-220
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• 2001

This paper presents the interrelationship between software quality character and engineering attributes. The software quality characteristics and subcharacteristics are excerpted from IS0/IEC 9126 standards, and the engineering attributes are from Deutsch and Willis〔4〕. Based on the previous studies a subjective judgement, trisected interrelationship(strong, medium, weak) bet these two groups are derived. The results are summarized in a table, and can be used as a quick reference guide to the software quality engineering application such as quality evaluations for software products, selection of key engineering attributes for high-quality software production, and so forth.

• 한국전산유체공학회:학술대회논문집
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• 2006.05a
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• pp.405-407
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• 2006

A full-scale simulation of steel mill reheating furnace was performed by using parallel computing technology. Turbulent flow as well as chemical reaction is considered and solved in a coupled manner while radiation is also calculated. The movement of slab is taken into account so that a more precise observation of its heating characteristics becomes possible through this numerical analysis.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.11
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• pp.33-41
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• 2007

Effect of finite substrate plane on the radiation characteristics of microstrip patch antennas is investigated. The variation of the characteristics of the radiation pattern due to the change of the length of a substrate is much larger than that due to the change of the width of a substrate. As the thickness of a substrate increases, the characteristics of the radiation pattern reveal more sensitive for the change of the size of a substrate.

• Journal of Mechanical Science and Technology
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• v.20 no.12
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• pp.2284-2291
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• 2006

The present study investigates gas residence time and mixing characteristics for various swirl numbers generated by injection of secondary air into a lab-scale cylindrical combustor. Fine dust particles and butane gas were injected into the test chamber to study the gas residence time and mixing characteristics, respectively. The mixing characteristics were evaluated by standard deviation value of trace gas concentration at different measurement points. The measurement points were located 25 mm above the secondary air injection position. The trace gas concentration was detected by a gas analyzer. The gas residence time was estimated by measuring the temporal pressure difference across a filter media where the particles were captured. The swirl number of 20 for secondary air injection angle of 5$^{\circ}$ gave the best condition: long gas residence time and good mixing performance. Numerical calculations were also carried out to study the physical meanings of the experimental results, which showed good agreement with numerical results.

• Journal of Biosystems Engineering
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• v.34 no.3
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• pp.161-166
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• 2009

This study was conducted to investigate the growth characteristics of cherry tomatoes in greenhouse using far infrared heating system. The far infrared greenhouse heating systems were installed in two ways on the greenhouse side wall and at the greenhouse ceiling. The heating characteristics of far infrared heating system were analyzed by investigating the heating load, internal temperature, energy consumption, growth characteristics and quality evaluation. The results were compared with heated air heating system using kerosene. The results showed that tomatoes grown in the greenhouse with the far infrared heating system had relatively better plant height, leaf length, leaf width, stem diameter than ones from the greenhouse with hot air heating system and both heating methods had no significant difference on Cherry tomato sugar contents. At the same time, the far infrared heating system reduced heating cost from 34.5 to 41.4% on comparing with hot air heating system.

• Journal of Korean Society on Water Environment
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• v.24 no.2
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• pp.169-173
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• 2008

A field monitoring was conducted in order to find out the discharge characteristics of non-point source pollutants in the agricultural area. Event Mean Concentration (EMC) of TSS, $BOD_5$, $COD_{Mn}$, TP, TN was calculated based on the monitoring data of 10 rainfall events at agricultural watersheds. A significant relationship was observed from the correlation between EMCs and rainfall characteristics. The result shows that EMC ranges of 95% confidence intervals were 50.5~203 mg/L for TSS, 0.8~14.2 mg/L for $BOD_5$, 4.2~20.7 mg/L for $COD_{Mn}$, 2.4~4.5 mg/L for TN and 0.2~0.5 mg/L for TP, respectively. The correlation coefficients between TSS and TP and between $BOD_5$ and $COD_{Mn}$ were found to be 0.912 and 0.961. But TN was lower correlated with other EMC factors. It was also found that rainfall characteristics was not correlated with EMCs.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.1213-1216
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• 2010

Developable areas nearby metropolitan areas, which has high the density of population are limited by highly industrialized. In recent, the redeveloping plans for the finished industrial and resident areas are pushing to resolve this problems. Getting to the exact properties for reclaimed wastes is very important to reuse of landfill. Also, a strategy for how to deal with follow-up measures have to based on the waste characteristics. A lot of environmental problems have been happened in finished waste landfill such as a nasty smell by seepage, pollution of surface and ground water, a poisonous gas and soil contamination. The environment pollution in waste landfill have been studied by many researchers. The goal of this study is estimate the effects for the ground properties with the environmental properties of waste in finished landfill. As the results, the chemical characteristics of seepage in landfill may effect directly or indirectly to capping layer. Therefore, sustainable researches are needed to develop a secure landfill over the long term.

• International Journal of Fluid Machinery and Systems
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• v.4 no.2
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• pp.255-261
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• 2011

Recently, as global-scale problems, such as global warming and energy depletion, have attracted attention, the importance of future environmental preservation has been emphasized worldwide, and various measures have been proposed and implemented. This study focuses on water hammer pumps that can effectively use the water hammer phenomenon and allow fluid transport without drive sources, such as electric motors. An understanding of operating conditions of water hammer pumps and an evaluation of their basic hydrodynamic characteristics are significant for determining whether they can be widely used as an energy-saving device in the future. However, conventional studies have not described the pump performance in terms of pump head and flow rate, common measures indicating the performance of pumps. As a first stage for the understanding of water hammer pump performance in comparison to the characteristics of typical turbo pumps, the previous study focused on understanding the basic hydrodynamic characteristics of water hammer pumps and experimentally examined how the hydrodynamic characteristics were affected by the inner diameters of the drive and lift pipes and the angle of the drive pipe. This paper suggests the effect of the air volume in the air chamber that affects the hydrodynamic characteristics and operating conditions of the water hammer pump.

• Structural Engineering and Mechanics
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• v.58 no.1
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• pp.21-38
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• 2016

Many studies have been carried out to investigate the important factors in calculating the realistic entropy amount of water distribution networks, but none of them have considered both mechanical and hydraulic characteristics of the networks. Also, the entropy difference in various networks has not been calculated exactly. Therefore, this study suggested a modified entropy function to calculate the informational entropy of water distribution networks so that the order of demand nodes and entropy difference among various networks could be calculated by taking into account both mechanical and hydraulic characteristics of the network. This modification was performed through defining a coefficient in the entropy function as the amount of outflow at each node to all dissipated power in the network. Hence, a more realistic method for calculating entropy was presented by considering both mechanical and hydraulic characteristics of network while keeping simplicity. The efficiency of the suggested method was evaluated by calculating the entropy of some sample water networks using the modified function.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.7
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• pp.767-773
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• 2014

This paper presents the reduction characteristics of electromagnetic penetration through a slit in conducting screen by loaded plate. The FDTD method is used in theoretical analysis. And the characteristics of penetrated electric fields are calculated in terms of length, width, shape, position, and height of the loaded plate to find out how the geometry of plate influences the reduction characteristics of the electromagnetic penetration and shielding effectiveness. The results show that the characteristics of penetrated electric field and shielding effectiveness depend on the geometry of loaded plate. In particular, the optimal geometry of loaded plate which minimize penetrated electric field are verified.