• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 1991.10a
• /
• pp.80-83
• /
• 1991

The need of UPS (Uninterruptible Power Sup-ply) system is dramatically increasing with the increased use of computers, telecommunica-tion system, building automation system, and office automation system in office buildings. The consequence of the power failure is very disas trous in intelligent office buil-dings. Thus, the nucessity of large scale UPS system with generations of large scale UPS system with generator is increasing. In this study, the configurations of large scale UPS system are reviewed and analyzed. The design guide and technical considerations of high reliability system are presented.

• KIEAE Journal
• /
• v.17 no.4
• /
• pp.33-39
• /
• 2017

Purpose: The use of renewable energy system is essential for building energy independence and saving energy consumption in the building sector. Among renewable energy technologies, ground source heat pump(GSHP) system is more energy-efficient and environmental-friendly than other heat source systems due to utilize stable ground heat source. However, the GSHP system requires a high initial installation cost and installation space in limited urban area, so it is difficult to have superiority in the market of heat source system. Therefore, it is necessary to develop the installation method of low-cost and improve system performance. This paper aims to evaluate the performance of double u-tube ground heat exchanger(GHX) and verify system feasibility through real-scale experiment. Method: In this study, the real-scale experiment of vertical closed-type GSHP system was conducted using double u-tube GHX and high-efficiency grout. Through the verification experiment, heat source temperature, heat exchange rate(HER) and seasonal performance factor(SPF) were measured according to the long-term operation. In addition, the feasibility analysis was conducted comparing to the single u-tube system. Result: In the results of experiment, average HER was 136.27 W/m and average SPF was 5.41. Furthermore, compared to the single u-tube, the installation cost of the developed system could be reduced about 70% in the same heating load condition.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.25 no.10
• /
• pp.1-13
• /
• 2011

The aim of this study is to analyze the emotion adjectives for light emitting diode(LED) light colors using a twofold adjective image scales from Kobayashi and I.R.I. A set of psychophysical experiments using category judgment was conducted in an LED light color simulation system, in order to evaluate each emotion scale coordinate for those test light colors in both adjective image scales. In total, 49 test light colors from a combination of 6 color series were assessed by 15 human observers. As a result, Kobayashi adjective image scale clearly expressed to emotion adjectives of 'Dynamic', 'Casual', 'Chic', 'Cool-casual', 'Modern', and 'Natural' for different hues. In contrast, I.R.I adjective image scale expressed only 2 adjectives of 'dynamic' and 'luxurious' for the all hues.

• Journal of the Korean Geosynthetics Society
• /
• v.17 no.4
• /
• pp.225-238
• /
• 2018

In this paper, to investigate the influence of installation damage, a variety of full-scale field installation tests with 15 geosynthetics reinforcements and fill materials of various grain size distribution have been performed. The full-scale field installation test was conducted with reference to the FHWA (2009) guidelines. The tensile strength tests were performed by sampling up to 20 specimens randomly from the excavated geosynthetics reinforcements after compaction of fill material, and the degree of decrease in tensile strength of reinforcements due to compaction was analyzed based on the experiment results. It was found that the degree of tensile strength reduction of geosynthetics reinforcements due to the compaction of fill material is greatly influenced by the type of reinforcement and the maximum diameter of fill material. In addition, it was found that the strength reduction ratio of PET geogrid (PVC coating) with relatively small stiffness was greatest, and that the larger the maximum grain size of the fill material, the greater the strength reduction ratio. And also, a more reasonable evaluation method for the installation damage reduction factor of geosynthetics reinforcements is proposed based on the results of full-scale field installation tests in present study and the existing test results.

• Nuclear Engineering and Technology
• /
• v.54 no.12
• /
• pp.4731-4742
• /
• 2022

RBMK fuel assemblies differ from other LWR FA due to a specific arrangement of the fuel rods, the low enrichment, and the used burnable absorber - erbium. Therefore, there is a challenge to adapt modeling tools, developed for other LWR types, to solve RBMK problems. A set of 10 different depletion simulation schemes were tested to estimate the impact on reactivity and spent fuel composition of possible SCALE code options for the neutron transport modelling and the use of different nuclear data libraries. The simulations were performed using cross-section libraries based on both, VII.0 and VII.1, versions of ENDF/B nuclear data, and assuming continuous energy and multigroup simulation modes, standard and user-defined Dancoff factor values, and employing deterministic and Monte Carlo methods. The criticality analysis with burn-up credit was performed for the SFP loaded with RBMK-1500 FA. Spent fuel compositions were taken from each of 10 performed depletion simulations. The criticality of SFP is found to be overestimated by up to 0.08% in simulation cases using user-defined Dancoff factors comparing the results obtained using the continuous energy library (VII.1 version of ENDF/B nuclear data). It was shown that such discrepancy is determined by the higher U-235 and Pu-239 isotopes concentrations calculated.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.21 no.9
• /
• pp.7-11
• /
• 2007

The objective of this study is to evaluate the characteristics of a newly proposed high-speed drive method for the gray scale display for high-resolution plasma display panels(PDP). In the experiment it was found that the characteristics of gray scale display are not closely affected by a priming period below 50[${\mu}s$], the width of the priming period, and that it can be driven stably from the brightest sub-field to the darkest sub-field even though a priming discharge is applied to the 1 TV-field only once. Moreover, from the experimental result, the gray scale pattern of 8-bit and 9 sub-fields was stably displayed in the experimental PDP with scan pulses having the pulse width of 0.7[${\mu}s$]. An address voltage margin of about 25[V] and a sustain voltage margin of about 10[V] was obtained.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.26 no.10
• /
• pp.72-80
• /
• 2012

In general, electronic conveyor scales are installed in a relatively distributed manner on the crushed rock and sand production site. It is one of the time-consuming and difficult engineering works to monitor and control the plant operation status such as the management of measuring data, malfunction of belt conveyor, and fault of electronic conveyor scale. Therefore, to alleviate the inefficient problems and to monitor the operating plant in the online and remote control room, a remote calibration and real-time monitoring system, which is practically applied to the electronic conveyor scale system and verified by onsite experiment, is developed based on the LabVIEW.

• Geomechanics and Engineering
• /
• v.17 no.1
• /
• pp.81-95
• /
• 2019

Due to the importance of soil reinforcement using geotextiles in geotechnical engineering, study and investigation into long-term performance, design life and survivability of geotextiles, especially due to installation damage are necessary and will affect their economy. During installation, spreading and compaction of backfill materials, geotextiles may encounter severe stresses which can be higher than they will experience in-service. This paper aims to investigate the installation damage of geotextiles, in order to obtain a good approach to the estimation of the material's strength reduction factor. A series of full-scale tests were conducted to simulate the installation process. The study includes four deliberately poorly-graded backfill materials, two kinds of subgrades with different CBR values, three nonwoven needle-punched geotextiles of classes 1, 2 and 3 (according to AASHTO M288-08) and two different relative densities for the backfill materials. Also, to determine how well or how poorly the geotextiles tolerated the imposed construction stresses, grab tensile tests and visual inspections were carried out on geotextile specimens (before and after installation). Visual inspections of the geotextiles revealed sedimentation of fine-grained particles in all specimens and local stretching of geotextiles by larger soil particles which exerted some damage. A regression model is proposed to reliably predict the installation damage reduction factor. The results, obtained by grab tensile tests and via the proposed models, indicated that the strength reduction factor due to installation damage was reduced as the median grain size and relative density of the backfill decreases, stress transferred to the geotextiles' level decreases and as the as-received grab tensile strength of geotextile and the subgrades' CBR value increase.

• Journal of Environmental Science International
• /
• v.16 no.11
• /
• pp.1209-1218
• /
• 2007

Advertisement signboards on the buildings have functionally a visual value as factor of urban and building design. But it is not easy to find any reasonable principles and regulations, how well the signboards deliver the information of stores to the customers, and how they contribute the visual amenity from the sight of urban landscape. Under this context, this study tries to analyze the information delivery power of signboards in relation to the visual cognition. The analysis method is the Two-Way ANOVA (Analysis of Variance) evaluation with factors, such as scale, amount and arrangement of signboards. The scale of letters or figures at Signboards is specified in 3 different sizes such as big, medium and small. The amount is classified into 5 grades from 100% to 20% installation. And the arrangement is divided into orderly and disorderly installation. As the results of the Two-Way ANOVA, the identical scale of signboards is much better for the awareness. And the orderly arrangement shows also the same result. Above all, including these two results, the 80% of installation showed the biggest different result of awareness.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.29 no.1
• /
• pp.47-56
• /
• 2015

Energy consumption in buildings is currently a real problem. That is why both assessment of energy performance and effective energy management including renewable energy system are essential. Thus, this paper focuses on a case study to analyze the energy performance and cooling & heating energy saving of a large scale shopping store in Daejeon city. The reference building is simulated by using TRNSYS dynamic simulation tool to examine its annual energy consumption. For annual energy analysis of building, one year energy consumption is surveyed in the field. The related study is carried out in large scale shopping store to investigate the energy consumption and energy use trend of heating, cooling, hot water, lighting, ventilation, equipments and other. The evaluation of energy performance of the geothermal heat pump system installed in a large scale shopping store is also analyzed by TRNSYS tool. From simulation results, it evaluated that the geothermal heat pump system is effective energy savings method in large scale shopping store.