• KIEAE Journal
• /
• v.13 no.3
• /
• pp.71-78
• /
• 2013

A need for building energy efficiency is on the issue since energy demand in the building stock in Korea represents about 24% of the final energy consumption. As a way of improving the thermal performance of buildings for reducing maintenance costs and environmental conservation, a lot of effort is shown to improve the building energy efficiency by applying improvement of envelope insulation performance for buildings whose energy efficiency is low relatively through the remodeling. The windows of building envelopes are areas that lead to the biggest heat loss in the building. So windows are considered to be the primary target of energy efficiency in remodeling and various studies for windows have been done. Currently, however, only U-factor and airtightness of windows performance are regulated. Window wall ratio(WWR) and solar heat gain coefficient(SHGC) of windows are not considered when conducting the remodeling. In this study appropriate performance of windows(U-factor and SHGC) for existing residential is proposed according to the window wall ratio by using EnergyPlus. As the results of this study, the U-factor of windows representing the maximum energy savings is $1.0W/m^2K$ but in case of SHGC, the values that indicate the maximum energy savings are different depending on the window wall ratio. Therefore, when conducting the remodeling of windows, to determine energy efficiency by considering only the U-factor is inadequate so it is necessary that appropriate windows are applied to buildings by considering window wall ratio and windows properties(U-factor and SHGC).

• Journal of the Korean Institute of Gas
• /
• v.11 no.2 s.35
• /
• pp.60-64
• /
• 2007

Chemical Process industry in Korea has over 30 year's of history and is likely to face potential incidents. The traditional risk analysis and control system in Chemical Process industry focuses on mechanical defects, overlooking the human performance control. Although development of automation technology and controlling technology was necessary, human decision factor is essential to preventing accidents in the Chemical Process. Almost all serious accidents take place when inappropriate humanperformance and mechanical defects of safety equipments simultaneously occurs. The AHRA(Advanced Human Reliability Analyzer) software has been developed to collect failure data and analyze human error probability (Reliability) in Chemical Process Industry in Korea. This paper describes the HRA analysis result of PIF(Performance Influencing Factor) evaluation, HEP(Human Error Probability) and root cause of accidents by applying a Chemical Process Industry related accident data. This analysis result should present a scheme that, by controlling human error factor other than putting safety management funds into the machinery in plants, can reduce cost and maximize the safety in Chemical Process Industry.

• International Area Studies Review
• /
• v.21 no.4
• /
• pp.3-17
• /
• 2017

The purpose of the paper is to suggest the empirical evidences for the effects of factor prices on the export performance in the Korean manufacturing industries during the period 1975:1-2016:4. The paper is to set up the error correction model derived from the autoregressive distributed lag scheme and to estimate the factor price elasticities of export in the 8 manufacturing industries. The real wage, interest and import price index elasticities of export all were estimated to be statistically significant at 1% level in the most industries with showing negative signs as expected. And the real wage elasticity proved to likely be smaller as the industries become more capital-intensive while the import price index elasticity tended to become larger in industries with larger ratio of imported intermediate goods to output. The empirical results suggest that the declines in input factor prices since the foreign exchange crisis in the end of 1997 have positive effects on the export performance in the Korean manufacturing industries.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.52 no.5
• /
• pp.238-245
• /
• 2003

In this paper, a single Phase voltage source voltage-controlled active power filter(APF) for power quality improvement was proposed. The proposed APF has the performance of harmonic suppression and unity power factor correction. The performance of harmonic suppression can be obtained by controlling the waveshape of the APF output voltage to be sine wave. And, unity power factor is controlled by the reactive power control loop of the APF output. Simulation and experimental results using diode rectifier showed that the voltage-controlled APF, unlike the current-controlled APF, can reduce the voltage harmonics as well as current harmonics. Also the results showed that the input dover factor and power quality were greatly improved.

• Journal of the Korean Statistical Society
• /
• v.29 no.3
• /
• pp.337-350
• /
• 2000

This paper suggests a new diagnostic measure and a stopping rule for detecting influential observations in multiple discriminant analysis (MDA). It is developed from a Bayesian point of view using a default Bayes factor obtained from the fractional Bayes factor methodology. The Bayes factor is taken as a discriminatory information in MDA. It is shown that the effect of an observation over the discriminatory information is fully explained by the diagnostic measure. Based on the measure, we suggest a stopping rule for detecting influential observations in a given training sample. As a tool for interpreting the measure a graphical method is sued. Performance of the method is used. Performance of the method is examined through two illustrative examples.

• Journal of Information Display
• /
• v.10 no.1
• /
• pp.28-32
• /
• 2009

The correlation between the optical performance of the reflective polarizer, which is a key optical component for the brightness enhancement of the liquid crystal display (LCD), and the configuration of optical sheets was investigated in a direct-lit CCFL (cold-cathode fluorescent lamp) backlight. The optical gain of the reflective polarizer, the polarization state of the light emitted from each film, and the loss factor for the polarization conversion process occurring in the lower part of the backlight were determined using a phenomenological approach for the polarization recycling process. The present study suggests that the correlation between the optical performance of the brightness enhancement films and the backlight configuration should be carefully considered in the optimization of the backlight structure.

• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 1997.11a
• /
• pp.63-66
• /
• 1997

The rule bases self organizing controller(SOC) has one of its main advantages in the fact that there is no need to have a mathematical description of the system to be controlled. In this controller, the rules are linguistics statements expressed mathematically through the concepts of fuzzy sets and correspond to the actions a human operator would take when controlling a given process. With this controller, we have performed to sight stabilization system, and we realize that it needs a scale factor tuning. The self tuning controller(STC) uses an instantaneous system fuzzy performance which can give an inspection to the scale factor. Therefore, the STC can compensate the scale factor when it is not adequately tuned. With this trial, we shows that STC can give a good transient characteristics in the nonlinearity which imposed basically in the conventional servo system.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.58 no.2
• /
• pp.217-224
• /
• 2009

This paper presents a new AC/DC converter scheme for HVDC system to achieve a high power factor operation. The new AC/DC converter consists of two 12-pulse bridge converters in series: the primary and auxiliary converters. Ignition angles of the main and auxiliary converters are controlled independently to maintain the nominal DC voltage and control auxiliary voltage. The resulted DC voltage obtained by superimposing the above two phase modulated voltages can be controlled very rapidly over a wide range, and a high power factor operation is achieved. Performance improvements in power factor and harmonic distortion are validated by theoretic derivations and experiments with prototype HVDC system. With the proposed converters, investment for reactive power compensation and filter in HVDC system can be saved significantly.

• Progress in Superconductivity and Cryogenics
• /
• v.23 no.4
• /
• pp.6-9
• /
• 2021

Superconducting coplanar waveguide (SCPW) resonators with high quality (Q) factor are widely used for developing quantum sensors and quantum information processors. Here we conducted numerical simulations of SCPW resonators to investigate the relationship between the Q factor and the coupling capacitance of the resonator. Varying the geometrical shape of both ends and coupling parameters of the SCPW resonator resulted in a change of the coupling capacitances and the Q factor as well. Our calculation results indicate that the performance of the SCPW resonator is highly sensitive to the capacitive coupling and searching for an optimal coupling condition would be crucial for developing high-performance SCPW resonator.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.20 no.1
• /
• pp.1-9
• /
• 2021

In this paper, we propose an IoT-based traffic safety pedestrian system for the elderly by factor analysis. The proposed system performs a factor analysis of the elderly safety variables and uses the analysis results to provide an optimal path for the elderly. In order to verify the performance of this system, we experimented with performance measurements on elderly pedestrian paths. As a result, we confirm that it provides a better safety path than mobile navigation.