• Journal of Information Display
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• v.12 no.2
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• pp.85-87
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• 2011

The contrast ratio is one of the most important performance parameters for display devices. The general method of measuring the contrast ratio is to determine the ratio of the full-screen white pattern to the full-screen black pattern, according to the Video Electronics Standards Association standard. Real TV images seldom have these images, however, and the conventional method does not reflect the true performance of the display in actual use. In this paper, a new contrast ratio measurement method that uses image patterns is proposed, to demonstrate that active matrix organic light-emitting diode TVs have a higher contrast than LED (LCD) TVs.

• Journal of the Korean Society for Railway
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• v.14 no.3
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• pp.234-239
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• 2011

Installing the temporary bridge after excavating the railway requires installing movable cross beam, but as it doesn't requires isolating the catenary or cutting the rail, it's applicable to double-track with frequent operation. In this study, a displacement meter was placed on temporary bridge to monitor the displacement pattern in curve section (R400) completed using temporary bridge method, and wheel load, lateral pressure and derailment coefficient were measured to evaluate the load imposed on track and the stability in curve section (R400) for quantitative evaluation of training running safety. As a result of the measurement, when trains passing over a temporary bridge, the maximum value of Wheel load and Lateral Force is analyzed as the 51% and 81% of standard level according to foreign country's performance tests, There is no trouble with stability analysis in Wheel load and Lateral Force occurring. Additionally, Wheel load and Lateral Force considered as the safety standard are tested 49% of limiting value regardless of trains, which the norm value quite well, there is no problem with train running.

• Structural Engineering and Mechanics
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• v.87 no.4
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• pp.347-361
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• 2023

This research aims to assess the behavior of reinforced concrete (RC) residential buildings when moment-resisting frames (MRFs) are used as the lateral resisting system. This investigation was conducted using MIDAS Gen v.19.0. Buildings with various plan footprints (Square, Rectangular, Circular, Triangular, and Plus-Shaped), and different heights (15 m, 30 m, 45 m, and 60 m) are investigated. The defined load cases, the equivalent static lateral load pattern, and the response spectrum function were defined as stated by the American Standard (ASCE 7-16), the 1997 Uniform Building Code (UBC97), the Egyptian Code for Loads (ECP-201), and the European Standard (EC8). Extensive comparisons of the results obtained by the different codes (including the story displacement, the story drift, and the base shear) were undertaken; to assess the response of moment-resisting multi-story framed buildings under lateral loads. The results revealed that, for all study cases under consideration, both ECP-201 and EC8 gave smaller base shear, displacement, and drift by one third to one fourth, around one fourth, around one fifth, respectively for both the ELF and RSA methods if compared to ASCE 7-16 and UBC97.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.1
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• pp.91-100
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• 2004

Energy efficiency evaluation method for a multi-type air conditioning system still has not been developed. In this study, analysis on capacity range and evaluating method of standards for air conditioners was conducted with world-wide Standards. It is not a proper approach to use the standards for residential air conditioner to multi type air conditioners. Some difficulties and problems are commented in this study with overview of the standards. Through the analytic research, an evaluating method for multi type air conditioner was suggested with Integrated Part Load Value (IPLV). The suggested concept for evaluating energy efficiency during part load condition considers building load pattern and operating hours of the system at different locations. Load was weighted in IPLV to consider not only the concept of occurrence of outdoor temperature such as bin method but also operation hours of the system. An experiment about the IPLV was conducted with variable air volume ducted type air conditioning system and multi-type system through modified code tester to give a glance at quantitative value of the IPLV.

• Steel and Composite Structures
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• v.45 no.5
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• pp.665-682
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• 2022

In the current study, punching behavior of Reinforced concrete (RC) isolated footings was experimentally and numerically investigated. The experimental program consisted of four half-scale RC isolated footing specimens. The test matrix was proposed to show effect of footing area, reinforcement mesh ratio, adding internal longitudinal reinforcement bars and stirrups on the punching response of RC isolated footings. Footings area varied from 1200×1200 mm2 to 1500×1500 mm2 while the mesh reinforcement ratio was in the range from 0.36 to 0.45%. On the other hand, a 3D non-linear finite element model was constructed using ABAQUS/standard program and verified against the experimental program. The numerical results agreed well with the experimental records. The validated numerical model was used to study effect of concrete compressive strength; longitudinal reinforcement bars ratio and stirrups concentration along one or two directions on the ultimate load, deflection, stiffness and failure patterns of RC isolated footings. Results concluded that adding longitudinal reinforcement bars did not significantly affect the punching response of RC isolated footings even high steel ratios were used. On the contrary, as the stirrups ratio increased, the ultimate load of RC isolated footings increased. Footing with stirrups ratio of 1.5% had ultimate load equal to 1331 kN, 19.6% higher than the bare footing. Moreover, adding stirrups along two directions with lower ratio (0.5 and 0.7%) significantly enhanced the ultimate load of RC isolated footings compared to their counterparts with higher stirrups ratio (1.0 and 1.5%).

• KIEAE Journal
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• v.15 no.1
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• pp.139-146
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• 2015

This is an experimental study on the engineering characteristics of perforated reinforced concrete beams with shells. In the material matter of this study, the water cement ratio put 60%, the ratio of substitution of oyster shells to fine aggregate 30%. And in the structural matter, the form of opening put circle and square, the size of opening as the radius and the length of it changed from one to three times of the beam depth with a change presence and absence of reinforced steel around opening. All thirteen reinforced concrete beam tests composed one standard beam and twelve six beams with the circle and square opening were tested in shear strength under two points loading and compared and analyzed the characteristics of test beams under the same conditions one another. The results of the study showed as followed. 1) The initial crack load value of the opening test beams is similar the standard beam but the maximum load value decreased with increase in proportion of the opening size, in the square opening than the circle opening and in the absence than the presence of reinforced steel. 2) As the difference between the circle opening and the square opening beams is represented 2.17~9.8% in the maximum load value and the load capacity of the square opening suddenly decrease than it of the circle opening, it is judged because of the shortage of concrete section, the concentration of the stress in the corner of the square opening and material influence of shell substitution. 3) The failure figure such as the pattern of the crack and so on is represented brittle failure as the opening size is the bigger and the ratio of substitution is higher because of the lack material properties.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.3
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• pp.154-161
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• 2005

The durability of a vehicle is a very important performance which can be evaluated from endurance test. This study developed a procedure for determination of a duty cycle theoretically. Vehicle load data is classified and rearranged using standard test road profile. A load pattern and a duty cycles are extracted from classified vehicle data using genetic algorithm. A duty cycle could be utilized in dynamo test to meet required test mileage. The derived duty cycles have been verified by fatigue test through the dynamometer test.

• The korean journal of orthodontics
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• v.21 no.1 s.33
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• pp.7-16
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• 1991

To estimate the possibility of the application of TiN ion-plating to the orthodontic appliance, colorimetric properties, and characteristics of ion-plated film as well as adhesive strength of TiN film to the substrate and mechanical properties of ion-plated orthodontic appliance were investigated. The obtained results were as follows: 1) TiN ion-plated film had the colorimetric properties which were the hue of about 2.5 Y, the brightness of about 6, and the chroma of about 4 by the standard color chip of JIS. 2) TiN ion-plated film was $2{\mu}m$ in thickness and its deposition pattern was rather irregular. 3) TiN phase was confirmed on the X-ray diffraction pattern. 4) Critical load for delamination of ion-plated film from stainless steel band was 10N. 5) Tensile and yield strength of ion-plated specimen was increased about 10Kg $f/mm^2$, while elongation was decreased $1\%$ compairing to the values of the non ion-plated specimen.

• Journal of Aquaculture
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• v.10 no.4
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• pp.387-394
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• 1997

A total of 353 farmed rockfish, Sebastes schlegli Hilgendorf, 1880 were sampled from 3 localities on Korean coastline over a 12 month period. Full parasitological examination revealed the polypisthocotylean monogenean Micorcotyle sebastis Goto, 1894 to be abundant with infections consistently reaching over 90~100% prevalence throughout the year. A seasonal pattern in parasite abundance on the gills is evident, with the population peaking twice, the largest in winter and again in summer. While the parasitic load on the left and right gills was not dissimilar, parasites within the gill sets were found to favour settlement of the II and III gill arches. A comparison of parasite abundance with host length, revealed that the smaller length fish classes (<17cm standard body length) had significantly heavier infections than those of larger fish (>17 cm standard body length). This report represents the fist record of Microcotyle sebastis on farmed rockfish in Korean coastal waters.

• Proceedings of the KIEE Conference
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• 1992.07a
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• pp.214-217
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• 1992

This paper introduces a new methodology to apply the interpolation technique wi th optimum pattern to voltage-reactive power control of power system. The conventional tool for the optimal operation of power system is Optimal Power Flow(OPF) by standard optimization techniques. The achievement of solution through OPF programs has a defect of computation time, so that it is impossible to apply the OPF programs to the real-time control area. The proposed method presents a solution in a short period of time and an output with a good accuracy. The optimum pattern is a set of input-output pairs, where an input is a load level and a type of outage and an output is the result of OPF program corresponding to the input. The output in the OPF represents control variables of voltage-reactive power control. The interpolation technique is used to obtain the solution for an arbitrary input. As a result, the new technique helps operators in the process of the real-time voltage-reactive power control in both normal and emergency operating states.