• Journal of the Korea Institute of Military Science and Technology
• /
• v.12 no.6
• /
• pp.711-718
• /
• 2009

During the preliminary design phase of a supersonic aircraft, it is necessary to evaluate many potential engine/airframe combinations to determine the best solution to given set of mission requirements. And it is very important to establish a methodology to predict precisely afterbody drag so that accurate engine installed performance can be estimated. It was carried out in this paper to establish a methodology to predict afterbody drag of F-15K supersonic aircraft based on IMS(Integral Mean Slope) methodology, acquire afterbody drag data and compare its calculated data with the test data acquired from the wind tunnel test data based on 4.7% model scale. The comparison results showed good agreement between the calculated data and test data and it was found that the methodology described here to predict and test afterbody drag is acceptable.

• 한국신재생에너지학회:학술대회논문집
• /
• 2007.06a
• /
• pp.284-287
• /
• 2007

This paper presents the performance evaluation of PV systems installed at Tibet area of China in order to identity the key factors that determines system operation at a severe climate conditions and promote the cooperation of PV technology between Korea and China. The installed systems consist of 100kW on-grid connected PV systems, BOS(balance of systems), data acquisition and transmission equipments. The Korea side supplied the solar cell, BOS like as inverter, control box and monitoring system. And the Chinese side assembled solar module, constructed site and built control house. It has been shown that the average radiation per monthly from Tibet is 1.5 times larger than that from Mokpo. Also, radiation time from Tibet is 2hour higher than that from Korea. The economical analysis has shown that with the current prices, investment in a grid connected PV systems is generally profitable

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2007.05a
• /
• pp.578-581
• /
• 2007

In this study, the seismic control performance of energy dissipation devices installed in a shear all-frame structure is investigated through nonlinear time history analysis of a 12-story building. Inelastic shear walls are modeled using the multiple vertical line element model (MVLEM) and inelastic columns and girders were modeled using fiber beam elements. For a seismic load increased by 38% compared to the design load, the seismic control performance was analyzed based on the results of a nonlinear time history analysis in terms of the inter-story drift, the story shear and the flexural strain. Friction type dampers was found to performs best if they are installed in the form of a brace adjacent to the shear wall with the friction force of 15 % of the maximum story shear force induced in the original building structure without dampers.

• Structural Engineering and Mechanics
• /
• v.46 no.3
• /
• pp.337-352
• /
• 2013

Seismic performance of critical facilities has been focused on the structural components over the past decade. However, most earthquake damages were observed to the nonstructural components during and after the earthquakes. The primary objective of this research was to develop the seismic fragility of the piping system incorporating the nonlinear Tee-joint finite element model in the full scale piping configuration installed in critical facilities. The procedure for evaluating fragility curves corresponding to the first damage state was considered the effects of the top floor acceleration sensitivities for 5, 10, 15, and 20 story linear RC and steel building systems subjected to 22 selected ground motions as a function of ground motion uncertainties. The result of this study revealed that the conditional probability of failure of the piping system on the top floor in critical facilities did not increase with increased level of story height and in fact, story level in buildings can tune the fragilities between the building and the piping system.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.16 no.5
• /
• pp.641-649
• /
• 2016

In this paper, a novel time-domain measurement technique on a high parallelism probe card with protection resistors installed is proposed. The measured signal amplitude decreases when the measurement is performed by Needle Auto Calibration (NAC) probing on a high parallelism probe card with installed resistors. Therefore, the original signals must be carefully reconstructed, and the compensation coefficient, which is related to the number of channel branches and the value of protection resistors, must be introduced. The accuracy of the reconstructed signals is analyzed based on the varying number of channel branches and various protection resistances. The results demonstrate that the proposed technique is appropriate for evaluating the overall signal performance of probe cards with Automatic Test Equipment (ATE), which enhances the efficiency of probe card performance test dramatically.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2005.11a
• /
• pp.295-298
• /
• 2005

In General, post-installed dowel bars are used as a shear connector to ensure the composite actions between new slabs and existing slabs in an apartment remodelling constructions expecially for enlarging the interior space outward the existing buildings. But, it has not been checked that the connection performance between existing and new slab is satisfactory not only for the structural safety condition but also the for serviceability and dwelling requirements. In this research, an experimental works were presented to evaluate the load transfer capacity for the planar joints between existing and new slab. The existing slabs were obtained from the existing apartment housing which will be demolished. Test results showed that the planar joints with post-installed dowel bars behaved in full composite modes until ultimate capacity of test specimens, so sufficient ultimate and serviceability performance are confirmed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2000.06a
• /
• pp.1772-1777
• /
• 2000

The Combat Computer Consoles installed in surface ships should endure harsh environment such as vibration from engine or propeller and shock from underwater explosion. Generally, commercial isolation mounts are selected and used for anti-vibration and anti-shock design. In this research, the environment of the Combat Computer Console was analyzed first. Selected proper mount was modeled and computer simulation was performed to emulate the environment test. The real environment test was conducted with a manufactured Combat Computer Console. The test results were same as the simulation and satisfied the performance requirements. The computer simulation proved to be a useful design tool to predict the performance before the final environment test.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.17 no.12
• /
• pp.1139-1144
• /
• 2007

The use of noise barrier is being increased to reduce the environmental noise in these days. Also, many noise reducers installed at the top of noise barrier are developed for improving the efficiency of noise reduction. So we evaluate the performance of the noise reducers and compare the results among the others. Results of field tests show that the insertion loss due to the noise reducers is up to 10.6 dB.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2014.10a
• /
• pp.10-12
• /
• 2014

In ISO 10140-5:2010, defines the reverberation time conditions of the receiving room. The sound absorption side of test specimen is installed in the source room generally. In this study, examined at the change in the sound insulation characteristics for the test specimen of asymmetric structure attached sound absorbing material by changing the installed position. A difference of sound insulation performance was maxium Rw 1 dB, it is preferable to place the larger sound absorption area in source room.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.26 no.5
• /
• pp.206-211
• /
• 2014

The objective of the present study was to identify ventilation problems, and also to suggest new axial fan systems for the improvement of IAQ in the underground parking lots. Numerical results for air mean-velocity, local mean age, and sound power level are presented along with some of fan angles. The results showed the influence of airflow patterns on the fan performances installed in the underground parking lots. Discharge air volume is increased with the angle of the blade. And also, the main factors affecting the noise of the ventilation fan was found to be a rotational speed.