• Journal of the Korean Institute of Educational Facilities
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• v.26 no.4
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• pp.19-25
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• 2019

Concrete wedge anchor is one of structural components to transfer load of an object attached to a primary structure. Recently, as retrofitting concrete structure is becoming a main issue, mechanical capacity of the anchor should be secured enough. In spite of the structural safety of Cast-in-place anchor, Post-installed anchor is more widely used with ease of placement or change of construction method. However, the post-installed anchors domestically produced have excessive coefficient of variation over 15% of ultimate tensile strength, which yields deteriorated quality in tensile strength. In this research, tensile strength test of anchors, which have improved sleeve and header and produced by a domestic company, was conducted for two variables, concrete strength and effective embedment depth. As a result, enough coefficients of variations were secured in all specimens. Also, in comparison to foreign products, the domestic ones have equal or higher performance.

• Journal of the Korean Solar Energy Society
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• v.39 no.3
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• pp.19-27
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• 2019

In commercial areas, outdoor units are typically installed close to one another in the narrow space between buildings due to insufficient regulations. This makes it difficult to ventilate the discharge airflow, which may lead to deterioration of the performance of outdoor units. This study conducted CFD simulation to analyze the thermal environment according to the installation distance of the outdoor unit. The outdoor unit was installed in the space between buildings, and the thermal environment was analyzed by changing installation distance and wind speed. The performance of the outdoor unit was evaluated by measuring the on-coil temperature. The results show that the closer the distance between outdoor units, the higher the condenser on-coil temperature. Also, the on-coil temperature appeared to rise dramatically at lower wind speed.

• Journal of Korean Association for Spatial Structures
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• v.24 no.1
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• pp.89-98
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• 2024

In this study, we investigated the dynamic characteristics of three irregular building models to analyze the effectiveness of displacement response control with Tuned Mass Damper (TMD) installation in twisted irregular buildings. The three irregular models were developed with a fixed angle of twist per story at one degree, subjected to three historical seismic loads and resonant harmonic loads. By designing TMDs with linear and dashpot attributes, we varied the total mass ratio of the installed TMDs from 0.00625% to 1.0%, encompassing a total of 10 values. Two TMDs were installed at the center of the top story of the analysis model in both X and Y directions to evaluate displacement response control performance based on TMD installation. Our findings suggest that the top displacement response control performance was most effective when a 1.0% TMD was installed at the top layer of the analysis model.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10a
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• pp.107-112
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• 1990

It is necessary to develop graphic MMI (Man-Machine Interface) for the maximum utilization of our installed ADS (Automated Distribution System) for which an operator types and executes string commands. Considering the restrictions and characteristics of the installed ADS and the data for modelled distribution lines, we calculated the time of periodic data acquisition for large number of points. And we presented the performance and characteristics of the graphic MMI system which will be developed and which will facilitate SCADA(Supervisory Control And Data Acquisition) functions.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.472-475
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• 2009

Nowadays, Short headway is a requirement of Signaling System applied to subway and Light Rail Transit (LRT) being constructed in Korea. To satisfy this Systematic Requirement, the accuracy of train position information on the line is one of the main element to improve ATC system safety and performance. On-board ATC system performs feasibility of Train Position as comparing data from balise installed along the track with data from tachometer installed at both axles of train.

• Journal of the Korean Society of Propulsion Engineers
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• v.10 no.4
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• pp.100-108
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• 2006

Experimental study has been a general way to evaluate inlet and exhaust duct performances, but this is not only costly but also time consuming. Computational simulation is hence replacing experimental study and consequently time and cost saving. This paper therefore aims to investigate typical component performance of the intake and exhaust ducts using 3D representation. In this study a specific inlet and exhaust was modeled and analyzed to estimate its losses and flow field using computational fluid dynamic program with flow visualization capabilities. A process that requires geometry data to be modeled. That allowed for possibility of design trade off in designing phase. Installed performance of a specific turbo shaft engine was finally evaluated with the estimated inlet, exhaust and other accessories losses.

• Wind and Structures
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• v.12 no.4
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• pp.313-332
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• 2009

This paper numerically and experimentally investigates the control performance of the active mass damper (AMD) systems in a 26-story high-rise building in use. This is the first full-scale application of the AMD system for suppressing the wind-induced vibration of a building structure in Korea. In addition, the AMD system was installed on top of the building already in use, which may be the world's first implementation case. In order to simultaneously mitigate the transverse-torsional coupled vibration of the building, two AMD systems were applied. Moreover, the H-infinity control algorithm has been developed to utilize the maximum capacity of the AMD system. From the results of numerical simulation using the wind load obtained from the wind tunnel tests, it was found that the maximum acceleration responses of the building were reduced significantly. Moreover, the control performance of the installed AMD system was examined by carrying out the free and forced vibration tests. The acceleration responses on top of the building in the controlled case measured under strong wind loads were compared with those in the uncontrolled case numerically simulated by using the wind load deduced from the measured data and a structural model of the building. It is demonstrated that the AMD system shows good control performance in reducing the building accelerations.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.04a
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• pp.625-629
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• 2014

For the purpose of the acoustic performance evaluation of noise reduction device(NRD) installed at the top of noise barrier for further decreasing of noise level of 400km/h class high-speed railroad(HEMU), the acoustic performance test method using speaker instead of really running railway vehicle was suggested in this paper. For this, noise source location and frequency spectrum of HEMU was analyzed through the field noise test. These data were used for the determination of speaker's installation positions and frequency correction values applied to the speaker noise source. And, 400 meters long NRD was installed at the site where HEMU will be running at a speed of 400km/h. Finally, the outdoor speaker test with and without NRD showed that this NRD could decrease noise level even more than 3dB(A). In the future, the acoustic performance results of NRD conducted with speaker test will be compared with that of field test for HEMU running at a speed of 400km/h.

• KIEAE Journal
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• v.7 no.1
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• pp.23-31
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• 2007

This study aims to evaluate the illuminance performance of sloped light guide with automated venetian blind systems. For the purpose, a mock-up model was constructed as a prototype of Korean office building with $12.0m{\times}7.3m{\times}3.7m$ ($w{\times}d{\times}h$) and south facing side-window mounted between the clerestory window($2.0m^2$) and the view window($5.6m^2$). The light guide of 1.28m deepth and $29^{\circ}$ tilted angle, is covered with 0.6mm galvanized steel sheet and 97% reflective film. To protect the room from low solar angle, a blind systems, 0.15m deepth and $30^{\circ}$ automated slat angle was installed. To assess illuminance performance, the totally 37 measuring points for illuminance were monitored. For the detailed analysis, photometric sensors were installed at work-plane (8 points), wall (7 points), ceiling (3points), and exterior horizontal illuminance (1 point) respectively. The performance was measured under clear sky and is monitored by Agilent data logger, photometric sensor Li-cor and the Radiant Imaging ProMetric 1400. Comparisons of light factor and uniformity are discussed.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.03a
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• pp.405-412
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• 2002

The performance of a hammer/driving systems is a major factor which affects bearing capacity and integrity of installed piles. Hammer performance can be evaluated from the results of dynamic pile testing using Pile Driving Analyzer(PDA). By comparing the rated energy with measured maximum transferred energy(EMX), the energy transfer ratio(ETR) can be calculated. This paper based on the dynamic measurements of 442 cases in 130 piling projects and evaluated ETR according to the hammer types(hydraulic and drop hammers) and pile types(steel and concrete piles).