• Wind and Structures
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• v.12 no.5
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• pp.401-412
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• 2009

A method is applied for the estimation of structural damage of tall slender structures using natural frequency and displacements measurements by GPS. The relationship between the variation in the global stiffness matrix (or in the stiffness of each finite element) and the change in the natural frequencies of the structure is given. In engineering practice the number of frequencies which can be derived by GPS measurement of long-period structures will be equal to one, two or three first natural frequencies. This allows us in initial studies to detect damage with frequency changes based on forward methods in which the measured frequencies are compared with the predicted analytical data. This idea, of health monitoring from possible changes to natural frequencies, or from a statement of excessive displacements is applied to the Stuttgart TV Tower.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.1155-1165
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• 2008

Full scale size model tests of the top-base foundation was performed in siwha marine clay and the site measurement results were compared with the analytical results from finite different programs, FLAC-2D to investigate the behavior of top-base foundation. The stress distribution obtained from the numerical analysis for the various types of foundation were compared and analysed during the application of allowable load as well as yield load. It was found that the top-base foundation prevents the lateral deformation of soft ground and stress dispersion effect to reduce the surface settlement, and that the foundation creates uniform stress distribution around it, therefore increasing bearing capacity.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.11a
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• pp.95-100
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• 2000

When compared with conventional retaining wall system, there are many advantages to reinforced soil such as cost effectiveness, flexibility and so on. The use of reinforced soil have been increased in the last 17 years in Korea. In this study, a full-scale reinforced soil with rigid facing were constructed to investigate the behavior of reinforcing system. The results of soil pressure and strain of reinforcement during construction are described. The influence of compaction on soil pressure and strain of reinforcement is addressed. The results show that lateral earth pressures on the wall are active state during backfill. It is obtained that the lateral soil pressure depends on the installation condition of pressure cell and construction condition. It is also observed that maximum tensile strains of reinforcement are located on 50cm to 150cm from the wall. Long-term measurement will be followed to verify the design assumptions with respect to the distribution of lateral stress in the reinforcement

• KIEAE Journal
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• v.5 no.4
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• pp.3-8
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• 2005

The objective of this study is to examine the impact of the Phytofiltration system on the improvement of indoor air quality. Measurement was performed in a full-scale mock up model to examine the purification efficiency of air by plants. Seven species of plants, which were recommended by NASA, were used in measurements. Two species of plants that showed outstanding purifying effects were chosen for further measurements. The measurements were performed according to the positions and amounts of plants. Thermal environment, the concentration of Toluene and Formaldehyde were monitored. Ficus Benjamiana and Aglaonema brevispathum were excellent in diluting the concentration of contaminants. The effect of diluting concentration became better as the amount of plants increased. The reducing effect was the best when the plants were placed near window.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.31A no.7
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• pp.76-84
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• 1994

The characteristics of 3 inch wafer scale GaAs epitaxial wafer grown by molecular beam epitaxy for LSI process application were studied. The thickness and doping uniformity are characterized and discussed. The growth temperature and growth rate were $600^{\circ}C$ by pyrometer, and 1 $\mu$m/h, respectively. It was found that thickness and doping uniformity were 3.97% and 4.74% respectively across the full 3 inch diameter GaAs epitaxial layer. Also, ungated MESFETs have been fabricated and saturation current measurement showed 4.5% uniformity on 3 inch, epitaxial layer, but uniformity of threshold voltage increase up to 9.2% after recess process for MESFET device.

• Journal of the Society of Naval Architects of Korea
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• v.30 no.4
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• pp.46-60
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• 1993

Accurate measurements of fluctuating pressure in the cavitation tunnel are necessary to predict vibration and noise intensities in full scale ship. In this paper, the results of an experimental study on fluctuating pressure induced by a cavitating propeller are presented and discussed. Extensive measurements at several propeller revolutions are made using the flat plate to understand controversial problems of the effects of propeller revolution in the cavitation tunnel. The analysis of the uncertainties in experimental measurements and results is used to estimate the errors in uniform flow.

• Journal of KSNVE
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• v.6 no.2
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• pp.245-251
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• 1996

This study is to suggest the improved noise barrier which is harmonized with surrounding landscape and maintained the similar reduction of reflected sound and diffraction effects in comparison with the aluminum noise barrier of absorbing type which is formed a great majority in Korea. In this study the two improved models of noise barrier(Diffuse and Disperse type) were designed and compared with the noise barriers of absorbing type in the acoustics performance (the reduction of reflected sound and diffraction effects) through the field and full-scale experimental measurement. As these two models have the same acoustic performance as the noise barrier of aluminum absorbing type, it is suggested that these models can be applied to the improved noise barrier as an alteration of aluminum absorbing type barrier.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.5
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• pp.100-107
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• 2000

The hydraulic couplings have been widely used in industries, automobile, and power-station drives including ships. A mathematical analysis by which the design and application of hydraulic couplings are made is used in conventional design formulae and general roto-dynamic theories. The fluid flow of hydraulic couplings can be considered to have two component, one circumferentially about the coupling axis, and the other passing fluid from the pump to the turbine in the plane of the coupling axis. Tests have been carried out on the full-scale production coupling. The performance test consists of taking measurement of torque of the fluid coupling for three different amount of working fluid inside with various loads to the output shaft. The purpose of this research is to construct the experimental test equipments and to establish a series of performance test for the domestically developed hydraulic couplings, and to obtain experimental results which can be used to improve the performance of the hydraulic coupling and to solve the practical problems confronted in operation.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.04a
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• pp.830-834
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• 2013

This study presents a method to monitor cable force of a long-span cable-stayed bridge using a smart piezoelectric sensor system. The following approaches are implemented in order to achieve the objective. Firstly, the method to utilize piezoelectric materials for the health monitoring of stay cables is presented. For strain measurement of a stay cable, a PZT-embedded smart skin is designed to overcome the difficulties of bonding PZT sensors directly on stay cables. Secondly, a piezoelectric strain monitoring system for stay cables is designed. For the operation of the sensor board, the Imote2 sensor platform is used to provide the computation, wireless communication and power supply units. The feasibility of the proposed monitoring system is then evaluated on a full-scale cable of a cable-stayed bridge.

• The Journal of Korean Academic Society of Nursing Education
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• v.12 no.2
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• pp.280-286
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• 2006

Purpose: To test whether a hope carries the influence of pain to health related quality of life in patients with cancer. Method: 114 cancer patients recruited with. Data were collected through the Visual analog Scale, the Herth Hope Index, and the SF-36 Standard Korean Version. Results: The results showed that the measurement variables (pain, hope and health-related quality of life) were all significantly interrelated. The results of MedGraph revealed that the full mediation effect of hope in the relation between pain and mental component summary of quality of life was significant. Conclusion: These results imply that hope need to be considered in planning intervention programs for the enhancement of quality of life in patients with cancer.