• Wind and Structures
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• v.6 no.6
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• pp.471-484
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• 2003

The rain-wind induced vibration of stays is a phenomenon discovered recently and not well explained yet. As it is influenced by a wide range of physical parameters (cable size and shape, wind speed, direction and turbulence, rain intensity, material repellency and roughness, cable weight, damping and pre-strain), this peculiar phenomenon is difficult to reproduce in laboratory controlled conditions. A successful wind tunnel experimental campaign, in which some basic physical quantities were measured, allowed an extensive analysis as to identify the parameters of the rain-wind induced excitation. The unsteady pressure field and water thickness around a cable model were measured under rainy-excited conditions. The knowledge of those parameters provided helpful information about the air-flow around the cable and allowed to clarify the physical phenomenon which produces the excitation.

• Journal of electromagnetic engineering and science
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• v.17 no.4
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• pp.238-240
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• 2017

In this paper, we analyze the radar cross section (RCS) of a battleship equipped with an integrated mast module (IMM). The RCS of a battleship equipped with an IMM is calculated based on physical optics (PO) and the physical theory of diffraction (PTD), and is analyzed in terms of the mast shape, incident angles, and polarization.

• The Journal of Korean Physical Therapy
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• v.27 no.4
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• pp.246-251
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• 2015

Purpose: The purpose of this study was to compare activities of shoulder girdle muscles according to types of closed chain exercise in the sixties. Methods: The subjects consisted of 15 persons in their sixties. Muscle activity of the pectoralis major, deltoid middle, deltoid posterior, upper trapezius, lower trapezius, and serratus anterior were measured using electromyography according to shape of the support base and angle of shoulder flexion. According to types of closed chain exercises, muscles activities were compared by paired t-test. Significance level to verify statistical significance was .05. SPSS win (ver. 22.0) program was used for statistical analysis. Results: Muscle activities of the pectoralis major, middle deltoid, trapezius lower, and serratus anterior showed significant difference according to types of closed chain exercise (p<0.05). Conclusion: According to types of closed chain exercises of the shoulder girdle, muscle activities of the pectoralis major, deltoid middle, posterior and lower trapezius showed change of muscle activities.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1582-1588
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• 2004

The present experimental study aimed to investigate the feasibility of physical water treatment (PWT) devices using catalytic materials to mitigation of crystalization fouling. Two PWT devices having different shape and material were used. The results from microscopic observation and SEM photographs demonstrate that the crystal structure of $CaCO_3$ is Argonite type without water treatment while Calcite type with water treatment, which clearly shows the feasibility of PWT techinque using catalytic materials to mitigate crystalization fouling. For 500 ppm solution, the fouling resistance decreased up to about 23% due to physical water treatment using catalytic materials. The results also reveal that if two more techniques are used simultaneously the additional effects could be expected.

• Journal of the Optical Society of Korea
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• v.17 no.5
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• pp.371-375
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• 2013

To improve the utilization efficiency of solar energy, a new solar optical concentrating system composed of a parabolic reflector with a square cross-section, a hyperbolic reflector with a square cross-section and two converging convex lenses has been designed. The proposed method can simultaneously focus and shape sun light into a square pattern on the solar panel. In addition, the total reflection property of photonic crystal within the range of the visible sunlight spectrum has been analyzed. Finally, the relationship between solar concentrating multiples and the diameter of the primary mirror has been discussed.

• Journal of Biosystems Engineering
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• v.32 no.4
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• pp.207-214
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• 2007

Based on the profiles of cone index with depth, physical properties of hardpan in selected rice fields were measured and analyzed in the study. An error correction algorithm removing a random measurement error from raw CI profile data was introduced in the study. The properties of hardpan included the shape, the thickness and the rice root growing layer. The analysis of physical properties of hardpan in the rice fields showed that the type of hardpan could be classified into 6 categories. The thickness of hardpan ranged from 6 cm up to 41 cm and the average hardness of hardpan was analyzed to be from 1.1 MPa through 3.2 MPa in Cone index.

• Journal of the Korea Institute of Military Science and Technology
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• v.10 no.3
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• pp.16-24
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• 2007

The high-frequency analysis method of back-scattering cross section spectrum of rotating targets is established. The time history of the back-scattering cross section is calculated using a quasi-stationary approach, based on a physical optics and a physical theory of diffraction, combining an adaptive triangular beam method to consider the shadow effect. And the spectra of back-scattering cross section by the Doppler effect are analyzed applying a simple fast Fourier transform method to its time history. The numerical calculation for rotating targets, such as rotating metal plates and underwater propeller, are carried out. The time history appears to be periodic with respect to the number of wings. The backscattering cross section spectrum level and its frequency shift are dependent on the rotating speed, direction, and the shape of the targets.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.80-81
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• 2022

In this paper, the physical properties of actual fabric data are predicted using the Cusick drape system, which is a means of measuring the physical properties of fabrics. Using a three-dimensional volumetric system, the cloth data of the actual Cusick drape system is acquired in a three-dimensional point cloud format. Cusick drape simulation is performed using mesh data of the same shape and size as the fabric, and the physical parameters of the draped fabric most similar to the actual draped fabric are acquired.

• Journal of the Korean housing association
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• v.15 no.3
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• pp.43-51
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• 2004

The purpose of this study is to examine the physical characteristics of the detached housing area in the housing site development district. The process of this study is to investigate the characteristics of the physical structure and the building use, then to analyze the relationship of physical structure and the building use in the aspect of the morphological characteristics. The case study focuses on the Chil-kok2, An-Siml in Taegu. The streets pattern is composited gird and loop type mixed. The block is composited by 2 lots in general. But the obscurity of organization and character of the streets, the size and shape of lots which is not fit to the building use. A whole residential characters appears high residential density ratio. so residential environment became worse. The improving level of residential environment and efficiency of land use in the detached housing area of the housing site development district, firstly the propriety of the physical structure must be considered about detached house characters, and the housing uses which fit to the physical structure are needed, and also for the concrete realization of this, the designation of district, the zoning of residential area, the guideline of the district design, and establishment of comprehensive master planning in detached housing area are needed in aspect of the housing policy. As the result of this study, it suggests several design guideline to improve housing site development.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.10a
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• pp.84-88
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• 2003

In this paper, The optimum design of a die shape has been carried out the FEM analysis of a pilger mill process considering various factors. The pilger mill forming process consists of a pair of rotating die which has appropriate surface shape. The important design parameters of the pilger mill are the feed rate and the profile of grooved die. Optimum design procedure was performed in order to investigated effects on the forming load and the deformed shape of material depending on the die radius profile. Profile of the die surface for the optimum design were suggested with the linear, the cosine and the quadratic curve considering a physical forming process. The surface of each die was modeled using the 3DAutoCAD and the analysis of pilger forming process was performed using the LS-DYNA3D. The optimum profile of the die shape for the pilger mill was determined to the quadratic profile. Since the analysis results provide that the model of the quadratic profile gives the lowest forming load and a proper deformed shape.