• Structural Engineering and Mechanics
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• 제88권3호
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• pp.287-299
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• 2023

This article describes experimental and numerical analyses of eccentrically loaded over the axially loaded circular concrete filled double-skinned steel tubular (CFDST) short columns. Tests on circular CFDST short columns under eccentric and concentric loading were conducted to assess their responses to the frequent intensity of 5-30 mm at the interval of each 5 mm eccentric loading conditions with constant cross-sectional proportions and width-to-thickness ratios of the outside and internal tubes. The non-linear finite-element analysis of circular CFDST short columns of eccentrically loaded over the axially loaded was performed using the ABAQUS to predict the structural behavior and compare the concentric loading capacity over the various eccentric loading conditions. The comparison outcomes show that the axial compressive strength of the circular CDFST short columns was 2.38-32.86%, lesser than the concentrically loaded short column with the inner circular section. Also, the influence of computer simulation employed is more efficient in forecasting the experimentally examined performance of circular CFDST stub columns.

• Journal of Information Technology Applications and Management
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• 제29권5호
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• pp.1-12
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• 2022

This research is situated at the intersection between industry 4.0, circular economy and tourism, in an attempt to observe the fourth industrial revolution at the service of the application of circular economy principles in the tourism industry. This approach has gained importance due to the COVID-19 pandemic, which has accelerated fundamental dynamics of change linked to business digitization and environmental sustainability. Within the theoretical framework delimited by the aforementioned intersection, the 'goCircular Radar' project, launched by 'TheCircularLab', from Ecoembes (Spain), has been taken as an empirical reference. Among the 165 startups in the circular economy sector, special attention has been paid to those that are oriented, or have a potential application, to tourism. The activities they carry out are described, with particular attention to the technologies they use and their contribution to circularity.

• Communications for Statistical Applications and Methods
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• 제15권2호
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• pp.273-282
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• 2008

An essential aspect of music is structure. Beran (2004) introduced a method of comparing piano plays via circular statistics based on the fact that there is circular structure in music. We expand the application of this method to a pair of two pop songs and discuss the possibility of applying it to detecting musical plagiarism. Circular statistics provides an objective view point comparing the musical works.

• Journal of the Korean Data and Information Science Society
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• 제22권5호
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• pp.961-966
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• 2011

Circular variables are those that have a period in its range. Their examples include direction of animal migration, and time of drug administration, just to mention a few. Statistical analysis of circular variables is quite different from that of linear variable due to its periodic nature. In this paper, the author proposes new circular regression models using geodesic lines on the surface of the sample space of the response and the predictor variables.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2001년도 종합학술발표회 논문집 Vol.11 No.1
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• pp.34-38
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• 2001

This paper proposes a CP-OFDM(Orthogonal Frequency Division Multiplexing using Circular Polarization) system for improving the system performance. The circular polarization has a characteristic that it cannot receive the reflected waves which are reflected by odd times. By reducing the influences of the reflected waves, the circular polarization can reduce the time delay spread and the inter-channel interference. The guard interval needed for the OFDM frame can be minimized and the orthogonality between subchannels can be improved by using circular polarization. Therefore the proposed CP-OFDM system can improve the system performance as well as the spectrum efficiency. Both theoretical analysis and system simulation results are described.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2003년도 가을 학술발표회 논문집
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• pp.227-234
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• 2003

This study presents the stress evaluation equations of circular column-box beam connection in steel frame piers. FEM analysis were carried out for circular column-box beam connection. Analysis models were made for design parameters such as joint angle, span length-width ratio(L/B), sectional-area ratio(S=A/sub w/A/sub f/), and circular column-box beam stiffness ratio(Ic/Ib). Analysis results were compared to the existing equation. Based on analysis results the stress evaluation equations of circular column-box beam connection are proposed by regression analysis.

• Spatial Information Research
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• 제20권2호
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• pp.165-172
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• 2012

최근의 검색시스템에서는 두 객체집합에 대하여 가장 근접해 있는 K개의 객체 쌍을 찾는 질의가 자주 발생한다. 이러한 K개의 최대근접 객체 쌍을 찾는 질의를 효율적으로 처리하기 위해서는 객체의 순환적 위치속성이 고려되어야 한다. 본 논문은 순환도메인을 갖는 검색공간에서 서로 간에 가장 근접해 있는 K개의 객체쌍을 찾는 최적의 알고리즘을 제안하고 그 성능을 실험을 통하여 보인다. 제안한 알고리즘은 객체의 순환적 위치속성이 반영된 순환검색거리를 이용하여 K개의 최대 근접객체 쌍을 찾는 비용을 최적화한다.

• Steel and Composite Structures
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• 제17권4호
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• pp.359-370
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• 2014

In this experimental and numerical study, the effect of plate thickness, the diameter of circular cutout, the distance between circular cutouts and rowing orientation angle effect (${\theta}$) on the buckling load of E-glass/vinylester pultruded composite beams with single and double circular cutouts, were investigated. The composite beam having 2, 4, and 6 mm thicknesses was produced as [Mat/${\theta}$ /Mat/${\theta}$ /Mat] by using pultrusion technique. Seven different fiber angles as $0^{\circ}$, $15^{\circ}$, $30^{\circ}$, $45^{\circ}$, $60^{\circ}$, $75^{\circ}$, and $90^{\circ}$ were chosen for investigation of rowing orientation angle. The distances between each circular cutout were selected as 15, 30, 45, 60, and 75 mm in the case of double circular cutouts. The diameters of circular cutouts were chosen as 2, 4, 6, 8, and 10 mm to investigate the effect of cutout size. The experimental buckling loads were compared with the results calculated from the numerical analysis. ANSYS 11 commercial software was used for numerical study. A good agreement was obtained between numerical and experimental results.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1144-1149
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• 2003

It is very important to measure circular motion accuracy of NC lathes it affects accuracy, performance, interchange ability and quality of machine parts machined by the NC lathes in industries. So, in this study, measuring units system to measure circular motion accuracy two axes circular motion accuracy of NC lathes was composed of two optical linear scales installed on the z and x-axes of work coordinate system on NC lathe and a computer inserted with PC counter card enables to obtain measuring data. Here, ATC(Automatic Tool Changer) and moving part of linear scales are fixed with magnet bases in order to measure circular motion accuracy of the ATC of NC lathe. And next, computer software was developed in order to measure the circular motion accuracy of NC lathe under resolution of 0.1 $\mu\textrm{m}$ using two linear scales, and also computer softwares were developed so that measuring data could be modeled on plots and be analyzed numerically,

• 한국전산유체공학회지
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• 제16권3호
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• pp.8-14
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• 2011

Although the geometry of circular cylinder is simple, the flow is complicate because of the flow separation and vortex shedding. In spite of many numerical and experimental researches, the flow around a circular cylinder has not been clarified even now. It has been known that the unsteady vortex shedding from a circular cylinder can vibrate and damage a structure. Lock-on phenomenon is very important in the flow around an oscillating circular cylinder. The lock-on phenomenon is that when the oscillation frequency of the circular cylinder is at or near the frequency of vortex shedding from a stationary cylinder, the vortex shedding synchronizes with the cylinder motion. This phenomenon can be recognized by the spectral analysis of the lift coefficient history. At the lock-on region the vortex is shedding by the modulated frequency to the body frequency. However, the vortex is shedding by the mixed frequencies of natural shedding and forced body frequency in the region of non-lock-on. In this paper, it was analyzed the relation between the frequency of rotary oscillating circular cylinder and the vortex shedding frequency.