• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.5
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• pp.105-112
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• 2015

In this paper, we propose a simultaneously streaming method of multimedia files. The main features and contributions of the proposed method are as follows. First, to share and play at the same time one video playback in more than two devices to provide convenience for users. Second, to contribute communications and multimedia technologies by developing a streaming technology that can work on two or more devices. The results of implementation and performance evaluation show successful UDP data communication and the simultaneous transfer of streaming multimedia with data to the receiving sides.

• Journal of Ocean Engineering and Technology
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• v.23 no.5
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• pp.1-8
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• 2009

This paper is a continuation of the recent development on Hermite-based divergence free element method and deals with a non-isothermal fluid flow thru the buoyancy driven flow in a square enclosure with temperature difference across the two sides. The basis functions for the velocity field consist of the Hermite function and its curl while the basis functions for the temperature field consists of the Hermite function and its gradients. Hence, the number of degrees of freedom at a node becomes 6, which are the stream function, two velocities, the temperature and its x and y derivatives. This paper presents numerical results for Ra = 105, and compares with those from a stabilized finite element method developed by Illinca et al. (2000). The comparison has been done on 32 by 32 uniform elements and the degree of approximation of elements used for the stabilized finite element are linear (Deg. 1) and quadratic (Deg. 2). The numerical results from both methods show well agreements with those of De vahl Davi (1983).

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.2211-2218
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• 2003

The present study investigates heat/mass transfer characteristics in a rotating two-pass duct for smooth and ribbed surfaces. The duct has an aspect ratio of 0.5 and a hydraulic diameter of 26.67 mm. 70-angled rib turbulators are attached on the leading and trailing sides of the duct in parallel and cross arrangements. The pitch-to-rib height ratio is 7.5 and the rib height-to-hydraulic diameter ratio is 0.075. The Reynolds number based on the hydraulic diameter is constant at 10,000 and the rotation number ranges from 0.0 to 0.2 Detailed local heat/mass transfer coefficients are measured using a naphthalene sublimation technique. The results show that the secondary flows generated by the $180^{\circ}-turn$, rib turbulators, and duct rotation affect the wall heat/mass transfer distribution significantly, As the duct rotates, the rotaion-induced Coriolis force deflects the main flow and results in differences on the heat/mass transfer distribution between the leading and trailing surfaces. Its effects become more dominant as the rotaion number increases. Discussions are presented describing how the rib configuration and the rotaion speed affect the flow patterns and local heat/mass transfer in the duct.

• Structural Engineering and Mechanics
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• v.57 no.6
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• pp.1051-1064
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• 2016

Link-to-column connections in Eccentrically Braced Frames (EBFs) have critical role in their safety and seismic performance. Accordingly, in this study, contribution of supplemental stiffeners on hysteretic behavior of the link-to-column connection is investigated. Considered stiffeners are placed on both sides and parallel to the link web between the column face and the first stiffener of the link. Hysteretic behaviors of the link beams with supplemental stiffeners are numerically investigated using a pre-validated numerical model in ANSYS. It turned out that supplemental stiffeners can change energy dissipation mechanism of intermediate links from shear-flexure to shear. Both rectangular and trapezoidal supplemental stiffeners are studied. Moreover, optimal placement of the supplemental stiffeners is also investigated. Obtained results indicate a discrepancy of less than 9% in maximum link shear of the numerical and experimental specimens. This indicates that the numerical results are in good agreement with those obtained from the test. Trapezoidal supplemental stiffeners improve rotational capacity of the link. Moreover, use of two supplemental stiffeners at both ends of the link can more effectively improve hysteretic behavior of intermediate links. Supplemental stiffeners would also alleviate the imposed demands on the connections. This latter feature is more pronounced in the case of two supplemental stiffeners at both ends of the link.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1694-1700
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• 2007

In the electrified section, both of return current and signal current are flowing in the same rail in common. But signal current shall be allowed to flow in the specific track circuit and not in the other circuit while the traction return current shall come back to power sub-station. This paper presents measuring system that use both sensor and antenna. The aim of the system is to achieve the difference in current between the two rails and the presence of trimming capacitors. In order to improve the transmission level, trimming capacitors are connected between the two rails at constant spacing. To maintain the balance of traction return current, rails of both sides may be jointed by the so-called SVPMM. The traction return current is sometimes unbalanced owing to the ill-contact of SVPMM. In this paper, we propose a diagnosis method based on a short-circuited current(Icc), trimming capacitors and traction return current measured by Korail inspection vehicles. Whether Icc is good or bad depends not only on the presence of trimming capacitors but also on the unbalance of the traction return current.

• Journal of Energy Engineering
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• v.12 no.2
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• pp.93-100
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• 2003

An estimation methodology of the mass and energy (M/E) release due to the main steam line break (MSLB) has been developed with the RETRAN-3D code. In the case of equipment qualification (EQ), the over-estimated temperature would exceed the design limits of some cables or valves. In order to have a more flexible EQ profiles from the MSLB M/E release, the methodology with the best-estimated code was used. The major conditions affecting the MSLB M/E were found to be the initial SG level, heat transfer between primary and secondary sides, power level, operable protection system, main or auxiliary feedwater availability, and break conditions. The RETRAN-3D models were developed for the Kori unit 1 (KRN-1) which is typical two loop Westinghouse (WH) designed plant. Particularly, a detailed model of the steam generators was developed to estimate a more realistic two-phase heat transfer effect of the steam flow. After the modeling, the methodology has been developed through the sensitivity analyses. The M/E release data generated from the analyses have been used as the input to the inside containment pressure and temperature (P/T) analysis. According to the results at the point of view containment P/T, the Kori unit 1 can have more margin of 5∼15 ㎪ in pressure and 8∼15$^{\circ}C$ in temperature.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.12
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• pp.41-45
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• 2015

In this paper, the single port dual-band resonator for magnetic resonance wireless power transfer is proposed. The proposed dual-band resonator is consists of 20 turns spiral coil, a single loop, matching circuit, lumped elements, and a single port. The two sides of the matching circuit are connected to via holes. The spiral coil is operated at MF-band and single loop is operated at HF-band, respectively. We use two of the same structure resonators and simulated and the power transfer efficiency was calculated. The efficiency of simulation and measurement is above 60% at the MF and HF bands, and the distance is 100 mm.

• Journal of Environmental Science International
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• v.12 no.2
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• pp.101-109
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• 2003

Yangdong village is located at Kangdong-myun, Kyungju, Kyungsangbuk-do, Korea. There are two major families, the Sons of Wallsung beginned from Son, So(1433∼1484) and the Lees of Yeohkang the descendant of Lee, Unjeok. They are lived together under check and help for 500 years. The village located on the hill of Ankang plain. There are Homyung mountain and Sonaiu peak in front of it and Solchang mountain on the back. 47 shaped ridges form Blue dragon to the east, and White tiger to the west. Ahnrockchon flows from north Joined Hyungsan river and flows into Youngilman. Therefore the village is located at mountain on it's back and along with stream. Buildings are deployed on the valley between hills, it is not easily detected, but it give it's atmosphere of mountain village. Village location and space composition combined with natural environment, folk belief, feng-shui, and social system of confucianism. Blended buildings affected between ruling and ruled classes or among different families shown environmental design accomplishing united cultural space. The prospect of Yangdong village, a mountain village, expressed two sides of visible scenery of open inside and invisible from outside. Observation point such as head family house, pavilion, and village school are deployed at the point taking bird's-eye view, which striving mental stability.

• Earthquakes and Structures
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• v.18 no.1
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• pp.57-72
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• 2020

This paper presents the results of a monodirectional shaking table test on a full-scale unreinforced masonry cross vault characterized by asymmetric boundary conditions. The specimen represents a vault of the mosque of Dey in Algiers (Algeria), reproducing in detail the mechanical characteristics of masonry, and the constructive details including the presence of some peculiar wooden logs placed within the vault's abutments. The vault was tested with and without the presence of two steel bars which connect two opposite sides of the vault. The dynamic behaviour of both the vault's configurations were studied by using an incremental dynamic analysis up to the collapse of the vault without the steel bars. The use of an innovative high-resolution 3D optical system allowed measure displacement data of the cross vault during the shake table tests. The experimental results were analysed in terms of evolution of damage mechanisms, and in-plane and out-of-plane deformations. Moreover, the dynamic properties of the structure were investigated by means of an experimental modal analysis.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.23 no.5
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• pp.661-669
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• 1999

The evolutionary structure of a tip vortex in the initial period have been investigated by the two-dimensional LDV system. Circumferential and axial components of mean velocities, their turbulences and Reynolds stresses were measured by the phase averaging technique at seven different wake ages within one revolution of the rotor. Core growth was also analyzed. It was resulted that circumferential velocity components showed a Rankine combined vortex shape and their circulation profiles viewed in the radial direction were close to the n = 2 model of Vatistas' algebraic formula, while axial velocity components seemed to have the Gaussian profiles In these measured ranges with the base width of three times of core radii. Peaks of circumferential velocities and core radii showed distinct asymmetric behaviors before the wake age of $150^{\circ}$ over inboard and outboard sides of the slipstream, but they became symmetric afterwards. Turbulence profiles which had two peaks Inside the core radii in the earlier wake age were also changed to single peaks after $150^{\circ}$. These trends imply that the tip vortex was barely mature at this wake age.