• Journal of the Korean Society of Costume
• /
• v.38
• /
• pp.73-82
• /
• 1998

There are two styles of Yoo(; ) Sang(;裳) in Koryo Women. One they wore the Snag(;裳) over the Yoo(; ), the other wore the Yoo(; ) over the Sang(;裳). In the Yoo(; ), Double breast styly was used for the adjustments of these clothes, Neckline and hem line were substituted by rectangular collar (;목판깃). Knot-button, Coat-string(;Okgolum), White straight collar (DongJung), side slit were used. In the Sang(;裳), Chimaheri(;치마허리)was mades of another fabric and Chima-string was dropped.

• Korean Journal of Plant Taxonomy
• /
• v.44 no.4
• /
• pp.257-260
• /
• 2014

While preparing a floristic study of Korean Pteridophytes, we discovered the following two unrecorded species from Jeju Island: Cyclosorus penangianus (Hook.) Copel. and Pteris fauriei Hieron. C. penangianus can be distinguished from other Korean congeners of the genus Cyclosorus by having exindusiate sori, toward with sinus of ultimate segments of veinlets more than 4. P. fauriei can be distinguished from other Korean congeners of the genus Pteris by having ultimate segments with entire margins, veins reaching to leaf margin and membraneous petiolar scales.

• The KSFM Journal of Fluid Machinery
• /
• v.15 no.2
• /
• pp.45-50
• /
• 2012

The flow characteristics in a vaneless diffuser with a backswept radial impeller have been experimentally investigated according to the variation of discharge flow rate. Particle image velocimetry(PIV) system was applied to measure velocity fields with several operating conditions and on some diffuser horizontal planes. Pressure transducers were installed on hub wall of the diffuser in order to analyze the pressure fluctuations and their corresponding velocity fields. The results show that the location of the main flow center moves from the hub to the shroud side as the flow rate decreases, and the reverse flow is locally generated on the hub side.

• Proceedings of the KSME Conference
• /
• 2000.11b
• /
• pp.391-396
• /
• 2000

The present experimental study is focused on the application of multi-point simultaneous measurement by PIV(Particle Image Velocimetry) to guide vane region within a diffuser pump. Various different kinds of clearance were selected as experimental conditions. Optimized cross correlation identification to obtain velocity vectors was implemented with direct calculation of correlation coefficients. Fine optical setup important in PIV performance is arranged for the accurate PIV measurement of high-speed complex flow. Various flow patterns are represented quantitatively at the stator passages.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.21 no.4
• /
• pp.391-397
• /
• 2001

The guided wave propagation in inhomogeneous multi-layered structures is experimentally explored based on theoretical dispersion curves. It turns out that proper selection of incident angel and frequency is critical for guided wave generation in multi-layered structures. Theoretical dispersion curves greatly depend on adhesive zone thickness, layer thickness and material properties. It was possible to determine the adhesive zone thickness of an inhomogeneous multi-layered structure by monitoring experimentally the change of dispersion curves.

• Journal of Digital Convergence
• /
• v.15 no.5
• /
• pp.37-48
• /
• 2017

Recently, the importance of software education is growing because computational thinking of software education is recognized as a key means of future economic development. Also human resources who will lead the 4th industrial revolution need convergence and creativity, computational thinking based on critical thinking, communication, and collaborative learning is known to be effective in creativity education. Software education is also a time needed to reflect social issues such as collaboration with developers sharing interests and open source development methods. Github is a leading social coding site that facilitates collaborative work among developers and supports community activities in open software development. In this study, we apply operational cases of basic learning of social coding sites, learning for storage server with sources and outputs of lectures, and open collaborative learning by using Github. And we propose educational model consisted of four stages: Introduction to Github, Using Repository, Applying Social Coding, Making personal portfolio and Assessment. The proposal of this paper is very effective for software education by attracting interest and leading to pride in the student.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.14 no.5
• /
• pp.1264-1271
• /
• 1990

The vortex lattice method was adopted to predict the aerodynamic performance of a horizontal axis wind turbine. For this simulation. the rotor blade was divided into many panels both in chordwise and spanwise direction and then replaced by horseshoe vortices. The wake was divided into two parts of near wake and far wake : the near wake was assumed as helical vortex line elements and the far wake was modeled by semi-infinite circular vortex cylinder. The induced velocity components were calculated by the Biot-Savart law. By this way the power coefficient was obtained and represented as a function of the tip speed ratio. The numerical results obtained were compared with those of the other methods and experimental results and showed good agreement with experimental results.

• Journal of the Society of Naval Architects of Korea
• /
• v.37 no.4
• /
• pp.56-65
• /
• 2000

This paper deals with the experimental study on the characteristics of current in the ocean engineering basin of KRISa, The unsteady characteristics of the flow is examined by analyzing time histories of streamwise velocity at some points. The major frequency of the fluctuating velocity was found by the spectral analysis of the measured data. The vertical and spanwise distributions of time averaged velocities were also examined. Especially, vertical distributions of the streamwise velocities with guide vanes are compared with those without guide vanes and it confirms the effeciency of the guide vane to improve the uniformity of the vertical profile of streamwise velocity. Finally, the measured data are regressed to give the relation between revolutions per minute(r.p.m.) and mean velocity.

• Journal of the Society of Naval Architects of Korea
• /
• v.40 no.4
• /
• pp.22-29
• /
• 2003

New high-speed depressurized circulating water channel was designed by using the CFD code. Flow in the channel has free surface and pressure in the test section can be depressed. In this study, Flow separation and bubble occurrence were considered in designing the contraction nozzle shape for better flow uniformity Tn the test section. To supplement velocity defect due to the free surface, nozzle injection system more effective in high-speed flow was installed instead of drum system. Necessary power and injection techniques were proposed. And guide vane arrangement was analyzed to reduce the flow resistance and keep quiet free surface from ´surging´. Wave absorber was devised to reduce the wave resistance and to prevent the entrainment of air to the diffuser.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.17 no.3
• /
• pp.260-267
• /
• 1992

In this paper, the performance of frequency hopped(FH) M-ary frequency shift keyed(MFSK)system is analyzed with the fading channel and the multione famming. In general, the performance degradation of FH/MFSK system is due to the Rayleigh fading and the multitone jamming environment. In order to improve the system performance. the time diversity is used. When the time diversity is applied to the Rayleigh fading and the mulitone jamming, we get around 18dB and 19dB improvements. respectively. And when it is applied to both the Rayleigh fading and the multitone jamming, we get around 4 dB improvement.