• Journal of The Korean Astronomical Society
• /
• v.40 no.2
• /
• pp.39-47
• /
• 2007

A high resolution spectrum of PU Vul obtained at Bohyunsan Astronomy Observatory on April 9, 2004 is presented. At this phase, PU Vul was an emission-line star and its continuum was very weak. Emission lines of He II, H I, [Ne IV], [N II], [O III], [Ar V ] and [Fe VII] dominated the spectrum of PU Vul. Many of them exhibited hat-top profiles with strong and multi-peaked emissions on flat-tops of their profiles. Radial velocities for these lines were measured. Origins of the spectral lines are discussed in terms of the wind and the photoionization models.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.18 no.9
• /
• pp.2386-2395
• /
• 1994

An experimental study on heat transfer and flow in compression molding of clss-B and A SMC(Sheet Molding Compounds) in a flat plate and a cross-sectional T-shape was carried out. The temperature was measured with thermocouples at two locations in the 4 layered SMC charge and pressure was measured at the center of the top mold during compression molding. Three different mold speeds, 15, 45, 50 mm/min and two different mold temperature, $130^{\circ}C{\;}and{\;}150^{\circ}C$ were used for compression molding experiments. Experiments with different colored SMC layers were used to study flow patterns at various compression stages. In oder to predict the pressure and load in SMC compression molding, slab method was used. The predicted values of pressure and load from the slab analysis were compared well with the measured data.

• Journal of architectural history
• /
• v.25 no.3
• /
• pp.7-22
• /
• 2016

Of all the annotations of Rites of Zhou for 2,000 years, there is no single line of history of ore contents related to city building in its current perspective. This is because the definitive evidence of the interpretation of related phrases is regarded as top-level guidelines called "辨方正位(Byeonbang-Jeongwi)", and their specific contents have been discussed in '匠人建國(Jangin-Geonguk)'. The phrases of '匠人營國(Jangin-Yeongguk)', considered to be the key buzzword related to city building, must be reconsidered for these reasons. As such, this paper strives to analyze the system of logic formed by consistent interpretation that flowed for 2,000 years from Han to Qing dynasties, and to discover the principles of city building used in Confucian classics.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 1991.04a
• /
• pp.26-28
• /
• 1991

In the recent years, a rigid pavement composed of a flat concrete slab has ken constructed due to the desirable structural strength of concrete, durability and economy. However, despite of precise design and construction of concrete highway pavement, some sections of the 88 Olympic express highway, Jung-bu express highway, and Kyung-bu express highway, which have shown premature cracking, faulting, and pumping before the end of their intended service life, have already been viewed with great concerns by highway officials and engineers. Since environmental variations and traffic loads might be considered as major factors to cause pavement failure problems, the thermal load due to temperature variations between top and bottom surface of the concrete slab was highlighted to verify analytical behavior of concrete slab using the finite element method.

• Proceedings of the KSR Conference
• /
• 2007.11a
• /
• pp.1835-1842
• /
• 2007

The purpose of this paper describes the changes of TGV & ICE series' nose shape by increasing train speed and according to the periodical characteristics. As the speed increases, the length of the nose shape trends to lengthen longer. But the nose shape length does not increase as speed improves by optimized nose shape to reduce aerodynamic drag and micro-pressure wave in tunnels. TGV & ICE series' nose shape can be classified into Advanced paraboloid type, Shape-nosed type, Organic double-edged type and Flat-nosed type by the advance research(the changes of Shinkansen vehicle' nose shape) of high speed railway. Because it trends to be diversified and characterized more and more. This paper analyzed and introduced as TGV & ICE series' nose shape by top 2 nation (Germany, France) and high speed railway in the past years(1980-2007) for their railway design trends by new positioning(Advance research).

• Transactions of Materials Processing
• /
• v.4 no.3
• /
• pp.222-232
• /
• 1995

The planar anisotripic FEM analysis for predicting earing profiles and draw-in amounts in the deep-drawing process is introduced. An implicit, incremental, updated Lagrangian formulation with a rigid-viscoplastic constitutive equation is employed. Contact and friction are considered through the mesh-based unit vector and normal contact pressure. The consistent full set of governing relations, which is comprising euilbrium and geometric constraint equations, is appropriately linearized. Barlat's strain-rate potential is employed, whose in-plane anisotropic properties are taken into account with anisotropic coefficients and potential parameters. The linear triangular membrane elements are used for depicting the formed sheet. In the numerical simulations of deep drawing processes of a flat-top cylindrical cup for 2090-T3 aluminum alloy sheet show good agreement with experiments, although some discrepancies were observed in the directional trend of cup height and thickness strains.

• Proceedings of the KIEE Conference
• /
• 1999.07e
• /
• pp.2167-2169
• /
• 1999

A pulse transformer producing pulses with the peak power of 200-MW (400 kV 500 A at load side with $4.4{\mu}s$ flat-top) is required to drive the 80-MW pulsed klystron in the PLS linac. We have designed and manufactured the high power pulse transformer with 1 : 17 turn ratio. Its primary functions are to match the impedance of klystron tube to the modulators, and to provide step-up of the voltage. To obtain a fast rise time of the pulse voltage. Low leakage inductance and low distributed capacitance design is very important. In this paper, we discuss the equivalent circuit analysis of the pulse transformer, and present the full power performance test results of pulse transformer.

• Proceedings of the KIEE Conference
• /
• 2006.07b
• /
• pp.781-782
• /
• 2006

This paper presents a drive strategy to reduce torque ripple of a permanent magnet Brushless DC Motor(BLDCM) with short $120^{\circ}$ flat top Back Electromotive Force(Back-EMF). In this strategy, the phase Back-EMF is divided into four sections. Then, in each section the phase current is regulated by corresponding PWM duty ratio to compensatethe torque ripple caused by imperfect Back-EMF. A program based on this strategy has been implemented in MATLAB@Simulink. The validity of the presented method is verified by simulation results.

• Transactions of the Society of Information Storage Systems
• /
• v.6 no.1
• /
• pp.1-5
• /
• 2010

Holographic data storage system(HDSS) has many noise sources - crosstalk, scattering and inter pixel interference, etc. Generally the intensity of a light generated from the laser source has Gaussian distribution and this ununiformity of light also can make the data page to have a low SNR. A beam apodizer is used to make the laser as a flat-top beam but the intensity distribution is not strictly uniform. The intensity of light can be controlled using image mask. In this paper the intensity distribution of light used for HDSS is controlled by a digital image mask. The digital image mask is changed arbitrarily in real-time with suggested algorithm for the HDSS.

• Steel and Composite Structures
• /
• v.2 no.6
• /
• pp.429-440
• /
• 2002

A finite strip method is developed for fatigue reliability analysis of steel highway bridges. Flat shell strips are employed to model concrete slab and steel girders, while a connection strip is formed using penalty function method to take into account eccentricity of girder top flange. At each sampling point with given slab thickness and modulus ratio, a finite strip analysis of the bridge under fatigue truck is performed to calculate stress ranges at fatigue-prone detail, and fatigue failure probability is evaluated following the AASHTO approach or the LEFM approach. After the failure probability is integrated over all sampling points, fatigue reliability of the bridge is determined.