• Journal of Astronomy and Space Sciences
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• v.11 no.2
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• pp.147-153
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• 1994

We present a deep(B, V) color-magnitude diagram (CMD) of the Galactic globular cluster NGC 4372. According to the recent inside-out picture of Galaxy formation, this cluster is predicted to be one of the oldest globulat clusters in the Galaxy. Our CMD shows a well defined main-sequence extending ∼ 2 magnitudes below the trunoff. Despite the uncertainty that stems from the small sample size of bright stars, comparison with the Revised Yale Isochrones suggests that this cluster may indeed be one of the oldest (∼16.6 Gyrs) globular clusters in our Galaxy.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.17 no.30
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• pp.153-160
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• 1994

In this paper, we present the application of knowledge-based system technique for generating of PLC ladder diagram The developed prototype system receives a time chart as an input and generates a ladder logic as its output This results in the computerization and intellegent processing of PLC programming. The system can be effectively applied to sequence control where the PLC programs need to be frequently changed and generated.

• Journal of The Korean Astronomical Society
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• v.22 no.2
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• pp.81-99
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• 1989

Applying five morphological parameters defined along the main sequence (MS), red giant branch (RGB) and horizontal branch (HB) in the C-M diagram (CMD), and the transition period-luminosity relation for RR Lyrae variables, some basic physical quantities such as helium abundance, age, mass and luminosity are determined for 21 well observed globular clusters with combination of evolutionary models and atmospheric models properly chosen by the numerical test. The dependences of these quantities on the age and chemical abundance are investigated.

• Kyungpook Mathematical Journal
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• v.64 no.1
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• pp.1-14
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• 2024

Recently, Zhao, Wang, and Pu introduced and studied new concepts of nonnil-commutative diagrams and nonnil-projective modules. They proved that an R-module that is nonnil-isomorphic to a projective module is nonnil-projective, and they proposed the following problem: Is every nonnil-projective module nonnil-isomorphic to some projective module? In this paper, we delve into some new properties of nonnil-commutative diagrams and answer this problem in the affirmative.

• Journal of KIISE:Software and Applications
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• v.30 no.3_4
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• pp.202-211
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• 2003

Abstract Formal definitions of syntax and semantics for the static and dynamic models in Object Oriented methods are already defined. But the behavior of interacting objects is not formalized. In this paper, we defined the common behavior of interacting objects in terms of process algebra using sequence diagram in UML and regularized properties of interacting objects. Based on the results, we can develop a formal specification by. using of the object interaction instead of the existence dependency suggested by M. Snoeck and G. Dedene[9].

• Journal of The Korean Astronomical Society
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• v.38 no.4
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• pp.415-422
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• 2005

UBVIJHK photometry of the open cluster NGC 2194 are presented. Color-Magnitude diagrams of this cluster show well-defined main sequence and red giant clump. The main sequence also contains clear evidence of binary populations. Based on color-color diagrams, absolute magnitude of red giant clump, ZAMS fitting, and comparisons of observed color-magnitude diagrams with theoretical models, we derive following parameters for the cluster; reddening $E(B-V)=0.44{\pm}0.04$, age of log $t{\sim}8.8$, and finally distance of $(m-M)_0=12.20{\pm}0.18$.

• Journal of Astronomy and Space Sciences
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• v.21 no.2
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• pp.83-92
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• 2004

The absolute dimensions of low mass contact binary, GR Vir and HV Aqr were obtained using WD program from the published spectroscopic and photometric observational data. The evolutionary status of this type of system including GR Vir and HV Aqr has been considered. The primary stars of low mass contact binary system were located on the Terminal Age Main-sequence and secondary stars were located under the Zero Age Main-sequence in H-R diagram.

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.14-16
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• 1988

With the development of VLSI technology, research on special processors for high-speed processing is on the increase and studies are focused on designing VLSI-oriented processors for signal processing. This paper processes a one-dimensional systolic array for Discrete Hartley Transform implementation and also processes processing element which is well described for algorithm. The discrete Hartley Transform(DHT) is a real-valued transform closely related to the DFT of a real-valued sequence can be exploited to reduce both the storage and the computation requried to produce the transform of real-valued sequence to a real-valued spectrum while preserving some of the useful properties of the DFT is something preferred. Finally, the architecture of one-dimensional 8-point systolic array, the detailed diagram of PE, total time units concept on implementation this arrays, and modularity are described.

• Journal of Astronomy and Space Sciences
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• v.19 no.4
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• pp.255-262
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• 2002

We present the infrared spectra of Herbig Ae/Be stars including the Infrared Space Ob-servatory (ISO) data. To investigate the overall properties of their circumstellar dust envelope and/or disk, we combine the IR spectra with photometric data ranging from the UV through the optical into the sub-mm region. We study the general characteristics of the spectral energy distributions using simple analysis. We plot the positions on the HR-diagram to compare with the theoretical pre-main-sequence evolution tracks.

• Journal of The Korean Astronomical Society
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• v.28 no.1
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• pp.45-59
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• 1995

In the best observed Pleiades cluster, the luminosity function(LF) and mass function(MF) for main sequence(MS) stars extended to $Mv{\approx}15.5(V{\approx}21)$ are very similar to the initial luminosity function(ILF) and initial mass function(IMF) for field stars in the solar neighborhood showing a bump at log $m{\simeq}-0.05$ and a dip at log $m{\simeq}-0.12$. This dip is equivalent to the Wielen dip appearing in the LF for the field stars. The occurence of these bump and dip is independent of adopted mass-luminosity relation(MLR) . and their characteristics could be explained by a time-dependent bimodal IMF. The model with this IMF gives a total cluster mass of $\~700M_\bigodot,\;\~25$ brown dwarfs and $\~3$ white dwarfs if the upper mass limit of progenitor of white dwarf is greater than $4.5M_\bigodot$. The cluster age on the basis of LF for brightest stars is given by $\~8\times10^7yr$ and all stars in the cluster lie along the single age sequence in the C-M diagram without showing a large dispersion from the sequence.