• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.6B
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• pp.627-634
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• 2008

In a numerical simulation of open channel turbulent flows using RANS (Reynolds averaged Navier-Stokes) equations model equipped with VOF (Volume of Fluid) scheme, the determination of wall roughness for wall function was studied. The roughness constant, based on the law-of-the-wall for flow on rough walls, obtained by experimental works for pipe flows is employed in general wall functions. However, this constant of wall function is the function of Froude number in open channel flows. Thus, the wall roughness should be determined by taking into account the effect of Froude number. In addition, the wall roughness should be corresponding to Manning's roughness coefficient widely used for open channels. In this study, the relation between wall roughness height as an input condition and Manning's roughness coefficient was investigated, and an equation for effective wall roughness height considering the characteristics of numerical models was proposed as a function of Manning's roughness coefficient.

• Journal of The Korean Astronomical Society
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• v.44 no.2
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• pp.39-48
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• 2011

UBV I CCD photometry of NGC 2353 is performed as a part of the "Sejong Open cluster Survey" (SOS). Using photometric membership criteria we select probable members of the cluster. We derive the reddening and distance to the cluster, i.e., E(B - V ) = 0.10 ${\pm}$ 0.02 mag and 1.17 ${\pm}$ 0.04 kpc, respectively. We find that the projected distribution of the probable members on the sky is elliptical in shape rather than circular. The age of the cluster is estimated to be log(age)=8.1 ${\pm}$ 0.1 in years, older than what was found in previous studies. The minimum value of binary fraction is estimated to be about 48 ${\pm}$ 5 percent from a Gaussian function fit to the distribution of the distance moduli of the photometric members. Finally, we also obtain the luminosity function and the initial mass function (IMF) of the probable cluster members. The slope of the IMF is ${\Gamma}=-1.3{\pm}0.2$.

• Journal of the Korean Magnetic Resonance Society
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• v.2 no.2
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• pp.131-140
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• 1998

The calcium-induced structural changes in the skeletal muscle regulatory protein troponin C (NTnC) involve a transition from a ‘closed’to an ‘open’structure with the concomitant exposure of a large hydrophobic interaction site for target proteins. Structural studies have served to define this conformational change and elucidate the mechanism of the linkage between calcium binding and the induced structural changes. There are now several structures of NTnC available from both NMR and X-ray crystallography. Comparison of the calcium bound structures reveals differences in the level of opening. We have considered the concept of a flexible open state of NTnC as a possible explanation for this apparent discrepancy. We also present simulations of the closed-to-open transition which are in agreement with the flexibility concept and with experimental energetics data.

• Journal of The Korean Astronomical Society
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• v.16 no.2
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• pp.43-54
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• 1983

The present day mass functions of main sequence stars in the well observed open clusters, Hyades, Praesepe, Pleiades, NGC 654 and NGC 6530 arc derived and compared with those computed from the model of time-dependent initial mass function and star formation rate. The agreements between the observed and computed present day mass functions suggest the importance of fragmentation process at the early phase and fragment interaction at the later phase of cluster evolution. This process of star formation is different from that related to the evolution of the solar neighborhood, and also could explain the lack of low mass stars observed in some open clusters.

• Korean Journal of Agricultural Science
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• v.21 no.2
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• pp.92-102
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• 1994

This study examined Public Evaluation for functions of urban open space environment using a marketing strategy called Importance-Performance analysis. 12 main function attributes for urban open space environment were selected 150 respondents were sampled in Taejon city by personal interview. Ratings used mean values from a seven-point scale. Results were then graphically displayed on an easily interpreted two-dimensional 'Action Grid'. Generally Importance Ratings were high, but Performance Ratings were low relatively for various open space environment functions. In air pollution control function the difference was the most large. The results of rating scale analysis indicated repondents' sexual and residence period difference.

• Journal of Mechanical Science and Technology
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• v.19 no.5
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• pp.1095-1106
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• 2005

Recently, the conventional controller of machine-tool has been increasingly replaced by the PC-based open architecture controller, which is independent of the CNC vendor and on which it is possible to implement user-defined application programs. This paper proposes CNC­implemented fault diagnosis and web-based remote services for machine-tool with open architecture CNC. The faults of CNC machine-tool are defined as the operational faults occupied by over $70{\%}$ of all faults. The operational faults are unpredictable as they occur without any warning. Two diagnostic models, the switching function and the step switching function, were proposed in order to diagnose faults efficiently. The faults were automatically diagnosed through the fault diagnosis system using the two diagnostic models. A suitable interface environment between CNC and developed application modules was constructed for the internal function of CNC. In addition, a suitable web environment was constructed for remote services. The web service functions, such as remote monitoring and remote control, were implemented, and their operability was tested through the web. The results obtained through this research could be a model of fault diagnosis and remote servicing for machine-tool with open architecture CNC.

• Journal of the Korean Mathematical Society
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• v.54 no.1
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• pp.267-280
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• 2017

In this paper, we study analytic and geometric properties of the solution q(z) to the differential equation q(z) + zq'(z)/q(z) = h(z) with the initial condition q(0) = 1 for a given analytic function h(z) on the unit disk |z| < 1 in the complex plane with h(0) = 1. In particular, we investigate the possible largest constant c > 0 such that the condition |Im [zf"(z)/f'(z)]| < c on |z| < 1 implies starlikeness of an analytic function f(z) on |z| < 1 with f(0) = f'(0) - 1 = 0.

• Proceedings of the KIEE Conference
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• 1999.07b
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• pp.761-763
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• 1999

When the controller designed by the $H{\infty}$ control technique is applied to the object system, sometimes the controller does not satisfy the robust stability and robust performance but only satisfy the nominal performance. In this paper, we derive the region on the frequency response curve of the open-loop transfer function which satisfy the robustness and robust performance of the designed controller. We also derive the region for the suitableness of the weighting function on the frequency response curve of the weighting function. We showed that the robust stability and the robust performance of the $H{\infty}$ optimal control)or by applying the designed controller on an electromechanical actuator system could be improved by determining parameter ${\gamma}$ and weighting function gain ${\alpha}$ using the derived region.

• Journal of KIISE
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• v.42 no.6
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• pp.713-722
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• 2015

As open-source software (OSS) becomes more widely used, many users breach the terms in the license agreement of OSS, or reuse a vulnerable OSS module. Therefore, a technique needs to be developed for investigating if a binary program includes an OSS module. In this paper, we propose an efficient technique to detect a particular OSS module in an executable program using its function-level features. The conventional methods are inappropriate for determining whether a module is contained in a specific program because they usually measure the similarity between whole programs. Our technique determines whether an executable program contains a certain OSS module by extracting features such as its function-level instructions, control flow graph, and the structural attributes of a function from both the program and the module, and comparing the similarity of features. In order to demonstrate the efficiency of the proposed technique, we evaluate it in terms of the size of features, detection accuracy, execution overhead, and resilience to compiler optimizations.

• Journal of the Korean Institute of Landscape Architecture
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• v.13 no.2
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• pp.99-114
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• 1985

^x Open space has become the subject o\ulcorner remarkable, new interest ; and many studies have been done recently. In urban pattern, the significance of open space is not its quantity but how it is arranged. The end of this article is to set up a plan for the open space system for Kyongiu city. This paper has three parts : first, a brief discussion of the concept and function of open space ; secondly, a review of open space system ; and finally, a case study of Kyongju City. Especially, this study is focuced on the methodology in conserving and using prototype plan for historic and cultural environment. The result of this study may be summed up as follows : 1) The open space network for kyongju city can be planned out as a belt and ripple pattern. 2) The linear element of open space must play an important role in connecting each element with the whole open space system. 3 ) The Hwangseong pork can be the focal element of the open space system.