• Journal of the Korea Society of Computer and Information
• /
• v.21 no.4
• /
• pp.89-96
• /
• 2016

In this paper, we study the relationship between vacancy duration and information items of a job posting by using generalized linear models and a decision tree analysis w.r.t. the three factors such as company characteristics, employment conditions, and constraints. The results indicate that the employment conditions rather than company characteristics are more influential to the vacancy duration. These effects are presumed to be based on the complex relations between the decisions of the employers and the job seekers. And in this paper we suggest the need to provide personalized and profiled labor market information tailored for a quick decision to job seekers and employers. Policy implication is that since employer's decision affects the vacation duration, employers may had better to provide a comprehensive labour market information including supply and demand of the required skills in order to reduce the time for judgment on the cost-effectiveness.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2000.10a
• /
• pp.285-290
• /
• 2000

A mathematical model which can simulate biaxial moment-curvature relations for reinforced concrete column is developed. The developed model is capable of tracing the post-peak behavior of a column after peak load. The model can take into account different sectional shapes of a column and various constitutive models of confined concrete. The developed model is used to evaluate constitutive models of confined concrete under concentric loading, suggested by different researchers. Error function which measures the overall constitutive behavior of a confined concrete is intrcduced. The constitutive model minimizing this error function is selected and is incorporated into the developed model in order to investigate the effect of main parameters on the general column behavior.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2003.11a
• /
• pp.371-374
• /
• 2003

The degree of changes in mechanical properties of fire-damaged reinforced concrete column depends mostly on sectional geometry, duration exposed to fire, and moisture containment. In order to reasonably assess the deterioration of structural capacity of fire-damaged reinforced concrete column, it is necessary to develop a theoretical model predicting column behavior based on nonlinear heat transfer equation in addition to the traditional mechanics. This research focuses on the development of theoretical model to predict moment-curvature relations of fire-damaged reinforced column. The model is used for the assessment of structural capacity of fire-damaged column in terms of moment-curvature relations and PM interaction curves.

• Journal of The Korean Astronomical Society
• /
• v.42 no.6
• /
• pp.155-159
• /
• 2009

In order to determine color excess in the $uvby\beta$ color system for high amplitude $\delta$ Scuti stars, reddening free $[m_1]$, $[c_1]$, and $\beta$ indices data were obtained from the existing literature for 21 stars. Then, the three intrinsic relations of $(b-y)_0$ - $[m_1]$, $(b-y)_0$ - $[c_1]$, and $(b-y)_0$ - $\beta$ were investigated. Among these, it was shown that the $(b-y)_0$-$[c_1]$ relation is the most useful. By establishing intrinsic $(b-y)_0$-$[c_1]$ relations for six reddening calibration stars, color excesses of other stars were determined.

• 한국초전도학회:학술대회논문집
• /
• v.10
• /
• pp.136-139
• /
• 2000

The relations between tensile stresses and critical current densities (J$_c$) of coated conductors were measured. Around 320 MPa of tensile stress, the critical current densities of coated conductor fabricated on pure Ni tape were reduced to zero at 77K, where J$_c$ for zero stress was order of 10$^5$A/cm. The critical tensile stress was much enhanced for the coated conductors fabricated on NiCr alloy tapes. However fabrication conditions for the growth on such alloys are much different from those on the pure Ni and it was not easy to get good textures and large critical currents. The detailed fabrication methods on those alloys will be presented.

• Journal of the Korean Mathematical Society
• /
• v.54 no.5
• /
• pp.1605-1621
• /
• 2017

The purpose of this paper is to construct a new family of the special numbers which are related to the Fubini type numbers and the other well-known special numbers such as the Apostol-Bernoulli numbers, the Frobenius-Euler numbers and the Stirling numbers. We investigate some fundamental properties of these numbers and polynomials. By using generating functions and their functional equations, we derive various formulas and relations related to these numbers and polynomials. In order to compute the values of these numbers and polynomials, we give their recurrence relations. We give combinatorial sums including the Fubini type numbers and the others. Moreover, we give remarks and observation on these numbers and polynomials.

• Journal of the Korean Society for Precision Engineering
• /
• v.13 no.6
• /
• pp.90-101
• /
• 1996

Determination of assembly sequence of components is a key issue in assembly operation. Although a number of articles dealing with assembly sequence determination have appeared, an efficient and general methodology for complex products has yet to appear. The objective of this paper is to present the problems and models used to generate assembly sequence from design data. An essential idea of this research is to acquire a finite number of voxels from any complex geometric entity, such as 3D planar polygons, hollow spheres, cylinders. cones, tori, etc. In order to find a feasible assembly sequence, the following four steps are needed: (1) The components composing of an assembly product are identified and then the geometric entities of each component are extracted. (2) The geometric entities extracted in the first step are translated into a number of voxels. (3) All the mating or coupling relations between components are found by considering relations between voxels. (4) The components to be disassembled are determined using CCGs (Component Coupling Graph).

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2002.10a
• /
• pp.86-93
• /
• 2002

A new error estimation method is proposed. This utilizes the variation of energy functional about the mapping function between the global and the master elements. The resultant system of equations is the weak form of the generalized conservation checks. However, This formulation has an important information about the relations between the connected elements. In other words, some relations between the connected elements are obtained and these can be used very usefully to measure it posteriori error. In this paper, the explicit formulations are presented for the 1-dimensional model and the 2-dimensional model problems. Numerical results are provided for first order shear deformation theody of beam model and the plane stress problem.

• Journal of Korean Society for Geospatial Information Science
• /
• v.9 no.2 s.18
• /
• pp.63-71
• /
• 2001

GPS allows a user with an appropriate receiver to obtain their position anywhere on the Earth's surface. The use of GPs has highlighted the shortcomings of national reference systems, and many countries are in the process of establishing new geodetic frameworks in order to overcome these shortcomings. Korea National Geography Institute has established a new geocentric datum and presented the its time frame for implementation. In this paper, I studied the considerable matters of digital mapping authority and users for converting the geodetic datum and coordinate system and suggested the steps of public relations for GIS users.

• 제어로봇시스템학회:학술대회논문집
• /
• 1998.10a
• /
• pp.58-63
• /
• 1998

B.Widrow established fundamental relations between the least-mean-square (LMS) algorithm and the digital Fourier transform［1］. By extending these relations, we proposed the short time spectra analysis system using the LMS algorithm［2]. In that paper, we used the normal LMS algorithm on the thought of dealing with only real analytical signal. This algorithm minimizes the real mean-square by recursively altering the complex weight vector at each sampling instant. But, the short time spectra analysis sometimes deals with the complex signal that is outputted from complex analog filter. So, in order to optimize and develop this methods, furthermore it is necessary to derive an algorithm for the complex analytical signal. In this paper, we first discuss the new adaptive system for the spectra analysis using the complex LMS algorithm and then derive convergence condition, time constant of coefficient adjustment and frequency resolution by extending the discussion. Finally, the effectiveness of the proposed method is experimentally demonstrated by applying it to the measurement of transfer performance on complex analog filter.