• Korean Journal of Social Welfare
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• v.59 no.3
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• pp.147-174
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• 2007

This study examines how path dependency of working poor labor market segmented from the primary and the secondary labor market affects employment and quality of employment of working poor. It Further examines how path dependency makes working poor to remain in the labor market and makes it difficult for them to escape from a vicious poverty cycle. Data is based on the $3{\sim}7th$ Korea Labor and Income Panel Study(KLIPS). Markov's transition probability and discrete-time hazard analysis are used for analysis. This study finds that Korea labor market is divided into three parts; the primary labor market, the secondary labor market and the working poor labor market. The proportion of employed poor has been reduced, but the proportion of non economically-active working poor has been increased and has become the main group among the working poor. This shows that labor demand of working poor is fundamentally lacking and there are structural barriers that block working poor's employment itself. The regression analysis shows that the longer working poor labor market participation is, the lower poverty-exit rate. This is an evidence of vicious poverty cycle that the poor have little chance to exit from working poor labor market, once they step into it. Therefore, the longer their participation in poor labor market, the more likely they would move only within the closed working poor labor market. Consequently, it is necessary to fundamentally reform labor market structure and to alleviate negative perception and discrimination about the poor labor while activating labor demand.

• Elastomers and Composites
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• v.39 no.3
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• pp.179-185
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• 2004

Frequency dependency or electrical property stabilization during vulcanization of modified NR/IR composite materials was studied using in-situ electrical property measuring technique. Volume resistivity(p) before and after vulcanization reaction of the sample was measured as the function or frequency in the range or 1Hz to 10kHz at reaction temperatures of 130, 140, 150, and $160^{\circ}C$, respectively. A double stabilization mode of frequency dependency was observed, in which a slow stabilization process of p to a value of ca. $1.0{\times}10^7\;{\Omega}-cm$ occurred after a drastic initial decrease from ca. $9.0{\times}10^7\;{\Omega}-cm$. In addition, notable temperature dependencies of p values were also observed before and after vulcanization reaction, that is, p values at 130 and $140^{\circ}C$ after vulcanization were observed as about 1/3 of those values before vulcanization. All the observed facts were considered as the results from the interaction between the electrode and the bulk sample materials, i.e., electronic charge-discharge, and from the structure change of samples including CB rearrangement by the vulcanization.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.10
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• pp.1306-1311
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• 2020

In this study, we proposed an anti-reflective nano-structure to improve the photoresponsivity of AlGaN UV photodiode that can be used as a receiver in a solar blind UV optical communication system. The anti-reflective nano-structure was fabricated by forming Ni nano-clusters on SiO2 film followed by etching the underneath SiO2 film. A sample with the anti-reflective nano-structure exhibited lower surface reflection along with less dependency on the wavelength in comparison with a sample without the nano-structure. Finally, a UV photodiode was fabricated by applying an anti-reflective structure produced by heat-treating a 2 nm-thick Ni layer. The photodiode fabricated with the proposed nano-structure exhibited noticeable improvement in the photoresponsivity at the wavelength range from 240 nm to 270 nm in comparison with the same photodiode with a SiO2 film without the nano-structure.

• Journal of Korean Port Research
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• v.14 no.1
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• pp.57-64
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• 2000

For composing the structure model of national maritime power system by system structural modeling, in this study, the 50 basic factors are selected by survey of the extensive and through literatures on maritime, sea, maritime power and sea power. And the basic factors are classified into 36 component factors by cluster method. The 9 attributes are extracted by the application of the principle component analysis method, one of the factor analysis method in system engineering, to component factors. In this study, we define the attributes composing the national maritime power system by integrating the result of this study and existed our studies relating to this topic. Which are showed in Table 2. and we show the structure model of national maritime power system in Fig. 3. In Table 2, the 9 attributes are as follows : the fundamental power of maritime, shipping and port power, naval power, fishing power, shipbuilding power, the power of ocean research and development, dependency on seaborne trade, the protection power of ocean environment and the will and inclination of govemment. Also, in the case of evaluating this system, we conform the importance of considering the interactions among the attributes which have strong interactions in structure model of national maritime power system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.6
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• pp.2207-2213
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• 2010

A new scheme for variable structure control design which is based on eigenvalues assignment of sliding mode is developed. In conventional methods, generally, specific type of system matrix like canonical or regular form is required to construct a switching surface. Furthermore, the methods are not explicit. The new method in this paper solved the problems. No special type of system matrix is required and very explicit. It is shown that the switching surface can be constructed and determined uniquely without any dependency on the system form. The proposed method is based on the fact that the dynamics of sliding mode is determined by system zeros. Finally, a numerical example is given to verify the validity of the results studied in this paper.

• Journal of Agricultural Extension & Community Development
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• v.11 no.1
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• pp.83-93
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• 2004

This paper investigated the characteristics of population structure and the determinants of population movement in the south west area of Kyonggi-do by grouping 9 cities in 3 categories and using Panel data of $1995{\sim}2001$. The major findings of this paper were identified as follows : 1) The population structure of regions was different to the stages of urbanization. The ratio of child and elder dependency was high in the rural regions and low in the urbanized regions. It was due to the movement of economically active population of $20{\sim}40$ aged groups, from rural regions to urban regions. This means that more productive segments of the rural population leave the country to the city. In addition. The ratio of male to female was higher in $20{\sim}40$ aged groups for rural regions. This suggested that young females moved from rural regions to urban regions more than young males in the process of industrialization. 2) Based in pooling regression, income was the most significant determinant that could explain the inter-regional and intra-regional movement of population for south west area studied, The next one was educational opportunity variable. The coefficients of income and education were 0.5, 0,7 for intra-regional migration and 0.01, 0.02 for interregional migration indicating that Todaro's hypothesis could be tested well rather than Tiebout' model for this area.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.8
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• pp.761-767
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• 2011

Free and forced vibration analysis of the global ship structure using the 3-dimensional finite element(FE) method requires not only the specialized knowledge such as ship structure interacted with fluid, damping and various excitations due to propulsion system but also time-consuming manual tasks in FE modeling, analysis and response evaluation. As a result, the quality of the vibration analysis highly depends on engineer's expertise and experience. In this study, a framework system to improve the efficiency of global ship vibration analysis is introduced. The system promising the utilization of MSC/Patran and MSC/Nastran consists of various modules to support data management, FE modeling of ship structure and loading, input deck generation for free and forced vibration analysis, data extraction and evaluation of analysis results, and databases for FE models of marine diesel engines and vibration criteria. The system may be useful for pursuing standardization of uncertain analysis factors as well as reducing time, cost and human dependency in ship vibration analysis.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.04a
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• pp.171-176
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• 2011

The purposes of the research were to evaluate system performance and response of building structure under external load for full scale modal-testing-tower applied toggle bracing and lead rubber damper(LRD). The dynamic properties of the structure were measured before and after installing damper under harmonic excitation using the AMD and the results were compared. The harmonic excitation condition is to increase 0.01Hz sine sweep signal from 0.49Hz to 0.63Hz. As a result of measuring resonant frequency, before installing damper is 0.55Hz and after installing damper is 0.62Hz. The experimental results after installing damper were also distinguished from simulation results and the main cause of this results is temperature dependency property of rubber material.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.04a
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• pp.779-784
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• 2011

Free and forced vibration analysis of the global ship structure using the 3-dimensional finite element(FE) method requires not only the specialized knowledge such as ship structure interacted with fluid, damping and various excitations due to propulsion system but also time-consuming manual tasks in FE modeling, analysis and response evaluation. As a result, the quality of the vibration analysis highly depends on engineer's expertise and experience. In this study, a framework system to improve the efficiency of global ship vibration analysis is introduced. The system promising the utilization of MSC/Patran and MSC/Nastran consists of various modules to support data management, FE modeling of ship structure and loading, input deck generation for free and forced vibration analysis, data extraction and evaluation of analysis results, and databases for FE models of marine diesel engines and vibration criteria. The system may be useful for pursuing standardization of uncertain analysis factors as well as reducing time, cost and human dependency in ship vibration analysis.

• Journal of the Korean Society of Radiology
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• v.9 no.2
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• pp.73-77
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• 2015

In order to observe the detailed structure of the detector, it was CT scanned to reproduce the detailed structure of the crystal shapes and traverse layer using the Monte Carlo calculation applying the detector model. The uncertainty of measurement was lowered by adjusting the detector core by the edge effect at a higher energy (400 keV or higher) through the offset of peak efficiency of the gamma ray at low energy. It was confirmed that there was the appropriate matching with spatial dependency using the PENELOPE calculation. That was achieved by adjusting the parameters describing the crystal core and rounding of edge and crystal core.