• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.11
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• pp.180-187
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• 2013

The dinger in solar generation is the amount of sunlight which the solar cells absorb. Various types of solar trackers, which rotate themselves in order to make the solar cells face the sun as much as possible, have been developed, and especially the method of tracking with two axes has greatly contributed in increasing the generation amount at work sites. Among theses 2-axis solar trackers, the inclination-dependent 2-axis solar tracker are widely utilized for its advantages of requiring less initial investment and easy maintenance due to a solid structure. However, the drawback is that the generation efficiency is relatively low because of the structural restriction that limits the rotation angle, thus making it less efficient when tracking the sun. This paper proposes a method to increase the generation efficiency of the inclination-dependent 2-axis solar tracker. It also contains the derived equations needed for precise controlling along with a method to keep tracking with the other axis even when one has reached its angle limit. To confirm that the proposed method increases the amount of incidence onto the solar cells, formulas needed for operation on the proposed method and tracking the exact position of the sun are derived, and applying this to the quarterly data of Korea Astronomy and Space Science Institute it shows maximum over 11.1% more incidence compared to existing methods.

• Journal of Electrochemical Science and Technology
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• v.1 no.1
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• pp.19-24
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• 2010

Alloying degree is an important structural factor of PtRu catalysts for direct methanol fuel cells (DMFC). In this work, carbon supported PtRu catalysts were synthesized by reduction method using anhydrous ethanol as a solvent and $NaBH_4$ as a reducing agent. Using anhydrous ethanol as a solvent resulted in high alloying degree and good dispersion. The morphological structure and crystallanity of synthesized catalysts were characterized by X-ray diffraction (XRD), high resolution transmission electron microscope (HR-TEM). CO stripping and methanol oxidation reaction were measured. Due to high alloying degree catalyst prepared in anhydrous ethanol, exhibited low onset potential for methanol oxidation and negative peak shift of CO oxidation than commercial sample. Consequently, samples, applying ethanol as a solvent, exhibited not only enhanced CO oxidation, but also increased methanol oxidation reaction (MOR) activity compared with commercial PtRu/C (40 wt%, E-tek) and 40 wt% PtRu/C prepared in water solution.

• Korean Journal of Social Welfare
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• v.56 no.4
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• pp.239-268
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• 2004

This study examined the role of self-construals in marital satisfaction among men and women, and explored how independent and interdependent self-construals contribute to or undermine marital satisfaction. Data were drawn from a self-administered questionnaire study in which 489 married people(aged 25-75) residing in Seoul participated. Path analyses were conducted using Structural Equation Modeling Program, and a goodness of fit of the proposed path model was evaluated. As expected, the positive impact of independent self-construal on marital satisfaction was mediated by self-esteem and clarity of communication, and that of interdependent self-construal on marital satisfaction was mediated by psychological stability and a sense of relational well-being. The direct effects of these two types of self-construal on marital satisfaction were opposite. As predicted, independent self-construal decreased marital satisfaction, whereas interdependent self-construal increased it. All of the direct and indirect effects of independent and interdependent self-construals on marital satisfaction were statistically significant, except the indirect effect of interdependent self-construal as mediated by psychological stability. The goodness of fit indexes of the path model indicated that the model was acceptable. However, the results of separate path analyses for men and women showed that some of the effects of self-construals on marital satisfaction differed by gender. Based on these results, implications for clinical social work practice were discussed.

• Journal of the Korean Institute of Gas
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• v.18 no.4
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• pp.63-67
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• 2014

Fischer-Tropsch synthesis mainly produces a wax which is a viscous liquid for long carbon chain. When a catalytic fixed-bed reactor is used for Fischer-Tropsch synthesis, the wax generated on a catalyst surface can keep adsorbing on the catalyst surface. This liquid hold-up causes significant pressure drop and clogging problems through the reactor. Thus, the model for liquid hold-up is required to design the size of reactor and catalyst particles. In this study, the liquid hold-up model considering structural and operational conditions was proposed based on empirical equations for convective mass transfer between the syngas flow and the wax-adsorbed catalyst. The developed model was validated by comparing with the experimental data from Knochen's work (2010). The influence of reactor length and coross section on the wax hold-up in reactor were analyzed and the optimal reactor size were proposed.

• Journal of Digital Convergence
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• v.15 no.4
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• pp.365-375
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• 2017

This study is executed to investigate convergent factors to Job Satisfaction(JS) among Hospital Administrative Staff(HAS). The survey was administered to 221 staff from 11 general hospitals located in Jeonbuk area from Nov. 1st, 2016 to Jan. 31st, 2017. The structured self-administered questionaries were used. The hierarchical multiple regression analysis shows the following results. The JS of respondents turned out to be significantly higher in following groups: a group without work shift, a group with more employees, a group in which self efficacy is higher, a group in which skill variety in job characteristics is higher, a group in which interpersonal conflict and lack of reward in occupational stress are lower. The results show explanatory power of 61.0%. The results of the study indicate that the efforts, to increase self efficacy, and to manage job characteristics and occupational stress, are required to improve the JS among HAS. The results are expected to be useful for the program and human resource management to related to the JS among HAS. In the following study, the analysis of structural equation modeling about additional factors of the JS among HAS will be needed.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.49 no.4
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• pp.17-22
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• 2012

Convolution filtering methods have been widely applied to various digital signal processing fields for image blurring, sharpening, edge detection, and noise reduction, etc. According to their application purpose, the filter mask size or shape and the mask value are selected in advance, and the designed filter is applied to input image for the convolution processing. In this paper, we proposed an image processing acceleration method for the convolution processing by using two-dimensional Look-up table (LUT) and overlap-region buffering technique. First, based on the fixed convolution mask value, the multiplication operation between 8 or 10 bit pixel values of the input image and the filter mask values is performed a priori, and the results memorized in LUT are referred during the convolution process. Second, based on symmetric structural characteristics of the convolution filters, inherent duplicated operation region is analysed, and the saved operation results in one step before in the predefined memory buffer is recalled and reused in current operation step. Through this buffering, unnecessary repeated filter operation on the same regions is minimized in sequential manner. As the proposed algorithms minimize the computational amount needed for the convolution operation, they work well under the operation environments utilizing embedded systems with limited computational resources or the environments of utilizing general personnel computers. A series of experiments under various situations verifies the effectiveness and usefulness of the proposed methods.

• Korean Journal of Social Welfare
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• v.68 no.3
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• pp.51-71
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• 2016

The purpose of this study is to clarify macro causes influencing on the diversity of single-mother households poverty among OECD Countries including Korea. This study carried out pooled time series cross-section analysis applying unbalanced panel design on the period from 1981 to 2012. There is marked diversity on single-mother households poverty. GDP per capita does not contributes to reduce poverty, and female employment rate and % population 0-14 exacerbate poverty. Several factors contribute on poverty reduction including social spending, child cash spending, union density, employment protection on regular workers, proportional representation system, cumulative left cabinet, cumulative women seat. In Korea, it needs to overcome the limit of anti-poverty strategy mainly based on economic growth and labor market flexibility. And it needs to enlarge universal welfare institutions, child benefits, work-family reconciliation policy, and to design adjusted labor market institutions including union density and employment protection, to introduce consensus political model including proportional representation system to enhance left power and women's representation.

• Trans-
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• v.3
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• pp.29-53
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• 2017

The film scholar Vincent Amiel divides into three types of montage through his book The Aesthetics of Montage ; Montage narratif, Montage discursif, and Montage decorrespondances. These three categories are the concept that encompasses the aesthetic class to which most movies belong. Early films pursued the essential and basic functions of editing, which tend to be modified in the direction of enhancing the director's goals over time. In this way, "Expressive Montage" is one of most important concepts of montage, not as a 'methodology' that combines narrative but as a 'purpose'. In the montage stage, the expressive montage work is done through three steps of decision. The process of 'combining' to combine the selected films in a certain order, after the process of 'selection' which selects only necessary parts of the rush film, and 'connection' to determine the scene connection considering the duration of the shot. The connection is the final stage of the montage. There are exceptions, of course. When fiction films of classical narratives use close-ups, or when using models or objects of neutered animals, the film induces the tendency of a "montage decorrespondances" rather than a "montage narratif" or "montage discursif". This study attempts to analyze the tendency of montage of works with 'uncertain connection' through 'collage' used by close-ups and montage decorrespondances as 'fragmentation tendency of modern films'. The fragmentation of the montage in contemporary film breaks the continuous and structural nature of the film, and confuses the narration structure that is visible on the surface of the film. The tendency of the fragmentation of the montage, which started from this close-up, seems to give an answer to the extensibility of the modern image.

• Journal of the Korea Concrete Institute
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• v.20 no.2
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• pp.249-256
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• 2008

With consideration of the ongoing construction of high-rise buildings, it is becoming increasingly important to be able to accurately predict the behavior of them on the stage of design, construction and service. Even though many researchers have developed the analysis method to predict the behavior of high-rise buildings, their studies were based on the two dimensional frame structures composed of line elements such as beams and columns. Recently the high-rise buildings with flat-plate system is widely used because of its advantages. In this study a three dimensional analysis method is developed to analyze the behavior of the high-rise buildings with flat-plate system since it is difficult to model the structural systems reasonably with the existing two dimensional analysis method. The analysis method considered the construction sequence including the temporary work such as installation of form, removal of form, installation of shore, and removal of shore. Line elements were used to describe columns, beams, and shores and plate elements were used to model slabs. The creep and drying shrinkage of concrete were also considered to account for the inelastic behavior of concrete.

• Journal of the Korea Institute of Building Construction
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• v.10 no.6
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• pp.127-135
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• 2010

As logistics facilities have a high ceiling height, simple structure, and the need for a quick return on investment, it is usually essential to advance the construction schedule of such facilities. Accordingly, PC structures, which require less labor, cost and schedule, can be more competitive than RC structures. However, most construction companies in Korea are familiar with RC structure design, have negative perceptions regarding PC structures, and do not sufficiently adopt new construction techniques. The structure that this research features has 110 columns that are 14 m high and are built to the same specification, and applying an RC design to the structure will lead to issues related to constructibility, economic viability, project duration and safety. Therefore, this study intends to feature PC design as an alternative to the RC warehouse design, and perform a comparative analysis of the reduction in labor, cost and construction schedule to highlight benefits. The research outcomes herein will provide inputs to subsequent studies on new construction strategies to advance the construction schedule, improve quality and constructibility, enhance safety and save costs.