• Steel and Composite Structures
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• v.44 no.1
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• pp.91-104
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• 2022

The purpose of the present work is to study the parametric nonlinear vibration behavior of three layered symmetric laminated plate. In the analytical formulation; both normal and shear deformations are considered in the core layer by means of the refined higher-order zig-zag theory. Harmonic balance method in conjunction with Galerkin procedure is adopted for simply supported laminate plate, to obtain its natural and damping properties. For these aims, a set of complex amplitude equations governed by complex parameters are written accounting for the geometric nonlinearity and viscoelastic damping factor. The frequency response curves are presented and discussed by varying the material and geometric properties of the core layer.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.158-160
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• 2015

Efficient scheduling and resource management are the key factor to reduce construction project budget (e.g., labor cost, equipment cost, material cost, etc.). Resource-based line of balance (LOB) technique has been used to complement the limitations of existing time-driven scheduling techniques (e.g., critical-path method). Optimizing construction alternatives contributes to cost savings while honoring the project deadline. However, existing LOB scheduling is lack of identifying optimal resource combination. This study presents a method which identifies the optimal construction alternatives, hence achieving resource minimization in a repetitive construction by using genetic algorithm (GA). The method provides efficient planning tool that enhances the usability of the system.

• Geomechanics and Engineering
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• v.5 no.5
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• pp.485-497
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• 2013

The factor of safety is the most common measure of the safety margin for slopes. When the traditionally defined factor is used in kinematic approach of limit analysis, calculations can become elaborate, and iterative methods have to be used. To avoid this inconvenience, the safety factor was defined in terms of the work rates that are part of the work balance equation used in limit analysis. It was demonstrated for two simple slopes that the safety factors calculated according to the new definition fall close to those calculated using the traditional definition. Statistical analysis was carried out to find out whether, given normal distribution of the strength parameters, the distribution of the safety factor can be approximated with a well-defined probability density function. Knowing this function would make it convenient to calculate the probability of failure. The results indicated that the normal distribution could be used for low internal friction angle (up to about $16^{\circ}$) and the Johnson distribution could be used for larger angles ${\phi}$. The data limited to two simple slopes, however, does not allow assuming these distributions a priori for other slopes.

• Journal of Climate Change Research
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• v.9 no.1
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• pp.69-74
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• 2018

The purpose of this study is to suggest the methodology of $CO_2$ Emission Factor Verification and Quantitative Assessment in Ethylene Product Processes. At first, this study compare the IPCC (Intergovernmental Panel on Climate Change) 1996 Guideline and 2006 Guideline. And analyse methodology for estimating $CO_2$ emission and $CO_2$ emission factor in Ethylene product process. Also analyse cases of estimating $CO_2$ emission factor based on material balance. Methodology of $CO_2$ Emission Factor Verification and Quantitative Assessment are following the categories proposed by GIR (Greenhouse Gas Inventory and Research Center). There are total 12 factors in 8 categories and give 5 or 10 points according to their importance. Also this study suggests necessary data of document to meet the conditions. The result would help estimate accuracy Greenhouse Gas Inventory. Also contribute to establish policy on environmental assessment, air conservation, etc.

• Proceedings of the Korean Geotechical Society Conference
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• 2003.03a
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• pp.475-480
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• 2003

Traditionally, the statistical methods analyze the relationship between landslide occurrence and related factors(soil depth, soil strength, slope angle, vegetation, etc.) in GIS technique. However, those methods have no mechanical meaning. Therefore, the deterministic model is suggested in this research. The method analyzes the mechanical equilibrium of a potential slide block and then calculates a slope safety factor. Since this method is able to consider the balance of forces applied to the slope and is a more reasonable method for an individual site. In this research, the spatial data is obtained, managed and analyzed using GIS technique. The infinite slope model is used to evaluate factor of safety and analyze the slope stability.

• Journal of Korea Technology Innovation Society
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• v.1 no.3
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• pp.364-373
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• 1998

This study examines the international competitiveness of the Korean information and telecommunication industry by using competitiveness index such as the RCA index, the Trade Specialization index, and the Total Factor Productivity. The results of this study show that the industry's competitiveness slightly decreases since 1995, but not its the total factor productivity. In conclusion, the industry has kept the competitiveness over all. Therefore, to keep or improve the competitiveness continuously, the industry is required the government's intensive investment and administrative support. And the industry should bring up by venture and small-medium-size-enterprises to have great economic impacts on other industries. Also, the increasing production and export promoting policy will be enhance the industry and improve nation's balance of trade.

• Journal of the Semiconductor & Display Technology
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• v.18 no.3
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• pp.1-6
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• 2019

Foreground/background segmentation in video sequences is often one of the first tasks in machine vision applications, making it a critical part of the system. In this paper, we present an improved sample-based technique that provides robust background image as well as segmentation mask. The conventional multiple interval sampling (MIS) algorithm have suffer from the unbalance of computation time per frame and the rapid change of confidence factor of background pixel. To balance the computation amount, a random-based pixel update scheme is proposed and a spatial and temporal smoothing technique is adopted to increase reliability of the confidence factor. The proposed method allows the sampling queue to have more dispersed data in time and space, and provides more continuous and reliable confidence factor. Experimental results revealed that our method works well to estimate stable background image and the foreground mask.

• Journal of the Korean Wood Science and Technology
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• v.47 no.2
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• pp.189-199
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• 2019

This study addresses the biorefinery feedstock from Pinus densiflora. This raw material is a major tree species in the Republic of Korea; it is renewable, has cost-effective, and is readily available. In this study, steam explosion of P. densiflora was performed in a reactor at $225^{\circ}C$ and with 1 to 13 min reaction times with or without previous water impregnation. The combined severity factor (Ro), which is an expression relating the reaction temperature and reaction time used in the steam explosion treatment, ranged from 3.68 to 4.79. The influence of both impregnation and steam explosion conditions were investigated by examining color variations, chemical composition, and mass balance on the pretreated solids. The results showed that steam-exploded P. densiflora that was not impregnated with water exhibited significantly darker color (chroma 28.8-41.4) than water-impregnated and steam-exploded P. densiflora (chroma 18.8-37.3). The increased ${\alpha}$-cellulose and lignin contents were detected as the severity factor increased. Furthermore, the ${\alpha}$-cellulose and lignin contents in the non-impregnated/steam-exploded P. densiflora were higher than those in the water-impregnated/steam-exploded P. densiflora. However, the decreased holocellulose content was detected as the severity factor increased. In mass balance, the holocellulose yield from water-impregnated/steam-exploded P. densiflora was higher than that from the non-impregnated P. densiflora.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.5
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• pp.725-739
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• 2022

This study conducted with 268 female elderly who visited welfare center and senior citizen center in Changwon city to identify the dietary status according to social frailty stage using nutrition quotient for elderly (NQ-E). As a result of the survey, 75.0% of the elderly had no nutrition education. The elderly in social frailty stage was 43.7%, pre-frail was 35.1%, and robust was 21.2%. The scores of NQ-E (61.65), balance (47.78), moderation (86.18), and dietary behavior (55.23) were within the medium-high grade, while diversity (48.37) was within the medium-low grade. Among the balance factor item, there was a significant difference only in the frequency of fruit intake according to social frailty stage (p<0.05). Among the diversity factor item, there were significant differences in vegetable intake (p<0.05) and the rate of eating alone (p<0.001) according to social frailty stage. Among the dietary behavior factor item, there were significant differences in whether to strive for a healthy diet (p<0.05), exercise time and depression (p<0.001), and subjective recognition rate of health (p<0.01) according to social frailty stage. Based on these results, education focusing on various food intake is needed, and continuous support from the government and local governments is needed to connect the social support network of the elderly and support programs to prevent them from going to social frailty stage.

• The Journal of the Korea Contents Association
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• v.16 no.8
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• pp.693-705
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• 2016

The purposes of this study were to develop work-life balance supportive organizational culture scale(WLB supportive organizational culture) and to verify it's validity. We reviewed comprehensive studies about work-life balance and organizational culture as well as scales related to them. We theoretically extracted some important factors of WLB organizational culture from reviews and then made 38 preliminary questions. 773 married workers in their 30s to 50s were responded to a questionnaire consisted of 38 preliminary questions and 9 variables(work-life balance, quality of life, job satisfaction, turnover etc) for criterion related validity verification. As the results of factor analysis such as EFA and CFA, we could confirm five factors including WLB organizational management, WLB supportive supervisors, empathetic communication with coworkers, coworkers' material support to WLB and accessibility to WLB programs. Second, correlation analyses were performed to investigate the validation of this scale. In result, it was revealed that the WLB supportive organizational culture scale was highly correlated with other family supportive organizational culture measures as well as dependent variables such as work-life balance, quality of life, job satisfaction, turnover. We expect this study contribute to improve the quality of studies about work-life balance and organizational culture.