• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.6
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• pp.469-481
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• 2016

The number of single households in Korea has been sharply increasing due to dissolution of the family community and changes in housing culture. Therefore, there is a need to develop a plan for diagnosis of changes in the housing market in response to a rapid increase of single household to suggest a proper direction of housing policy. This study was conducted to clarify the factors influencing housing occupancy type targeting a single adult household. To accomplish this, a cross-sectional analysis was conducted using the multi-nominal logit model and the Korea Welfare Panel's 9th survey materials. Occupants of ingle households in their 20s and 30s were found to be much poorer than those in their 40s, or older. Additionally, single household in their 20s and 30s, the characteristic of a household having an influence on the choice of housing occupancy type showed a result in a different direction even from the same household characteristic of those in their 40s, or older. Finally, the characteristics of occupants of single households in their 20s and 30s showed room for improvement through public support. Overall, the results of this study implied the need to inquire into the government's periodic support in more diverse ways.

• Journal of the Korea Society of Computer and Information
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• v.26 no.8
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• pp.187-196
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• 2021

This study uses data from the 11th year(2016) to the 15th year(2020) of the Korea Welfare Panel(KOWEPS) for the five years that the survey was completed to predict the life satisfaction of each individual by generation, centered on single-person households. This is a longitudinal analysis using a latent growth model. The generational division was based on the turning point of a major event experienced by the cohort that brought about a decisive change in the socialization process, historical event, and technological development as factors. The analysis data used in this study were of 27,447 persons in the 15th year of the Korea Welfare Panel(2020), 2,778 persons who were single-person households even in the first year from the last 5 years, and 1,448 persons who were single-person households continuously for 5 years. Excluding those born in 1922 to 1944(843 persons), 605 persons born between 1945 and 1996 were included. As a result of the study, Generation Y(millennials) than Generation X(new generation) and Generation X generation than Baby Boomers showed higher overall life satisfaction. Since overall life satisfaction by generation does not have an effect on the rate of change, it was found that this difference remains the same for all generations.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.16 no.12 s.117
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• pp.1252-1261
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• 2006

This paper summarizes theoretical work on the multichannel decentralized feedback control of sound radiation from aircraft trim panels using piezoceramic actuators. The aircraft trim panels are generally honeycomb structures designed to meet the design requirement of low weight and high stiffness. They are resiliently-mounted to the fuselage for the passive reduction of noise transmission. It is motivated by the localization of reduction in vibration of single channel active trim panels. 12-channel decentralized feedback control systems are investigated in terms of the reduction of noise and vibration for three configurations of sensor actuator pairs. Local coupling of the closely-spaced sensor and actuator pairs was modeled using single degree of freedom systems. The multichannel control system is characterized using the state-space model. For the stability point of view, the relative stability or robustness is evaluated by comparing the real part of eigenvalues of the system matrix for the three configurations. The control performance is also evaluated and compared for the three configurations. It is found that the multichannel system can lead to the globalization of the reduction in vibration and radiated noise. It does not appear to yield a significant improvement in the vibration because of decreased gain margin. However, the reduction in the radiated noise is remarkably improved due to the variation of the vibration pattern with the actuation configurations.

• Journal of the Korean Wood Science and Technology
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• v.30 no.4
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• pp.96-105
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• 2002

Shear wall is the most important component resisting lateral loads imposed to a building by wind or earthquake. In shear walls, lateral load applied to framing is transmitted to sheathing panel through nailed joints between sheathing and framing so that the load is resisted by in-plane shear strength of sheathing. Therefore, nailed joints are the most basic and important component in the viewpoint of stiffness and strength of shear walls. In this study, stiffness and strength of single nailed joint were measured by single shear tests of nailed joints and used as input for theoretical models developed to estimate racking behavior of shear walls. And shear walls were tested to check the accuracy of theoretical models estimating racking resistance of shear walls. Stiffness of nailed joint was affected by grain direction of stud but direction of sheathing panel had little effect. Behavior of nailed joint and shear walls under lateral loads could be represented by three lines. Theoretical model II was more accurate than theoretical model I in estimating racking behavior of shear wall under loads.

• Environmental and Resource Economics Review
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• v.27 no.3
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• pp.463-493
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• 2018

As the population structure of Korea changes with the increase of single households and elderly households, this may have effect on domestic energy consumption pattern. Our study analyzes whether the energy consumption of single and elderly households are distinguishable from those of general households. For empirical analysis, Household Energy Standing Survey panel data and regional fixed effect model are employed. The result strongly shows that single households consume more energy than other households. The consumption of single households from 40s to 60s was the highest. On the other hand, the effect of aging was different from energy sources. Electricity consumption of elderly household was more than other age groups, while oil consumption of elderly household was less than others. Gas and total energy consumptions turned out to be not much different among different age groups.

• Journal of Korea Trade
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• v.24 no.5
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• pp.1-17
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• 2020

Purpose - This paper tries to estimate the effects of China's and Japan's free trade agreement (FTA) by panel generalized least squares (GLS). Design/methodology - The GLS model includes the basic gravity theory and Difference in Difference (DD) method to divide FTA conclusion countries and non-FTA conclusion countries with China and Japan. In order to empirically research the difference between Chinese and Japanese FTAs, we use the Difference in Difference in Difference (DDD) method. Findings - This paper finds the distance variable has more influence on Japanese than Chinese trade. The exchange rate indicates that Chinese trade depends on export and Japanese trade has the structure of re-import; shows that the countries that concluded FTAs with China and Japan have more positive trade effects than those that did not; finds the Chinese FTA promotion effects greater than the Japanese FTA because China had pushed ahead with trade policy since joining the WTO in 2001. Originality/value - This study shows that a single country's FTA and trade policies are an important factor concerning not just the promotion of trade but also the issue of trade conflicts.

• Asia-Pacific Journal of Business
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• v.13 no.3
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• pp.389-400
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• 2022

Purpose - This study empirically analyzes the effects of food delivery service use frequency and the proportion of single-person households on the generation of MSW (Municipal Solid Waste). Additionally, the study analyzes MSW increase during the COVID-19 period. Design/methodology/approach - The study uses annual information on MSW and related characteristics of 228 Si, Gun, and Gu, which are administrative districts of Korea, from 2015 to 2020. Panel fixed effect model is employed for estimations. Findings - The study finds that food delivery and single-person household have significant effects only on recyclable and standard garbage bag MSW, respectively, not on all produce types of MSW. Additionally, it is estimated that, during the COVID-19 period, the increasing effect of food delivery is intensified while single-person households diminish its increasing effect. Lastly, the study confirms that the marginal effect on the increasing effect of MSW generation by the number of household members. Research implications or Originality - The estimated results are expected to provide useful information for the related policies. In particular, it is necessary to focus more on recyclable MSW concerning the developing delivery culture, and regarding changes in the family structure, focus more on the number of household members than single-person households.

• Journal of Information Display
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• v.9 no.3
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• pp.33-38
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• 2008

A simple ray tracing model is developed to establish the relationship between the distributions of observed visible light and the excited Xe species in a PDP cell. The ray tracing model can obtain the density distribution of the excited Xe species. It shows the two independent discharge modes created during a single period of sustaining discharge. The maximum density of excited Xe species is located about $148{\mu}m$ away from the center of the gap between two sustaining electrodes. We also found the loss rate of VUV photons by comparing the luminance profile predicted in our theoretical model from experimental results. According to calculations based on our model, only about 22 percent of the photons can impinge the phosphor layer.

• Structural Engineering and Mechanics
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• v.68 no.6
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• pp.721-733
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• 2018

The modal frequency responses of functionally graded (FG) sandwich doubly curved shell panels are investigated using a higher-order finite element formulation. The system of equations of the panel structure derived using Hamilton's principle for the evaluation of natural frequencies. The present shell panel model is discretised using the isoparametric Lagrangian element (nine nodes and nine degrees of freedom per node). An in-house MATLAB code is prepared using higher-order kinematics in association with the finite element scheme for the calculation of modal values. The stability of the opted numerical vibration frequency solutions for the various shell geometries i.e., single and doubly curved FG sandwich structure are proven via the convergence test. Further, close conformance of the finite element frequency solutions for the FG sandwich structures is found when compared with the published theoretical predictions (numerical, analytical and 3D elasticity solutions). Subsequently, appropriate numerical examples are solved pertaining to various design factors (curvature ratio, core-face thickness ratio, aspect ratio, support conditions, power-law index and sandwich symmetry type) those have the significant influence on the free vibration modal data of the FG sandwich curved structure.

• Structural Engineering and Mechanics
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• v.78 no.5
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• pp.519-528
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• 2021

One of the most efficient designs of solar trackers for photovoltaic panels is the single-axis tracker, which holds the panels along a torque tube that is driven by a motor at the central section. These trackers have evolved to become extremely slender structures due to mechanical optimization against static load and the need of cost reduction in a very competitive market. Owing to the corresponding decrease in mechanical resistance, some of these trackers have suffered aeroelastic instability even at moderate wind speeds, leading to catastrophic failures. In the present work, an analytical and experimental approach has been developed to study that phenomenon. The analytical study has led to identify the dimensionless parameters that govern the motion of the panel-tracker structure. Also, systematic wind tunnel experiments have been carried out on a 3D aeroelastic scale model. The tests have been successful in reproducing the aeroelastic phenomena arising in real-scale cases and have allowed the identification and a close characterization of the phenomenon. The main results have been the determination of the critical velocity for torsional galloping as a function of tilt angle and a calculation methodology for the optimal sizing of solar tracker shafts.