• Journal of Environmental Science International
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• v.27 no.7
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• pp.519-529
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• 2018

With rapid economic growth, the urban environment has created a problem of human physical and mental illness. In order to solve these problems, urban forests have emerged as a way to mitigate the environmental risks through improving the polluted environment of the city and improve the quality of life. As the urban forests have expanded, the school forests movement has also been taking an important place recently. The study focused on the performance of school forests by comparing the perceptions among teachers and students about their functions. The questionnaire was composed of 4 questions concerning human matters, 10 questions for space recognition, 4 questions for thermal environment, 2 questions for health promotion, and 20 total questions for composition of survey items. The reliability of the school forest function, number of tree planting areas and quantities, the harmony of the planting, and the satisfaction of the school forest were analyzed in the questionnaire conducted by the school members. Although it does not recognize school forests, it has a positive response to the green space that is built outdoors. It is considered that outdoor education and environmental education are sufficient in school forests and green spaces. The results showed that the outdoor green space was more satisfactory when compared with the general school. Teachers and students' preferences were similar to 'seasonal changes' and' trees of various colors and shapes'. The reliability analysis between each item shows that the coefficient for cronbach's ${\alpha}$ was .700 to .834. The purpose of this study is to identify the perception of forest function among school forest members and to utilize them as a basic data in the future.

• Journal of Korea Trade
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• v.23 no.5
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• pp.27-44
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• 2019

Purpose - The purpose of this paper is to analyze the net effect of the green total factor productivity (GTFP) of China's manufacturing industry from the China-Korea Free Trade Area (China-Korea FTA) quantitatively. Design/methodology - Firstly, the Global Malmquist-Luenberger (GML) index based on the SBM directional distance function is used to measure the GTFP of China's manufacturing and analyze the driving force for its growth. Secondly, the regression discontinuity quantitative analysis is used to determine the impact of the China-Korea FTA on China's manufacturing GTFP. Findings - Our main findings can be summarized as follows: the China-Korea FTA has promoted the GTFP of China's manufacturing with an effect evaluation mainly resulting from green technology progress. And there is industry heterogeneity in the policy effect on the manufacturing GTFP due to the China-Korea FTA. Namely, policy promotion from the China-Korea FTA is more effective on the GTFP of equipment manufacturing than it is on those of other industries. Originality/value - First, an evaluation and analysis of the GTFP development of China's manufacturing that employs GML index based on SBM directional distance function. Second, a quantitative estimate of China-Korea FTA's net effect on China's manufacturing industrial GTFP that uses regression discontinuity analysis, which is considered to be the closest method to natural experiments and superior to other causal inference methods. Third, an in-depth discussion of the practical steps that China's manufacturing can take to improve GTFP development and integrate China-Korea FTA construction into economic development.

• Journal of the Chungcheong Mathematical Society
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• v.19 no.1
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• pp.101-110
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• 2006

In this paper, we develop existence and uniqueness criteria to certain class of three point boundary value problems associated with third order nonlinear fuzzy differential equations, with the help of Green's functions and contraction mapping principle.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.10a
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• pp.133-134
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• 2009

• The Pure and Applied Mathematics
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• v.1 no.1
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• pp.29-33
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• 1994

There are various aspects of the solution of boundary-value problems for second-order linear elliptic equations in two independent variables. One useful method of solving such boundary-value problems for Laplace's equation is by means of suitable integral representations of solutions and these representations are obtained most directly in terms of particular singular solutions, termed Green's functions.(omitted)

• Journal of the Korean Institute of Telematics and Electronics
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• v.16 no.5
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• pp.42-48
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• 1979

In this paper, it is shown that a microwave frequency discriminator can be realized by use of a simple ring resonator. Its characteristics have been analyzed by employing Green's function and verified experimentally. The maximum frequency bandwidth obtained from the experiments is 45MHz at S-band(center frequency 50=3GHz).

• Advances in nano research
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• v.7 no.3
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• pp.209-221
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• 2019

Graphene, with impressive electronic properties, have high potential in the microelectronic field. However, graphene itself is a zero bandgap material which is not suitable for digital logic gates and its application. Thus, much focus is on graphene nanoribbons (GNRs) that are narrow strips of graphene. During GNRs fabrication process, the occurrence of defects that ultimately change electronic properties of graphene is difficult to avoid. The modelling of GNRs with defects is crucial to study the non-idealities effects. In this work, nearest-neighbor tight-binding (TB) model for GNRs is presented with three main simplifying assumptions. They are utilization of basis function, Hamiltonian operator discretization and plane wave approximation. Two major edges of GNRs, armchair-edged GNRs (AGNRs) and zigzag-edged GNRs (ZGNRs) are explored. With single vacancy (SV) defects, the components within the Hamiltonian operator are transformed due to the disappearance of tight-binding energies around the missing carbon atoms in GNRs. The size of the lattices namely width and length are varied and studied. Non-equilibrium Green's function (NEGF) formalism is employed to obtain the electronics structure namely band structure and density of states (DOS) and all simulation is implemented in MATLAB. The band structure and DOS plot are then compared between pristine and defected GNRs under varying length and width of GNRs. It is revealed that there are clear distinctions between band structure, numerical DOS and Green's function DOS of pristine and defective GNRs.

• Communications of the Korean Mathematical Society
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• v.3 no.2
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• pp.225-229
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• 1988

• Journal of the Korean Institute of Landscape Architecture International Edition
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• no.1
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• pp.37-42
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• 2001

In order to answer the challenge that development gave to environment, Chinese cities are making up and putting into effect the green space system planning. The planning main keys are: set down standards and scope of green space; bring the characteristics of every types of green space in to full play and made into basic units of the system; formed powerful links of the system; make full use of the natural system of city, constituted the urban and countryside as a organic whole green space system, therefore give full play their function and ecological effect. In fact, this green space system is a complex system. It is the main body of city ecological system, a main container of the citizen activities of leisure and recreation and a leading factor for making characteristic city landscape. Therefore it is a system carrying city's environment sustainable development.

• Journal of Korea Trade
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• v.25 no.2
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• pp.95-110
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• 2021

Purpose - This paper intends to conduct theoretical analysis and empirical test on the action mechanism of South Korea-China trade and South Korea's FDI to China on green total factor productivity, so as to provide a new perspective and ideas for the improvement of China's green total factor productivity and promote the high-quality development of China's economy Design/methodology - This paper uses the data of 30 provinces, autonomous regions and municipalities in China from 2004 to 2017 as the research sample, adopts the GML index method of SBM Directional Distance Function to measure GTFP, and analyzes the influence of South Korea-China trade and FDI from South Korea on China's GTFP. Findings - Trade is conducive to promoting technological progress, which has a significant promotion effect on China's green total factor productivity. While FDI has a significant inhibitory effect on China's green total factor productivity, which verifies the "pollution haven" hypothesis. In addition, such influence has certain regional overall heterogeneity. Trade has a more significant promoting effect on GTFP in eastern coastal areas, while FDI has a more significant inhibitory effect on GTFP in central and western inland areas. The interaction between trade and FDI is conducive to the improvement of green total factor productivity, indicating that the benign mechanism of trade and FDI has been formed. Urbanization, industrial structure, human resource level and investment in science and technology are all conducive to the improvement of GTFP. Originality/value - Through theoretical analysis and empirical test on the action mechanism of South Korea-China trade and South Korea's FDI on green total factor productivity, this paper provides a solid theoretical foundation for the further development of China-South Korea economic and trade cooperation in the future.