Earticle

연구의 목적은 소파제의 설치 유무에 따른 도제 방파제 부근에서의 회절 파고비를 조사한 것이다. 그리고, 다양한 입사각도를 갖는 파랑의 조건과 각각 다른 반사율을 갖는 소파제의 영향에 따른 파고 감쇠 효과의 정도를 조사한다. 본 연구의 해는 경계적분방정식을 기본으로 하여 얻어진 Green 함수를 이용하여 수치계산을 실시한다. 해저 준설을 실시하여 그 위를 통과하는 진행파가 도제 방파제에 도달할 때 파고 감쇠 효과 또한 조사한다. 소파제의 설치 및 해저 준설로 인해 파고 감쇠 효과가 나타나고, 파형이 완만해 짐이 나타났다. 본 연구의 결과는 도제 방파제의 배치 및 설계, 그리고 방파제의 안전성을 확보하기 위한 수리학적 인자를 발견하는 데 많은 정보를 제공할 것으로 기대된다.

The purpose of this study is to investigate diffracted wave height at the vicinity of insular breakwater. And it is to estimate the effect of the wave reduction under the condition of the various incident wave angle and reflection ratio. The numerical simulation is performed by using the solution of the Green function based on the boundary integral equation. When the channel is dredged on the seabed, the effect of wave reduction at the wave field is to be investigated. With the reflection and the dredge, the wave height is reduced and the wave height patton is mild. The results of this study can give an information for the layout and design of insular breakwater, and it will be informed to understand the hydraulic factor for safety of breakwater.

The purpose of this study was to investigate the effects of green tea catechin on mixed function oxidase system (MFO), lipofuscin contents, carbonyl value, oxidative damage and the antioxidative defense system in lung of microwave exposed rats. Experimental groups were divided to normal group and microwave exposed group. The microwave exposed groups were subdivided into three groups: catechin free diet (MW-0C) group, 0.25% catechin (MW-0.25C) group and 0.5 ％ catechin (MW-0.5C) group according to the levels of dietary catechin supplementation. The rats were irradiated with microwave at frequency of 2.45 GHz for 15 min. Experimental animals were sacrificed at 6th day after microwave irradiation. The contents of cytochrome P$_{450}$ contents in MW-0C group was increased to 95% , compared with normal group. MW-0.25C and MW-0.5C groups were reduced to 16% and 31%, respectively, compared with MW-0C group. The activity of NADPH-cytochrome P$_{450}$ reductase in MW-0C group was increased to 44%, compared with normal group. MW-0.25C and MW-0.5C groups were reduced to 12% and 17％, respectively, compared with MW-0C group. The activity of superoxide dismutase (SOD) in MW-0C group was decreased to 21 ％, compared with normal group. MW-0.25C and MW-0.5C group were significantly (p < 0.05) increased, compared with MW-0C group. The activity of glutathione peroxidase (GSHpx) in MW-0C group was significantly decreased, compared with normal group. MW-0.25C and MW-0.5C groups were recovered to the level of normal group. The thiobarbituric acid reactive substances (TBARS) content in MW-0C group was increased to 34 ％, compared with normal group. Catechin supplementation groups were maintained the level of normal group. The levels of caybonyl value in MW-0C group was increased to 21 ％, compared with normal group. MW-0.25C and MW-0.5C groups were reduced to 14% and 12%, respectively, compared with MW-0C group. The lipofuscin contents in MW-0C group were increased to 23.4 ％, compared with normal group. That of MW-0.5C group was significantly reduced, compared with MW-0C group. In conclusion, MFO system was activated and the formation of oxidized protein, lipofuscin was increased and antioxidative defense system was weakened of lung tissue in microwave exposed rats, thus oxidative damage was increased. But it was rapidly recovered to normal level by green tea catechin supplementation.n.

In small and medium-sized cities where large parks are not common, campuses function as parks and green areas with many trees. Meanwhile, a program that quantifies the functions of trees have been developed and used mainly in North America and Europe. Through this, the functions provided by trees can be quantified, and further, the programs show the value of trees to people even with the form of monetary units. It helps citizens to improve understanding and awareness of the importance of trees. However, in Korea, estimating the value of trees is limited to the forest management fields. Therefore, in this study, we attempted to evaluate the value of the trees especially on Kangwon National University campus located in Chuncheon-si. KNU campus provides citizens with green space, so we found out the value of trees in the forest area and green space on KNU campus in terms of regulating ecosystem services. The services are carbon storage and sequestration, air pollutant removal and capturing run-off. The value of the parameters of trees measured in green spaces are higher than in forest areas, but the density of trees in forest areas are higher than in green space. From these facts, there was differences in value between trees in forests and green spaces. While uncertainties remain without correction considering the area of forests and green spaces, these results can be utilised to show people the values and functions of trees quantitatively. Especially when planning and managing them with intention of improvement on tree management.

대기오염물질 배출 수준은 배출 국가의 경제 성장 수준과 밀접한 관련을 맺고 있고, 경제가 성장함에 따라 초기에는 배출 수준도 상승하다가 점차 환경 보호 의지와 규제 수준이 강화되어 배출 수준이 감소되는 역U자형의 환경쿠즈네츠 곡선을 나타내는 것으로 알려져 있다. 온실가스의 경우에도 최근 많은 국내외 연구를 통해 경제성장과 역U자형의 관계가 존재하는지에 대한 연구가 활발해졌다. 본 연구는 시계열 자료에 기초한 타 연구와 달리 우리나라 156개 시군에 대한 온실가스 배출량과 지역총생산간의 비선형 관계에 초점을 맞추고, 지역총생산 수준이 다시 노동과 자본, 에너지 투입량에 관한 생산함수에 의해 결정되는 연립 방정식 모형을 적용하였다. 3SLS에 의한 연립 방정식 추정 결과를 SUR 추정 결과와 비교한 결과 환경쿠즈네츠 곡선이 전자에서만 관찰되었다. 또한 일인당 지역총생산액이 3천만원 수준이 되었을 때 온실가스 배출 수준이 감소하기 시작하였고, 소득 전환점을 통과한 시군은 16개로 나타났다. 한편 노동과 자본, 에너지 투입수준의 온실가스 배출 수준에 대한 탄력성을 추정한 결과 에너지보다 노동에 대한 탄력성이 더 높게 나타났고, 이는 향후 시군 단위에 서 온실가스 저감을 위해서는 에너지와 노동 투입량보다 자본 투입량을 상대적으로 늘려야 함을 의미하는 것으로 해석될 수 있다.

It is generally known that emission level of air pollutants has inverse U shape relationship with the economic growth as the economy gradually transforms from developing stage to developed one. This inverse U shape between the emission of air pollutants and economic growth is called an 'Environmental Kuznets Curve(EKC)'. Many studies have focused on whether there exists the EKC phenomena for either developed or developing countries with regard to the green house gases(GHGs). While most studies on the EKC hypothesis are based on time series data in country level, This study focuses on cross sectional data regarding Korean basic municipalities. This study applies a production function approach reflecting the relationship between the gross regional products (GRP) and factor inputs and a simultaneous equation method was employed to link the production function with the EKC equation. A 3SLS estimation method was used to estimate coefficients of the simultaneous equation. The EKC was identified for the simultaneous equation and turning point of the GRP was 30million KRW. 16 municipalities are expected to show the EKC and elasticity of the GHGs for labor input was higher than that for energy which was higher than that for capital. Ultimately, we emphasize that each municipality should invest more on capital in order to replace labor or energy by capital input in coping with the future nation-wide or global GHGs regulation.

중국은 1979년 이후 지속적인 경제성장으로 2010년 세계 2대 경제대국으로 부상했지만, 그동 안 환경보존의 중요성에 대한 인식 부족과 느슨한 환경규제로 심각한 오염 문제에 직면하고 있다. 한편, 지속적인 산업고도화의 진전에 따라 중국의 철강산업은 국가 기간산업으로 급속하게 발전해왔다. 특히, 1996년 중국은 세계 최대 철강생산국으로 자리매김했지만, 화석연료 등의 과다소비로 인하여 각종 대량 의 환경오염물질 배출을 초래하기도 하였다. 현재 중국은 세계 최대 철강생산국이기도 하지만 세계 최대 철강소비국이기도 하다. 또한, 중국 철강산업의 에너지 소비구조는 석탄과 코크스가 에너지의 89% 이상 을 차지하기 때문에 CO2 배출은 심각한 환경오염을 더욱 가중시킬 수밖에 없다. 이에 따라 중국은 철강산업의 에너지 절약과 CO2 배출 감축을 위하여 에너지효율성을 향상시키고, 경 쟁력을 유지하는 것은 국가적으로 매우 중요한 문제이다. 따라서 철강산업의 지속가능한 온실가스 감축 목표는 경제적 잠재감축량에 대한 목표설정 이외에는 에너지생산성 증가나 기술효율성 향상을 중심으로 추구하고 있다. 본 연구의 목적은 첫째, 확률변경 초월대수함수를 기반으로 쌍곡선 거리함수(hyperbolic distance function)를 이용하여 중국 철강산업의 에너지효율성을 측정하고, 이 모형에 기초하여 중국 29개 성(省) 과 지역별(동부･중부･서부) 에너지효율성을 비교하는 데 있다. 둘째, 다수의 산출요소를 반영하여 쌍곡 선 거리함수를 결합한 초월대수 확률변경함수(translog stochastic frontier function)를 사용하였다. 특히, 거리함수를 이용하여 녹색생산성을 분해하고 지역간 생산성을 비교하는 동시에 탄소배출 오염 여부를 고려하여 생산성 변화와 녹색생산성 변화를 측정･비교하는 데 있다. 이에 본 연구는 2003년부터 2016년 까지 중국 29개 성의 철강산업을 대상으로 화석에너지 투입, 탄소배출량, 에너지효율성, 생산성을 연계하 여 에너지효율성, 탄소배출을 고려한 녹색생산성, 녹색기술효율성 그리고 기술혁신 변화 등을 측정하였 다. 분석결과에 의하면 첫째, 온실가스 배출량은 철강산업 생산과 유의한 역 U자 형태를 가지며, 또한 자본스톡과 노동 그리고 화석에너지에 대한 사용량을 증가시키면 철강생산을 증가시키지만 효율적 프론 티어로부터 대상평가 성과와의 거리를 확대시키므로 에너지효율성에 부정적으로 영향을 미치는 것으로 나타났다. 둘째, 분석대상 기간 중국 29개 성의 화석에너지효율성은 평균 0.483으로 나타났으며, 매년 화 석에너지효율성은 조금씩 향상되는 것으로 나타났다. 셋째, 중국 철강산업의 녹색생산성을 3개 지역으로 분류하여 평가할 때 동부지역, 중부지역 그리고 서부지역의 녹색생산성은 2004년부터 2016년 기간 동안 평균이 각각 0.821, 0.938, 0.969를 기록하였으며, 모든 지역이 매년 증가하는 추세를 보이고 있다. 그리고 녹색생산성의 향상은 주로 녹색기술효율성의 변화가 아닌 녹색기술의 변화에 기인하는 것으로 나타났다. 본 연구결과를 바탕으로 정책적 시사점을 도출하면 다음과 같다. 철강산업은 많은 환경오염물질을 배 출하고 있는 산업이다. 특히, 철강산업에서 발생하는 이산화탄소 배출량은 전 세계 이산화탄소 배출량의 3.1%, 전체 산업의 15%에 이르고 있다. 최근에는 환경규제가 본격적으로 강화되고 있어서 환경친화적인 설비와 기술을 선택하고 개발하는 것이 철강산업의 중요한 과제로 부상하고 있다. 이제 중국의 철강산업 은 당면한 환경 문제를 극복하지 않고서는 글로벌 경쟁에서 뒤처질 수밖에 없다. 이에 중국 정부는 다른 산업 분야보다 환경규제에 대한 대응과 친환경기술개발에 대한 집중적인 투자가 요구된다.

China has emerged as the world’s second largest economy in 2010 according to continued economic growth since 1979, but has faced serious pollution problems due to lack of awareness of the importance of environmental preservation and loose environmental regulations. On the other hand, China’s iron and steel industry has rapidly developed into a national infrastructure industry as the industrial advancement continues. In particular, in 1996, China was established as the world’s largest iron and steel producer, but caused excessive amounts of environmental pollutants due to excessive consumption of fossil fuels. At present, China is not only the world’s largest iron and steel producer but also the world’s largest iron and steel consumer. In addition, in the energy consumption structure of the Chinese iron and steel industry, since coal and coke account for more than 89% of the energy, the emission is bound to further increase the serious environmental pollution. Accordingly, it is a very important issue in the country to improve energy efficiency and maintain competitiveness to save energy and reduce emissions in the iron and steel industry. Therefore, the goal of the sustainable reduction of greenhouse gases in the steel industry is to focus on increasing energy productivity or improving technical efficiency other than setting targets for economic potential reduction. This paper extends recently developed parametric hyperbolic distance functions to the analysis of energy efficiency for a panel data of 29 provinces in China’s iron and steel industry from 2003-2016, and then decomposes the growth of green total factor productivity into two component measures, namely, energy efficiency change and energy technical change based on the estimated hyperbolic distance functions. We find that firstly, the increase of capital stock, labor and fossil fuel inputs makes industrial output increase significantly. Secondly, the energy efficiency of China’s iron and steel industry was 0.483 on average across the 29 provinces for 2004-2016, and there exists a great dispersion in energy efficiencies across provinces and regions. Thirdly, the growth of green total factor productivity is almost due to the environmental technical change rather than the environmental efficiency change. Moreover, the energy productivity growth in China’s iron and steel industry may be underestimated if CO2 emissions is ignored. Based on the results of this study, the policy implications are as follows. The iron and steel industry is an industry that emits many environmental pollutants. In particular, carbon dioxide emissions from the iron and steel industry account for 3.1% of global carbon dioxide emissions and 15% of the total industry. In recent years, environmental regulations have been strengthened in earnest, so selecting and developing environmentally friendly facilities and technologies is emerging as an important task for the iron and steel industry. Chinese iron and steel industry is now forced to lag behind in global competition without overcoming its immediate environmental problems. Therefore, the Chinese government needs more intensive investment in developing environmentally friendly technologies and responding to environmental regulations than other industries.

In the given paper one determines the constituent mass of the bound state and binding energy of hadronic exotic system, according to the basis investigation of the asymptotically behavior of the loop function of scalar particles in the external electromagnet field are analytically determined exploration of these states through relativistic and non-perturbative corrections. It is shown that, the mass spectrum of a relativistic bound state of protonium consisting from proton and anti-proton is differing from a mass of initial particles.

오래 전부터 연료의 가격은 상승하고 있다. 제조업체는 보증을 통해 실용적인 대안을 찾고자 전기와 강력한 바이오 연료를 이용하여 차량의 성장가능을 연구하고 있다. 이제, 이러한 녹색 환경(emission) 관련된 보증은 보증기간이 확장되며, 이러한 보증을 '수퍼 보증" 이라 불린다. 본 논문의 주요 결과는 라돈 변환의 역행렬을 보증공간의 수치를 줄이기 위해 사용되며, 응용 프로그램 및 RBF 네트워크를 사용하여 대략적인 이변량의 보증 기능에 새로운 방법을 제시한다. 이 방법은 다음과 같은 단계로 구성되어 있다. 첫째, 라돈 변환을 이용하여, 이변량 보증 함수의 1 차원 함수를 줄일 수 있다. 둘째, 1 차원 함수의 각 신경 서브 네트워크와 신경 네트워크 기법을 사용하여 근사할 수 있다. 셋째, 이러한 신경 sub-networks 형태로 최종 근사 신경망 함께 결합 된다. 넷째, 라 돈 변환의 역함수 값을 사용 하여 최종 근사 신경 네트워크에 우리가 주어진 함수 근사화를 얻을 수 있다. 또한, 우리는 자동차 회사의 일부 그린 보증 데이터를 가지고 위의 방법을 적용한다.

As the price of traditional fuels soar, the alternatives are becoming more viable. And manufacturers are promoting the growing viability of electric and biofuel-powered vehicles through longer warranties. Now, these longer green environment (emission)warranties, sometimes called extended warranties or “super warranties,” have been adapted. The main result of this paper is to present a new method to approximate a bivariate warranty function by using Radial Basis Function Network with application of Radon Transform and its inverse which is used to reduce the dimension of the warranty space. This method consist of the following stages: First, by using the Radon Transform, the bivariate warranty function can be reduced to one dimensional function. Second, each of the one dimensional functions is approximated by using neural network technique into neural sub-networks. Third, these neural sub-networks are combined together to form the final approximation neural network. Four, by using the inverse of radon transform to this final approximation neural network we get the approximation to the given function. Also, we apply the above method to some green warranty data of automotive vehicle company.

In this paper, we express the Green function in terms of the classical kernel functions in potential theory. In particular, we obtain a formula relating the Green function and the Szeg? kernel function which consists of only the Szeg? kernel function in a $C^{\infty}$ smoothly bounded finitely connected domain in the complex plane.

The elastic theory of beams is fundamental in engineering of design and structure. In this study, we construct Green's function for inhomogeneous fourth-order differential operators subjected to associated constraints that arises in dealing with dynamic problems in the Rayleigh beam. We obtain solutions for homogeneous and completely inhomogeneous beam problems using Green's function. This enables us to consider rotational influences in determining the eigenfrequency of beam vibrations. Additionally, we investigate the dynamic vibration model of inhomogeneous beams incorporating rotational effects. The eigenvalues of Rayleigh beams, including first-order correction terms, are also computed and displayed in tabular forms.

A Green's function approach is adopted to solve the two-dimensional thermoelastic problem of a thin hollow circular disk. Initially, the disk is kept at temperature T0(r, z). For times t > 0, the inner and outer circular edges are thermally insulated and the upper and lower surfaces of the disk are subjected to convection heat transfer with convection coefficient hc and fluid temperature T∞, while the disk is also subjected to the axisymmetric heat source. As a special case, different metallic disks have been considered. The results for temperature and thermal deflection has been computed numerically and illustrated graphically.

We describe a detailed numerical scheme to calculate electron transport in quantum wires using the Green function formalism combined with tight-binding orbital basis. As an example of the application, we study the electron transport in a Si nanowire containing a finite potential barrier. The effects of nonzero bias, temperature, and disorder on the barrier-induced oscillatory conductance are investigated within the context of coherent transport model. The oscillatory behavior of the conductance as a function of the Fermi energy is found to be highly sensitive to sample disorder and limited to a very low temperature and a small bias range.

시간과 에너지에 종속된 중성자 전도 방정식에 나타나는 연속 에너지 전도 연산자의 스펙트럼(Spectrum)을 분석했다. 스펙트럼에 관한 4가지 정리를 증명하고 일반화된 Mellin 에너지변화의 Convolution 정리를 얻었다. 또한 최종해에 필요한 완전성정리를 증명하고 점근적으로 가장 우세한 시간붕괴상수 1 - c를 발견하였다.

The spectrum of continuous transfer operator arising in a time-energy dependent neutron transport equation is analyzed. Four theorems concerning on the spectrum are proved. A convolution theorem of the generalized Mellin energy transform is given. Also the completeness theorem necessary for a final solution is proved. A unique time decay constant 1 - c is found, which is dominant asymptotically.

About 40% of reactors in the world are being operated beyond design life or are approaching the end of their life cycle. During long-term operation, various degradation mechanisms occur. Fatigue caused by alternating operational stresses in terms of temperature or pressure change is an important damage mechanism in continued operation of nuclear power plants. To monitor the fatigue damage of components, Fatigue Monitoring System (FMS) has been installed. Most FMSs have used Green's Function Approach (GFA) to calculate the thermal stresses rapidly. However, if temperature-dependent material properties are used in a detailed FEM, there is a maximum peak stress discrepancy between a conventional GFA and a detailed FEM because constant material properties are used in a conventional method. Therefore, if a conventional method is used in the fatigue evaluation, thermal stresses for various operating cycles may be calculated incorrectly and it may lead to an unreliable estimation. So, in this paper, the modified GFA which can consider temperature-dependent material properties is proposed by using an artificial neural network and weight factor. To verify the proposed method, thermal stresses by the new method are compared with those by FEM. Finally, pros and cons of the new method as well as technical findings from the assessment are discussed.

We investigate the spin transfer torque in metallic multilayer system by employing Keldysh non-equilibrium Green function method. We study the dependences of the spin transfer torque on the detailed energy configuration of ferromagnetic, spacer, and lead layers. With Keldysh non-equilibrium Green function method applied to a single band model, we explore spin transfer torque effect in various layer structures and for various material parameters.

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)

고체내의 열에너지의 전달을 분석하기 위하여 고전적인 Fourier 열전도 법칙과 에너지 보존식에서 유도되는 열전도 방정식을 사용해 왔다. 이러한 열전도 방정식은 열전도가 무한한 속도로 진행된다는 것을 의미하고 있다. 그러나 극저온상태에서나 매우 급속한 열전도과정 중 매우 짧은 시간의 상태에서 non-Fourier 모델에 기초를 둔 쌍곡선형 열전도 방정식이 도입되었다. 최근의 이에 관한 연구에서 열전도가 파장의 형태로 유한한 전파속도를 갖는다는 것이 실험적으로 증명되었고 이로부터 여러 가지 실험적인 해석과 이론 해석이 전개되었다. 본 논문에서는 열전파 속도의 유한한 성질을 나타내는 수정된 열전도 법칙을 이용하여 1차원 평판에 대하여 공간에 대한 finite Fourier 변환 방법과 Green 함수 방법으로 해석하여 열전도파의 파동 성질, 공진 현상 및 위상차를 고찰하고자 한다. 열전도파가 갖는 모달 주파수에 대해 임계값을 갖으며 이 임계값을 초과할 때 공진 현상과 위상차를 고찰할 수 있었다.

An analytical solution procedure for the dynamic response of beams with variable properties is developed by using an asymptotic solution and the Green's function. This asymptotic closed form solution is derived for the transverse vibration of beams under the assumption of slowly varying properties, such as mass, cross-section, tension etc., along the beam length. However, this solution is still found to be very accurate even in the case of large variation, such as step change in cross-section, mass, and tension. Therefore, this derived asymptotic closed form solution and the Green's function can be easily applied to find dynamic responses for various kind of beam vibration problems.

An accurate evaluation of three-dimensional (3D) Time-Domain Green Function (TDGF) in infinite water depth is essential for ship's hydrodynamic analysis. Various numerical algorithms based on the TDGF properties are considered, including the ascending series expansion at small time parameter, the asymptotic expansion at large time parameter and the Taylor series expansion combines with ordinary differential equation for the time domain analysis. An efficient method (referred as "Present Method") for a better accuracy evaluation of TDGF has been proposed. The numerical results generated from precise integration method and analytical solution of Shan et al. (2019) revealed that the "Present method" provides a better solution in the computational domain. The comparison of the heave hydrodynamic coefficients in solving the radiation problem of a hemisphere at zero speed between the "Present method" and the analytical solutions proposed by Hulme (1982) showed that the difference of result is small, less than 3%.

The Gauss-Legendre integral method is applied to numerically evaluate the Green function and its derivatives in finite water depth. In this method, the singular point of the function in the traditional integral equation can be avoided. Moreover, based on the improved Gauss-Laguerre integral method proposed in the previous research, a new methodology is developed through the Gauss-Legendre integral. Using this new methodology, the Green function with the field and source points near the water surface can be obtained, which is less mentioned in the previous research. The accuracy and efficiency of this new method is investigated. The numerical results using a Gauss-Legendre integral method show good agreements with other numerical results of direct calculations and series form in the far field. Furthermore, the cases with the field and source points near the water surface are also considered. Considering the computational efficiency, the method using the Gauss-Legendre integral proposed in this paper could obtain the accurate numerical results of the Green function and its derivatives in finite water depth and can be adopted in the near field.