• Environmental and Resource Economics Review
• /
• v.21 no.2
• /
• pp.211-235
• /
• 2012

This paper presents an alternative decomposition technique to identify the relative importance of factors associated with changes in $CO_2$ emissions by using directional distance function to model the joint production of desirable and undesirable outputs. The key feature of the proposed approach is the introduction of fossil and non-fossil fuel energy input efficiencies, productivity change and emission intensity change. For the 27 OECD countries as a whole, the empirical results indicate that economic growth is the most important contributor to $CO_2$ emissions increase, while efficiency change is the most important component to $CO_2$ emissions reduction between 1980 and 2007. For more extensive insights, this paper divided 3 groups according to the emission growth rate and find out that high emission countries show relatively low production efficiencies and technical changes contributing $CO_2$ emissions increase. The results also provide that more strict environmental regulations are needed to improve the pollution intensity in these countries.

• International Commerce and Information Review
• /
• v.16 no.2
• /
• pp.185-198
• /
• 2014

The purpose of this paper is to examine a causal relationship and interaction among payment of education expenses, economic growth, imports and exports. The results of 'the Granger causality test' suggest that payment of education expenses are affected by imports and exports; and the other factors are not related. In addition, payment of education expenses and the relationship among variables confirmed by IRF show that payment of education expenses has a minus(-) effect on exports at the beginning and then it turns into plus(+) as a certain time passes. On the other hand, it has a minus(-) effect on imports at the beginning, and this gradually changes to zero(0). Lastly, it turns out that it has a plus(+) effect on GDP. It is therefore estimated that the demand for high-quality manpower is expected to grow and new investments for education to rise with increases in imports and exports with initial acceleration. The findings show that government education investment in foreign languages and research manpower must take precedence in order to meet the demand for high-quality manpower.

• The KIPS Transactions:PartD
• /
• v.8D no.6
• /
• pp.835-842
• /
• 2001

We propose a software-reliability growth model incoporating the amount of testing effort expended during the software testing phase. The time-dependent behavior of testing effort expenditures is described by a Weibull curve. Assuming that the error detection rate to the amount of testing effort spent during the testing phase is proportional to the current error content, a software-reliability growth model is formulated by a nonhomogeneous Poisson process. Using this model the method of data analysis for software reliability measurement is developed. After defining a software reliability, we discuss the relations between testing time and reliability and between duration following failure fixing and reliability are studied in this paper. The release time making the testing cost to be minimum is determined through studying the cost for each condition. Also, the release time is determined depending on the conditions of the specified reliability. The optimum release time is determined by simultaneously studying optimum release time issue that determines both the cost related time and the specified reliability related time.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.28 no.2
• /
• pp.9-16
• /
• 2024

In this paper, we aimed to convert the fire curve in volume units to a fire curve per unit area for application in the Fire Dynamic Simulator (FDS) surface heat release rate method. The fire curve was expressed dimensionlessly considering the total combustion characteristic time, and improvements were made to represent the appropriate ratios for the growth , steady, and decay phases concerning the fire intensity. Additionally, a correction function for combustion characteristic time varying with mass increase was derived. Also to control the growth time values according to the increase in mass, a function to correct the growth phase ratio was derived. Consequently, utilizing existing data, a formula was established to determine the reference mass for combustion materials and predict the fire curve based on mass increase.

• Journal of Korea Technology Innovation Society
• /
• v.10 no.1
• /
• pp.47-72
• /
• 2007

Ideas do not become exhausted, and there are no diminishing returns in the creation of knowledge. Nonetheless, growth ultimately ceases in this simplest model of endogeneous innovation. The reasons are similar to those that are discussed in the context of the neoclassical model of capital accumulation. Even if the resource cost of creating new goods does not rise, the economic return to invention may decline as the number of available products increases. When the rate of return to R&D falls to the level of the discount rate, private agents cease to be willing to defer consumption in order to invest in product development. But, if we treat knowledge capital as a public capital considering of its non-appropriable benefits, economic growth can be sustained in the economy. Romer(1986) has pointed out that growth might be sustainable if the accumulation of knowledge is not subject to long-run diminishing returns. Actually Romer assumed diminishing returns in the production of private knowledge from available resources, but increasing returns in the production of output from labor and total (public and private) knowledge. His condition for the sustainability of long-run growth amounts to an assumption that the diminishing returns in the former activity do not outweigh the increasing returns in the latter. The Johansen(1988) cointegration test method is used for finding long-run equilibrium relationship between R&D input and the product innovation. Test results indicate the existence of cointegrating equation between each pair of regression variables including dependent variable in the knowledge production function. And, the signs of cointegrating vectors are well accord to the prediction of sustainable growth. In the empirical analysis, from all cases of the form for the knowledge production function, we could not reject the null hypothesis that R&D spillover effect is significant($H_{0}:\;{\gamma}=1$). In summary, we showed that considering goodness of fit of regression model, we can see that the empirical evidence is strongly in favor of the character of knowledge as the public knowledge capital. So, we can expect that by product innovation, economic growth can be sustained in the Korean economy.

• International Commerce and Information Review
• /
• v.14 no.4
• /
• pp.89-107
• /
• 2012

Recently, the successful appointment of the general directorate of GCF (Green Climate Fund) in Songdo of Korea made a great history for the golden triangle with GGGI (global Green Growth Institute) and GTC (Green Technology Center). Now, Korea became the Mecca for the global green growth and it gave a great opportunity foe the Korea to lead the global economy in the future. However, to successfully manage the GCF, the Korean government should show their willingness as well as the readiness for the green prowth and green productivity. It is really hard for the Korea, since it takes the second rank for the growth rate of carbon dioxide emission in the world. To overcome this shameful status, it should make the best effort to promote the green productivity, especially in a field of logistics industry, because it takes 21% of global CO2 emission, the second largest portion. The research aims to systematically introduce the Global Malmquist-Luenberger Index (GML) and to evaluate the logistics industry of Korea based on the GML approach. It concludes the innovative technology is utmost important to improve the green productivity of the logistics industry and thus the Korean government should make more aggressive role to fill this missing link in the innovation network.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.12 no.3
• /
• pp.123-131
• /
• 2012

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.

• Proceedings of the Korea Crystallographic Association Conference
• /
• 2002.11a
• /
• pp.40-41
• /
• 2002

차세대 반도체 및 나노소자 산업에 대한 국제적 기술은 고밀도 직접화의 추세에 따라서 .게이트 산화막의 두께가 급속히 작아지는 추세이다. 지금까지 이산화규소(A1₂O₃)가 게이트 산화막으로 주로 사용되어 왔으나 점차 SiON 혹은 high k 박막으로 바뀌고 있다. 본 연구에서는 차세대 반도체 소자에 사용될 게이트 산화막 물질인 SiON 박막과 Al₂O₃박막에 대한 SE(Spectroscopic Ellipsometry)분석 모델을 확립하였고, SE 측정결과를 TEM, MEIS, XRR의 결과들과 비교하였다. SiON 박막의 굴절률 값은 Si₃N₄와 SiO₂가 물리적으로 혼합되어 있다고 가정하여 Bruggeman effective medium approximation을 사용하여 구하였다. 동일한 시료를 절단하여 TEM, MEIS, 그리고 XRR에 의하여 SiON 박막의 두께를 측정하였으며, 그 결과 SE와 XRR에 의해 얻어진 박막두께가 TEM과 MEIS의 결과 값보다 약 0.5 nm 크게 주어짐을 알 수 있었다(Table 1 참조). 본 연구결과는 비파괴적이며 비접촉식 측정방법인 SE가 2～4nm 두께의 초미세 SiON 박막의 두께와 N 농도의 상대적 값을 빠르고 쉽게 구할 수 있는 유용한 측정방법 임을 보여주었다. 기존의 게이트 산화물인 SiO₂를 대체할 후보 물질들 중의 하나인 A1₂O₃의 유전함수를 구하기 위하여 8 inch, p-type 실리콘 기판 위에 성장된 5 nm, 10 nm, 및 20 nm 두께의 A1₂O₃ 박막의 유전함수와 두께를 측정하였다. 이 시료들에 대한 SE data는 vacuum-UV spectroscopic ellipsometer를 사용하여 세 개의 입사각에서 0.75 eV에서 8.75 eV까지 0.05 eV 간격으로 측정되었다. A1₂O₃ 박막의 유전함수와 두께를 얻기 위하여 공기층/A1₂O₃ 박막/Si 기판으로 구성된 3상계 모델을 사용하였다. Si 기판에 대한 복소 유전함수는 문헌상의 값(1)을 사용하였고, A1₂O₃ 박막의 유전함수는 5개의 미지상수를 갖는 Tauc- Lorentz(TL) 분산함수(2)를 사용하였다. A1₂O₃ 박막의 경우 두께가 증가함에 따라서 굴절률이 커짐을 알 수 있었다.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.11 no.6
• /
• pp.449-453
• /
• 2001

In this paper, we propose an algorithm to design the adaptive structure of wavelet neural network with F-projection and geometric growing criterion. Geometric growing criterion consists of estimated error criterion considering local error and angle criterion which attempts to assign a wavelet function that is nearly orthogonal to all other existing wavelet functions. These criteria provide a methodology that a network designer can construct wavelet neural network according to one's intention. We apply the proposed constructing algorithm of the adaptive structure of wavelet neural network to approximation problems of 1-D and 2-D function, and evaluate the effectiveness of the proposed algorithm.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2010.05a
• /
• pp.46.1-46.1
• /
• 2010

일반적으로 석출물의 석출은 핵생성(Nucleation)-성장(Growth)-조대화(Coarsening)의 단계를 거친다. 핵생성에 의해 생성된 개개의 핵들은 아직 열역학적으로 평형 상태가 아니다. 석출물의 부피 분율은 아직 상태도에서 예측할 수 있는 값까지 도달하지 못했다. 과포화된 기지에서 생성된 핵은 계속적으로 기지로부터 용질 원자를 공급받아 성장하게 된다. 석출물의 성장은 그 부피 분율이 상태도에서 예상되는 값에 도달할 때까지 계속된다. 시간에 따른 석출 분율 계산과 분산된 석출물들이 matrix내에서 어느 정도 용해도를 갖는다면, 보다 작은 크기의 입자들은 용해되어 보다 큰 입자로 석출(성장)하려는 경향이 있다. 이러한 현상의 구동력은 전체 시스템의 계면 에너지 감소에 의해 주어지며, 결국 하나의 큰 입자만이 존재하게 될 것이다. 본 연구에서는 석출분율을 계산하기 위해 상용프로그램인 Pandat을 통해 Mg-Al 2원계합금의 상태도 및 석출분율 계산을 위한 열역학 데이터를 계산하였다. 계산된 열역학 데이터는 C언어로 함수화 하여 입력하고 Excell을 통해 석출분율을 계산하였다. 계산된 석출분율과 실험값의 비교를 통해 fitting parameters를 대입하여 계산값 및 실험값의 오차율을 줄였다. 본 연구에서 계산된 석출분율은 미래의 석출상 크기 및 분포 등을 개발하는 기초데이터로 활용할 수 있을 것이다.