• Progress in Medical Physics
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• v.13 no.3
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• pp.120-128
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• 2002

To investigate differences between the metabolic ratios of normal controls and brain tumors such as astrocytomas and glioblastoma multiforme (GM) by proton MR spectroscopy (MRS) at 37 high field system. Using 3T MRI/MRS system, localized water-suppressed single-voxel technique in patients with brain tumors was employed to evaluate spectra with peaks of N-acetyl aspartate (NAA), choline-containing compounds (Cho), creatine/phosphocreatine (Cr) and lactate. On the basis of Cr, these peak areas were quantificated as a relative ratio. The variation of metabolites measurements of the designated region in 10 normal volunteers was less than 10%. Normal ranges of NAA/Cr and Cho/Cr ratios were 1.67$\pm$018 and 1.16$\pm$0.15, respectively. NAA/Cr ratio of all tumor tissues was significantly lower than that of the normal tissues (P=0.005). Cho/Cr ratio of glioblastoma multiforme was significantly higher than that of astrocytomas (P=0.001). Lactate was observed in all tumor cases. The present study demonstrated that the neuronal degradation or loss was observed in all tumor tissues. Higher grade of brain tumors was correlated with higher Cho/Cr ratio, indicating a significant dependence of Cho levels on malignancy of gliomas. This results suggest that clinical proton MR spectroscopy could be useful to predict tumor malignancy.

• Journal of the Korean Vacuum Society
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• v.17 no.6
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• pp.528-537
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• 2008

60 nm and 20 nm thick hydrogenated amorphous silicon(a-Si:H) layers were deposited on 200 nm $SiO_2$/single-Si substrates by inductively coupled plasma chemical vapor deposition(ICP-CVD). Subsequently, 30 nm-Ni layers were deposited by an e-beam evaporator. Finally, 30 nm-Ni/(60 nm and 20 nm) a-Si:H/200 nm-$SiO_2$/single-Si structures were prepared. The prepared samples were annealed by rapid thermal annealing(RTA) from $200^{\circ}C$ to $500^{\circ}C$ in $50^{\circ}C$ increments for 40 sec. A four-point tester, high resolution X-ray diffraction(HRXRD), field emission scanning electron microscopy(FE-SEM), transmission electron microscopy(TEM), and scanning probe microscopy(SPM) were used to examine the sheet resistance, phase transformation, in-plane microstructure, cross-sectional microstructure, and surface roughness, respectively. The nickel silicide from the 60 nm a-Si:H substrate showed low sheet resistance from $400^{\circ}C$ which is compatible for low temperature processing. The nickel silicide from 20 nm a-Si:H substrate showed low resistance from $300^{\circ}C$. Through HRXRD analysis, the phase transformation occurred with silicidation temperature without a-Si:H layer thickness dependence. With the result of FE-SEM and TEM, the nickel silicides from 60 nm a-Si:H substrate showed the microstructure of 60 nm-thick silicide layers with the residual silicon regime, while the ones from 20 nm a-Si:H formed 20 nm-thick uniform silicide layers. In case of SPM, the RMS value of nickel silicide layers increased as the silicidation temperature increased. Especially, the nickel silicide from 20 nm a-Si:H substrate showed the lowest RMS value of 0.75 at $300^{\circ}C$.

• 한국벤처창업학회:학술대회논문집
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• 2018.11a
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• pp.165-175
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• 2018

Since the 1997 financial crisis, large scale unemployment and poverty have become serious, and public and social job creation projects have been carried out. However, with the limitations of low-wage and short-term jobs, the need for long-term and high quality jobs gradually began to attract attention. In recent years, social enterprises have grown both quantitatively and qualitatively and interest in social enterprises has increased. And also it is interested in the determinants of success and failure of social enterprises in the academic field. In this study, we examined the effects of social enterprise characteristics on financial and social performance, and we analyzed empirically by using social enterprises registered in the Korea Social Enterprise Agency. The financial performance of the social enterprise is measured by the net income ratio, operating income ratio, and the return on asset. The social performance of the social enterprise is measured by total number of workers and the employment rate of the vulnerable social groups. The characteristics of the social enterprise include the CEO characteristics (gender, age, experience in operating the social enterprise), the firm size, and the elapsed time of the authentication. The results of the empirical analysis are as follows. First, as a result of analysis for the effect on financial performance, we found that the financial performance have a statistically significant positive relationship with firm size, organizational form, government subsidies and capital adequacy ratio. And it is found that the social performance have a statistically significant negative relationship with CEO age, credit debt dependence. Second, as a result of analysis for the effect on social performance, we foumd that total number of workers have a significant positive relationships with CEO gender, CEO age, and firm size, government subsidies, while total number of workers have a significant negative relationship with certification type and industry dummy. On the other hand, the employment rate of the vulnerable social groups have a siginificant positive relationship with CEO gender and certification type and It have not statistically significant relationship with the government subsidies and the firm size.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.14 no.2
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• pp.61-72
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• 2019

Since the financial crisis in 1997, large scale unemployment and poverty have become serious, but there has been a surge in public and social job creation projects. However, with the limitations of low-wage and short-term jobs, the need for long-term, high quality jobs gradually began to garner attention. In recent years, social enterprises have grown both quantitatively and qualitatively and interest in social enterprises has increased; more specifically, scholars are interested in the determinants of success and failure of social enterprises in the academic field. In this study, we examined the effects of social enterprise characteristics on financial and social performance. In particular, we empirically analyzed social enterprises registered in the Korea Social Enterprise Agency. The financial performance of the social enterprise was measured using the net income ratio, operating income ratio, and the return on asset. The social performance of the social enterprise was measured by the total number of workers and the employment rate of vulnerable social groups. The characteristics of the social enterprise included CEO characteristics (gender, age, experience in operating the social enterprise), firm size, and the elapsed time of authentication. The results of the empirical analysis are as follows. First, as a result of analysis for the effect on financial performance, we found that the financial performance has a statistically significant, positive relationship with firm size, organizational form, government subsidies, and capital adequacy ratio. And we found that the social performance has a statistically significant, negative relationship with CEO age and credit debt dependence. Second, as a result of analysis for the effect on social performance, we found that the total number of workers had a significant, positive relationship with CEO gender and CEO age, as well as firm size, government subsidies; whereas the total number of workers had a significant, negative relationship with certification type and industry dummy. Comparatively, the employment rate of the vulnerable social groups had a significant, positive relationship with CEO gender and certification type, but there was no statistically significant relationship with the government subsidies or firm size.

• Journal of Korean Society of Forest Science
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• v.100 no.3
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• pp.423-431
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• 2011

The changes of forest degradation in North Korea have closely been related to political, economic and social conditions at all different times. The deforestation by local people for their livelihood has been accelerated when the recession has been worsened due to the 1990's collapse of socialism and the years of natural disasters, and the fall of the centralized and planned economy system. The serious recession in the 1990's has brought many changes in the North Korean society since the 2000's. Not only the underground economy, but also the market in which personal trades are occurred have been expanded as the distribution system of the planned economy system had fallen. In addition, even many state institutions have also increased timber harvest for export to acquire insufficient foreign currency. Eventually, North Korea felt the limits of utilization of forest resources under socialism then started to seek measures to restore devastated forest, while realizing the need of support from the international society. Therefore, some NGOs of South Korea started to give financial support on building tree nurseries in which seedlings for planting are produced to help the rehabilitation of the degraded forests in North Korea. Therefore, Planning of the basic directions for forest rehabilitation programs considering to economic and social conditions of North Korea are needed based on the successful rehabilitation experience of South Korea in the 1970's. First of all, relationships which was built after collapse of centrally planned economy between districts, businesses and workers must be consider to rehabilitate forests in North Korea. Secondly, due to the nature of forest rehabilitation projects this is very needs voluntary participation of resident for a long time, and then forest rehabilitation projects can create jobs for local resident, they can obtain continuous income on the forest rehabilitation projects field in order to promote resident's work in forest rehabilitation projects. Thirdly, the rate dependence on forests of the residents living must keep the level down by rural development projects going side by side with forest rehabilitation projects. Fourthly, use of exsisting forest management system in North Korea is also needed to ensure administrative power and labor for grand scale plantations in a short period of time. Meanwhile after the success of Forest Rehabilitation, it is very important to improve exsisting forest management system.