• Journal of Environmental Impact Assessment
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• v.20 no.6
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• pp.891-905
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• 2011

Climate vulnerability index is usually defined as a function of the climate exposure, sensitivity, and adaptive capacity, which requires adequate selection of proxy variables of each variable. We selected and used 9 proxy variables related to climate exposure in the literature, and diagnosed the adequacy of them for application in Korean peninsula. The selected proxy variables are: four variables from temperature, three from precipitation, one from wind speed, and one from relative humidity. We collected climate data over both previous year (1981~2010) and future climate scenario (A1B scenario of IPCC SERES) for 2020, 2050, and 2100. We introduced the spatial and temporal diagnostic statistical parameters, and evaluated both spatial and time variabilities in the relative scale. Of 9 proxy variables, effective humidity indicated the most sensitive to climate change temporally with the biggest spatial variability, implying a good proxy variable in diagnostics of climate change vulnerability in Korea. The second most sensitive variable is the frequency of strong wind speed with a decreasing trend, suggesting that it should be used carefully or may not be of broad utility as a proxy variable in Korea. The A1B scenario of future climate in 2020, 2050 and 2100 matches well with the extension of linear trend of observed variables during 1981~2010, indicating that, except for strong wind speed, the selected proxy variables can be effectively used in calculating the vulnerability index for both past and future climate over Korea. Other local variabilities for the past and future climate in association with climate exposure variables are also discussed here.

• Journal of the Korea Society for Simulation
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• v.12 no.2
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• pp.25-34
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• 2003

Because of explosive growth in demand for web-based multimedia applications, proper proxy caching for large multimedia object (especially video) has become needed. For a video object which is much larger in size and has different access characteristics than the traditional web object such as image and text, caching the whole video file as a single web object is not efficient for the proxy cache. In this paper, we propose a proxy caching strategy with the constant-sized segment for video file and an improved proxy cache replacement policy. Through the event-driven simulation under various conditions, we show that our proposal is more efficient than the variable-sized segment strategy which has been proven to have higher hit ratio than other traditional proxy cache strategies.

• ETRI Journal
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• v.25 no.4
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• pp.258-265
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• 2003

In our study, we extracted the market, finance, and government factors determining R&D investment of individual firms in the IT industry in Korea. We collected the financial data of 515 individual firms belonging to IT and non-IT industries between 1980 and 1999 from the Korea Investors Service's database and investigated the empirical relationship between the factors using an ordinary regression model, a fixed effects model, and a random effects model. The main findings of our study are as follows: i) The Herfindahl Index variable representing the degree of market concentration is statistically insignificant in explaining R&D expenditures in the IT manufacturing industry. ii) Assets, which is used as a proxy variable for firm size, have a positive and statistically significant coefficient. These two results suggest that the Schumpeterian Hypothesis may be only partially applied to the IT manufacturing industry in Korea. iii) The dividend variable has a negative value and is statistically significant, indicating that a tendency of high dividends can restrict the internal cash flow for R&D investment. iv) The sales variable representing growth potential shows a positive coefficient. v) The subsidy as a proxy variable for governmental R&D promotion policies is positively correlated with R&D expenditure. This suggests that government policy has played a significant role in promoting R&D activities of IT firms in Korea since 1980. vi) Using a dummy variable, we verified that firms reduced their R&D investments to secure sufficient liquidity under the restructuring pressure during Korea's 1998 and 1999 economic crisis.

• Journal of Agricultural Extension & Community Development
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• v.30 no.1
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• pp.43-52
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• 2023

This study aims to examine the effects of GDP as a proxy variable of income, consumer price index as a proxy variable of price, and foot-and-mouth disease and avian influenza as derby variables on rural tourism demand. The independent variables in this research were gross domestic product(GDP), consumer price index(CPI), and dummy variable(DM) such as food & mouth disease & highly pathogenic avian influenza. Results showed that GDP affected tourism demand positively whereas DM influenced negatively. The study suggested that it was important for policy-mconsider GDP and DM when making decision on strategic tourism management. In conclusion, first, gross domestic product was found to have a statistically significant effect on rural tourism demand. Second, avian influenza was found to have a statistically negative effect on rural tourism demand. The results of this study can be used to establish a reasonable rural tourism policy in the future economic dimension.

• The Korean Journal of Financial Management
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• v.24 no.2
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• pp.1-40
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• 2007

We test a model of investment-cashflow-growth opportunities relationship in order to estimate the sensitivities to investments. In this study, we use a new proxy variable for the value of growth opportunities(hereafter "VGO"), which is based on the seminal papers of M&M(1958:1961:1963) and Lee(2006;2007). The empirical findings on the sensitivities of cashflow and growth opportunities are as follows. First, when the traditional proxy variables for the growth opportunities such as Tobin's Q, MBR and sales growth are included with the new proxy VGO in the estimation, their coefficients are turned out to be insignificant. Second, only the new proxy variable VGO shows a statistically significant positive sensitibity to investment, which can be regarded that the growth opportunities hold the positive influences to investments. Third, the Tobin's Q can be decomposed into three factors such as the value of growth opportunities(VGO), the value of asset-in-place and valuation errors. It turns out that only the VGO shows a statistically significant positive relationship with investment among others. This means that the new variable VGO is a good proxy variable for the growth opportunities in the investment-cashflow sensitivity analysis. In sum, thanks to the above findings in this study, we can say that it will not be proper to choose a proxy variable for the growth opportunities from the traditional set of proxies such as Tobin's Q, MBR, or sales growth rate.

• Journal of Digital Convergence
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• v.14 no.5
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• pp.207-215
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• 2016

The objective of this study is to examine the relevance between Job Characteristic and Organizational Effectiveness by Job Stress. The proxy variable of the Job Characteristic are skill variety, task identity, task significance, task autonomy, and task feedback. The proxy variable of Job Stress are role conflict, role ambiguity, and role overload. And the proxy variable of Organizational Effectiveness are job satisfaction, organizational commitment, and turnover intention. The sample consists of 379 data belonging to manufacturing and service industry located on Busan, Ulsan, and Gyungnam in 2015. The result of this study shows that there is difference on the relevance between Job Characteristic and Organizational Effectiveness according to the Job Stress. Therefore, it is more important to reduce the job stress to enhance the Organizational Effectiveness.

• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.1
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• pp.40-47
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• 2009

Recently, dynamic proxy caching has been proposed on the distributed environment so that media objects by user's requests can be served directly from the proxy without contacting the server. However, it makes caching challenging due to multimedia large sizes, low latency and continuous streaming demands of media objects. To solve the problems caused by streaming demands of media objects, this paper has been proposed the grouping scheme with fuzzy filtering based on partition and mapping. For partition and mapping, this paper divides media block segments into fixed partition reference block(R$_f$P) and variable partition reference block(R$_v$P). For semantic relationship, it makes fuzzy relationship to performs according to the fixed partition temporal synchronization(T$_f$) and variable partition temporal synchronization(T$_v$). Simulation results show that the proposed scheme makes streaming service efficiently with a high average request response time rate and cache hit rate and with a low delayed startup ratio compared with other schemes.

• Journal of Labour Economics
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• v.33 no.3
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• pp.129-149
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• 2010

We find that there is the height premium in the Korean labor market. The wage increases by 1.5% with a centimeter increase of height among male workers of ages 30-49. This estimate is barely affected by family backgrounds such as a worker's father's education or occupation. It is rejected that a worker's height is a proxy variable for his health, which increases his wage. The height premium is unrelated with obesity. It is not also supported that a worker's height affects his wage through his occupational choice. We partly confirm that a worker's height affects his wage through his educational choice. The estimated height premium of 30's in Korea is comparable to that of age 33 in Great Britain.

• KDI Journal of Economic Policy
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• v.40 no.4
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• pp.1-22
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• 2018

We estimate three continuous-time stochastic volatility models following the approach by Aït-Sahalia and Kimmel (2007) to compare the Korean and US stock markets. To do this, the Heston, GARCH, and CEV models are applied to the KOSPI 200 and S&P 500 Index. For the latent volatility variable, we generate and use the integrated volatility proxy using the implied volatility of short-dated at-the-money option prices. We conduct MLE in order to estimate the parameters of the stochastic volatility models. To do this we need the transition probability density function (TPDF), but the true TPDF is not available for any of the models in this paper. Therefore, the TPDFs are approximated using the irreducible method introduced in Aït-Sahalia (2008). Among three stochastic volatility models, the Heston model and the CEV model are found to be best for the Korean and US stock markets, respectively. There exist relatively strong leverage effects in both countries. Despite the fact that the long-run mean level of the integrated volatility proxy (IV) was not statistically significant in either market, the speeds of the mean reversion parameters are statistically significant and meaningful in both markets. The IV is found to return to its long-run mean value more rapidly in Korea than in the US. All parameters related to the volatility function of the IV are statistically significant. Although the volatility of the IV is more elastic in the US stock market, the volatility itself is greater in Korea than in the US over the range of the observed IV.

• International journal of advanced smart convergence
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• v.13 no.2
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• pp.94-102
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• 2024

This study examines the factors influencing loyalty to cultural arts events using data from the Survey Report on National Culture and Arts Activity in 2022 and 2023. The dependent variable is a binary variable representing the intention to revisit in the future, which serves as a proxy for loyalty. Given that the dependent variable is binary, the logit model specification is employed to estimate the average marginal effects. The estimation results indicate that audience satisfaction exerts the strongest influence on loyalty in both years. It can be observed that participation in cultural arts events is the second most important variable in determining loyalty. This suggests that the government should support the expansion of the scope of these activities and the diversification of programs in order to facilitate greater participation in a wider range of cultural arts activities.