• Journal of Preventive Medicine and Public Health
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• v.40 no.1
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• pp.29-35
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• 2007

Objectives : To assess whether the risk-adjusted in-hospital mortality rates for non-emergent and isolated coronary artery bypass graft surgery (CABG) patients exhibited a consistent trend from 2001 to 2003. Methods : The data used in this study came from CABG claims that were submitted to a Korean Health Insurance Review Agency (HIRA) in 2001, 2002, and 2003. Study datasets included data from 17 tertiary hospitals, which had at least 25 claims each year over 3 years. The inter-hospital differences in patients' risk-factors were identified and controlled in the risk-adjustment model. Actual and predicted mortality rates for each hospital were calculated in 2001, 2002, 2003, and 2001+2002, and were then examined to identify consistent rate patterns over time. Kappa analysis was applied to assess the agreements between rates. Results : Hospitals with lower-than-expected inpatient mortality rates showed more consistent rates than those with higher-than-expected mortality rates. The mortality rates that were calculated based on data obtained over multiple years had less variation among hospitals than rates based on single year data. Based on the Kappa score, the highest agreement was found when the rates were compared between the 2-year combined data (2001+2002) and 2003. Conclusions : Consistent patterns over 3 years were most evident for hospitals which had lower-than expected mortality rates. Policy makers can use this information to identify the degree of outcomes in hospitals and help motivate or channel the behaviors of providers.

• Journal of Korean Society for Atmospheric Environment
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• v.20 no.1
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• pp.111-118
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• 2004

In order to compare the NVOC (Natural Volatile Organic Compound) emission rates from oak trees, the emission rates of isoprene were quantitatively measured in situ based on tree species and region. As a result, the emission rates from Quercus serrata T. were found to be 1000 times greate. than those from Quercus acutissima C. However, the emission rates at the Chili and Gumsung mountain sites did not show any significant differences in summer. Cuvette tests using four different oak species also supported that there was a tremendous difference in emission rates between Quercus serrata T. and Quercus acutissima C. It was found that the emission rates from the trees were highest on the order of Quercus serrata T., Quercus aliena B., Quercus acutissima C. and Quercus variabilis B.

• Health Policy and Management
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• v.14 no.2
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• pp.138-162
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• 2004

This study was performed to investigate small area variation in rates of three common surgeries in general surgery department across 156 small areas. Three surgery rates were analyzed; Anal and/or stomal procedures, inguinal and/or femoral hernia procedures, appendectomy. Methods: We used health insurance claims data and the number of patients were 13,845, 2,154 and 7,151 persons respectively. Surgery rates were directly standardized with age and sex and logistic regression was used to analyze surgery rates. Results: Mapping of the surgery rates, there was small area variation in anal and/or stomal procedures. The clinic which was located in more competitive market and chose DRG payment system tends to do more anal and/or stomal procedures. There was no factor except DRG bed rates had effect on rate of inguinal and/or femoral hernia procedures. Conclusions: Findings of this study will contribute to developing investigation method on small area variation and policy to reduce the variation such as developing evidence based medical practice guideline.

• Interdisciplinary Bio Central
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• v.1 no.3
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• pp.11.1-11.5
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• 2009

One of the main issues of molecular evolution is to reveal the principles dictating protein evolutionary rates. A traditional hypothesis posits that protein evolutionary rates are mostly determined by the average functional importance of amino acids in a given protein. Thus the correlations of evolutionary rates with different variables such as PPI, gene essentiality and expression abundance have been studied to test the traditional hypothesis. Recently, mRNA expression abundance among the variables has drawn much attention, not only because it shows relatively strong correlation with protein evolutionary rates, but also because of the controversies surrounding an alternative hypothesis against the traditional one. Here, I will give an overview over the traditional hypothesis, and summarize the different variables that have been found to correlate with protein evolutionary rates. Then I will introduce pros and cons on the two different hypotheses.

• Economic and Environmental Geology
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• v.32 no.6
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• pp.661-667
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• 1999

Estimation of inflow rates into subsection of a tunnel is establishing the proposed grouting part, measuring the degree of grouting, and settling the dispute over deplrtion of groundwater which may be resulted from tunneling. A current meter was used to calculate inflow rates of groundwater to each subsection of the tunnel. The study area is composed of section 1 and 2 of Imha-Youngchun waterway trnnel which has 32.976km length, with each section having 3,745m and 4,079m, respectively. The depth from groung surface to tunnel ranges from 122.45m to 358.3m. Total inflow rates of groundwater into each section measured three times by the current meter, together with bottle and eye measurement, were compared with groundwater inflow rates of each section measured by datalogger. The calcuated inflow rates of the sections by bottle and eye measurement were 8.8%∼54.7% of inflow rate (averaging 27,4%), whwewas those by the current meter were 76.9%∼110.6%(averaging 92.9%). Therfore, the current meter is regarded as useful method to calculate groundwater inflow rates into subsections of a tunnel.

• Journal of The Geomorphological Association of Korea
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• v.25 no.4
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• pp.1-19
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• 2018

This study tries to identify distributional characteristics of stream incision rates at 23 points in the northern part of the Taebaek Mountains. Soyang-gang, Naerin-cheon, Odae-cheon, Dong-gang and upper reaches of Okdong-cheon Rivers closed to the Range show higher incision rates and the rates clearly decrease with distance from the Range. Therefore, the incision process in the northern part of the Range has been greatly influenced by uplift around the Range, and the Sobaek Mountain Range seem to play a role in the incision process. Limestone areas show lower incision rates due to degradation of terrace surface by dissolution. This study suggests that local hydrological, geological and geomorphological conditions can be regarded as an important factor in stream incision rates, although stream incision rates are greatly influenced by regional uplift.

• International Area Studies Review
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• v.20 no.3
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• pp.123-144
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• 2016

This paper investigates the linkages between returns both in foreign exchange and stock markets, and uncertainties in two markets using daily data for the period of 16 July 2004 to 30 June 2014 in Nepalese economy. Four hypotheses are tested about how uncertainty influences the stock index and exchange rates. From the empirical results, a bivariate EGARCH-M model is the best to explain the volatility in the two markets. There is a negative relationship from the exchange rates return to stock price return. Empirical results do provide strong empirical confirmation that negative effect of stock index uncertainty and positive effect of exchange rates uncertainty on average stock index. GARCH-in-mean variables in AR modeling are significant and shows that there is positive effect of exchange rates uncertainty and negative effect of stock index uncertainty on average exchange rates. Stock index shocks have longer lived effects on uncertainty in the stock market than exchange rates shock have on uncertainly in the foreign exchange market. The effect of the last period's shock, volatility is more sensitive to its own lagged values.

• The Korean Journal of Applied Statistics
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• v.23 no.4
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• pp.635-650
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• 2010

We model surrender rates with a few explanatory variables such as the difference between reference marke rates and product crediting rates, the policy age since the contract was issued, unemployment rates, economy growth rates, and seasonal effects using logit function. We investigate the policy holder surrender behaviors of US single premium deferred annuities(SPDA) and Korean interest indexed annuities under extreme financial conditions.

• Journal of the Korean Institute of Telematics and Electronics
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• v.24 no.6
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• pp.980-985
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• 1987

The thin metal films of Cr, Al, Mn and were made in various evaporation rates with 100\ulcornerthickness under 2x10**-9 bar vacuum level. We analized and discussed the relationships between changes of structure, morphology and sheet resistance, light transmittance for the corresponding evaporation rates. As the evaporation rates were decreased at higher rates, grain sizes of all film were decreased, however both of the sheet resistance and light transmittance were increased. At lower evaporation rate, films of Cr and Cu porduced non-stoi-chiometric oxides but Al an Mn showed up amorphous structures.

• Journal of the Korean Statistical Society
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• v.23 no.2
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• pp.251-269
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• 1994

In this paper we extend Kim and Pollard's cube root asymptotics to other rates of convergence, to establish an asymptotic theory for a multidimensional mode estimator based on uniform kernel with shrinking bandwidths. We obtain rates of convergence depending on shrinking rates of bandwidth and non-normal limit distributions. Optimal decreasing rates of bandwidth are discussed.