• Journal of the Korean earth science society
• /
• v.35 no.1
• /
• pp.19-28
• /
• 2014

The radiative transfer for TIROS operational vertical sounder (RTTOV) and the community radiative transfer model (CRTM) are two fast radiative transfer models (RTM) that are used as observation operators in numerical weather prediction (NWP) systems. This study compares the basic structure and input data of the two models. With data from Advanced Microwave Sounding Unit-A (AMSU-A), which has channels of various frequencies, observed brightness temperature ($T_B$) and simulated $T_B$s from the two models are compared over the ocean surface in two cases-one where cloud information is included and the other without it. Regarding AMSU-A sounding channels (5-14), the two models produce no large significant differences in their calculated $T_B$, but RTTOV produces smaller first guess (FG) departures (i.e., better results) in window and near-surface sounding channels than does CRTM. When adding cloud water and ice particles from Unified Model (UM), the $T_B$ bias between observations and simulations are reduced in both models and the bias at 31.4 and 89 GHz is substantially decreased in CRTM compared to those of RTTOV.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.3
• /
• pp.1233-1239
• /
• 2014

Background: The incidence of brain metastases (BM) varies in patients with non-small cell lung cancer (NSCLC), calls into question the value of prophylactic cranial irradiation (PCI). It is possible that clinicopathologic characteristics are associated with the development of BM, but these have yet to be identified in detail. Thus, we conducted the present meta-analysis on risk factors for BM and the value of PCI in patients with NSCLC. Methods: Eligible data were extracted and the risk factors for BM and the value of PCI in patients with NSCLC were analyzed by calculating the pooled odds ratio (OR). Heterogeneity was detected using Q and I-squared statistics, and publication bias was tested by funnel plots and Egger's test. Results: Six randomized controlled trials with a focus on the value of PCI and 13 eligible studies with a focus on risk factors for BM were included. PCI significantly reduced the incidence of BM in patients with NSCLC (p=0.000, pooled OR=0.34, 95% confidence interval = 0.37-0.59). Compared with non-squamous cell carcinoma, squamous cell carcinoma was associated with a low incidence of BM in patients with NSCLC (p=0.000, pooled OR=0.47, 95% confidence interval =0.34-0.65). The funnel plot and Egger's test suggested that there was no publication bias in the current meta-analysis. Conclusions: This meta-analysis provides statistical evidence that compared with non-squamous cell carcinoma, squamous cell carcinoma can be used as a predictor for BM in patients with NSCLC, and PCI might reduce the incidence of BM in patients with NSCLC, but does not provide a survival benefit.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.12
• /
• pp.4787-4793
• /
• 2014

Background: Many cancer patients experience poor pain control due to various factors, including misconceptions regarding the use of opioid analgesics. For management of cancer pain, interventions involving education of both patients and physicians have been attempted. Objectives: This review aimed to assess the current evidence of the benefits of education for the management of cancer pain. Methods: We searched the Medline, EMBASE, Cochrane library, and major Korean databases to identify relevant studies. We included most study designs, but excluded case series. The primary outcomes were pain intensity and quality of life (QoL). Two reviewers assessed the risk of bias using the Cochrane's tool for RCT and Risk of Bias Assessment tool for Non-randomized Studies (RoBANS) for non-randomized studies, independently. Results: After extensive searches, 3,324 publications were screened, and 32 studies were selected. The education interventions used in the included studies included a wide variety of education methods, but the most common method was a booklet produced for patients. Regardless of the education method used, the results of the meta-analysis were as follows. The SMDs of the most severe, average, and current pain in the RCTs were significant. The SMD of worst, average, and current pain were -0.34 (-0.55, -0.13), -0.40 (-0.64, -0.15), and -0.79 (-1.35, -0.23). In the non-randomized studies, the effects on average pain were significant, but those on worst and current pain were not. Conclusions: Education intervention reduced the pain of cancer patients. Therefore, patient education could be considered to be an effective method of cancer pain management. However, our data should be interpreted with caution, and studies using standardized protocols are needed to confirm these observations.

• Journal of the Korean Magnetics Society
• /
• v.11 no.4
• /
• pp.141-145
• /
• 2001

The Mn$\_$80/Ir$\_$18.1/Pt$\_$1.9/ exchange bias layers (EBLs), which have a small amounts of Pt, exhibit a high value of H$\_$ex/. The Si/Ni-Fe/Mn$\_$80/Ir$\_$18.1/Pt$\_$1.9/ EBL shows the largest H$\_$ex/ of 187 Oe, which is equivalent to a exchange energy (J$\_$ex/) of 0.146 erg/cm$^2$. Mn$\_$80/Ir$\_$18.1/Pt$\_$1.9/ EBLS are estimated to have blocking temperature of about 250 $\^{C}$, which is higher than those of Mn-Ir EBLs and Mn-Ir-Pt EBLs with higher Pt contents. This result implies that a little addition of Pt element promotes thermal stability in the Mn-Ir-Pt EBLs. The chemical stability of Mn-Ir-Pt EBLs was characterized by potentiodynamic test, which was performed in 0.001 M NaCl solution. The current density of Mn-Ir-Pt films was gradually reduced with increasing Pt content. The present results indicate that the Mn-Ir-Pt with a small amount of Pt is suitable for an antiferromagnetic material for a reliable spin valve giant magnetoresistance device.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.10 no.1
• /
• pp.69-78
• /
• 2005

ARCO and TAO data which supply three dimensional global ocean information are assimilated to the background field from a general circulation model, MOM3. Using a variational Analysis using Filter (VAF), which is a spatial variational filter designed to reduce computational time and space efficiently and economically, observed ARGO and TAO data are assimilated to the OGCM-generated background sea temperature for the generation of initial condition of the model. For the assessment of the assimilation impact, a comparative experiment has been done by integrating the model from different intial conditions: one from ARGO-, TAO-data assimilated initial condition and the other from background state without assimilation. The assimilated analysis field not only depicts major oceanic features more realistically but also reduces several systematic model bias that appear in every current OGCMs experiments. From the 10-month of model integrations with and without assimilated initial conditions, it is found that the major assimilated characteristics in sea temperature appeared in the initial field remain persistently throughout the integration. Such implies that the assimilated characteristics of the reduced sea temperature bias is to last in the integration without rapid restoration to the non-assimilated OGCM integration state by dispersing mass field in the form of internal gravity waves. From our analysis, it is concluded that the data assimilation method adapted in this study to MOM3 is reasonable and applicable with dynamical consistency. The success in generating initial condition with ARGO and TAO data assimilation has significant implication upon the prediction of the long-term climate and weather using ocean-atmosphere coupled model.

• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.8
• /
• pp.3687-3693
• /
• 2012

Objective: The current meta-analysis was performed to address a more accurate estimation of the association between glutathione S-transferase P1 (GSTP1) codon 105 polymorphism and risk of gastric cancer (GC), which has been widely reported with conflicting results. Methods: A comprehensive literature search was conducted to identify all the relevant studies. Fixed or random effect models were selected based on the heterogeneity test. Publication bias was estimated using Begg's funnel plots and Egger's regression test. Results: A total of 20 studies containing 2,821 GC cases and 6,240 controls were finally included in the analyses. Overall, no significant association between GSTP1 polymorphism and GC risk was observed in worldwide populations. However, subgroup analysis stratified by ethnicity showed that GSTP1 polymorphism was significantly associated with increased risk of GC in Asians (G vs. A, OR = 1.273, 95%CI=1.011-1.605; GG vs. AA, OR=2.103, 95%CI=1.197-3.387; GG vs. AA+AG, OR =2.103, 95%CI=1.186-3.414). In contrast, no significant association was found in Caucasians in any genetic models, except for with AG vs. AA (OR=0.791, 95%CI=0.669-0.936). Furthermore, the GSTP1 polymorphism was found to be significantly associated with GC in patients with H. pylori infection and in those with a cardiac GC. Subgroup analysis stratified by Lauren's classification and smoking status showed no significant association with any genetic model. No studies were found to significantly influence the pooled effects in each genetic mode, and no potential publication bias was detected. Conclusion: This meta-analysis suggested that the GSTP1 polymorphism might be associated with increased risk of GC in Asians, while GSTP1 heterozygote genotype seemed to be associated with reduced risk of GC. Since potential confounders could not be ruled out completely, further studies are needed to confirm these results.

• Journal of the Korean Magnetics Society
• /
• v.12 no.3
• /
• pp.103-108
• /
• 2002

We investigated magnetoresistance(MR) and exchange bias properties by annealing in top and bosom type spin valves (SV) with nano-oxide layers (NOL). In top SVs with NOL, MR ratio of 9.2% is obtained after postdeposition annealing at 250$\^{C}$. In bottom SVs with NOL, MR ratio of 10.1 % is obtained after postdeposition annealing at 250$\^{C}$. Therefore, specular reflection of the NOL in bottom SVs is higher than that of the NOL in top SVs. Exchange biasing of bottom SVs with NOL is 28% higher than that of bottom SVs without NOL after annealing. This enhancement of exchange biasing is thought to be due to the reduced magnetic moment of the pinned layer with NOL and enhanced (111) FeMn texture.

• Journal of Korea Water Resources Association
• /
• v.51 no.11
• /
• pp.1031-1041
• /
• 2018

ANFIS-based methodology for improving GloSea5 ensemble weather forecast is developed and evaluated in this study. The proposed method consists of two steps: pre & post processing. For ensemble prediction of GloSea5, weights are assigned to the ensemble members based on Optimal Weighting Method (OWM) in the pre-processing. Then, the bias of the results of pre-processed is corrected based on Model Output Statistics (MOS) method in the post-processing. The watershed of the Chungju multi-purpose dam in South Korea is selected as a study area. The results of evaluation indicated that the pre-processing step (CASE1), the post-processing step (CASE2), pre & post processing step (CASE3) results were significantly improved than the original GloSea5 bias correction (BC_GS5). Correction performance is better the order of CASE3, CASE1, CASE2. Also, the accuracy of pre-processing was improved during the season with high variability of precipitation. The post-processing step reduced the error that could not be smoothed by pre-processing step. It could be concluded that this methodology improved the ability of GloSea5 ensemble weather forecast by using ANFIS, especially, for the summer season with high variability of precipitation when applied both pre- and post-processing steps.

• Korean Journal of Remote Sensing
• /
• v.35 no.6_4
• /
• pp.1373-1389
• /
• 2019

KOMPSAT-5 is the first satellite in Korea equipped with X-band Synthetic Aperture Radar (SAR) instrument and has been operated since August 2013. KOMPSAT-5 is used to monitor the global environment according to its observation purpose and the availability of KOMPSAT-5 is also highlighted as the need of high resolution wind data for investigating the coastal region. However, the previous study for the validation of wind derived from KOMPSAT-5 showed that the accuracy is lower than that of other SAR satellites. Therefore, in this study, we developed the correction equation of normalized radar cross section (NRCS or backscattering coefficient) for improvement of wind from the KOMPSAT-5 and validated the effect of the equation using the in-situ measurement of ocean buoys. Theoretical estimated NRCS and observed NRCS from KOMPSAT-5 showed linear relationship with incidence angle. Before applying the correction equation, the accuracy of the estimated wind speed showed the relatively high root-mean-square errors (RMSE) of 2.89 m s^-1 and bias of -0.55 m s^-1. Such high errors were significantly reduced to the RMSE of 1.60 m s^-1 and bias of -0.38 m s^-1 after applying the correction equation. The improvement effect of the correction equation showed dependency relying on the range of incidence angle.

• Journal of Life Science
• /
• v.20 no.11
• /
• pp.1738-1741
• /
• 2010

Caliper measurements of tumor volume have been widely used in the assessment of tumors in animal models. However, experiments based on caliper data have resulted in unreliable estimates of tumor growth, due to necrotic areas of tumor mass. To overcome this systematic bias, we engineered a new luciferase-expressing rat prostate cancer cell line (MLL-Luc) that produces bioluminescence from viable cancer cells. MLL-Luc cells showed a strong correlation between bioluminescence intensity and cell number ($R^2$=0.99) and also accurately quantified tumor growth, with reduced bioluminescence signals caused by necrotic cells in a subcutaneous MLL-Luc xenograft model. The accurate quantification of tumor growth with bioluminescence imaging (BLI) was confirmed by a better antitumor effect of combination chemotherapy, compared to that based on caliper measurements with a correlation between the bioluminescence signal and tumor volume ($R^2$=0.84). These data suggest that bioluminescent MLL xenografts are a powerful and quantitative tool for monitoring tumor growth and are useful in evaluating the efficacy of anticancer drugs, with less systematic bias.