• Asian Pacific Journal of Cancer Prevention
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• v.16 no.18
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• pp.8293-8298
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• 2016

Background: Urinary stones are known predisposing factors for upper urinary tract carcinoma (UUTC) which are commonly detected at advanced stage with poor outcome because of rarity and lack of specific criteria for early detection. Aims and objectives: The main aim was to evaluate the impact of age, gender andstone characteristics on risk of developing UUTC in patients with chronic nephrolithiasis. We also discuss the role of aberrant angiogenesis (AA) and immunohistochemical expression of p53, p16INK4a, CK20 and Ki-67 in diagnosis of pelvicalyceal neoplastic (NL) and pre-neoplastic lesions (PNL) in these patients. Materials and Methods: Retrospective analysis of pelvicalyceal urothelial lesions from 88 nephrectomy specimens were carried out in a tertiary care centre from June 2012 to December 2014. Immunohistochemistry (IHC) was performed on 37 selected cases. Computed image analysis was performed to analyse aberrant angiogenesis. Results: All UUTC (5.7%) and metaplastic lesions were found to be associated with stones. Some 60% were pure squamous cell carcinoma and 40% were transitional cell carcinoma. Odd ratios for developing NL and PNL lesions in presence of renal stone, impacted stones, multiple and large stag horn stones were 9.39 (95% CI 1.15-76.39, p value 0.05), 6.28 (95% CI 1.59-24.85, p value 0.000) and 7.4 (95% CI, 2.29-23.94, p value 0.001) respectively. When patient age was ${\geq}55$, the odds ratio for developing NL was 3.43 (95% CI 1.19-9.88, p value 0.019). IHC analysis showed that mean Ki-67 indices were $3.15{\pm}3.63%$ for non-neoplastic lesions, $10.0{\pm}9.45%$ for PNL and $28.0{\pm}18.4%$ for NL. Sensitivity and specificity of CK20, p53, p16INK4a, AA were 76% and 95.9%; 100% and 27.5%; 100% and 26.5%; 92.3 % and 78.8% respectively. Conclusions: Age ${\geq}55years$, large stag horn stones, multiple stones and impacted stones are found to be associated with increased risk of NL and PNL in UUT. For flat lesions, a panel of markers, Ki 67 index >10 and presence of aberrant angiogenesis were more useful than individual markers.

• Korean Journal of Radiology
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• v.23 no.1
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• pp.112-123
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• 2022

Objective: To investigate the relationship between ¹⁸F-FDG PET/CT semi-quantitative parameters and the International Association for the Study of Lung Cancer, American Thoracic Society/European Respiratory Society (IASLC/ATS/ERS) histopathologic classification, including histological subtypes, proliferation activity, and somatic mutations. Materials and Methods: This retrospective study included 419 patients (150 males, 269 females; median age, 59.0 years; age range, 23.0-84.0 years) who had undergone surgical removal of stage IA-IIIA lung adenocarcinoma and had preoperative PET/CT data of lung tumors. The maximum standardized uptake values (SUVmax), background-subtracted volume (BSV), and background-subtracted lesion activity (BSL) derived from PET/CT were measured. The IASLC/ATS/ERS subtypes, Ki67 score, and epidermal growth factor/anaplastic lymphoma kinase (EGFR/ALK) mutation status were evaluated. The PET/CT semi-quantitative parameters were compared between the tumor subtypes using the Mann-Whitney U test or the Kruskal-Wallis test. The optimum cutoff values of the PET/CT semi-quantitative parameters for distinguishing the IASLC/ATS/ERS subtypes were calculated using receiver operating characteristic curve analysis. The correlation between the PET/CT semi-quantitative parameters and pathological parameters was analyzed using Spearman's correlation. Statistical significance was set at p < 0.05. Results: SUVmax, BSV, and BSL values were significantly higher in invasive adenocarcinoma (IA) than in minimally IA (MIA), and the values were higher in MIA than in adenocarcinoma in situ (AIS) (all p < 0.05). Remarkably, an SUVmax of 0.90 and a BSL of 3.62 were shown to be the optimal cutoff values for differentiating MIA from AIS, manifesting as pure ground-glass nodules with 100% sensitivity and specificity. Metabolic-volumetric parameters (BSV and BSL) were better potential independent factors than metabolic parameters (SUVmax) in differentiating growth patterns. SUVmax and BSL, rather than BSV, were strongly or moderately correlated with Ki67 in most subtypes, except for the micropapillary and solid predominant groups. PET/CT parameters were not correlated with EGFR/ALK mutation status. Conclusion: As noninvasive surrogates, preoperative PET/CT semi-quantitative parameters could imply IASLC/ATS/ERS subtypes and Ki67 index and thus may contribute to improved management of precise surgery and postoperative adjuvant therapy.

• Journal of Intelligence and Information Systems
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• v.29 no.4
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• pp.185-205
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• 2023

As the tourism industry recovers post the COVID-19 pandemic, an increasing number of tourists are utilizing various platforms to leave reviews. However, amidst the vast amount of data, finding useful information remains challenging, often leading to time and cost inefficiencies in selecting travel destinations. Despite ongoing research, there are limitations due to the absence of ratings or the presence of different rating formats across platforms. Moreover, inconsistencies between ratings and the content of reviews pose challenges in developing recommendation models. To address these issues, this study utilized 7,104 reviews of tourist spots in Jeju Island to develop a specialized satisfaction index for Jeju tourist attractions and employed this index to construct a 'Rating Prediction Model.' To validate the model's performance, we predicted the ratings of 700 experimental data points using both the developed model and an LSTM approach. The proposed model demonstrated superior performance with a weighted accuracy of 73.87%, which is approximately 4.67% higher than that of the LSTM. The results of this study are expected to resolve the discrepancies between ratings and review contents, standardize ratings in reviews without ratings or in various formats, and provide reliable rating indicators applicable across all areas of travel in different domains.

• Journal of Korea Port Economic Association
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• v.38 no.2
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• pp.49-67
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• 2022

This study applied the method of Diebold and Yilmaz (2012, 2014, 2016) to analyze the connectedness between the Freight Index (BDI, BDTI, BCTI), energy price(oil, natural gas, coal), and grain price(soybean, corn, wheat) from July 19, 2007 to March 31, 2022. The main analysis results of this paper are as follows. First, according to the network analysis results, the total connectedness was measured to be 20.43% for the entire analysis period, indicating that there was a low correlation between the freight index and the commodity price. In addition, looking at the directional results, the variable with the greatest effects was corn, and conversely, the variable with the lowest effects BDI. When classified by events, BCTI was found to play a major role only during the COVID-19 period. Second, according to the results of the rolling-sample analysis, the total connectedness be found to be highly correlated with changes in economic conditions such as the financial crisis, trade war, and COVID-19 when specific events occurred.

• Bulletin of the Korean Chemical Society
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• v.27 no.5
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• pp.679-686
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• 2006

The positions of $PbI _2$ molecule synthesized into the molecular-dimensioned cavities of $\mid K_6 (Pb _4I_2)(PbI_2) _{0.67}-(H_2O)_2\mid [Si _{12}Al _{12}O _{48}]$-LTA have been determined. A single crystal of $\mid Pb _6\mid [Si _{12}Al _{12}O _{48}]$-LTA, prepared by the dynamic ion-exchange of $\mid Na _{12}\mid [Si _{12}Al _{12}O _{48}]$-LTA with aqueous 0.05 M $Pb _(NO _3)_2$ and washed with deionized water, was placed in a stream of flowing aqueous 0.05 M KI at 294 K for three days. The resulting crystal structure of the product $( \mid K_6 (Pb _4I_2)(PbI_2) _{0.67}(H_2O)_2\mid [Si _{12}Al _{12}O _{48}]$-LTA, a = 12.353(1) $\AA$) was determined at 294 K by single-crystal X-ray diffraction in the space group Pm3 m. It was refined with all measured reflections to the final error index $R_1$ = 0.062 for 623 reflections which $F_o$ > 4$\sigma$($F_o$). 4.67 $Pb ^{2+}$ and six $K^+$ ions per unit cell are found at three crystallographically distinct positions: 3.67 $Pb ^{2+}$ and three $K^+$ ions on the 3-fold axes opposite six-rings in the large cavity, three $K^+$ ions off the plane of the eight-rings, and the remaining one $Pb ^{2+}$ ion lies opposite four-ring in the large cavity. 0.67 $Pb ^{2+}$ ions and 1.34 $I^-$ ions per unit cell are found in the sodalite units, indicating the formation of a $PbI _2$ molecule in 67% of the sodalite units. Each $PbI _2$ (Pb-I = 3.392(7) $\AA$) is held in place by the coordination of its one $Pb ^{2+}$ ion to the zeolite framework (a $Pb ^{2+}$ cation is 0.74 $\AA$ from a six-ring oxygens) and by the coordination of its two $I^-$ ions to $K^+$ ions through six-rings (I-K = 3.63(4) $\AA$). Two additional $I^-$ ions per unit cell are found opposite a four-ring in the large cavity and form $Pb _2K_2I^{5+}$ and $Pb _2K_2I^{3+}$ moieties, respectively, and two water molecules per unit cell are also found on the 3-fold axes in the large cavity.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.12
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• pp.482-487
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• 2016

Ultra-violet rays are very harmful to eye health care. The blocking of ultra-violet rays and a reduction of optical reflection in the visible light range, which is to increase the share of transmitted light, and avoid the formation of ghost images in imaging, are important for the applications of polymer eyeglasses lenses. In this study, the high-refractive index polymer lenses, n=1.67, were fabricated by injection-molded method with the xylene diisocyanate monomer, 2,3-bis-1-propanethiol monomer, and benzotriazol UV absorber (SEESORB 709) mixture. To reduce the reflection of the polymer lens surfaces, multi-layer anti-reflection (AR) coatings were coated for both sides of the polymer lens using an E-beam evaporation system. The optical properties of the UV blocking polymer lens were characterized using a UV-visible spectrometer. The material properties of the thin films, which were composed AR coating layers, refractive index, and surface roughness, were analyzed by ellipsometry and atomic force microscopy. As a result, the fabricated polymer lens perfectly blocked ultra-violet rays below 395 nm with a blocking rate greater than 99%.

• Journal of Korea Spatial Information System Society
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• v.6 no.1 s.11
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• pp.19-29
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• 2004

Recently, studies have been performed to improve the cache performance of the R-Tree in main memory. A general mothed to improve the cache performance of the R-Tree is to reduce size of an entry so that a node can store more entries and fanout of it can increase. However, this method generally requites additional process to reduce information of entries and do not support incremental updates. In addition, the cache miss always occurs on moving between a parent node and a child node. To solve these problems efficiently, this paper proposes and evaluates the PR-Tree that is an extended R-Tree indexing method using prefetching in main memory. The PR-Tree can produce a wider node to optimize prefetching without additional modifications on the R-Tree. Moreover, the PR-Tree reduces cache miss rates that occur in moving between a parent node and a child node. In our simulation, the search performance, the update performance, and the node split performance of the PR-Tree improve up to 38%. 30%, and 67% respectively, compared with the original R-Tree.

• The Journal of Korean Medicine
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• v.24 no.4
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• pp.1-5
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• 2003

Leptin has a close correlation with obesity, which is known to be a major factor for stroke. This study was performed to determine whether serum leptin level would be an independent risk factor for stroke and whether it would change significantly early after stroke. Subjects were selected from those within I month after onset and non-stroke referents at Kyung Hee Oriental Medical Center in Seoul, Korea. We compared leptin and the other characteristics between stroke subjects and referents. Body mass index, hypertension history, presence of drinking and smoking, waist/hip ratio, total cholesterol and triglyceride were recorded. To assess odds ratio of leptin for stroke, we used logistic regression analysis. Leptin was rechecked 2 weeks later and compared with the former value in acute stroke subjects. In this study, serum leptin did not differ significantly between stroke subjects and referents, and its odds ratio was not significant in male (OR=0.52, 95％ Cl; 0.13-2.08) and female (OR=1.57, 95％ Cl; 0.53-4.67). In acute stroke subjects, leptin did not change significantly 2 weeks later. Hypertension had a significant odds ratio in male (OR=3.39, 95％ Cl; 1.02-11.24) and female (OR=12.37, 95％ Cl; 3.67-41.65). High waist/hip ratio was only in female (OR=6.70, 95％ Cl; 1.73-26.02). In conclusion, leptin was not an independent risk factor for stroke and its serum level did not change significantly early after stroke. Hypertension and waist/hip ratio had significant relative risks.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.12
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• pp.4965-4969
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• 2015

LCN2 (Lipocalin 2) is a 25 KD secreted acute phase protein, reported to be a novel regulator of angiogenesis in breast cancer. Up regulation of LCN2 had been observed in multiple cancers including breast cancer, pancreatic cancer and ovarian cancer. However, the role of LCN2 promoter methylation in the formation of microvessels is poorly understood. The aim of this study was to analyze the association of LCN 2 promoter methylation with microvessel formation and tumor cell proliferation in breast cancer patients. The LCN2 promoter methylation status was studied in 64 breast cancer tumors by methylation specific PCR (MSP). Evaluation of microvessel density (MVD) and Ki67 cell proliferation index was achieved by immunohistochemical staining using CD34 and MIB-1 antibodies, respectively. LCN2 promoter unmethylation status was observed in 43 (67.2%) of breast cancer patients whereas LCN2 methylation status was seen in 21 (32.8%). Further, LCN2 promoter unmethylation status was associated with aggressive tumor phenotype and elevated mean MVD in breast cancer patients.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.10 no.6
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• pp.53-61
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• 2007

Most of the plants and trees are landscaping plants at the university campus, Thus, the natural flora can be found on sidewalks like urban area. In order to investigate the flora on sidewalks of the university campus, the vegetation survey was done. The study site is Natural Science Campus, Sungkyunkwan University which is located at Suwon, Korea. Vascular plants surveyed were consisted of 130 taxa, 39 families, 99 genera, 115 species, 15 varieties. Indigenous weeds was 101 species (77.7%). Naturalized weeds was 29 species (22.3%). In the families, Compositae 30 species (23%), Gramineae 18 species (14%), Leguminosae 9 species (7%), Caryophyllaceae 8 species (6%), Cruciferae 8 species (6%), Polygonaceae 5 species (4%), Euphorbiaceae 5 species (4%), Scrophulariaceae 4 species (3%), Rosaceae 3 species (2%), Violaceae 3 species (2%), Convolvulaceae 3 species (2%) and etc. 34 species (27%). Life Form of flora in the site by Raunkiaer classification was Therophytes 67 species (51.5%), Hemicryptophytes 46 species (35.4%), Geophytes 8 species (6.2%), Nanophanerophytes 4 species (3.1%), Phanerohytes 3 species (2.3%) and Chamaephytes 2 species (1.5%). Naturalized Ratios was 10.7%.