• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.10
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• pp.665-671
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• 2017

Herein, we report the fabrication of low-voltage N-type organic field-effect transistors by using high capacitance fluorinated polymer gate dielectrics such as P(VDF-TrFE), P(VDF-TrFE-CTFE), and P(VDF-TrFE-CFE). Electron-withdrawing functional groups in PVDF-based polymers typically cause the depletion of negative charge carriers and a high contact resistance in N-channel organic semiconductors. Therefore, we incorporated intermediate layers of a low-k polymerto prevent the formation of a direct interface between PVDF-based gate insulators and the semiconducting active layer. Consequently, electron depletion is inhibited, and the high charge resistance between the semiconductor and source/drain electrodes is remarkably improved by the in corporation of solution-processed charge injection layers.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.975-979
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• 2008

Since tram has the advantages to reduce construction cost of infrastructure, to improve accessibility of passengers, and to offer visual pleasures, nowadays, it is one of light rails attracting public attention. Tram can be classified into two groups, one is a conventional steel-wheeled type, and the other is a rubber-tired type (bi-modal tram). The bi-modal tram propelled by the serial CNG hybrid propulsion unit has been developing since 2003 in Korea, which can realize both scheduled operation of railway and route flexibility of bus. Because the bimodal will be operated on both railway mode and bus mode, however, specific criteria and regulations for its design, certification, construction, operation and maintenance have not been determined definitely yet. In consideration of mobility enhancement for the old and the handicapped, motor vehicle safety standard and urban transit (railway vehicle) safety standard, several design specifications were proposed for car body and interiors of the bimodal tram vehicle. The design specifications proposed in this paper can be expected to promote passengers' comfort and safety, operation efficiency of the bimodal tram.

• Nano
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• v.13 no.11
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• pp.1850132.1-1850132.14
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• 2018

The direct synthesis of metal-organic frameworks (MOFs) with acidic and basic active sites is challenging due to the introduction of functional groups by post-functionalization method often jeopardize the framework integrity. Herein, we report the direct synthesis of acid-base bifunctional MOFs with tuning acid-base strength. Employing modulated hydrothermal (MHT) approach, microporous MOFs named $UiO-66-NH_2$ was prepared. Through the ring-opening reaction of 1,3-propanesultone with amino group, $UiO-66-NH_2-SO_3H-type$ catalysts can be obtained. The synthesized catalysts were well characterized and their catalytic performances were evaluated in one-pot glucose to 5-HMF conversion. Results revealed the acid-base bi-functional catalyst possessed high activity and excellent stability. This work provides a general and economically viable approach for the large-scale synthesis of acid-base bi-functional MOFs for their potential use in catalysis field.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.12
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• pp.3868-3888
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• 2022

A widely used social networking service like Twitter has the ability to disseminate information to large groups of people even during a pandemic. At the same time, it is a convenient medium to share irrelevant and unverified information online and poses a potential threat to society. In this research, conventional machine learning algorithms are analyzed to classify the data as either non-rumor data or rumor data. Machine learning techniques have limited tuning capability and make decisions based on their learning. To tackle this problem the authors propose a deep learning-based Rumor Detection Neural Network model to predict the rumor tweet in real-world events. This model comprises three layers, AttCNN layer is used to extract local and position invariant features from the data, AttBi-LSTM layer to extract important semantic or contextual information and HPOOL to combine the down sampling patches of the input feature maps from the average and maximum pooling layers. A dataset from Kaggle and ground dataset #gaja are used to train the proposed Rumor Detection Neural Network to determine the veracity of the rumor. The experimental results of the RDNN Classifier demonstrate an accuracy of 93.24% and 95.41% in identifying rumor tweets in real-time events.

• Genomics & Informatics
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• v.21 no.3
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• pp.28.1-28.13
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• 2023

Mild cognitive impairment (MCI) is a clinical syndrome characterized by the onset and evolution of cognitive impairments, often considered a transitional stage to Alzheimer's disease (AD). The genetic traits of MCI patients who experience a rapid progression to AD can enhance early diagnosis capabilities and facilitate drug discovery for AD. While a genome-wide association study (GWAS) is a standard tool for identifying single nucleotide polymorphisms (SNPs) related to a disease, it fails to detect SNPs with small effect sizes due to stringent control for multiple testing. Additionally, the method does not consider the group structures of SNPs, such as genes or linkage disequilibrium blocks, which can provide valuable insights into the genetic architecture. To address the limitations, we propose a Bayesian bi-level variable selection method that detects SNPs associated with time of conversion from MCI to AD. Our approach integrates group inclusion indicators into an accelerated failure time model to identify important SNP groups. Additionally, we employ data augmentation techniques to impute censored time values using a predictive posterior. We adapt Dirichlet-Laplace shrinkage priors to incorporate the group structure for SNP-level variable selection. In the simulation study, our method outperformed other competing methods regarding variable selection. The analysis of Alzheimer's Disease Neuroimaging Initiative (ADNI) data revealed several genes directly or indirectly related to AD, whereas a classical GWAS did not identify any significant SNPs.

• Journal of the East Asian Society of Dietary Life
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• v.15 no.2
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• pp.158-164
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• 2005

The present study was undertaken to evaluate the effect of Rhodiola sachalinensis root ethanol extract (RS), on the body weight, organ weight, plasma glucose and plasma lipid in diabetic rats caused by streptozotocin (STZ). The body weight decreased more slowly in the RS group than in the diabetic, and the food intake increased significantly in all diabetic groups. The food efficiency was very low in all diabetic groups, but increased significantly in the RS groups than diabetic control (p<0.05). In comparing the weight of organ, the weight of liver and kidney were increased in all diabetic groups than in the control, and decreased slightly in RS groups. The weight of heart and spleen were not different among all test groups. The glucose in serum was decreased significantly in the RS groups fed the RS for 4 weeks, compared to the diabetic control (p<0.05). Total cholesterol, triglyceride and atherogenic index (AI) in serum were significantly higher in diabetic control, compared to the normal (p<0.05), and decreased $16.7\%,\;18.3\%\;and\;45.0\%$, respectively, in the RS fed $300\;\cal{mg/kg}$ of RS. HDL-cholesterol was increased slightly more in the $RS-300\;\cal{mg/kg}$, compared to diabetic control. These findings suggest that RS treatment has protective effect in diabetes.

• Journal of Life Science
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• v.20 no.11
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• pp.1683-1690
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• 2010

There is an increasing interest in the potential of isoflavone in reducing the risk of cardiovascular disease and cancer, however, although several effects of isoflavone as a component of soy protein are well established, the hypolipidemic and antioxidant effects of purified isoflavone are still controversial. This study was to investigate the effects of isoflavone on serum lipid profiles and antioxidant status in rats. 7-week old male Sprague Dawley rats were fed one of the following diets for 8 weeks: basal diet (B), basal+0.3% isoflavone (BI), basal+0.5% cholesterol (BC), or basal+0.3% isoflavone +0.5% cholesterol (BIC). Two-way ANOVA was used to test the effects of dietary isoflavone and cholesterol supplementation and their interaction on variables. Serum lipid profiles and total antioxidant status (TAS) were examined spectrophotometrically. Degree of serum lipid peroxidation was measured by malondialdehyde (MDA) assay. The activities of serum antioxidant enzymes (GSH-Px, total-SOD) was determined. Levels of serum total cholesterol, VLDL+LDL-cholesterol and Atherogenic index were significantly lower in BI than those levels in group B (p=0.0002, p<0.0001, and p=0.0042, respectively). Serum total antioxidant status (TAS) levels were significantly higher, in both isoflavone supplemented groups (BI, BIC) compared to those levels in each control group (B, BC) (p<0.0001). Activity of total-SOD was significantly higher in BI compared to the activities in group B (p=0.0317). There was no interaction between isoflavone and cholesterol supplementation. In conclusion, isoflavone supplementation showed positive effects on the serum lipid profiles and total antioxidant activities in both conditions, either when fed a diet with or without cholesterol. These effects of isoflavone were independent of cholesterol supplementation.

• Economic and Environmental Geology
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• v.43 no.5
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• pp.491-503
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• 2010

Geochemical characteristics of the Moisan epithermal gold-silver deposit with total 140 samples in Haenam area, Jeollanamdo were studied by using multivariate statistical analysis (correlation analysis, factor analysis and cluster analysis). The correlation analysis reveals that Ag, Cu, Bi, Te are highly correlated with Au in the both non-mineralized and mineralized zone. It is resulted from the presence of Au-Ag bearing minerals (electrum, sylvanite, calaverite and stuezite) and non Au-Ag containing minerals (chalcopyrite, tellurobismuthite and bismuthinite). Mo shows relatively much higher correlation at the mineralized zone (0.615) than non-mineralized zone (0.269) which implies Mo content is strongly affected by Au-mineralization. While Mn, Cs, Fe, Se correlated with Au at the nonmineralized zone, they have negative correlation at the mineralized zone. Therefore, they seem to be eluviated elements from the host rock during gold mineralization. Sb is enriched during the gold mineralization showing high correlation at the mineralized zone and negative correlation at the non-mineralized zone. According to the factor analysis, Se, Ag, Cs, Te are the indicators of gold mineralization presence due to the strong affection of gold content in the non-mineralized zone. In the mineralized zone, on the other hand, Mo, Te and Sb, Cu are the indicators of gold and silver mineralization, respectively. While the cluster analysis reveals that Cd-Zn-Pb-S, Bi-Fe-Cu-Mn, Se-Te-Au-Cs-Ag, As-Sb-Ba are the similar behavior elements groups in the non-mineralized zone, Cd-Zn-Mn-Pb, Fe-S-Se, As-Bi-Cs, Ag-Sb-Cu, Au-Te-Mo are the similar behavior elements groups in the mineralized zone. Using multivariate statistical analysis as mentioned above makes it possible to compare the behavior of presented minerals and difference of geochemical characteristics between mineralized and non-mineralized zone. Therefore, it will be expected a useful tool on the similar type of mining exploration.

• Journal of the Korean housing association
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• v.20 no.1
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• pp.37-44
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• 2009

Sleep has big influence on our life, for example productivity, character formation of babies, mortality and the people who suffered from sleep problem are also diverse. Therefore, indoor environmental supports for good sleep, might be different with the situation and need of respective person. The objectives of this study are: 1) to investigate the current bedroom condition, sleep problem, and life pattern of Korean. 2) to classify Korean into several groups and explain their characteristics relevant to sleep, in order to understand Korean's need for good sleep. The questionnaire was sent out to Seoul and its environs in Jan.$\sim$Feb. 2008, and total of 702 questionnaires were collected. The research on the bedroom condition was conducted around perceived influence of environmental factors, opening and closing of the door, cooling and heating strategy, clo value during sleep, bedding type, lighting, sharing bedroom. People are divided into 6 groups by 8 factors, and 5 groups could be seen that they need some management for good sleep because of their sleep problem.

• Journal of Korean Neurosurgical Society
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• v.50 no.5
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• pp.409-414
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• 2011

Objective : The aim of this study was to evaluate the impact of sodium hyaluronate-sodium carboxymethyl cellulose (HA-CMC), an anti-adhesive material for spinal surgery, on bone fusion by applying it to rat spinal models after lumbar posterolateral fusion. Methods : Lumbar posterolateral fusion was performed at L4-5 using bone graft substitutes in 30 rats. HA-CMC was injected in 15 rats at a dose of 0.2 cc (HA-CMC group) and a saline solution of 0.2 cc in the other 15 rats (control group). Simple radiographs were taken until postoperative 9 weeks with an interval of one week. At postoperative 4 and 9 weeks, three dimensional computed tomography (3D CT) scanning was performed to observe the process of bone fusion. At 9 weeks, bone fusion was confirmed by gross examination and manual palpation. Results : There were no statistically significant differences in bone fusion between the two groups. 3D CT scanning did not reveal significant differences between the groups. The gross examination and manual palpation after autopsy performed at 9 weeks confirmed bone union in 93.3% of both groups. Conclusion : The anti-adhesive material used for spinal surgery did not have adverse effects on spinal fusion in rats.