• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.7
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• pp.1951-1975
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• 2023

Recent advances in Cognitive Radio Networks (CRN) have elevated them to the status of a critical instrument for overcoming spectrum limits and achieving severe future wireless communication requirements. Collaborative spectrum sensing is presented for efficient channel selection because spectrum sensing is an essential part of CRNs. This study presents an innovative cooperative spectrum sensing (CSS) model that is built on the Firefly Algorithm (FA), as well as machine learning artificial neural networks (ANN). This system makes use of user grouping strategies to improve detection performance dramatically while lowering collaboration costs. Cooperative sensing wasn't used until after cognitive radio users had been correctly identified using energy data samples and an ANN model. Cooperative sensing strategies produce a user base that is either secure, requires less effort, or is faultless. The suggested method's purpose is to choose the best transmission channel. Clustering is utilized by the suggested ANN-FA model to reduce spectrum sensing inaccuracy. The transmission channel that has the highest weight is chosen by employing the method that has been provided for computing channel weight. The proposed ANN-FA model computes channel weight based on three sets of input parameters: PU utilization, CR count, and channel capacity. Using an improved evolutionary algorithm, the key principles of the ANN-FA scheme are optimized to boost the overall efficiency of the CRN channel selection technique. This study proposes the Artificial Neural Network with Firefly Algorithm (ANN-FA) for cognitive radio networks to overcome the obstacles. This proposed work focuses primarily on sensing the optimal secondary user channel and reducing the spectrum handoff delay in wireless networks. Several benchmark functions are utilized We analyze the efficacy of this innovative strategy by evaluating its performance. The performance of ANN-FA is 22.72 percent more robust and effective than that of the other metaheuristic algorithm, according to experimental findings. The proposed ANN-FA model is simulated using the NS2 simulator, The results are evaluated in terms of average interference ratio, spectrum opportunity utilization, three metrics are measured: packet delivery ratio (PDR), end-to-end delay, and end-to-average throughput for a variety of different CRs found in the network.

• Journal of Nutrition and Health
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• v.42 no.7
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• pp.605-614
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• 2009

Most cancer patients are treated with surgery, chemotherapy or radiation as anticancer therapies. Especially in the case of radiation, these treatments produce adverse effects such as vomiting, weight loss, anorexia, normal cell damage and malabsorption. The major goal of this study was to determine the effect of irradiation on the nutritional and immune status in irradiated rats. A secondary goal was to determine the effectiveness of high protein diet (HP) and resveratrol (Res) in minimizing the adverse effects of radiation. Rats were divided into four groups: normal diet (NP), HP, NP + Res and HP + Res groups. Each group was further divided into subgroups that received radiation (RT group) and one that did not (non-RT group). Each diet was supplied from $12^{th}$ day prior to irradiation treatment with irradiation dose of 17.5 Gy. The diets were continued until 10th day after radiation treatment and animals were sacrificed. The radiation treatment showed decreased body weight, serum protein and HDL levels and increased TG and LDL levels in nutritional status. HP, NP + Res and HP + Res groups reduced the level of serum LDL and TG in irradiated rats. NP + Res and HP + Res groups increased reduced albumin level of serum in RT group. In case of immune status, the radiation treat-ment showed decreased WBC, lymphocytes and increased neutrophil and eosinophil levels. The levels of serum IL-2 and IL-6 were significantly increased by radiation, however the cytokine levels decreased in all dietary treatment groups. These results showed that high protein diet and resveratrol supplementation seem to minimize the adverse effects of radiation on lipid nutritional status and inflammation response in the rat model.

• The Korean Journal of Pesticide Science
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• v.17 no.4
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• pp.264-270
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• 2013

Imidacloprid is a systemic insecticide which act as an insect neurotoxin. It used for control of pest such as aphids and other sucking insects in fruits and vegetables. Systemic pesticides move inside a crop following absorption by the plant, and these were converted into a variety of metabolites. Sometimes these metabolites make a problem about safety of agricultural products. So a simultaneous determination method of pesticide and its metabolites is needed, to monitor their presence in agricultural product and study on the fate of pesticide in a plant. This study's aim is to investigate simultaneous analysis method of imidacloprid and its metabolites, imidacloprid guanidine, imidacloprid olefin, imidacloprid urea, and 6-chloronicotinic acid in red pepper using QuEChERS method and LC-MS/MS systems. QuEChERS method was modifed beacuase $MgSO_4$ salts decreased the recoveries of 6-chloronicotinic acid in extraction procedure. Imidacloprid and its metabolites were extracted by acetonitrile with 1% glacial acetic acid and the extracts were purified through QuEChERS with primary secondary amine (PSA) and $C_{18}$ and analyzed with LC-MS/MS in ESI positive mode. Standard calibration curves were made by matrix matched standards and their correlation coefficients were higher than 0.999. Recovery studies were carried out on spiked pepper blank sample at four concentration levels (0.01, 0.04 and 0.1, 0.4 mg/kg). The average recoveries of imidacloprid and its metabolites were in the range of 70~120% with < 20% RSD. This result indicated that the method using QuEChERS and LC-MS/MS was suitable for the simultaneous determination of imidacloprid and its metabolites in red pepper.

• Journal of dental hygiene science
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• v.10 no.1
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• pp.39-44
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• 2010

The purpose of this study is to cover dental hygienists who work for metropolitan dental hospitals or clinics in Seoul city, Incheon city and Gyeonggi province from January to April 2009 and profile their awareness of Long-term Senior Care Insurance System (hereinafter called 'LSCI (System)', so that it may provide material reference data to contribute to expanding and establishing oral health medical services in the framework of LSCI System. As a result, this study could come to the following conclusions: 1. It was found that the highest priority of dental hygienists' visiting oral hygienic services under LSCI System was focused on 'caring and preventive treatment', and their secondary priority was focused upon 'oral health education.' 2. In response to a question item about whether dental hygienists need dentist's prescription in written before performing their visiting oral hygienic services, it was found that 38.2% dental hygienists answered 'Yes (necessary)' and 61.8% answered 'No (unnecessary).' 3. In response to a question item about whether dental hygienists may open up long-term senior care center, it was found that absolute majority of dental hygienists (93.4%) answered 'No' and only 6.6% dental hygienists answered 'Yes.' The standardized professional education are thought to be needed to be developed aiming at the success in oral-hygiene service within a LSCI, by strengthening professionalism in dental hygienists.

• Journal of Life Science
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• v.22 no.4
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• pp.499-507
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• 2012

Previous work has characterized myomodulin A (MMA, PMSMLRLamide) and myomodulin E (MME, GLQMLRLamide) purified from the central nervous systems of the sea hare, $Aplysia$ $Kurodai$, using the anterior byssus retractor muscle (ABRM) of the mussel, $Mytilus$ $edulis$. The amino acid sequences of MMA and MME were the same as those of the myomodulin family peptide found in other mollusks. In this study, we synthesized MME, its derivatives, and other neuropeptides to investigate the relationship between the structure and biological activity of MME. The primary structures of MME's derivatives, Des[$Gly^1$]-MME, Des[$Gly^1,Leu^2$]-MME, and Des[$Gly^1,Leu^2,Gln^3$]-MME, were LQMLRLamide, QMLRLamide, and MLRLamide, respectively. MMA and synthetic peptides were tested on ABRM in $M.$ $edulis$ as well as muscle preparations in $Achatina$ $fulica$. MME displayed an inhibitory effect on phasic contraction of the ABRM at $1{\times}10^{-9}$ M or higher. MME also had a relaxing effect on the catch-tension of AMRM at $1{\times}10^{-8}$ M. Both MMA and its analogs stimulated a contractile response on the crop and relaxed the catch-relaxing response on the penial retractor muscle of $A.$ $fulica$. These results suggest that MME and its analogs have modulatory effects on various muscles of mollusks. This study has also laid the groundwork for future neural and circuit modulation studies during animal behavioral changes.

• Journal of Nutrition and Health
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• v.51 no.4
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• pp.275-286
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• 2018

Purpose: Our previous study demonstrated that persimmon (Diospyros kaki Thumb.) at different stages of ripening provided different protective effects against high-fat/cholesterol diet (HFD)-induced dyslipidemia in rats. In this study, we compared the metabolites profile and gene expressions related to triglyceride (TG)/cholesterol metabolism in vitro and in vivo after treating with persimmon water extracts (PWE) or tannin-enriched persimmon concentrate (TEP). Methods: Primary and secondary metabolites in test materials were determined by GC-TOF/MS, UHPLC-LTQ-ESI-IT-MS/MS, and UPLC-Q-TOF-MS. The expression of genes related to TG and cholesterol metabolism were determined by RT-PCR both in HepG2 cells stimulated by oleic acid/palmitic acid and in liver tissues obtained from Wistar rats fed with HFD and PWE at 0, 150, 300, and 600 mg/d (experiment I) or TEP at 0, 7, 14, and 28 mg/d (experiment II) by oral gavage for 9 weeks. Results: PLS-DA analysis and heatmap analysis demonstrated significantly differential profiling of metabolites of PWE and TEP according to processing of persimmon powder. In vitro, TEP showed similar hypolipidemic effects as PWE, but significantly enhanced hypocholesterolemic effects compared to PWE in sterol regulatory element-binding protein 2 (SREBP2), HMG-CoA reductase (HMGCR), proprotein convertase subtilisin/kexin type 9 (PCSK9), cholesterol $7{\alpha}-hydroxylase$ (CYP7A1), and low density lipoprotein receptor (LDLR) gene expression. Consistently, TEP and PWE showed similar hypolipidemic capacity in vivo, but significantly enhanced hypocholesterolemic capacity in terms of SREBP2, HMGCR, and bile salt export pump (BSEP) gene expression. Conclusion: These results suggest that column extraction after hot water extraction may be a good strategy to enhance tannins and long-chain fatty acid amides, which might cause stimulation of hypocholesterolemic actions through downregulation of cholesterol biosynthesis gene expression and upregulation of LDL receptor gene expression.

• Journal of Korean Home Economics Education Association
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• v.21 no.2
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• pp.83-107
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• 2009

The purpose in this study was to provide a basic resource for enhancing teachers' professional competence by examining how the Home Economics(HE) teachers had formed, developed, and introspected the pedagogical content knowledge in the HE classes of secondary schools. Data were collected through in-depth interviews with six HE teachers working at secondary schools. NVivo program, a kind of CAQDAS was used to analyze the data inductively. This study revealed that the HE teachers reflectively introspected the pedagogical content knowledge in Home Economics Education(H-PCK) as follows: First, as for knowledge of perspective on Home Economics Education(HEE), the research participants encouraged students to solve practical problems regarding the objective of HEE. They tried to foster the students' critical thinking ability related to the daily life. They made eager efforts to achieve the mission of HEE as a practical science. Second, as for knowledge of HE curriculum, the research participants mentioned that there was lack of systematic approach concerned with curriculum development. While reorganizing, they always paid attention to its relation to the students' daily lives, to the relationship between the curriculum contents and the social context. Third, as for knowledge of teaching strategies on practical problem-based instruction, the research participants developed the practical problem-based instruction skills. They mentioned students' difficulties in relating the practical problem-based instruction, too. Fourth, regarding knowledge of context, as teachers mostly prepared for progressed instruction alone without communicating with colleagues in the same school, they yearned for and also formed networks with other HE teachers in order to overcome their limitations.

• Journal of Microbiology and Biotechnology
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• v.10 no.3
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• pp.281-286
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• 2000

2,3,7,8-Tetrachlorodibenzo-p-Dioxin (TCDD), a ubiquitous environmental contaminant, causes a variety of adverse effects on the male reproductive system in rats. The effect of green tea extract (GTE) was investigated on the testicular function in Spragure-Dawley rats after a single exposure of 10$\mu\textrm{g}$ TCDD/kg body weight. The exposure of rat to TCDD significantly increased the weights of the epididymis and ventral prostate, yet significantly decresed the weight of the seminal vesicle when compared to the controls (p<0.05). In a combined treatment of TCDD with GTE, the organ weight changes caused by TCDD treatment disappeared. Significant decreases in sperm motility and sperm numbers were observed in the TCDD-treated rats, when compared to the control (p<0.05). GTE treatment reversed the decrease of sperm motility and sperm numbers caused by TCDD. There were no differences in sperm morphology, histological changes of the reproductive organs, and spermatogenesis between all the treated groups. In the ventral prostate and seminal vesicle, TCDD increased the CYP1A1 mRNA level, however, it did not affect the estrogen receptor $\beta$ (ER-$\beta$) mRNA level. GTE treatment did not influence the effect of TCDD on the levels of CYP1A1 and Er-$\beta$ mRNA. These results seem to indicate that green tea protects the testicular function against TCDD-induced reproductive toxicity, not because of a receptor-mediated mechanism but rather due to a secondary change of testes or accessory sex organs.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.28 no.4
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• pp.152-158
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• 2018

PVT (Physical Vapor Transport) method has advantages in producing high quality, large scale wafers where many researches are being carried out to commercialize nitride semiconductors. However, complex process variables cause various defects when it had non-equilibrium growth conditions. Annealing process after crystal growth has been widely used to enhance the crystallinity. It is important to set appropriate temperature, pressure, and annealing time to improve crystallinity effectively. In this study, the effect of the annealing conditions on the crystalline structure variation of the AlN single crystal grown by PVT method was investigated with synchrotron whitebeam X-ray topography, electron backscattered diffraction (EBSD), and Rietveld refinement. X-ray topography analysis showed secondary phases, sub-grains, impurities including carbon inclusion in the single crystal before annealing. EBSD analyses identified that sub-grains with slightly tilted basal plane appeared and the overall number of grains increased after the annealing process. Rietveld refinement showed that the stress caused by the temperature gradient during the annealing process between top and bottom in the hot zone not only causes distortion of grains but also changes the lattice constant.

• Journal of Dental Rehabilitation and Applied Science
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• v.34 no.2
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• pp.80-88
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• 2018

Purpose: Implant surface modification and implant design are the principle targets for achieving successful primary stability. The aim of this study was to measure implant stability quotient (ISQ) values of sandblasted, large-grit, acid-etched (SLA) implants with tapered straight body design during the healing period, and to determine the various factors affecting implant stability. Materials and Methods: To measure implant stability, resonance frequency analysis (RFA) was performed in 26 patients (13 women and 13 men) with 44 SLA implants with tapered straight body design. Implant stability (ISQ values) was evaluated at baseline and healing abutment connection (12 weeks), and the correlations between RFA and insertion torque (IT), bone quality, and jawbone were determined. Results: The mean ISQ value of the implants was $69.4{\pm}10.2$ at the time of implant placement (baseline) and $81.4{\pm}6.9$ at the time of healing abutment connection (P < 0.05). Significant differences were found between RFA and bone quality and between RFA and jawbone (P < 0.05). No significant differences were found between RFA and IT, insertion area, fixture diameter, and implant length (P > 0.05). Conclusion: ISQ values of SLA implants with tapered straight body design were high at baseline and healing abutment connection. It was concluded that SLA implants with tapered straight body design show improved primary and secondary stability, and that immediate or early loading may be applicable.