• Title/Summary/Keyword: Activation Model

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A study on Social Environmental Factors Affecting University Students' Entrepreneurial Intention (사회적 환경이 대학생 창업의도에 미치는 영향에 관한 연구)

  • Cho, Young Jo;Lee, Bo Young
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.11 no.4
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    • pp.17-25
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    • 2016
  • This research paper aims to provide valuable data to the policy makers in establishing business activation plan through improving university students'entrepreneurial intention by carrying out international comparison research regarding the social environmental factors that influences entrepreneurial intention. There have been multiple researches on personal traits that affect entrepreneurial intention in the past, but this paper examines the social environmental factors that impact entrepreneurial intention. The result of this study is as follows. First, university's assistive activity for entrepreneurship, successful entrepreneurial role model, and business market scale has positive effect on entrepreneurial intention, while government assistive policies for entrepreneurship has no direct effect on entrepreneurial intention. Second, there were some differences of entrepreneurial intention in demographic characteristics. The mean of entrepreneurial intention was highest in Chinese students. Students who have ever started their own business were highest in total mean comparison of entrepreneurial intention. Also entrepreneurial intention mean was higher in men generally. Beside, discussion is made on the implication of the study, the limitations of the study, and some directions for future studies.

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Effects of Ketotifen on an Experimental Model of IgA Nephropathy (IgA 신증의 실험모델에서 케토티펜의 효과)

  • Do, Young-Sun;Soon, Eu-Jene;NamGoong, Mee-Kyung
    • Childhood Kidney Diseases
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    • v.13 no.2
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    • pp.153-160
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    • 2009
  • Purpose : The intestinal mucosal defect has been known as one of the pathogenicmechanisms of IgA nephropathy. Oral antigens usually induce the activation of Th2 cells and mast cells. These cells secrete cytokines IL-4, IL-5 and TGF-$\beta$, which increase IgA production. Although ketotifen (benzocycloheptathiophene) is an H1 antagonist and a mast cell membrane stabilizer, it could protect the gastrointestinal membrane through inhibiting the production of IL-4, IL-5, PGE2, and LTB4, and decreasing the activity of nitric oxide synthease. Therefore, we have investigated if ketotifen may protect the development of IgA nephropathy with an oral antigen. Methods : ICR mice were used as an animal model orally with Poliovax only [ketotifen (-)], the other group was given oral ketotifen [ketotifen (+)] in addition to Poliovax. Results : Mesangial IgA deposition developed in 11 out of the 18 mice in the ketotifen (-) group, while in three out of the nine mice in ketotifen (+) group. The mesangial change developed in 16 out of the 18 mice in the ketotifen (-) group, while in five out of the nine mice in the ketotifen (+) group. Serum IL-4 and IL-5 levels were not significantly lower in the latter group than in the former. Conclusion : According to the statistical results from the above, ketotifen therapy would be beneficial to reducing mesangial changes in IgA nephropathy.

Nitrate and Phosphate Adsorption Properties by Aminated Vinylbenzyl Chloride Grafted Polypropylene Fiber (아민형 PP-g-VBC의 NO3-N과 PO4-P 흡착특성)

  • Lee, Yong-Jae;Song, Jee-June;Na, Choon-Ki
    • Journal of Korean Society of Environmental Engineers
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    • v.38 no.10
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    • pp.543-550
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    • 2016
  • Amine-type PP-g-VBC-EDA adsorbent, which possesses anionic exchangeable function, was prepared through photoinduced graft polymerization of vinylbenzyl chloride (VBC) onto polypropylene non-woven fabric and subsequent amination reaction using ethylenediamine (EDA). Adsorption characteristics of anionic nutrients on the PP-g-VBC-EDA adsorbent have been studied by batch adsorption experiments. The equilibrium data well fitted the Langmuir isotherm model, and the maximum monolayer sorption capacity was found to be 59.9 mg/g for $NO_3-N$ and 111.4 mg/g for $PO_4-P$. The adsorption energies were higher than 8 kJ/mol indicating anion-exchange process as the primary adsorption mechanism. The pseudo-second order kinetic model described well the kinetic data and resulted in the activation energy of 9.8-36.7 kJ/mol suggesting that the overall rates of $NO_3-N$ and $PO_4-P$ adsorption are controlled by the chemical process. Thermodynamic parameters such as ${\Delta}G^o$, ${\Delta}H^o$ and ${\Delta}S^o$ indicated that the adsorption nature of PP-g-VBC-EDA for anionic nutrients is spontaneous and exothermic. The PP-g-VBC-EDA could be regenerated by washing with 0.1 N HCl.

Integrating UAV Remote Sensing with GIS for Predicting Rice Grain Protein

  • Sarkar, Tapash Kumar;Ryu, Chan-Seok;Kang, Ye-Seong;Kim, Seong-Heon;Jeon, Sae-Rom;Jang, Si-Hyeong;Park, Jun-Woo;Kim, Suk-Gu;Kim, Hyun-Jin
    • Journal of Biosystems Engineering
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    • v.43 no.2
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    • pp.148-159
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    • 2018
  • Purpose: Unmanned air vehicle (UAV) remote sensing was applied to test various vegetation indices and make prediction models of protein content of rice for monitoring grain quality and proper management practice. Methods: Image acquisition was carried out by using NIR (Green, Red, NIR), RGB and RE (Blue, Green, Red-edge) camera mounted on UAV. Sampling was done synchronously at the geo-referenced points and GPS locations were recorded. Paddy samples were air-dried to 15% moisture content, and then dehulled and milled to 92% milling yield and measured the protein content by near-infrared spectroscopy. Results: Artificial neural network showed the better performance with $R^2$ (coefficient of determination) of 0.740, NSE (Nash-Sutcliffe model efficiency coefficient) of 0.733 and RMSE (root mean square error) of 0.187% considering all 54 samples than the models developed by PR (polynomial regression), SLR (simple linear regression), and PLSR (partial least square regression). PLSR calibration models showed almost similar result with PR as 0.663 ($R^2$) and 0.169% (RMSE) for cloud-free samples and 0.491 ($R^2$) and 0.217% (RMSE) for cloud-shadowed samples. However, the validation models performed poorly. This study revealed that there is a highly significant correlation between NDVI (normalized difference vegetation index) and protein content in rice. For the cloud-free samples, the SLR models showed $R^2=0.553$ and RMSE = 0.210%, and for cloud-shadowed samples showed 0.479 as $R^2$ and 0.225% as RMSE respectively. Conclusion: There is a significant correlation between spectral bands and grain protein content. Artificial neural networks have the strong advantages to fit the nonlinear problem when a sigmoid activation function is used in the hidden layer. Quantitatively, the neural network model obtained a higher precision result with a mean absolute relative error (MARE) of 2.18% and root mean square error (RMSE) of 0.187%.

A Kinetic Study of Steam Gasification of Low Rank Coal, Wood Chip and Petroleum Coke (저등급 석탄, Wood Chip, Petroleum Coke의 수증기 가스화반응 Kinetics 연구)

  • Gong, Sujin;Zhu, Xueyan;Kim, Yangjin;Song, Byungho;Yang, Won;Moon, Woongsig;Byoun, Yoonseop
    • Korean Chemical Engineering Research
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    • v.48 no.1
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    • pp.80-87
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    • 2010
  • Lignite of low rank coal and petroleum coke of high sulfur content can be high potential energy sources for coal gasification process because of their plentiful supply. The kinetic study of steam gasification has been performed in an atmospheric thermobalance with wood chip, lignite, bituminous, anthracite, pet-coke. The effects of gasification temperature($600{\sim}850^{\circ}C$) and partial pressure of steam(30~90 kPa) on the gasification rate have been investigated. The modified volumetric reaction model was applied to the experimental data to describe the behavior of carbon conversion and to evaluate the needed kinetic parameters. Lignite and wood chip with high volatile content showed high average gasification rates comparing to other fuel and thus they might be proper fuel for gasification processes. The activation energies for wood chip, lignite, bituminous, anthracite, and pet-coke through Arrhenius plot were found to be 260.3, 167.9, 134.6, 82.2, 168.9 kJ/mol, respectively. The expression of apparent reaction rates for steam gasification of various chars have been proposed as basic information for the design of coal gasification processes.

Characteristics of Isotherm, Kinetic and Thermodynamic Parameters for the Adsorption of Acid Red 66 by Activated Carbon (활성탄에 의한 Acid Red 66의 흡착에 대한 등온선, 동력학 및 열역학적 특성)

  • Lee, Jong-Jib
    • Clean Technology
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    • v.26 no.1
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    • pp.30-38
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    • 2020
  • The kinetic and thermodynamic parameters of Acid Red 66, adsorbed by granular activated carbon, were investigated on areas of initial concentration, contact time, and temperature. The adsorption equilibrium data were applied to Langmuir, Freundlich, Temkin, Redlich-Peterson, and Temkin isotherms. The agreement was found to be the highest in the Freundlich model. From the determined Freundlich separation factor (1/n = 0.125 ~ 0.232), the adsorption of Acid Red 66 by granular activated carbon could be employed as an effective treatment method. Temkin's constant related to adsorption heat (BT = 2.147 ~ 2.562 J mol-1) showed that this process was physical adsorption. From kinetic experiments, the adsorption process followed the pseudo-second order model with good agreement. The results of the intraparticle diffusion equation showed that the inclination of the second straight line representing the intraparticle diffusion was smaller than that of the first straight line representing the boundary layer diffusion. Therefore, it was confirmed that intraparticle diffusion was the rate-controlling step. From thermodynamic experiments, the activation energy was determined as 35.23 kJ mol-1, indicating that the adsorption of Acid Red 66 was physical adsorption. The negative Gibbs free energy change (ΔG = -0.548 ~ -7.802 kJ mol-1) and the positive enthalpy change (ΔH = +109.112 kJ mol-1) indicated the spontaneous and endothermic nature of the adsorption process, respectively. The isosteric heat of adsorption increased with the increase of surface loading, indicating lateral interactions between the adsorbed dye molecules.

The Effectiveness of Ulmus Davidiana Planch Herbal Acupuncture to Inhibit MIF Activation on Lipopolysaccharide-induced Rheumatoid Arthritis Model (유근피(楡根皮) 약침이 lipopolysaccharide 유발 류마티스 관절염 모델에서 MIF 활성 억제에 미치는 영향)

  • Byun, Hyuk;Park, In-Shik;Cho, Hyun-Seok;Kim, Kap-Sung;Lee, Seung-Deok
    • Journal of Acupuncture Research
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    • v.23 no.6
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    • pp.117-132
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    • 2006
  • Objectives : The purpose of this study is to investigate the effect of Ulmus davidiana Planch herbal acupuncture solution in LPS-stimulated RAW 264.7 cells and mouse knee joints, perfom1ed several experimental items: those are MIF mRNA, MIF, $TNF-{\alpha}$, $NF-{\kappa}B$ p65, iNOS mRNA, iNOS, NO, synovial hyperplasia, angiogenesis and fibrosis. Methods : In order to observe mRAN expression of MIF and iNOS in LPS-stimulated RAW 264.7 cells, RT-PCR was used. NO production in LPS-stimulated RAW 264.7 cells was measured by nitrite assay. All the female BALB/c mice were bred and maintained in pathogen-free mouse colonies and were 6 weeks of age on beginning of the experiment. The experimental model of RA was induced by injection of $50{\mu}g/kg$ LPS. Ulmus davidiana Planch herbal acupuncture solution was injected into either S 35 (犢鼻) or EX-LE 202 (內膝眼) of mice in turn daily for 19 days. Immunohistochemical staining was carried out to assess $TNF-{\alpha}$, $NF-{\kappa}B$ p65 and iNOS expression in synovial membrane. Synovial hyperplasia, angiogenesis and fibrosis in synovial membrane was observed with a microscope. Results : 1. Ulmus davidiana Planch herbal acupuncture solution inhibited mRNA expression of MIF and iNOS in dependence on a density of it in LPS-stimulated RAW 264.7 cells. 2. Ulmus davidiana Planch herbal acupuncture solution decreased synovial hyperplasia, angiogenesis and fibrosis in LPS-stimulated mouse knee joints. 3. Ulmus davidiana Planch herbal acupuncture solution curtailed production of MIF, $TNF-{\alpha}$, $NF-{\kappa}B$ p65, iNOS in LPS-stimulated mouse knee joints. Conclusion : On the basis of these results, It was shown that Ulmus davidiana Planch herbal acupuncture solution is significantly able to inhibit the production of MIF as a top in cytokines related to inflammatory or irrlll1une responses. Our results may provide that Ulmus davidiana Planch herbal acupuncture solution has beneficial effect in not only RA but other inflammatory or immune deases.

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Tat-indoleamine 2,3-dioxygenase 1 elicits neuroprotective effects on ischemic injury

  • Park, Jung Hwan;Kim, Dae Won;Shin, Min Jea;Park, Jinseu;Han, Kyu Hyung;Lee, Keun Wook;Park, Jong Kook;Choi, Yeon Joo;Yeo, Hyeon Ji;Yeo, Eun Ji;Sohn, Eun Jeong;Kim, Hyoung-Chun;Shin, Eun-Joo;Cho, Sung-Woo;Kim, Duk-Soo;Cho, Yong-Jun;Eum, Won Sik;Choi, Soo Young
    • BMB Reports
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    • v.53 no.11
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    • pp.582-587
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    • 2020
  • It is well known that oxidative stress participates in neuronal cell death caused production of reactive oxygen species (ROS). The increased ROS is a major contributor to the development of ischemic injury. Indoleamine 2,3-dioxygenase 1 (IDO-1) is involved in the kynurenine pathway in tryptophan metabolism and plays a role as an anti-oxidant. However, whether IDO-1 would inhibit hippocampal cell death is poorly known. Therefore, we explored the effects of cell permeable Tat-IDO-1 protein against oxidative stress-induced HT-22 cells and in a cerebral ischemia/reperfusion injury model. Transduced Tat-IDO-1 reduced cell death, ROS production, and DNA fragmentation and inhibited mitogen-activated protein kinases (MAPKs) activation in H2O2 exposed HT-22 cells. In the cerebral ischemia/reperfusion injury model, Tat-IDO-1 transduced into the brain and passing by means of the blood-brain barrier (BBB) significantly prevented hippocampal neuronal cell death. These results suggest that Tat-IDO-1 may present an alternative strategy to improve from the ischemic injury.

Improved Preservation and Shelf-life Extension of Fish Cake by Modified Atmosphere Packaging (변형기체포장에 의한 어묵의 저장성 향상 및 유통기한 연장)

  • Park, Su Yeon;An, Duck Soon;Kang, Jun Soo;Lee, Dong Sun
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.23 no.2
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    • pp.75-81
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    • 2017
  • Modified atmosphere packaging (MAP) of vacuum, 60% $N_2/40%$ $CO_2$, 100% $N_2$ and 100% $CO_2$ were examined to preserve fried fish cakes and extend their shelf life. When product packages in air were stored at 5, 10, and $15^{\circ}C$ with measurement in quality attributes, aerobic bacterial growth was found to be primary quality factor to determine the shelf life of the product. Huang's model was adopted to obtain the parameters for use in shelf life determination for a variety of packaging and storage conditions. Temperature dependence expressed in Arrhenius equation showed activation energies of 139.4 and 41.8 kJ/mol for inverse of lag time and growth rate of the microbial spoilage, respectively. MAP of 100% $CO_2$ could double the product shelf life at $10^{\circ}C$ compared to air package. High $CO_2$ concentration MAP at low temperature was found to be effective to prolong the shelf life.

Rheological Properties of Hot-Water Extractable Concentrates of Boxthorn (Lycii Fructus) and Mixed Boxthorn (구기자 및 혼합구기자 열수 추출 농축액의 리올로지적 특성)

  • Lee, Boo-Yong;Kim, Heung-Man;Kim, Chul-Jin;Park, Moo-Hyun
    • Korean Journal of Food Science and Technology
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    • v.24 no.6
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    • pp.597-602
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    • 1992
  • To improve utilization of boxthorn (Lycii Fructus), the boxthron and mixed boxthron (Lycii Fructus, Schizandrae Fructus, Corni Fructus, Zizyphi Fructus, Zingiberis Rhizoma, Cinnamami Cortex) hot-water extractable concentrates were prepared by vaccum evaporation and its rheological properties were investigated. The rheological properties of concentrates $(20{\sim}50^{\circ}Bx)$ followed power low model and showed a pseudoplastic behavior at the temperature range of $20{\sim}60^{\circ}C$. The apparent viscosity of $20^{\circ}Bx$, $30^{\circ}Bx$, $40^{\circ}Bx$ and $50^{\circ}Bx$ boxthron hot-water extractable concentrate was 0.0074 Pa s, 0.0175 Pa s, 0.0431 Pa s and 0.0988 Pa s, that of mixed boxthorn hot-water extractable concentrate was 0.0099 Pa s, 0.0328 Pa s, 0.0720 Pa s and 0.1940 Pa s at $20^{\circ}C$ and 1500 l/s, respectively. The yield stress of boxthron and mixed boxthron hot-water extractable concentrates ranged from 0.045 to 6.253 Pa and from 0.022 to 8.891 Pa, respectively. The activation energy for the flow of boxthron and mixed boxthorn hot-water extractable concentrates increased from 1.6182 to $2.0543{\times}10^7\;J/kg{\cdot}mol$ and from 1.7057 to $2.1462{\times}10^7\;J/kg{\cdot}mol$ with the concentrations of concentrates, respectively.

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