• Title/Summary/Keyword: size comparison ability

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Effect of field-of-view size on gray values derived from cone-beam computed tomography compared with the Hounsfield unit values from multidetector computed tomography scans

  • Shokri, Abbas;Ramezani, Leila;Bidgoli, Mohsen;Akbarzadeh, Mahdi;Ghazikhanlu-Sani, Karim;Fallahi-Sichani, Hamed
    • Imaging Science in Dentistry
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    • v.48 no.1
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    • pp.31-39
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    • 2018
  • Purpose: This study aimed to evaluate the effect of field-of-view (FOV) size on the gray values derived from cone-beam computed tomography (CBCT) compared with the Hounsfield unit values from multidetector computed tomography (MDCT) scans as the gold standard. Materials and Methods: A radiographic phantom was designed with 4 acrylic cylinders. One cylinder was filled with distilled water, and the other 3 were filled with 3 types of bone substitute: namely, Nanobone, Cenobone, and Cerabone. The phantom was scanned with 2 CBCT systems using 2 different FOV sizes, and 1 MDCT system was used as the gold standard. The mean gray values(MGVs) of each cylinder were calculated in each imaging protocol. Results: In both CBCT systems, significant differences were noted in the MGVs of all materials between the 2 FOV sizes(P<.05) except for Cerabone in the Cranex3D system. Significant differences were found in the MGVs of each material compared with the others in both FOV sizes for each CBCT system. No significant difference was seen between the Cranex3D CBCT system and the MDCT system in the MGVs of bone substitutes on images obtained with a small FOV. Conclusion: The size of the FOV significantly changed the MGVs of all bone substitutes, except for Cerabone in the Cranex3D system. Both CBCT systems had the ability to distinguish the 3 types of bone substitutes based on a comparison of their MGVs. The Cranex3D CBCT system used with a small FOV had a significant correlation with MDCT results.

Effects of Transcranial Direct Current Stimulation on Lower Extremity Function of Stroke Patients : A meta-analysis of domastic research (뇌졸중 환자의 다리 기능에 대한 경두개직류자극의 효과: 국내 연구의 메타분석)

  • Lee, Jeong-Woo;Lim, Ji-Sun
    • Journal of The Korean Society of Integrative Medicine
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    • v.9 no.3
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    • pp.87-97
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    • 2021
  • Purpose : The purpose of this meta-analysis was to evaluate the effects of transcranial direct current stimulation on the lower extremity function of stroke patients. Methods : Domestic data were gathered from studies that conducted clinical trials associated with transcranial direct current stimulation and its impact on lower extremity function of stroke patients. A total of 592 studies published between 2012 and 2020 were identified, with 7 studies satisfying the inclusion data. The studies consisted of patient, intervention, comparison, and outcome (PICO) data. The search outcomes were items associated with muscle activity, balance, muscle strength and walking ability. Cochrane risk of bias (ROB) was used to evaluate the quality of 3 randomized control trials. The quality of 4 non-randomized control trials was evaluated using risk of bias assessment tool for non-randomized studies (RoBANS). Effect sizes in this study were computed as the corrected standard mean difference (SMD). A random-effect model was used to analyze the effect size because of the high heterogeneity among the studies. Egger's regression and 'trim-and-fill' tests were carried out to analyze the publishing bias. Results : The following factors had a large total effect size (Hedges's g=2.10, 95 %CI=1.54~2.66) involving transcranial direct current stimulation on stroke patients: muscle activity (Hedges's g=2.38, 95 %CI=1.08~3.68), balance (Hedges's g4=2.41, 95 %CI=1.33~3.60), walking ability (Hedges's g=1.54, 95 %CI=0.49~2.59), and muscle strength (Hedges's g=2.45, 95 % CI: 0.85~4.05). Egger's regression test showed that the publishing bias had statistically significant differences but 'trim-and-fill' test showed that there was still statistical difference. Conclusion : This study provides evidence for the effectiveness of transcranial direct current stimulation on the lower extremity in terms of muscle activity, balance, walking ability, and muscle strength in stroke patients. However, due to the low quality of studies and high heterogeneity factors, the results of our study should be interpreted cautiously.

Comparison of Anti-oxidative Activity in a Single Serving Size of the Commercial Coffees and Teas

  • Kim, Tae-Hun;Lee, Seulgi;Seo, Jin Woo;Bing, Sun Hye;Kim, Jong Im;Kwon, Eui-Ra;Jo, Gune-Hee;Lee, Jae-Myean;Choi, Joon Sig
    • Journal of Food Hygiene and Safety
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    • v.32 no.6
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    • pp.460-469
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    • 2017
  • The aim of this work was to study the comparison of anti-oxidative activity in a single serving size of commercial coffees and teas. Commercial regular coffees and teas, including, brand regular coffees ($BC_A$, $BC_B$, $BC_C$, $BC_D$, and $BC_E$), green tea ($GT_A$, $GT_B$, $GT_C$, and $GT_D$), black tea ($BT_A$, $BT_B$, and $BT_C$), pu-erh tea ($PT_A$, $PT_B$, and $PT_C$), chamomile tea ($CT_A$, $CT_B$, and $CT_C$), peppermint tea ($P_A$, $P_B$, and $P_C$), polygonatum odoratum tea ($POT_A$, $POT_B$, and $POT_C$), and jujube tea ($JT_A$, $JT_B$, and $JT_C$) were assayed for the levels of ascorbic acid, caffeine, total content of polyphenols and flavonoids, and ability to scavenge free radicals, using two in vitro antioxidant assays. The scavenging abilities of $BC_A$ and $BC_C$ were $664.91{\pm}48.87mg$ ascorbic acid equivalent/serving size and $624.36{\pm}16.18mg$ ascorbic acid equivalent/serving size, respectively. The four beverage samples ($BC_A$, $BC_C$, $GT_D$, and $BT_A$) significantly reduced the production of reactive oxygen species (ROS) and intracellular oxidative stress induced by $H_2O_2$. These results suggest that the beverages possess significant radical scavenging ability, which may be due to the presence of antioxidants. Furthermore, the significant reducing level of ROS evidences the potential antioxidant effects of these beverages in human cells.

Micro-computed tomographic evaluation of the flow and filling ability of endodontic materials using different test models

  • Torres, Fernanda Ferrari Esteves;Guerreiro-Tanomaru, Juliane Maria;Chavez-Andrade, Gisselle Moraima;Pinto, Jader Camilo;Berbert, Fabio Luiz Camargo Villela;Tanomaru-Filho, Mario
    • Restorative Dentistry and Endodontics
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    • v.45 no.2
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    • pp.11.1-11.9
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    • 2020
  • Objectives: This study compared the flow and filling of several retrograde filling materials using new different test models. Materials and Methods: Glass plates were manufactured with a central cavity and 4 grooves in the horizontal and vertical directions. Grooves with the dimensions used in the previous study (1 × 1 × 2 mm; length, width, and height respectively) were compared with grooves measuring 1 × 1 × 1 and 1 × 2 × 1 mm. Biodentine, intermediate restorative material (IRM), and mineral trioxide aggregate (MTA) were evaluated. Each material was placed in the central cavity, and then another glass plate and a metal weight were placed over the cement. The glass plate/material set was scanned using micro-computed tomography. Flow was calculated by linear measurements in the grooves. Central filling was calculated in the central cavity (㎣) and lateral filling was measured up to 2 mm from the central cavity. Results: Biodentine presented the least flow and better filling than IRM when evaluated in the 1 × 1 × 2 model. In a comparison of the test models, MTA had the most flow in the 1 × 1 × 2 model. All materials had lower lateral filling when the 1 × 1 × 2 model was used. Conclusions: Flow and filling were affected by the size of the test models. Higher grooves and materials with greater flow resulted in lower filling capacity. The test model measuring 1 × 1 × 2 mm showed a better ability to differentiate among the materials.

Characterization of Leuconostoc mesenteroides B-742CB Dextransucrase Expressed in Escherichia coli

  • Park, Mi-Ran;Ryu, Hwa-Ja;Kim, Do-Man;Choe, Jun-Yong;John F. Robyt
    • Journal of Microbiology and Biotechnology
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    • v.11 no.4
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    • pp.628-635
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    • 2001
  • Recombinant E. coli DH5$\alpha$ harboring a dextransucrase gene (dsrB742) produced an extracellular dextransucrase in a 2% sucrose medium. The enzyme was purified by DEAE-Sepharose and Phenyl-Sepharose column chromatographies upto a 142.97-fold purification with a 11.11% recovery to near homogeneity. The enzyme had a calculated molecular mass of 168.6 kDa, which was in good agreement with the activity band of 170 kDa on a nondenaturing SDS-PAGE. An expression plasmid was constructed by inserting the dsrB742 into a pRSET expression vector. The activity after expression in E. coli BL21(DE3)pLysS increased about 6.7-fold compared to the extracellular dextransucrase from L. mesenteroides B-742CB. The expressed and purified enzyme from the clone showed similar biochemical properties (acceptor reaction, size of active dextransucrase, optimum pH, and temperature) to B-742CB dextransucrase, however, the ability to synthesize ${\alpha}$-(1$\rightarrow$3) branching decreased in comparison to that of L. mesenteroides B-742CB dextransucrase.

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Capacity of Concrete Filled Carbon Tube Columns Based on the Comparison of Ductility and Energy Dissipation Capacity (연성도 및 에너지 소산능력 비교에 따른 콘크리트충전 탄소섬유튜브 기둥의 성능)

  • Lee, Kyoung-Hun;Hong, Won-Kee;Lee, Young-Hak;Kim, Hee-Cheul
    • Journal of the Earthquake Engineering Society of Korea
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    • v.11 no.1 s.53
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    • pp.29-35
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    • 2007
  • Flexural capacity estimation test of concrete filled carbon tube (CFCT) column under the cyclic lateral load was carried out in this study. Thickness of carbon tube and winding angles of carbon fiber were chosen as test parameters and two types of column with square and circular sections were manufactured. To act axial and lateral load, three dynamic actuators were used and all specimens were made with actual size. Flexural stiffness, ability of deformation, energy dissipation capacity and ductility behavior. of CFCT column were analyzed with test data.

Economic Security of Household: The Comparison of Short-term and Long-term Indicators (가계의 경제적 안정도: 단기지표와 장기지표의 비교)

  • 김강자
    • Journal of Families and Better Life
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    • v.11 no.1
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    • pp.107-118
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    • 1993
  • A dimension of well-being economic security was analyzed and compared with economic adequacy. Again it was tested whether two indicators of economic security(short-term vs. long-term) yield same distribution across all household groups. Economic Security was defined as the household ability to sustain a given level of consumption in the case of economic emergency; specifically loss of income. Measure of 8 different kinds of economic security were constructed from household net worth including and excluding home equity. Data were taken from the 1988 U.S. Consumer Expenditure Survey and 2148 households were selected to test hypotheses concerning the economic security of American households Empirical results showed a very low level of economic security in general. The first hypothesis that distribution of economic adequacy and economic security are same across all population groups was rejected. On the average security measure rather than adequacy measure was favor to white female-headed households and households who have old and highly educated house-holder. The second hypothesis that the indicators of long-term and short-term economic security yield the same results across all household was not rejected. In general the level of economic security was relatively higher when long-term indicator was used than short-term indicator was however the direction and relative size of effect of income and each control variable was almost same.

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A Comparative Analysis on the e-Business Adoption Factors and Performance in Large and Small Companies (e-비즈니스 채택요인과 성과에 관한 대기업과 중소기업의 차이분석)

  • Lee, Dong-Man;Ahn, Hyun-Sook;Kim, Hyo-Jung
    • The Journal of Information Systems
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    • v.17 no.4
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    • pp.157-180
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    • 2008
  • The majority of studies was undertaken on large companies that had adopted e-Business or on the specific case of dot.com companies. However, despite this interest in the effect of the size of an organization on its approach to e-Business, little direct comparison has been undertaken between small and large companies. This study examined the differences of e-Business adoption factors and e-Business performance between large and small companies. Reviewing the literature, we suggest a research model and develop nine hypotheses to be tested. Data are collected from 109 companies Implemented e-business. The results of hypothesis testing show as follows. First, e-Business performance of efficiency has a positive influence of perceived e-Business advantage, top management support, organizational learning ability and financial slack. Second, e-Business performance of sales performance has a positive influence of top management support. Third, e-Business performance of customer satisfaction has a positive influence of technology competence, perceived e-Business advantage, top management support, financial slack and institutional pressure. Finally, there are differences in the e-business factors(perceived e-Business advantage, top management support, institutional pressure) and e-Business performance(efficiency) between large and small companies.

A Study of CFRD using a Gravel Fill (하상사력재를 이용한 CFRD의 연구)

  • Jeong, Chan-Kyun;Noh, Tae-Gil;Lee, Song
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.10a
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    • pp.842-853
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    • 2008
  • In the construction of dam, the key factor which decides the type of dam is security of materials resource. Because of the large scale earth work, the ability to supply the materials is essential part about economical efficiency. The research is the case study about controlling the plan to secure the material resources in the design of Buhang multipurpose dam. In case of Buhang multipurpose dam, at that time of basic design, it was planned to use a rock fill material. From the detail investigation about the river bed accumulative layer widely spread on the submerged district on the basic design, the research is accomplished to replace rock material with gravel material. After the investigation of whole reserves of gravel material, estimation of conformity as dam construction material from analysis of grain size distribution, the case study of oversea construction, and the material property comparison between rock fill material and gravel fill material, it is verified th possibility of using the gravel fill. Thereafter, the analysis of dam stability using a gravel fill material is accomplished. Finally, A gravel fill material can be used as the main construction material of CFRD, therefore the efficiency of resource recycling in the submerged area is maximized, and the established plan is more advantageous to stability, constructibility, environmentibility than the case of using a rock fill.

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Second order of average current nodal expansion method for the neutron noise simulation

  • Poursalehi, N.;Abed, A.
    • Nuclear Engineering and Technology
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    • v.53 no.5
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    • pp.1391-1402
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    • 2021
  • The aim of this work is to prepare a neutron noise calculator based on the second order of average current nodal expansion method (ACNEM). Generally, nodal methods have the ability to fulfill the neutronic analysis with adequate precision using coarse meshes as large as a fuel assembly size. But, for the zeroth order of ACNEM, the accuracy of neutronic simulations may not be sufficient when coarse meshes are employed in the reactor core modeling. In this work, the capability of second order ACNEM is extended for solving the neutron diffusion equation in the frequency domain using coarse meshes. For this purpose, two problems are modeled and checked including a slab reactor and 2D BIBLIS PWR. For validating of results, a semi-analytical solution is utilized for 1D test case, and for 2D problem, the results of both forward and adjoint neutron noise calculations are exploited. Numerical results indicate that by increasing the order of method, the errors of frequency dependent coarse mesh solutions are considerably decreased in comparison to the reference. Accordingly, the accuracy of second order ACNEM can be acceptable for the neutron noise calculations by using coarse meshes in the nuclear reactor core.