• Title/Summary/Keyword: Natural Experiment

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Building Hybrid Stop-Words Technique with Normalization for Pre-Processing Arabic Text

  • Atwan, Jaffar
    • International Journal of Computer Science & Network Security
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    • v.22 no.7
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    • pp.65-74
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    • 2022
  • In natural language processing, commonly used words such as prepositions are referred to as stop-words; they have no inherent meaning and are therefore ignored in indexing and retrieval tasks. The removal of stop-words from Arabic text has a significant impact in terms of reducing the size of a cor- pus text, which leads to an improvement in the effectiveness and performance of Arabic-language processing systems. This study investigated the effectiveness of applying a stop-word lists elimination with normalization as a preprocessing step. The idea was to merge statistical method with the linguistic method to attain the best efficacy, and comparing the effects of this two-pronged approach in reducing corpus size for Ara- bic natural language processing systems. Three stop-word lists were considered: an Arabic Text Lookup Stop-list, Frequency- based Stop-list using Zipf's law, and Combined Stop-list. An experiment was conducted using a selected file from the Arabic Newswire data set. In the experiment, the size of the cor- pus was compared after removing the words contained in each list. The results showed that the best reduction in size was achieved by using the Combined Stop-list with normalization, with a word count reduction of 452930 and a compression rate of 30%.

Analyses of International Standard Problem ISP-47 TOSQAN experiment with containmentFOAM

  • Myeong-Seon Chae;Stephan Kelm;Domenico Paladino
    • Nuclear Engineering and Technology
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    • v.56 no.2
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    • pp.611-623
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    • 2024
  • The ISP-47 TOSQAN experiment was analyzed with containmentFOAM which is an open-source CFD code based on OpenFOAM. The containment phenomena taking place during the experiment are gas mixing, stratification and wall condensation in a mixture composed of steam and non-condensable gas. The k-ω SST turbulence model was adopted with buoyancy turbulence models. The wall condensation model used is based on the diffusion layer approach. We have simulated the full TOSQAN experiment which had a duration 20000 s. Sensitivity studies were conducted for the buoyancy turbulence models with SGDH and GGDH and there were not significant differences. All the main features of the experiments namely pressure history, temperature, velocity and gas species evolution were well predicted by containemntFOAM. The simulation results confirmed the formation of two large flow stream circulations and a mixing zone resulting by the combined effects of the condensation flow and natural convection flow. It was found that the natural convection in lower region of the vessel devotes to maintain two large circulations and to be varied the height of the mixing zone as result of sensitivity analysis of non-condensing wall temperature. The computational results obtained with the 2D mesh grid approach were comparable to the experimental results.

Combustion Characteristics of Pre-mixed Charge Compression Ignition Engines with Natural Gas Applied to 4-Cylinders Diesel Engine (4기통 디젤기관에 적용한 천연가스 예혼합 압축착화 기관의 연소특성)

  • Jung, S.H.
    • Journal of Power System Engineering
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    • v.13 no.2
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    • pp.5-10
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    • 2009
  • In recently, studies concerned to the diesel engine uses a natural gas as a fuel oil whose infra has been built already was approached to PCCI or HCCI with keeping a high thermal efficiency and reducing NOx and PM have been researching actively in normally single cylinder. An ignition source is required to bum the natural gas by a spark plug in gasoline engines, due to a higher auto-ignition temperature of natural gas. Then gas oil and DME were introduced as the ignition source. In this study as basic data for practical use of natural gas PCCI and HCCI engines, combustion characteristics and emission characteristics on 4-cylinders natural gas PCCI and HCCI engines with gas oil and DME as ignition sources were analyzed and the engine load range that is main object for practical use of PCCI and HCCI engines was made clearly by empirical experiment.

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The Characteristic of Natural Dyeing with Mulberry Leaf and Coffee Powder using Zinc Mordant (아연 매염제를 이용한 뽕잎, 커피 천연염재의 염색특성)

  • Lee, Jonggwan;Ko, Jaehoon
    • Textile Coloration and Finishing
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    • v.28 no.2
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    • pp.118-123
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    • 2016
  • The use of natural organic dyes obtained from renewable resources such as plants and trees has the potential for not only preserving petrochemicals but also all-endangered environment for coming next generations. In spite of inferior fastness, natural dyes can be employed in the colouration of natural as well as synthetic fibers. Recently, the potentiality of using natural dyes in colouration with additional UV-protection and antimicrobial properties has been reported. This study is aimed to investigate the effect of Zinc compounds compared to another metallic compounds as mordants on the dyeing properties of natural dye extracted from mulberry leaves and coffee. In this study, the results showed Zinc compounds was expose that is more similar than other mordants in washing fastness through a repeated experiment. Also, Zinc is the environmental impact is less material compared with other mordants, essential edibility minerals ingredient that is necessary in human body.

Effects of Lactation Stage and Individual Performance on Milk cis-9, trans-11 Conjugated Linoleic Acids Content in Dairy Cows

  • Wang, T.;Oh, J.J.;Lim, J.N.;Hong, J.E.;Kim, J.H.;Kim, J.H.;Kang, H.S.;Choi, Y.J.;Lee, H.G.
    • Asian-Australasian Journal of Animal Sciences
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    • v.26 no.2
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    • pp.189-194
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    • 2013
  • The goal of this study was to evaluate the effects of lactation stage and individual performance on milk cis-9, trans-11 conjugated linoleic acid (CLA) content in dairy cows. In experiment 1, the milk cis-9, trans-11 CLA content from dairy cows in early ($0.33{\pm}0.014%$), middle ($0.37{\pm}0.010%$), and late stages ($0.44{\pm}0.020%$) showed significant differences (p<0.05); and the individual contents of the major fatty acids, especially cis-9, trans-11 CLA in cows of the same lactation were also variable. In the second experiment design as a validation test, our results once again showed that the individual contents of cis-9, trans-11 CLA were various, and a difference of about 2-fold (0.55% vs 0.95%) was observed, although the animals were offered same diet. These data demonstrated that lactation stage and individual performance have considerable effects on milk cis-9, trans-11 CLA contents.

Optimal Design System of Grillage Structure under Constraint of Natural Frequency Based on Genetic Algorithm (고유진동수 제한을 갖는 골조구조의 GA 기반 최적설계 시스템)

  • Kim, Sung Chan;Kim, Byung Joo;Kim, E Dam
    • Journal of the Society of Naval Architects of Korea
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    • v.59 no.1
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    • pp.39-45
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    • 2022
  • Normal strategy of structure optimization procedure has been minimum cost or weight design. Minimum weight design satisfying an allowable stress has been used for the ship and offshore structure, but minimum cost design could be used for the case of high human cost. Natural frequency analysis and forced vibration one have been used for the strength estimation of marine structures. For the case of high precision experiment facilities in marine field, the structure has normally enough margin in allowable stress aspect and sometimes needs high natural frequency of structure to obtain very high precise experiment results. It is not easy to obtain a structure design with high natural frequency, since the natural frequency depend on the stiffness to mass ratio of the structure and increase of structural stiffness ordinary accompanies the increase of mass. It is further difficult at the grillage structure design using the profiles, because the properties of profiles are not continuous but discrete, and resource of profiles are limited at the design of grillage structure. In this paper, the grillage structure design system under the constraint of high natural frequency is introduced. The design system adopted genetic algorithm to realize optimization procedure and can be used at the design of the experimental facilities of marine field such as a towing carriage, PMM, test frame, measuring frame and rotating arm.

Effect of Permanent Hypoinsulinemia on Appetite, Performance, Carcass Composition, Blood Metabolites and Leptin Concentrations in Lambs

  • Moslemipur, F.;Torbatinejad, N.M.;Khazali, H.;Hassani, S.;Ghoorchi, T.
    • Asian-Australasian Journal of Animal Sciences
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    • v.22 no.6
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    • pp.827-835
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    • 2009
  • Insulin has crucial roles in energy metabolism in all mammals but has been less studied in ruminants. An experiment was conducted to investigate the effects of hypoinsulinemia induction on appetite, performance, carcass composition and blood metabolite levels in sheep. Treatments were intravenous injection of four doses of streptozotocin; 0, 25, 50 and 75 mg/kg BW named C, L, M and H, respectively. Twenty male lambs were divided into four treatment groups. Animals in group H could not continue the experiment because of abnormalities. The duration of the experiment was eight consecutive weeks, and injection was performed at the end of week 3. Feed and water intakes were measured weekly and weight changes of animals were recorded and used for calculation of other growth parameters. Blood samples were collected weekly via venipuncture at fasting and 2.5 h post-prandial and analyzed for hormones and blood metabolites. Results showed a marked hypoinsulinemia in group M with significant decrease in fasted and postprandial insulin concentrations and also fasted leptin concentrations vs. the control group C (p<0.05). Group M showed significant increases in blood glucose, triglycerides, cholesterol, total protein, blood urea nitrogen and ketone body levels vs. group C (p<0.05). After injection, animals in group M showed diabetic hyperphagia and enhanced water intake as compared to group C (p<0.05) but, despite increased feed intake, they did not gain more weight than controls (p<0.05), and consequently, their feed conversion ratio was greater. Protein and fat contents of meat and liver were not significantly different among groups (p>0.05). In conclusion, the results suggested a regulatory role of insulin in energy metabolism of ruminants by exerting two opposing effects; central catabolic and peripheral anabolic.