• Korean journal of applied entomology
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• v.19 no.2 s.43
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• pp.73-78
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• 1980

Some experiment were conducted to evaluate the joint toxic action of carbofuran(2,3-Dihydro-2, 2-dimethyl-benzofuranyl methyl carbamate) and diazinon (0.0-Diethyl-0-(2-isopropyl-6-methyl-e-pyrimidinyl)-0-thionophosphate) against 3rd-instar larvae of the common cutworm, Agrotis fucosa (Butler). Acetone solutions of carbofuran or diazinon or mixture of these two insecticides, were topically applied to the mesonotum of the insect in a constant volume of $1.0{\mu}l$ per larva by means of Burkard microapplicator. Joint toxic action of carbofuran and diazinon for 3rd-instar larva of common cutworm was synergistic. The maximum synergistic effect might be obtained when the ratio of carbofuran to diazinon was 4.8 : 5.2.

• Advances in nano research
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• v.9 no.2
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• pp.83-90
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• 2020

This research investigates the effect of single walled carbon nanotubes (SWCNTs) dimensions in terms of diameter on the mechanical properties (longitudinal and transverse Young's modulus) of the simulated nanocomposites by molecular dynamics (MDs) method. MDs utilized to create nanocomposite models consisting of five case studies of SWCNTs with different chiralities (5, 0), (10, 0), (15, 0), (20, 0) and (25, 0) as the reinforcement and using polymethyl methacrylate (PMMA) as the common matrix. The results show that with increasing of SWCNTs diameter, the mechanical and physical properties increase. It is important that with the increasing of SWCNTs diameter, density, longitudinal and transverse Young's modulus, shear modulus, poisson's ratio, and bulk modulus of simulated nanocomposite from (5, 0) to (25, 0) approximately becomes 1.54, 3, 2, 1.43, 1.11 and 1.75 times more than (5, 0), respectively. Then to validate the results, the stiffness matrix is obtained by Materials studio software.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2001.04a
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• pp.414-421
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• 2001

Recently, the damping effect of building structures are greatly reduced because the use of non-structures members as like curtain wall are decreased and large open space are in need for the service of buildings. Assembly and office buildings with a lower natural frequency have a higher possibility of experiencing excessive vibration induced by human activities as like jumping, running and walking. These excessive vibration make the occupants uncomfortable and the serviceability deterioration. The common method of application of walking loads for the vibration analysis of structures subjected to walking loads is to inflict a series unit walking load and a periodic function at a node. But this method could not consider the moving effect of walking. In this study, natural frequency and damping ratio of plate structure are evaluated by heel drop tests. And new application of equivalent walking loads are introduced for vibration analysis of real slab system subjected to walking loads. The response obtained from the numerical analysis are compared well to the results measured by experimental tests. It is possible to efficiently analyze the vibration of floor which is subjected to walking loads by applying equivalent walking loads.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.627-628
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• 2006

The present work is a study on the argon gas pressure effects of Sinter/HIP sintering on microstructure and strength of different grades of TiC-NiMo cermets. Titanium carbide in the composition of different grades of TiC-NiMo cermets was ranged from 40 to 80 wt.% and the ratio of nickel to molybdenum in the initial powder composition was 1:1, 2:1 and 4:1 respectively. On the sintered alloys, the main strength characteristic, transverse rupture strength (TRS) was measured. Furthermore, the microstructure parameters of some alloys were measured and the pressure effect on pore elimination was evaluated. All the results were compared with common, vacuum sintered alloys. The TRS values of TiC-NiMo cermets could be considerably improved by using Sinter/HIP technique, for high-carbide fraction alloys and for alloys sintered at elevated temperatures.

• Journal of ILASS-Korea
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• v.14 no.4
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• pp.171-177
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• 2009

This study proposes a new stratified charge system for low emission and ultra lean burn. In order to examine combustion characteristics of the new system, sparkplug with a hole at positive pole and a common CNG injector for injecting fuel were used in this study as injector-type spark plug. The new stratified charge system injects fuel of extremely small quantities and ignites mixture around sparkplug gap. Also, the system was fitted in a visualized constant volume chamber. Then, for analysis of the combustion characteristics, we examined combustion pressure, lean inflammable limit, and visualized combustion flame according to equivalence ratio by comparison with homogeneous charge (HC) method and the new stratified charge (SC) method. As results of this study, in the case of using this system, the propagation speed of initial flame was increased and total combustion period was reduced in the ultra lean burn in the same equivalence ratio. These phenomena occurred clearly under the conditions of lean equivalence ratio. Furthermore, the lean inflammable limit of mixture was extended by using the injector-type spark plug.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.12
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• pp.739-748
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• 2020

The study aims to estimate the effect of current ratio (CR), current liability to inventory (CLI), total asset turnover (TAT), net profit margin (NPM), sales growth (SG), and company size (FS) on profit growth (PG). The research population was 18 companies in the Food and Beverage (F&B) sector listed on the Indonesia Stock Exchange (IDX) from 2014-2018. The data estimation method uses the common effect panel data regression model. The empirical findings show that the CR and CLI ratios have a negative effect on PG, while the TAT, NPM, and SG ratios have a positive effect. Company size is a factor that does not affect the growth of company profits. The results of the study imply that an increase in company profits can be achieved if the company operates efficiently and with low liquidity to encourage higher sales growth. The limitations of the research are as follows: first, this research considers only one type of industry, hence the results of this study would not be the same if applied to another type of industry. Second, the author observes profit growth by using the company's financial ratios and size and ignores other factors that may affect profit growth, for example, the number of employees, total net sales, and market capitalization.

• Journal of radiological science and technology
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• v.2 no.1
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• pp.95-99
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• 1979

When the ${\gamma}-ray$ of average energy 375KeV emitted by Ir-192 is exposed to each film through lead foil with various thickness, the film sensitivity will be different according to the thickness of lead foil and film type. The results on the study, different density and sensitive ratio appeared depending on exposed time and film type, but was made on the following common points. 1. The effect of film sensitivity by the front lead foil showed rapid increase up to the thickness of more or less 0.03mm, and the thicker lead foil was decreased more in the thickness of about $0.05{\sim}0.09mm$. 2. The effect of film sensitivity by the back lead foil was increased up to around of $0.03{\sim}0.08mm$ thickness, the maximum sensitivity was obtained in the thickness of more than $0.03{\sim}0.08mm$ without any change in the above effect. 3. The sensitivity of front lead foil was higher than that of back lead foil in thin lead foil with about 0.127mm thickness, but the sensitivity of back lead foil was higher than that of front lead foil when thickness became thicker.

• Nuclear Engineering and Technology
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• v.52 no.7
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• pp.1579-1586
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• 2020

Dissimilar metal joints (DMJs) are more common in the application of piping system of many industries. A 2- D and 3-D finite element analysis (FEA) is carried out on dissimilar metal Single Edged Notch Bending (DMSENB) specimens fabricated from ferritic steel, austenitic steel and Inconel - 182 alloy to study the behavior of DMJs with constraints by using linear elastic fracture mechanics (LEFM) principles. Studies on DMSENB specimens are conducted with respect to (i) dissimilar metal joint width (DMJW) (geometrical constraints) (5 mm, 10 mm, 20 mm, 30 mm and 50 mm) (ii) strength mismatch (material constraints) and (iii) crack lengths (16 mm, 20 mm and 24 mm) to study the DMJ behavior. From the FEA investigation, it is observed that (i) SIF increases with increase of crack length and DMJWs (ii) significant constraint effect (geometry, crack tip and strength mismatch) is observed for DMJWs of 5 mm and 10 mm (iii) stress distribution at the interfaces of DMSENB specimen exhibits clear indication of strength mismatch (iv) 3-D FEA yields realistic behavior (v) constraint effect is found to be significant if DMJW is less than 20 mm and the ratio of specimen length to the DMJW is greater than 7.4.

• Journal of Preventive Medicine and Public Health
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• v.31 no.1 s.60
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• pp.27-48
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• 1998

This study was conducted to integrate the results of studies which evaluated or identified the risk factors of CVD(cerebrovascular disorders) for Koreans. We retrieved the literature published in Korean by manual search and the English literature by Medline database to identify studies on the relationship between reported risk factors and CVD conducted for the Korean from 1980 to August, 1997. Hypertension and total serum cholesterol were selected as subjects of quantitative meta-analysis on risk factors of CVD in Koreans. The overall effect sizes of the risk of CVD due to hypertension and total serum cholesterol were calculated by common odds ratio(OR) and average standardized mean difference, retrospectively. Before the integration of each effect sizes into common effect sizes, the heterogeneity tests were conducted. Also, sensitivity tests were conducted for the estimated common effect sizes. Regarding hypertension and CVD, a total of 9 epidemiologic studies were identified with a total of 2,271 cases of CVD. The overall OR of hypertension associated CVD was 4.10(95% confidence interval[CI] 3.56 to 4.71). The OR of hypertension associated with hemorrhagic CVD and ischemic CVD were 6.56(95% CI : 4.92 to 8.80) and 3.28 (95% CI : 2.77 to 3.90), retrospectively. The OR of hypertension in relation to hemorrhagic CVD was significantly higher than that of hypertension in relation to overall CVD or ischemic CVD. Regarding total serum cholesterol and ischemic CVD, total 9 epidemiologic studies were identified with a total of 843 cases of ischemic CVD. Average mean difference as an effect size was 0.76, which was judged an important value according to Cohen's criteria. Our data suggested that hypertension was an important risk factor of overall CVD and its subtypes, and that the total serum cholesterol was associated with ischemic CVD in Koreans. For the lack of reliable prospective studies, however, we concluded that further research designed longitudinally would be required in this area.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.2
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• pp.296-304
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• 1998

The effects of common Korean dietary fiber-rich foods(dried sea mustard, Lentinus edodes and Korean radish leaves) on total gut transit time of diet, serum cholesterol level and mineral apparent absorption ration and tissue level were investigated. Twenty eight male were divided into 4 groups and were fed a control diet(containing 2% cellulose) and three fiber supplementary diet mixed with 10% of the above dietary fiber rich foods for 4 weeks, respectively. Body weight gain and food efficiency ration were not affected by the supplementary diet of fiber but the total gut transit time of diet was shortened in all dietary fiber groups. The Lentinus edodes reduced significantly serum total cholesterol and increased the HDL-cholesterol/total cholesterol ratio at 4th week without and effect on calcium and iron apparent absorptions and tissue levels of the minerals. Radish leaves decreased significantly iron apparent absorption ration with a tendency to increase iron retention in spleen and did not alter serum cholesterol level. Serum cholesterol concentration and calcium and iron apparent absorptions were not significantly altered by the ingestion of sea mustard, while it had more soluble dietary fiber than mushroom and radish leaves.