• Journal of Ship and Ocean Technology
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• v.12 no.4
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• pp.7-19
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• 2008

In preliminary ship design, a parametric study is a more realistic way to explore design space and analyze design problem than an optimization technique due to time-consuming computational work or a difficulty in incorporating all constraints into the optimization formulation. In the parametric study, feasible alternatives are examined in various aspects; the best one can be selected. Among the aspects, the strength assessment by FE analysis is an essential process in the ship design. This paper proposes a system to facilitate a parametric study for FE model based on design of experiment (DOE). It works on a FE pre-processor environment and assists a user to define a parametric study by interacting with FE model. It also provides an interface module with a FE solver in order to control the input file and extract predefined FE results from the output file. Based on the proposed system, a better understating and a better design are expected to be achieved.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.4
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• pp.504-511
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• 1995

This study was conducted to investigate the superoxide dismutase (SOD) characteristics and antioxidant activity by nonenzymatic(Fe$^{2+}$/Ascorbate) and Fe$^{3+}$-ADP/NADPH method in perilla(Perilla frutescens var. japonica Hara.) and jaso(Perilla frutescens Briton var. acuta Kudo.) leaves. The characteristics were evaluated by the nitro blue tetrazolium reduction method. Perilla leaves contained three or four major SODs depending on the varieties. The inhibitor test indicated that the Perilla leaves contained two Cu /ZnSODs and one or two FeSODs, but Jaso leaves have only Cu/ZnSOD. However, no varietal differences were detected in the Cu /ZnSOD isozyme patterns. FeSODs, however, showed different varietal isozyme patterns through the different combinations of the two FeSOD isozymes. Among MeOH extractes, "mil yang 2" showed very strong antioxidant activity. Relatively large differences in the levels of SOD and antioxidant activity detected in the Perilla varietites. There was significantly different in the comparison between perilla leaves and red jaso leaves.s.etween perilla leaves and red jaso leaves.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.104-108
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• 2003

Finite element (FE) model updating is a procedure to minimize the differences between analytical and experimental results, which can be usually posed as an optimization problem. This paper aims to introduce a hybrid optimization algorithm (GA-SA), which consists of a Genetic algorithm (GA) stage and an Adaptive Simulated Annealing (ASA) stage, to FE model updating for a shrunk shaft. A good agreement of the first four natural frequencies has been achieved obtained from GASA based updated model (FEgasa) and experiment. In order to prove the validity of GA-SA, comparisons of natural frequencies obtained from the initial FE model (FEinit), GA based updated model (FEga) and ASA based updated model (FEasa) are carried out. Simultaneously, the FRF comparisons obtained from different FE models and experiment are also shown. It is concluded that the GA, ASA, GA-SA are powerful optimization techniques which can be successfully applied to FE model updating, the natural frequencies and FRF obtained from all the updated models show much better agreement with experiment than that obtained from FEinit model. However, FEgasa is proved to be the most reasonable FE model, and also FEasa model is better than FEga model.

• 한국전기화학회:학술대회논문집
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• 1999.04a
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• pp.61-61
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• 1999

• Applied Biological Chemistry
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• v.21 no.1
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• pp.40-50
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• 1978

Effects of Zn, P and Fe on Cd uptake and accumulations by tomato (Lycopersicum esculentum Mill) and also their interactions on the uptake of Zn, Fe, Mn, P and Cd were investigated using batch type solution culture technique. Experiment 1 was a factorial scheme with 3 levels of Zn (0, 0.5, 2.5 ppm) and 3 levels of Cd (0, 0.2, 1.0 ppm). At 1.0 ppm Cd, significant yield reduction of dry matter and visual toxicity symptoms (yellowing and necrosis) of Cd was observed for all zinc levels. At this Cd level, increasing Zn treatment from 0 to 2.5 ppm increased Cd concentration from 199 to 235 ppm in leaves and from 124 to 145 ppm in stems. Similarly, Cd treatment did not suppress Zn uptake in leaves, and rather significantly increased in stems. Fe concentrations in leaves and stems were significantly reduced due to Cd treatment while Mn were increased by both Zn and Cd treatment. The results of experiment 2 with 3 levels of P (0.5, 2.0, 4.0m Mol) and 3 levels of Cd (0, 1.0, 2.0 ppm) in a factorial scheme also showed a growth reduction and visual toxic symptons from 1.0 ppm Cd level. Increasing P treatment tend to increase Cd concentrations in leaves and stems although it was not statistically significant. Increasing P concentration due to Cd treatment could be the 'concentration' effect as a result of reduced growth, while there was significant decrease in Fe concentration due to Cd treatment in spite of possible 'concentration' effect. Mn concentration was increased at 1.0 ppm Cd level and then dropped at 2.0 ppm Cd level. Zu concentration in leaves and stems showed significant increase as Cd treatment increased as observed in experiment 1. Experiment 3 had 3 levels of Fe (0.5, 1.0, 2.0 ppm) and 3 levels of Cd (0, 0.8, 1.6 ppm) treatments in a factorial design. Significant growth reduction and visual toxic symptoms as observed in experiment 1 and 2 were also observed from 0.8 ppm Cd level. Increasing Fe treatment obviously alleviated toxic symptoms, improved growth and significantly increased dry matter yield. At 0.8 ppm Cd treatment level, increasing Fe treatment from 0.5 to 2.0 ppm significantly decreased Cd concentration from 141 to 92 ppm in leaves and from 101 to 46 ppm in stems. At 1.6 ppm Cd treatment level the decrease was from 224 to 167 ppm in leaves and from 124 to 109 ppm in stems. As in the case of experiment 1 and 2, Fe concentration in leaves and stems were reduced as Cd treatment increased to 1.6 ppm at 0.5 and 1. 0 Fe treatment levels, whereas at 2.0 ppm Fe level, Cd treatment increased Fe concentration in leaves and stems showing significant interactions of Fe and Cd on Fe uptake. Cd effect on Zn and Mn showed similar results to experiment 1 and 2 and Fe treatments reduced Zn and Mn concentrations in plant tissue. The results of 3 experiments show that P and Zn did not manifest suppressive effect on Cd uptake, Fe significantly demonstrated it. Fe also alleviated Cd toxicity symptoms significantly in terms of visual symptoms and dry matter yield. Visual toxicity symptoms were definitely related to Fe status in plant tissue as well as possible physiological effect of Cd itself, and the results suggest that Fe requirement for normal growth increase as Cd element is present in plant tissue. Zn accumulated more in stems than in leaves whereas Cd, Fe and Mn showed the opposite trend in all experiments.

• Transactions of Materials Processing
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• v.15 no.4 s.85
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• pp.319-325
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• 2006

The laser forming process is a new flexible forming process without forming tools and external force, which is applied to various fields of industry. Especially, applications of the laser forming process focused on cutting, welding and marking process. In this paper, the laser bending process of sheet metal which is heated by laser beam and formed by internal stress is simulated by using thermo elastic-plastic analysis model. Based on the result of FE-analysis, the laser bending machine is made to obtain reliable data for sheet bending. Under the same condition as FE-analysis, the laser bending experiment has been performed to ver 펴 the result of FE-analysis and good agreement has been obtained between FE-analysis and experiments. Additional laser bending experiments have been performed to evaluate the laser bending machine.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.6
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• pp.67-76
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• 2020

This paper reports an experimental study to evaluate the flexural behavior of concrete beams reinforced using Fe based shape memory alloy (Fe-SMA) bars. For the experiment, a concrete beam of 200mm×300mm×2,200mm was produced, and a 4% pre-strained Fe-SMA bar was used as a tensile reinforcement. As experimental variables, type of tensile reinforcement (SD400, Fe-SMA), reinforcement ratio (0.2, 0.39, 0.59, 0.78), activation of Fe-SMA (activation, non-activation), and joint method of Fe-SMA bar (Continuous, welding, coupler) were considered. The electric resistance heating method was used to activate the Fe-SMA bar, and a current of 5A/㎟ was supplied until the specimen reached 160℃. After the upward displacement of the specimen due to the camber effect was stabilized, a three-point flexural loading experiment was performed using an actuator of 2,000 kN capacity. As a result of the experiment, it was found that the upward displacement occurred due to the camber effect as the Fe-SMA bar was activated. The specimen that activated the Fe-SMA bar had an initial crack at a higher load than the specimen that did not activate it. However, as with general prestressed concrete, the effect of the prestress by Fe-SMA activation on the ultimate state of the beam was insignificant.

• Proceedings of the Korean Magnestics Society Conference
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• 2011.06a
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• pp.134-135
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• 2011

The fundamental properties of $Fe_3P$ intermetallic compound was investigated in terms of the FLAPW method within GGA. The FM state of $Fe_3P$ was found to be energetically more stable compared to the NM one. It is consistent with the experiment. In addition, the calculated magnetic moments of Fe atoms were calculated to be 2.367, 1.665, and 2.104 ${\mu}B$ for FeI, FeII, and FeIII atoms, respectively.

• Korean Journal of Veterinary Research
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• v.39 no.4
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• pp.679-688
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• 1999

The combined effects of iron and selenium status on glutathione peroxidase (GSHPx) activity, cytochrome P-450 activity, and lipid peroxidation in the liver and intestinal mucosa of rats were investigated. In experiment one, four experimental groups (+Se+Fe, -Se+Fe, +Se++Fe, -Se++Fe) were manipulated for 3 weeks with intramuscular administration of irondextran (++Fe) and/or normal diet (+Fe) and deionized water (-Se) and/or selenium-supplemented deionized water (+Se). In experiment two, 2% dietary carbonyl iron (instead of the parenteral administration) was fed for 3 weeks to rats. Body weight of rats was significantly decreased in both parenterally and orally iron-overloaded groups (p<0.01), regardless of Se supplement. Serum iron was significantly increased in parenterally iron-overloaded groups but it was marginally increased in orally iron-overloaded groups. There was no significant difference in hemoglobin content among experimental groups in either experiment one or two. Total iron in the small intestine, intestinal mucosa, and livers was significantly high in both parenterally and orally iron-overloaded rats, regardless of selenium status. In the liver and intestine, GSHPx activity was significantly higher in all selenium-supplemented groups, compared to Se-deficient groups (p<0.01) and lipid peroxidation was significantly enhanced in both parenterally and orally iron-overloaded groups, compared to iron-adequate groups. There was no significant difference in cytochrome P-450 activity in the livers between groups in both experiment one and two. These results indicated that GSHPx activity in liver and intestinal mucosa was depended on selenium status, regardless of iron status, and iron-overload enhances lipid peroxidation in liver and intestinal mucosa by increasing the tissue iron content.

• Journal of Environmental Health Sciences
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• v.27 no.1
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• pp.63-68
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• 2001

A laboratory experiment was performed to invstigate the nitrate removal using FeCl$_3$ -treated activated carbon. Iron chloride(III) was coated onto the surface of activated carbon. The removal efficiency of nitrate was increased with increasing of FeCl$_3$ was used for coating material. About 22~26mg of Fe per unit g of activated carbon was adsorbed. The nitrate removal was not affected by the pH under the experiment range of pH, but the pH value in solution decrease to 3.5~4.0 after reaction. The removal efficiency of nitrate was increased with increasing of dosage of adsorbents. Ammonia was not detected and the Fe concentration as low as 0.22mg/$\ell$ was desorbed from the adsorbents. The adsorbents was regenerated using KCl solution, and recovery was 76.6% at 1 M of KCl. The adsorption of nitrate by FeCl$_3$-treated activated carbon followed the Freundlich isotherm equation and the Freundlich constant, 1/n, was 0.346. These results showed that the FeCl$_3$-treated activated carbon could serve as the basis of a useful nitrate removal.