• Structural Engineering and Mechanics
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• v.17 no.3_4
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• pp.493-526
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• 2004

Semiactive control systems have received considerable attention for protecting structures against natural hazards such as strong earthquakes and high winds, because they not only offer the reliability of passive control systems but also maintain the versatility and adaptability of fully active control systems. Among the many semiactive control devices, magnetorheological (MR) fluid dampers comprise one particularly promising class. In the field of civil engineering, much research and development on MR fluid damper-based control systems has been conducted since this unique semiactive device was first introduced to civil engineering applications in mid 1990s. In 2001, MR fluid dampers were applied to the full-scale in-service civil engineering structures for the first time. This state-of-the-art paper includes a detailed literature review of dynamic models of MR fluid dampers for describing their complex dynamic behavior and control algorithms considering the characteristics of MR fluid dampers. This extensive review provides references to semiactive control systems using MR fluid dampers. The MR fluid damper-based semiactive control systems are shown to have the potential for mitigating the responses of full-scale civil engineering structures under natural hazards.

• Korean Journal of Adult Nursing
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• v.27 no.3
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• pp.325-336
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• 2015

Purpose: This study was conducted to identify factors influencing compliance of multidrug-resistant organism infection control in intensive care units (ICU) nurses. Methods: Data were collected from 254 ICU nurses who were working at 6 general and advanced general hospitals in D city and G Province. Results: 77.2% and 84.4% of the subjects correctly answered to questions about Methicillin-Resistant Staphylococcus Aureus (MRSA) and Vancomycin-Resistant Enterococcus (VRE), respectively. The scores of MRSA infection control compliance and VRE infection control compliance were 3.41 and 3.43, respectively. The factors influencing MRSA infection control compliance were empowerment, environmental safety recognition, and education satisfaction, which explained 30% of MRSA infection control compliance. The factors significantly related to VRE infection control compliance were empowerment, hospital types, environmental safety recognition, number of education sessions, and neonatal ICU, which explained 37% of VRE infection control compliance. Conclusion: It is necessary to develop efficient educational programs for infection control including educational contents to improve empowerment and environmental safety recognition of nurses. Furthermore, administrative support for those infection control programs is also necessary.

• Environmental Analysis Health and Toxicology
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• v.22 no.3
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• pp.235-245
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• 2007

Toxicity of nonlyphenol (NP) one of EDCs was studied with focus on reproduction of the crucian carp, Carassius auratus. Fishes were cultured under control and nonylphnol exposure conditions for 32 weeks. Experimental group was composed of total of 4 groups, 1 control condition and 3 nonylphenol exposure condition ($18\;{\mu}g\;NP\;L^{-1},\;37\;{\mu}g\;NP\;L^{-1}\;and\;83\;{\mu}g\;NP\;L^{-1}$). Survival rate was found to be similar in control and $18\;{\mu};NP\;L^{-1}$. However, it is lower In the $37\;{\mu};NP\;L^{-1}$ and $83\;{\mu};NP\;L^{-1}$ in comparison to the control group. Deformation of gonads was the highest in the exposure condition of $18{\mu};NP\;L^{-1}$ with the female illustrating higher ratio than the male. GSI was not much different in the male but in the female, NP exposure group illustrated lower value compared to the control group. HSI and GI did not illustrate any clear differences between the control and exposure group for both male and female. Intersex was 0% in the wild group, 4.16% in the laboratory control group, and 25.67% in the NP exposure condition with female illustrating higher compared to male. Concentration of blood vitellogenin in female illustrated no clear differences between the control and NP exposure group. However, in the male, it was higher in the NP exposure group in comparison to the control group, and illustrated higher values of vitellogenin compared to the figures found in the female of same con-centration condition.

• Structural Engineering and Mechanics
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• v.17 no.3_4
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• pp.557-572
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• 2004

Control systems are used to limit structural lateral deflections during large external loads such as winds and earthquakes. Most recently, the semi-active control approach has grown in popularity due to inexpensive control devices that consume little power. As a result, recently designed control systems have employed many semi-active control devices for the control of a structure. In the future, it is envisioned that structural control systems will be large-scale systems defined by high actuation and sensor densities. Decentralized control approaches have been used to control large-scale systems that are too complex for a traditional centralized approach, such as linear quadratic regulation (LQR). This paper describes the derivation of energy market-based control (EMBC), a decentralized approach that models the structural control system as a competitive marketplace. The interaction of free-market buyers and sellers result in an optimal allocation of limited control system resources such as control energy. The Kajima-Shizuoka Building and a 20-story benchmark structure are selected as illustrative examples to be used for comparison of the EMBC and centralized LQR approaches.

• Proceedings of the Korean Environmental Health Society Conference
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• 2004.06a
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• pp.12-20
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• 2004

• Environmental Engineering Research
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• v.9 no.6
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• pp.256-268
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• 2004

• Development and Reproduction
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• v.21 no.2
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• pp.215-221
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• 2017

Bitter melon (Momordica charantia, MC) has been used in traditional Korean medicine in treating diabetes. In addition, some reports were emerged, showing the antifertility activities of MC in mammals. We investigated the effects of ethanolic MC extract on the reproductive activity of golden hamsters whose spermatogenetic capacity is controlled by their photoperiods. The animals were divided into 4 groups: long photoperiod (LP) control, short photoperiod (SP) control, and LP animals treated with MC. The animals were orally ingested with low (0.03 g/kg) or high (0.15 g/kg) concentrations of the ethanolic extracts for 8 weeks on the daily basis. The control animals received the vehicle. The animals were then mated with age-matched females, experienced pregnancy. As results, the LP control animals showed active large testes but SP control animals displayed remarkably reduced testes. The animals treated with both concentrations of MC extracts demonstrated large testes, indicating fertile activity as animals in LP. LP control animals had litters as expected, but SP controls had no litters at all. MC extract showed the same results as LP animals in generating offsprings. These results suggest that the MC extract does not change the photoperiodic influence on reproductive activity of male golden hamsters.

• Journal of Environmental Science International
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• v.19 no.9
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• pp.1077-1082
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• 2010

This study was performed to investigate the nutritional conditions controlling keratinase activity in Bacillus megaterium F7-1. B. megaterium F7-1 produced keratinase using chicken feather as a sole source of carbon, nitrogen and sulfur. Addition of the feather medium with glucose enhanced keratinase production (68.9 U/ml), compared to control without glucose (63.2 U/ml). The synthesis of keratinase was repressed by addition of $NH_4Cl$ in B. megaterium F7-1. The highest keratinase production (70.9 U/ml) was obtained with the feather medium containing glucose and $MgSO_4{\cdot}7H_2O$. Keratinase was produced in the absence of feather (4.9 U/ml), indicating its constitutive synthesis. Feather degradation resulted in free SH group formation. B. megaterium F7-1 effectively degraded chicken feather meal (86%), whereas duck feather, human nail, human hair and sheep wool displayed relatively low degradation rates (8-34%).

• Structural Engineering and Mechanics
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• v.11 no.6
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• pp.617-636
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• 2001

For the potential application of smart materials to seismic structural control, this paper reviews seismic control techniques for civil engineering structures, and developments of smart materials for vibration and noise control. Analytical and finite element methods adopted for the design of distributed sensors/actuators using piezoelectric materials are discussed. Investigation of optimum position of sensors/actuators and damping are also outlined.

• Journal of Animal Environmental Science
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• v.4 no.2
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• pp.113-126
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• 1998

This study was conducted to develop pig-housings based on the forecasting models of swine production, the weather conditions, and so on in Korea. The Korean pig-housings were developed according to the following basis : 1. They should be suitable to domestic weather conditions. 2. They should be designed based on the forecasting models of swine production of farrow to finish operation among the forecasting models of swine production in Korea. 3. Proper environments should be offered to pigs according to the growth. 4. The environmental control, the treatment of swine wastewater, and so on should be interrelated. 5. Manual energy should be saved by effective arrangements of pig-housings. In the future, performance test of the Korean pig-housings and development of facility automation systems which are suitable to these should be accomplished.