• Korean Journal of Medicinal Crop Science
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• v.26 no.4
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• pp.271-280
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• 2018

Background: Astragalus membranaceus is a well known oriental medicinal herb. The polysaccharides of the aboveground parts (AMA) and the radix (AMR) of A. membranaceus are the most important functional constituents. Methods and Results: The aim of this study was to determine the effects of AMA and AMR on the oxidative damage induced in the skeletal muscle of rats subjected to exhaustive exercise. Sprague-Dawley rats were randomly divided into exercise and non-exercise groups; in the groups receiving the test compounds, AMA and AMR were administered orally for 30 days. Skeletal muscle samples were collected from each rat after running to exhaustion on a treadmill to determine the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) and the concentation of malondialdehyde (MDA). The antioxidant enzyme activities of SOD and GSH-Px of skeletal muscle of AMA- and AMR-treated groups were significantly higher than those of the control and commercial sports drink (SPD)-treated groups in exhaustive exercise rats. In addition, MDA concentrations in the skeletal muscle of the AMA- and AMR-treated groups were significantly lower than those of the control and SPD-treated groups. In the present study, the effects of AMA and AMR on exercise endurance capacity were also evaluated in mice subjected to a swimming exercise test. AMA and AMR supplementation prolonged the swimming time of mice and enhanced exercise endurance capacity. AMA and AMR possess the ability to retard and lower the production of blood lactate, and prevent the decrease of serum blood glucose. Conclusions: These results showed that, AMR and AMA exerted beneficial effect in mice, increasing the activity of the antioxidant systems and inhibiting oxidative stress induced by exhaustive exercise. The compounds improved exercise performance and showed anti-fatigue effects against exhaustive exercise.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.325-330
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• 2004

Recently, the request for the high strength of material is more and more increased in the area of industrial environment and machinery. To accomplish the high strength of materials, carbonizing treatment, nitrifying treatment, shot-peening method are representatively applied, however, shot-peening method is generally used among the surface processes. Shot peening is a cold working process used to impact Compressive residual stressed in the exposed surface layers. Benefits due to shot peening are increase in resistance to fatigue, stress corrosion cracking, fretting, galling, erosion and closing of pores. In this study, the influence of shot peening on the corrosion was investigated on spring steel immersed in 3.5% NaCl. The immersion test as performed on the two kinds of specimens. Corrsion potential, polarization curve, residual stress and etc, were investigated from experiment results. From test result the effect of shot peening on the corrosion was evaluated. The important results of the experimental study on the effects of shot peened on the environment corrosion of spring steels are as follows; In case of corrosion potential, shot peened specimen shows more activated negative direction as compared with parent mental. Surface of specimen, which is treated with the shot peened is placed as more activated state against inner base metal. It can cause t도 anti-corrosion effect on the base metal.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.18 no.1
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• pp.35-38
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• 1982

Ship hull Vibration is caused by troubling measure instruments installed in the ship, fatigue of the hull girder. Vibration has been studied by the View point of anti-Vibration. However, the theoretical calculation values of the Vibration analysis were not obtained accurately. Therfore, in this paper, Vibration analysis were made on the two (cylinder form, ship form) of ship hull girder by the transfer matrix method. The super-structure length was determined to be 0, 20, 40, 60, 80, 100, percentage of the ship's length from the stern. The results of analysis by the transfer matrix method are as follow. 1. Natural frequency may be determined by the order of node numbers and superstructure length. 2. Natural frequency inereased when the ship form is a finess and increasing ratio followed by high order of node numbers.

• Corrosion Science and Technology
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• v.11 no.5
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• pp.184-190
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• 2012

Cu alloy is widely used for marine applications due to its excellent ductility and high resistance for corrosion as wells as cavitation. However, long term exposure of the material to marine environments may result in damages caused by cavitation and corrosion. Water cavitation peening has been introduced in order to improve resistance of Cu alloy to corrosion and cavitation. The technology induces compressive residual stress onto the surface, and thus enhances the fatigue strength and life. In this study, the characteristics of the material were investigated by using water cavitaiton peening technique, and results showed that 2 minutes of water cavitation peening indicated the considerable improvement in hardness. On the other hand, over 10 minutes of water cavitation peening accelerated damages to the surface. In the case of ALBC3, water cavitation peening in the range of 2 to 10 minutes has shown the excellent durability and corrosion resistance while minimizing surface damages.

• Journal of Advanced Marine Engineering and Technology
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• v.20 no.2
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• pp.92-92
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• 1996

Recently, with the rapid development in the oceanic systems such as the oceanic structures and vessel, there occurs much interest in the impingement erosion-corrosion. In this paper, Cu-metal was tested by using of erosion apparatus with water-jet type and was investigated under the behaviour of impingement erosion-corrosion according to various environmental conditions, and the properties of Cu-metal were evaluated through the measurement by weight loss, weight loss rate, protective efficiency. The results were compared with those obtained using Cu-metal applied to cathodic protection and Cu-alloys added to Zn or Al-metal. As a basis of those results, the best protective efficiencies could be taken as using cathodic protection method and Cu-alloy with Al & Zn material addings, and will be suggested as the fundamental data of the anti-impingement erosion-corrosion on Cu-metal of impeller material for oceanic centrifugal pump.

• Journal of Advanced Marine Engineering and Technology
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• v.20 no.2
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• pp.24-31
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• 1996

Recently, with the rapid development in the oceanic systems such as the oceanic structures and vessel, there occurs much interest in the impingement erosion-corrosion. In this paper, Cu-metal was tested by using of erosion apparatus with water-jet type and was investigated under the behaviour of impingement erosion-corrosion according to various environmental conditions, and the properties of Cu-metal were evaluated through the measurement by weight loss, weight loss rate, protective efficiency. The results were compared with those obtained using Cu-metal applied to cathodic protection and Cu-alloys added to Zn or Al-metal. As a basis of those results, the best protective efficiencies could be taken as using cathodic protection method and Cu-alloy with Al & Zn material addings, and will be suggested as the fundamental data of the anti-impingement erosion-corrosion on Cu-metal of impeller material for oceanic centrifugal pump.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.1
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• pp.159-165
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• 2005

Shot peening can be defined as the process of work hardening of the surface of components by means of propelled stream of spherical shot. Benefits due to shot peening are increase in resistance to fatigue, stress corrosion cracking, fretting, galling, erosion and closing of pores. In this study, the influence of shot peening on the corrosion was investigated on spring steel immersed in $3.5\%\;NaCl$. The immersion test was performed on the two kinds of specimens. Corrosion potential, polarization curve, residual stress and etc. were investigated from experimental results. From test results, the effect of shot peening on the corrosion was evaluated. The important results of the experimental study on the effects of shot peened spring steels on the environment corrosion are as follows; In case of corrosion potential, shot peened specimen shows more activated negative direction as compared with parent metal. Surface of specimen, which is treated with the shot peened, is placed as more activated state against inner base metal. It can cause the anti-corrosion effect on the base metal.

• Journal of Korea Association of Health Promotion
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• v.2 no.2
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• pp.154-159
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• 2004

Rheumatoid arthritis(RA) is the most common inflammatory joint disease and a major cause of disability, morbidity, and mortality. It occurs worldwide, affecting approximately one percent of adults. Inflammation of the synovial membrane surrounding a joint leads to swollen, tender, and stiff joints RA has no known cure and the diagnosis is made based on clinical criteria and many different options exist for treatment. All of these factors magnify the importance of the patient-physician interaction and place a premium on the art rather than the science of medicine. The major goals of therapy for RA are to relive pain, swelling, and fatigue; improve joint function; stop joint daage, and prevent disability and disease-related morbidity. Some combination of nonsteroidal anti-inflammatory drugs(NSAIDs), steroids, and DMARDs is necessary in almost patients. In many combinations of different DMARDs or DMARDs plus biologicals are necessary for optimal control. Additionaly, all patients with RA should be educated about their disease and the therapies that will be used. Patient education is essentially early in the disease course and on going basis Much research is focused on the further development of biological agent for treatment of RA. Elucidation of the trigger or trigers for RA may allow us to begin to think about prevention of RA.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.4
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• pp.973-979
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• 2006

Cordyceps sinensis has been clinically used for the treatment of recovering fatigue, promoting the production of body fluid and qi, resolving sputum and arresting cough. Recent studies showed that Cordyceps sinensis produced immune-modulatory, anticarcinogenic and antioxidative effects. But, there are lack of studies regarding the effects of Cordyceps sinensis on the asthma. So, this study was performed to investigate the oral administrated effects of this herb against the disease. Asthma was induced to Balb/c mouse by i.p. injection and aerosol immunization with ovalbumin, and the change of the eosinophil number in the bronchoalveolar avage fluid(BALF) was observed. Concentrations of Interleukine-4(IL-4), Interleukine-5(IL-5) in BALF and splenocyte were assessed by ELISA, ImmunoglobinG(IgG) and ImmunoglobinE(IgE) from serum were calculated by same method. We found that the effects of Cordyceps sinensis in asthma mouse was implicated in reductions of IL-4, IL-S released from type2 T helper (Th2) cell, and decreases of IgE from plasma cell. These findings suggest that Cordyceps sinensis can produce anti-asthmatic effect, which may play a role in allergen-induced asthma therapy.

• Journal of Fashion Business
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• v.6 no.4
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• pp.62-82
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• 2002

The purpose of this study was to investigate the Avant-garde's aesthetic values and expressoinal characteristic, and to find out(analysis) the design characteristic of Avant garde fashion since 1995. Expressoinal characteristics of Avant garde with the anti-aesthetic, radically pursuing newness, and open mind, are revealed dynamism, hostile innovation, and experimentalism. Futuristic images expressed in dynamism represent space style, body conscious style, cyborg style, kinetic style, and primitive style. And deconstructional images related to hostile innovation show punk style, grunge style, humor style, and abstractive style. Also surreal images related to experimentalism hold erotic style, depasemant style, deformation style, and collage style. The proper usage of newness offers the escape, the vividness, and the humour from the fatigue of the life and so, it is expected to offer the chance of transfering the active individuals and societies directly or indirectly By analyzing the instances for the images of avant-garde fashion since 1995, the contribution about the expectation of the design trends of the present and future is expected.