• 한국공작기계학회논문집
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• 제16권2호
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• pp.100-105
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• 2007

Electro-rheological(ER) fluid and valve are fabricated and evaluated experimentally in its durability to utilize the hydraulic control systems for long term operation. The two-ports ER valve used in the experiment consist of twelve parallel multi-layer electrodes and provide a restriction to the passage of ER fluid because of the viscous pressure drop and a component induced by the electric field. The durability test of ER valve are performed by measuring the surface roughness of electrodes with variation of an electric field strength and test time(1000 or 1800min.). Also, the shear stress and shear rate are measured to evaluate the durability of ER fluid as function of time. After durability test, ER shear stress increases approximately proportional to the shear rate with applied electric field intensity, In the ER valve, the center line average height roughness(Ra) of copper electrode increases about 1.56 times and ten-point median height roughness(Rz) increases about 2.2 times after the durability test. An understanding of these durability is essential to predicting the service life of ER fluid and valves.

• 한국정밀공학회지
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• 제18권4호
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• pp.151-159
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• 2001

As huge energy transfer systems like a nuclear power plant, steam power plant and petrochemical plant are operated for a long time, mechanical properties are changed by degradation. The life time of the systems can be affected by the mechanical properties. BI(Ball Indentation) test has a potential to replace conventional fracture tests like a uniaxial tensile test, fracture toughness test, hardness test and so on. In this paper, we would like to present the ageing evaluation technique by the BI method. The four classes of the thermally aged 1Cr-!mo-0.25V specimens were prepared using an artificially accelerated aging method. Tensile tests, fracture toughness tests, hardness tests and BI tests were performed. The results of the BI tests were in good agreement with fracture characteristics by a standard fracture test method within 5%. The IDE(Indentation Deformation Energy) of a BI technique as a new parameter for evaluating a degradation was suggested and the new IDE parameter clearly depicts the degradation degree.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집A
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• pp.171-176
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• 2000

As huge energy transfer systems like a nuclear power plant, steam power plant and petrochemical plant are operated for a long time, mechanical properties are changed by degradation. The life time of the systems can be affected by the mechanical properties. BI(Ball Indentation) test has a potential to replace conventional fracture tests like a uniaxial tensile test, fracture toughness test, hardness test and so on. In this paper, we would like to present the aging evaluation technique by the BI method. The four classes of the thermally aged 1Cr-1Mo-0.25V specimens were prepared using an artificially accelerated aging method. Tensile tests, fracture toughness tests, hardness tests and BI tests were performed. The results of the BI tests were in good agreement with fracture characteristics by a standard fracture test method. The IDE(Indentation Deformation Energy) of a BI technique as a new parameter for evaluating a degradation was suggested and the new IDE parameter clearly depicts the degradation degree.

• 약학회지
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• 제57권2호
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• pp.139-149
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• 2013

Glaucoma is a potentially blinding chronic disease requiring life-long commitment to medical therapy. Failure to adhere to anti-glaucoma treatment may lead to disease progression and visual loss. This study surveyed the adherence to glaucoma eye drop and eye drop instillation technique of glaucoma patients and analyzed the improvement of the adherence and installation technique after patient education for eye drop instillation instructions. Collected responses were statistically analyzed using Kruskal-Wallis test, Mann-Whitney test, Chi-square test, Fisher's exact test, Spearman's correlation coefficient, or one sample proportion test. The survey after patient education for proper eye drop instillation revealed that, even if the patients experienced the adverse effect of their eyes getting dry, they used the eye drop more regularly. They were better at instillation techniques like putting the eye drop inside the eye, and also avoiding applying too much medication or touching their eye with the eye drop bottle. Also, when the patients were divided into groups based on etiologic division, there was difference among groups regarding which category they answered has improved. The result showed improvement in adherence to glaucoma eye drop and eye drop instillation technique after patient education, implicating that patient education is an important aspect of eye care for glaucoma patient and helps them participate in the proper management.

• 대한물리치료과학회지
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• 제10권1호
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• pp.47-57
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• 2003

The purpose of this study was to evaluate the problem on activities of daily living ; the problem which spinal cord injured patients have when they adapt in daily living ; Subjects were 113 members who used the hospital which is located in Kwangju-city from November 20, 2001 to May 20, 2002. The evaluation of the ADL was performed according to MBI and collected data were statistically analysed by SPSS PC for paired Chi-square test T-test, One way ANOVA and Duncan's post-hoc test. The result's were as follows; 1. Modified Barthel Index average mark was $63.77{\pm}33.60$ points and MBI score distribution according to characteristics of injury is as following. 1) A patient who had long duration of injury, small injury region, incomplete paralysis in paralysis degree, paraplegia in paralysis type got high MBI score as statistical and significantly(p<0.05). 2. Society adaptation state by characteristics of spinal cord injured is an following. 1) After lapse of time of disease, a patient who is injured for a long term present surrounding environmental problem, a patient who is injured for a short term shows psychological problem. In society activity, as lapse of time of disease is long, patient did many hobby activity and same private club, on the other hand as lapse of time of diseases is short, the others appeared high and significantly as statistical(p<0.01). 2) In society activity by injury region, cervical injury and thoracic injury did more hobby activity than lumbar injury and in lumbar injury same private club or religion life appeared higher than thoracic injury of cervical injury significantly as statistical(p<0.01). 3) In walk method by paralysis degree Complete paralysis had more wheelchair life than incomplete paralysis(p<0.01). 4) In serious problem by paralysis type psychological problem in quadriplegia and surrounding environmental problem in paraplegia appeared high and significantly as statistical(p<0.01). 3. In society adaptation state by MBI score difference between variables appeared but it wasn't significantly.

• 한국약용작물학회지
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• 제15권5호
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• pp.352-356
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• 2007

The present study was investigated the anti-oxidative effects of aloe vera ingestion on brain and kidney in aged rats by monitoring several oxidative-related parameters. Male specific pathogen-free Fischer 344 rats were randomly divided into four groups of five rat each: Group A was fed test chow without aloe supplementation; Group B was fed a diet containing a 1% freeze-dried aloe filet; Group C was fed a diet containing a 1% charcoal-processed, freeze-dried aloe filet; and Group D was fed a diet containing a charcoal-processed, freeze-dried, whole leaf aloe in drinking water. Analyses of tissues were done at 4 months and 16 months of age. Results showed that a long-term intake of aloe, regardless of the preparation used, enhanced antioxidant defenses against lipid peroxidation, as indicated by reduced phosphatidylcholine hydroperoxide levels in both brain and kidney. The additional benefit of aloe intake on the anti-oxidative action was evidenced by enhanced superoxide dismutase and catalase activity in all aloe-ingested groups. Another beneficial effect of aloe shown in this study, although not an anti-oxidative parameter, was its cholesterol-lowering effect as detected in brain and kidney with significant decreases at age16 months of aloe-fed rats. Based on these findings, we conclude that a long-term dietary aloe supplementation modulated the anti-oxidative defense systems and cholesterol level.

• The Korean Journal of Physiology and Pharmacology
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• 제11권3호
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• pp.113-119
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• 2007

Developmental disability shows life-long behavioral abnormality with no significant physical malformation. This study was undertaken to develop an animal model for developmental disability by using two-factor approach. Lipopolysaccharide (LPS), a bacterial toxin, and NAN-190, a $5-HT_{1A}$ receptor antagonist, were administered to Sprague-Dawley rats on postnatal day (PND) 5 to induce inflammation and an altered 5-HT system, respectively. Long-term alteration of behavior occurred in the drug-treated groups. The LPS-treated group showed impaired motor coordination in the Rota-rod test. The LPS- treated or both LPS and NAN-190-treated groups showed impaired fore-paw muscle power in the wire maneuver test. These groups also showed decreased white matter volume and increased serotonergic fibers. The LPS and NAN-190-treated group also exhibited neurologic deficit in the placing reaction test and impaired equilibrium function in the tilt table test. The results showed that a variety of altered behaviors can be generated by two factor model, and suggested that combination of important etiologic factors and possible underlying defects is a promising strategy of establishing an animal model for developmental disabilities.

• Steel and Composite Structures
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• 제28권1호
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• pp.39-49
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• 2018

The concrete bridge decks are usually precast and in-situ assembled with steel girders with post-pouring joint in the construction practice of super-wide steel-concrete composite beam. But the difference of concrete age between the precast slabs and the post-pouring joint has been not yet considered for the long-term performance analysis of this kind composite beam. A simply supported precast-assembled T-shaped beam was taken as an example to analyze the long-term performance of steel-concrete composite beam with post-pouring joint. Based on the deformation coordination conditions of the old-new concrete deck and steel girder, a theoretical model for the long-term behavior of precast-assembled composite beam is proposed in this paper according to age-adjusted effective modulus method. Then, the feasibility of the proposed model is verified by the available test data from the Gilbert's composite beams. Parametric studies were preformed to evaluate the influences of the cross-sectional area ratio of the post-pouring joint to the whole bridge deck, as well as the difference of concrete age between the precast slabs and the post-pouring joint, on the long-term performance of the composite beam. The results indicate that the traditional method without considering the age difference would seriously underestimate the effect of creep and shrinkage of concrete bridge decks. The concrete age difference between the precast slabs and the post-pouring joint should be demonstrated for the life cycle design and long-term performance analysis of precast-assembled steel-concrete composite beams.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집A
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• pp.31-36
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• 2000

High temperature and pressure materials in power plant are degraded by creep damage, if they are exposed to constant loads for long times, which occurs in the load bearing structures of pressurized components operating at elevated temperatures. Many conventional measurement techniques such as replica method, electric resistance method, and hardness test method for measuring creep damage have been used. So far, the replica method is mainly used for the Inspection of High temperature and pressure components. This technique is, however, restricted to applications at the surface of the testpieces and cannot be used to material inside. In this paper, ultrasonic evaluation for the detection of creep damage in the form of cavaties on grain boundaries or integranular microcracks are carried out. And the absolute measuring method of quantitative ultrasonic velocity technique for Cr-Mo material degradation is analyzed. As a result of ultrasonic tests for crept specimens, we find that the sound velocity is decreased as the increase of creep life fraction$({\Phi}_c)$ and also, confirmed that hardness is decreased as the increase of creep life fraction$({\Phi}_c)$ but the coefficient of ultrasonic attenuation is increased as the increase of creep life fraction$({\Phi}_c)$. Finally based on the result in this paper, it can be recognized that the ultrasonic techniques using velocities and attenuation coefficient factor are very useful non-destructive methods to evaluate the degree of material degradation in fossile power plants.

• 호스피스학술지
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• 제5권2호
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• pp.1-14
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• 2005

The purpose of this study was to promote the popularization of hospice services by providing the information about the influences of hospice training on participants. We compared differences of attitudes toward death between those of pre-training and post-training by use of questionnaire. This study involved 137 volunteers participating in the hospice training held by one hospice center located in K-city. The questionnaire was composed of 46 items, 21 items of general information and 25 items of information about attitudes toward death. We applied Park's translated version(1992), originally distributed by Thorson and Powell(1988), in the assessment of participants' changed attitudes toward death. Participants were asked to fill out the questionnaire before and after the hospice training. The data were analged by frequency. ANOVA t-test, paired t-test. The results were as follows, 1.Pre-training items holding a high rank were 'The subject about the future life after death is distressing'(F=5.20), 'No worry about any occurrences around the body after a funeral'(F=4.75), 'Having little interest in being laid in a coffin after death'(F=4.56); items holding a low rank were 'Having little interest in any occurrences around the body after death'(F=2.22), 'Willing to deal with the aftermath of the death in detail'(F=1.94), 'No fear to have an idea to be cancerous'(F=1.72). 2.Post-training items holding a high rank were 'No fear to be dead as a result of sufferings from long-lasting illness'(F=3.18), 'No fear to have an idea to be cancerous'(F=3.16)', Having little interest in the future life after death'(F=3.09); items holding a low rank were 'Unpleasant to be not able to move after death(F=1.74), 'Distressing not to know about the future life after death'(F=1.61), 'The subject about the future life after death is distressing'(F=1.60). 3.There were significant difference in participants' attitudes toward death. Compared with pretraining(F=3.97), more positive were developed in post training(F=2.30). The results of this study indicate that hospice training renders positive regards toward death to the participants. Therefore every human being, who is able to speculate about the meaning of death, has to be exposed to the hospice training. In conclusion, hospice training should be popularized in the near future.