• Journal of the Microelectronics and Packaging Society
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• v.23 no.4
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• pp.93-99
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• 2016

In this paper, we investigated the mechanical and electrical reliability of silver nanowire (AgNW) films. In particular, the durability and reliability of AgNW films were studied when the AgNW film was subjected to the bending deformation under current flow. The electrical durability of AgNW was evaluated by observing changes in heat generation and current density occurring in AgNW through voltage and current tests. The AgNW film showed a constant resistance change up to a bending radius of 2 mm and 200,000 cycles in the bending fatigue tests. The over-coating layer has an effect of improving the durability of the AgNW film. In the case of AgNW with the over-coating layer, heat was uniformly dissipated on the surface of AgNW film, whereas in the case of AgNW film without the over-coating layer, heat was generated locally. In the bending test under the current flow, the current density of the AgNW film was continuously decreased up to 52.4%. During bending, the AgNW was deformed due to mechanical deformation such as tensile, bending and sliding of the AgNW, consequently contact resistance of the AgNW was increased, leading to a electrical breakdown of AgNW by Joule heating. It was found that the application of the over-coating layer can improve the electrical and mechanical reliability of the AgNW film.

• Food Science and Preservation
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• v.8 no.1
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• pp.109-117
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• 2001

Cordyceps militaris is a parasitic fungus that has been used as a Chinese medicine for the treatment of fatigue, debility, kidney disease, tuberculosis, asthma and cardiac insufficiency etc. This study was carried out to determine the antioxidative and antimutagenic effects of Cordyceps militaris using DPPH free radical donating method and Ames test, respectively. They were extracted with ethanol and then further fractionated to n-hexane, chloroform, ethyl acetate, butanol and water, stepwise. Among five fractions, the EtOAc and BuOH fractions showed the highest electron donating activities, about 2-fold higher than other fractions. In Ames test, most of the extracts had strong antimutagenic effects against the mutagenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine(MNNG), 4-nitroquinoline-1-oxide(4NQO), benzo($\alpha$)pyrene(B($\alpha$)P) and 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indol (Trp-P-1). The EtOH extracts of C. militaris (200 $\mu\textrm{g}$/plate) showed 62.8%, 74.4% and 67.2% inhibitory effects on the mutagenesis induced by 4NQO, B($\alpha$)P and Trp-P-1, respectively, against TA98 strain, whereas 78.1%, 78.6%, 78.6% and 82.7% inhibition were observed on the mutagenesis induced by MNNG, 4NQO, B($\alpha$)P and Trp-P-1, respectively, against TA100 strain. Especially, the BuOH fraction showed the highest antimutagenic effects against mutation induced by MNNG.

• Korean journal of food and cookery science
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• v.28 no.1
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• pp.41-49
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• 2012

This purpose of this study was to develop a tea with small red bean which have been known to have effect regarding anti-obesity, fatigue recovery, edema recovery, blood circulation, etc. In order to provide baseline data for small red bean tea we investigated the general components, antioxidative effect and proanthocyanidin analysis in small red beans[Phaseolus angularis W.F. Wight.]. Physicochemical analysis(pH, sugar content, salinity, turbidity), color, anti oralmicrobial activity, content of saponin and sensory test of small red bean with different boiling time in 8 minutes(SR1), 16 minutes(SR2), 24 minutes(SR3), 32 minutes(SR4), 40 minutes(SR5) was also measured. It was shown that the crude fat, carbohydrate, moisture, crude protein, crude ash content of small red bean were 1.0%, 63.9%, 12.8%, 18.7%, 3.6%. DPPH free radical scavenging activity, the total phenolic compounds content and flavonoid content increased significantly (p<0.001). The results of analyzed proanthocyanidin was distinguished by characteristic UV-visible spectra with absorption maximum at 320 nm($t_R$ 7.589 min). As the boiling time(8 minutes:SR1, 16 minutes:SR2, 24 minutes:SR3, 32 minutes:SR4, 40 minutes:SR5) of small red beans increaseds, the pH significantly decreased(p<0.001). The sugar content, salinity and turbidity significantly increased(p<0.001). Moreover, Hunter L, a and b values, crude saponin also increased(p<0.001). The results of analyzed activity against oral bacteria, S. mutans, S. sobrinus, P. intermedia and P. gingivalis showed a higher antibacterial activities than E. coli and S. aureus. MIC was measured that S. mutans, S. sobrinus, P. intermedia and P. gingivalis showed a lower MICs than E. coli and S. aureus. The results regarding sensory test measures, In case of color, refreshing taste and overall quality, SR3 had the highest preference overall among tested samples. In cases conceming odor and taste, SR5 had the highest preference and with regards to sweetness and saltyness, SR4 had the highest preference.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.6 no.3
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• pp.464-476
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• 1999

This study was conducted between October 1, 1998, and December 31, 1998, in order to provide basic data to develop better self-management educational programs for systemic lupus erythematosus (lupus) patients. In the study, the extent of each patients knowledge on the disease and their learning needs about it were examined for 100 lupus inpatients and outpatients at the Kangnam St. Marys Hospital. Data were collected by using questionnaires to those patients. Frequencies, percentage, average, standard deviation, t-test, ANOVA, and Duncans multiple range test were examined through the SAS program. The result of study follows : 1) The average score of patients knowledge on the disease was 15.7 (range, 7-20; standard deviation, 2.74). Subjects scored higher as far as the extent of their knowledge in the following categories : management of daily life, diet, characteristics of the disease, risk factors, and medication. Two categories shared the highest percentage of correct answers : 99% of subjects correctly identified that fatigue and stress aggravate symptoms of lupus and symptoms of lupus vary among individuals in range and type. However, when subjects were asked if patients should get a regular examination by an ophthalmologist every 4-6 months while they are on medication to treat rashes, lupus can be completely cured, and contraceptives that include a female hormone (estrogen) are good as contraceptive methods, the percentages of correct answers were low (32%, 31%, and 20%, respectively). In terms of subjects knowledge about the disease by their general characteristics, single subjects had more knowledge about the disease than married subjects did (t=2.14, p=0.0353). The extent of knowledge also varied by monthly income (F=4.96. p=0.0097). Those with more formal education had more knowledge about lupus than those who had less formation education did (t=2.95, 0.0039). Additionally, those who were satisfied with their education about the disease had better knowledge about it than those who were dissatisfied with their education did (t=2.71, p=0.0090). 2) The extent to which lupus patients wanted to be educated about the disease was, on average, 64.5 (range, 46-75; standard deviation, 7.91). Areas for which patients requested education are listed here in order : risk factors, sexual lives and patients associations. Patients who had been hospitalized demonstrated wanting more education than those who had not been did(t=3.73, p=0.0003). The extent to which they wanted the information was different by the number of educational sessions they had (F=3.98, p=0.0249). In conclusion, the results above would be considered when the education programme is planned for SLE patients.

• KEPCO Journal on Electric Power and Energy
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• v.3 no.2
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• pp.79-88
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• 2017

In this paper, the wind tunnel test for the measurement of aerodynamic characteristics of transmission conductors with asymmetric sections is described. A single conductor model and bundled conductor models with ice accreted shapes are tested both in steady and turbulent flow, and the aerodynamic coefficients are acquired. Transmission conductor galloping is a kind of wind-induced vibration which is characterized by primarily vertical oscillation with a very low frequency and a high amplitude. It is well known that transmission conductor galloping is generally caused by moderately strong, steady winds when a transmission conductor has an asymmetric cross-section shaped by accreted ice. Galloping should be considered from the design stage of overhead lines because it can cause severe wear and fatigue damage to attachments as well as transmission conductors. It is reported that there have been normally 20 events of galloping per year in Korea, which may be followed by serious consequences in the electric power system. Therefore, this research is performed to measure aerodynamic characteristics of ice accreted transmission conductors to understand and control transmission conductor galloping so that it would help to prevent unexpected failures and reduce the maintenance costs caused by galloping.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.6
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• pp.715-721
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• 2018

This study examined energy saving and elevating the worker's neuro energy (comfort, concentration, physical, and psychological stability) by compensating for the unpleasant tactile sensation to stimulate auditory and olfactory senses and reduce energy consumption. The experiment was conducted in an environment test room under the test conditions of temperature $25[^{\circ}C]$, relative humidity 50[RH%], illumination 1,000[lux] and air current speed 0.02[m/sec] by stimulating the auditory senses with a 1/f change in rhythm and the olfactory senses with an aroma scent. The experiment utilized the method of EEG, which evaluates human body's psychological status via tactile means, and the method of the vibra image, which evaluates the learning abilities, HRV and human body's psychological status via non-tactile means. The subjects were selected as eight university students (four males and four females) in their 20s, the type that have high relative ${\alpha}$(8~13[Hz]) activation in occipital lobe, which brings the highest level of mind stability and concentration, who had no difficulty in physical activities. The subjects' posture and physical activity was fixed to 1met - when the subjects are seated and relaxing in a comfortable environment - and their clothes condition was standardized as 0.7clo. As a result, the sentimental and psychological stability and concentration were the highest in the multisensory stimulation of jasmine scent and change rhythm of an a=1.106 sound source. In addition, under this condition, the relative $M{\alpha}$ and relative $M{\beta}$ increased by 70.49[%] and 89.72[%], respectively; the HRT decreased by 39.09[%]; and the fatigue and tension/anxiety decreased by 36.85[%] and 15.54[%], respectively.

• International Journal of Highway Engineering
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• v.8 no.3 s.29
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• pp.49-61
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• 2006

This study suggests long-life asphalt pavement method which can save maintenance cost by increasing the design and performance period of pavements. The high modulus asphalt binder developed and then various physical tests are performed. Laboratory performance tests and accelerated pavement test are conducted for the high modulus and conventional mixtures. The test results show that dynamic modulus values of high modulus mixtures are higher than those of the conventional mixtures, The high modulus mixtures yield better fatigue, rutting and moisture damage performance than conventional mixtures. Structural analysis is performed and a database is built up for long life asphalt pavement design. Pavement response model is developed through a multiple regression analysis program, SPSS using the database. A design software for the long life pavements is developed based on the pavement response model and laboratory and field performance tests results. In addition, optimum pavement sections and materials are suggested. The suggested AC thickness of long life asphalt pavement is 29cm. A Life cycle cost analysis(LCCA) is conducted to check the economical efficiency of the long life pavement section. The LCCA result shows that initial construction costs of long life and conventional pavements are almost equal, but long life pavement is more profitable in terms of the LCCA.

• The Journal of Internal Korean Medicine
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• v.26 no.1
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• pp.213-220
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• 2005

Objective : Thyroid diseases are one of the most common endocrine disorders. However, the first chosen-treatments including anti-thyroidal and hormone-supplement therapy in western medicines, sometimes have failed to improve abnormal thyroid hormone secretions and clinical symptoms. Therefore, there has been a growing expectation for Oriental Medicine to take the role of alternative therapy. However, there has been little analysis of clinical characteristics. In this study, clinical characteristics of thyroidal disease patients who visited Kyung-Hee oriental hospital from January to July 2004 were analyzed. Methods : A total 86 patients diagnosed as hyperthyroidism, hypothyroidism or thyroid nodule were selected. Clinical history, including sex, age, symptoms, disease duration and methods of previous therapy and thyroidal test, such as thyroid function test (TFT), thyroid scan and other thyroid examinations. Results : In distribution of onset age and sex, the patients who have visited oriental hospital with thyroidal diseases showed similar characteristics with typical patients. In clinical symptom, the most frequent clinical sign was fatigue in both hyperthyroidism and hypothyroidism, which differs from the classical characteristics of those diseases. Most patients complained the unresolved symptoms, some of which are attributable to abnormal thyroid hormone secretions, in spite of western therapy with anti-thyroidal and hormone supplement agents. Conclusions : In oriental therapy, it will be necessary to consider the unique clinical features of thyroidal diseases different from classical patterns, and this study suggests that oriental therapy is a good alternative method for patients whose first treatment with western agents failed. Furthermore, more public information to these patients about oriental medicine would be helpful to increase cure rates, and give various choices to patients with thyroid diseases.

• Journal of Dental Rehabilitation and Applied Science
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• v.25 no.2
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• pp.157-169
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• 2009

The aim of this study was to evaluate effect of implant abutment screw coating treatment on joint stability, investigating mechanical properties of these. For this study used $ExFeel^{(R)}$ external hexed implant system and $15mm{\times}1mm$ discs. Experimental group was $1{\mu}m$ TiN, TiCN, TiC coated abutment screws and discs. To know mechanical property, i evaluated adhesion strength, surface hardness, using disc, corrosion test using screw. The results were as follows : rotation angle of coated screws increased than that of non-coated screw because of lower friction coefficient, especially TiC coated screw group had the largest value, but removal torque decreased in all coated screws (p<0.05). Torque loss before and after fatigue test was the smallest in TiC-coated screws, and the largest in non-coated screws (p<0.05), and there was no statistically significant difference between dry condition and wet condition of screws because of higher surface hardness and lower friction coefficient. From the above results, TiN, TiCN, TiC coating group had high abrasion resistance, especially TiC coated group which had low torque-consuming, high rotation angle as low friction coefficient will be considered to influence on implant abutment screw joint stability positively.

• Journal of Korea Foundry Society
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• v.11 no.6
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• pp.475-481
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• 1991

In this study the fabrication technology and mechanical properties of AC8A/$Al_2O_3$ Composites by squeeze casting process were investigated to develope for application as the piston materials that require good friction, wear resistance, and thermal stability. AC8A/$Al_2O_3$ composistes without a porosity and the break of preform were fabricated at the melt temperature of $740^{\circ}C$, the preform temperature of $500^{\circ}C$, and mold temperature of $400^{\circ}C$ under the applied pressure of $1200kg/cm^2$ as the results of the observation of microstructures. As the results of this study, the tensile strength of AC8A/$Al_2O_3$ composites was not increased linearly with $Al_2O_3$ volume fraction and so it seemed not to agree with the rule of mixture, which had been used often in metal matrix composite. Also the tensile strength after thermal fatigue test was little different from that before the test. Consequently it was thought that AC8A/$Al_2O_3$ composites fabricated under our experimental conditions had a good thermal stability and subsequently a good interface bonding. Wear rate(i.e., volume loss per unit sliding distance) of AC8A/$Al_2O_3$ composites was decreased with $Al_2O_3$ volume fraction and the sliding speed at both room temperature and $250^{\circ}C$ and so there was a good correlation between wear rate and hardness. Also the wear rate of AC/8A20% $Al_2O_3$ composities was obtained the value of $1.65cm^3/cm$ at sliding speed of 1.14m/sec as compared with about $3.0\;{\times}10^{-8}cm^3/cm$ hyereutectie Al-Si alloy(Al-16%Si-2%Cu-1%Fe-1%Ni), which applied presently for piston materials. The wear behavior of $Al_2O_3$ composites was observed to a type of abrasive wear by the SEM view of wear surface.