• The Journal of the Korean life insurance medical association
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• v.29 no.1
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• pp.16-21
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• 2010

The measurement of prostate specific antigen (PSA) in screening for prostate cancer is recently performed as a routine check-up in clinical medicine and insurance medicine. Several factors may affect serum PSA levels. As prostate size increases with increasing age, the PSA concentration also rises. Increasing body mass index (BMI) is associated with a lower mean PSA concentration. Inhibitors of 5-alpha-reductase such as finasteride and dutasteride produce a 50 percent or greater decrease in serum PSA during the first three months of therapy, which persists as long as the drug is continued. Men who are regularly taking non-steroidal antiinflammatory drugs (NSAIDs) or acetaminophen have lower PSA levels. Emerging concepts regarding PSA testing that may help refine the interpretation of an elevated concentration include: PSA density, PSA velocity, and Free versus complexed or bound PSA. With many insurance companies, PSA level has become part of a standard battery of blood tests, along with HIV, cholesterol, liver enzymes, and other predictors of premature death. But, there is no clear proof of benefit, so we have to monitor the value of PSA test as a prostate cancer screening test in insurance medicine.

• Journal of Life Science
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• v.9 no.5
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• pp.548-555
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• 1999

Long-term effects of Ganoderma lucidum (GL) on memory and oxidative stress of senescence-accelerated mice (SAM) were investigated. Senescence-resistant (R1) and prone (P8) strains of SAM were fed GL diets, premixed with low (20 mg/kg/day, T1) or high (200 mg/kg/day, T2) levels of GL powder for 9 months starting from young (3 months of age) or for 5 months starting from old (7 months of age). After the final feeding at 12 months of age, all animals were subjected to passive avoidance test for the evaluation of memory function. In addition, the changes in hepatic thiobarbituric acid-reactive substance (TBARS) and glutathione were analyzed. SAMP8 fed GL diets from old age (7 months) exhibited the improvement of memory, although GL rather inhibited the memory function of both SAMR1 and SAMP8 mice fed diets from young (3 months of age). Hepatic TBARS contents were decreased in SAMP8 fed high GL diet for 9 months and in SAMR1 fed low GL diet for 5 months. Hepatic glutathione content was also remarkably increased in SAMR1 following both feeding periods, and less extent in SAMP8 fed diet for 5 months of age. Taken together, it is proposed that GL extracts may play an anti-aging role through antioxidant action, and thereby may improve the senescence-related memory dysfunction.

• Korean Journal of Pharmacognosy
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• v.39 no.3
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• pp.241-245
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• 2008

Quantitative methods for the marker compounds of Cimicifugae Rhizoma, Achyranthis Radix, Artemisiae Capillaris Herba, Moutan Cortex Radicis and Arecae Semen, respectively, were developed using HPLC-DAD. Using the established methods, each extract of the natural medicines were evaluated. In addition, long term and accelerated stability test in the extracts were examined for six months. No significant change in content of the marker compounds of each extract observed during the time of investigation.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.9
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• pp.1257-1263
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• 2010

The naval structure exposes to environmental vibration of shafted propeller propulsion and engine vibration. The shipboard equipments are developed compliance to MIL-STD-167-1A. For this purpose, vibration fatigue life of shipboard equipment for long lives should be estimate via an analytical approach and vibration test. In this paper, High cycle fatigue strength of cast aluminum alloy A356 using shipboard equipment was evaluated by 14 S-N method. The stress applied on the structure is evaluated by an analytical method(frequency response analysis with sinusoidal input and a fatigue evaluation) to simulate a MIL-STD-167-1A test. The frequency with the maximum equivalent stress is shown by Max. test frequency and the vibration fatigue life of shipboard equipment was estimated by Miner's rule.

• Journal of the Korean institute of surface engineering
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• v.52 no.1
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• pp.16-22
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• 2019

The structural change of DLC coatings during long-term wear test and dicing test under the low loading condition was investigated. DLC coatings were applied for the precision injection molds of a modified SNCM steel for the extension of life and the micro-diamond blades for the high cutting efficiency and the increase in life. A ball-on-disc wear tests in the mold steel and a dicing tests in the micro-diamond blades were conducted to understand degradation of DLC coatings. The degradation of DLC coatings for the injection mold steel and the micro-diamond blades during the wear and dicing tests were studied with Raman Spectroscopy. Raman peaks were divided two bands(D band and G band) to study the degradation process of DLC structure. By the wear test, polished condition of wear marks were observed to be maintained until 10 hrs of wear test period is given, but small striation marks appeared in 20 hours wear test. It was observed that $I_D/I_G$ ratios changed as the degradation of DLC coatings is proceeded during the wear tests and the dicing tests. It is suggested that the change in $I_D/I_G$ value possibly reflected from the composition of $sp^2$ and $sp^3$ bondings in DLC layers relevant to the change in mechanical and physical property.

• Journal of Korean Academy of Nursing
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• v.30 no.1
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• pp.29-38
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• 2000

To determine whether personal history of lactation in premenopausal women influence bone mineral density, a cross-sectional study was conducted. One hundred eighty-four premenopausal women were selected from women who had been checked for bone mineral density by dual energy x-ray absortiometry in lumbar spine, femoral neck, Ward's triangle, and trochanteric site at general hospitals in Seoul and Pusan. They completed a questionnaire including life style factors and reproductive history. In the data analysis, Pearson correlation coefficients were used to test any association between individual variables and bone mineral density and a statistical comparisons between long term lactation(>24 months) and short term lactation(<24 months) were made by one way analysis of covariance. The results were summarized as follows: 1) There was no significant difference in the bone mineral density of the lumbar vertebrae in premenopausal women between the long term lactation group(>24months) and the short term lactation group(<24months). 2) There was no significant difference in the bone mineral density of the femur neck, Ward's triangle, and trochanteric site in premenopausal women between the long term lactation group (>24months) and the short term lactation group (<24months). Considering these results, we suggest prospective studies that measure bone mineral density before and after, in addition to those during lactation. We also suggest the further study with premenopausal women less than 35 who have achieved peak adult bone mass.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.04b
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• pp.8-9
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• 2008

In the procedure of the estimation, the short time breakdown characteristics for the epoxy composite specimens, which were made with the variation of hardener and/or filler, were tested firstly. Then the long time voltage-to-time test was implemented. Finally, the long time breakdown voltage of each specimen was estimated with the parameters obtained from the statistical treatment with Weibull distribution. Base on the results, it has been found that the optimal weight ratio of epoxy resin/hardener/filler that has the excellent long time breakdown characteristic was 100/100/65. It was due to the silane treatment which relieves the electric field at the interface between filler and epoxy.

• The Journal of the Korea Contents Association
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• v.20 no.11
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• pp.511-524
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• 2020

Purpose: This study aims to examine the effect of increased physical activity (PA) regarding health-related quality of life (QOL) and nutrition intake in hemodialysis patients. Methods: The research was quasi-experimental using pre-test and posttest design. The participants were 60 patients, 30 each in the experimental and control group. The program was up to eight weeks long and involved two kinds of aerobic exercises: intradialytic aerobic exercise to be performed thrice a week and walking for up to seven days a week. The 60 patients undergoing hemodialysis for end-stage renal disease underwent assessment of International Physical Activity Questionnaires (IPAQ), 24-hour diet recall and a 12-item short-form health survey (SF-12; physical component summary score(PCS) and mental component summary score(MCS)) before and after the exercise program. Nutrition intake was assessed using CAN-2.0. Data were analyzed using descriptive statistics, independent t-test, 𝑥2 test, and Mann-Whitney U test. Results: In the experimental group, PA post-test scores were also significantly higher than the pre-test scores and the levels of physical component summary score (PCS) in QOL were significantly improved post-test, but the scores on nutrient intake did not improve. The levels of PCS were significant correlations animal protein, manganese, selenium, and Vitamin C. Although there was no group effect, total calorie of nutrition intake was higher than the comparison group. Conclusion: Combined intradialytic exercise and walking was found to be effective on PA, and PCS in QOL. Therefore, the findings of the current study may provide an appropriate guidance for encouraging exercise by hemodialysis patient.

• Corrosion Science and Technology
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• v.4 no.4
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• pp.147-154
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• 2005

The creep resistance of geogrids is one of the most significant long-term safety characteristics used as the reinforcement in slopes and embankments. The failure of geogrids is defined as creep strain greater than 10%. In this study, the accelerated creep tests were applied to polyester geogrids at various loading levels of 30, 50% of the yield strengths and temperatures using newly designed test equipment. Also, the new test equipment permitted the creep testing at or above glass transition temperature($T_g$) of 75, 80, $85^{\circ}C$. The time-dependent creep behaviors were observed at various temperatures and loading levels. And then the creep curves were shifted and superposed in the time axis by applying time-temperature supposition principles. The shifting factors(AFs) were obtained using WLF equation. In predicting the lifetimes of geogrids, the underlying distribution for failure times were determined based on identification of the failure mechanism. The results confirmed that the failure distribution of geogrids followed Weibull distribution with increasing failure rate and the lifetimes of geogrids were close to 100 years which was required service life in the field with 1.75 of reduction factor of safety. Using the newly designed equipment, the creep test of geogrids was found to be highly accelerated. Furthermore, the time-temperature superposition with the newly designed test equipment was shown to be effective in predicting the lifetimes of geogrids with shorter test times and can be applied to the other geosynthetics.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2004.09a
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• pp.93-99
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• 2004

At present, LG Electronics pushes ahead to eliminate the Pb(Lead) -a hazardous material- from all products. Especially, we have performed to select the optimum standard composition of lead free alloy for the application to products for about 3 years from 2000. These days, we have the chance for applying to the mass-production. This project constructed the system for applying the lead free solders on consumer electronic products, which is one of the major products of the LG Electronics. To select the lead free solders with corresponding to the product features, we have passed through the test and applied with Sn-3.0Ag-0.5Cu alloy system to our products, and for the application to the high melting temperature composition, we secured the thermal resistance of the many parts and substrate and optimized the processing conditions. We have operated the temperature cycling test and the high temperature storage test under the standards to confirm the reliability of the products. On these samples, we considered the consequence of our decision by the operating test. For the long life time of the product, we have operated the temperature cycling test at $-45^{\circ}C-+125^{\circ}C$, 1 cycle/hour, 1000 cycles. Also we have tested the tin whisker growth about lead free plating on lead finish. We have analyzed with the SEM, EDS and any other equipment for confirming the failure mode at the joint and the tin whisker growth on lead free finish.