• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2008년도 춘계학술대회 논문집
• /
• pp.1264-1281
• /
• 2008

Around two years have passed since the beginning of aptitude test required by 2006 Rail Safety Act. At this point, it is necessary to evaluate the validity of the aptitude test. Through this study, the structural system for all the tests would be overviewed, which will show the correlation among each tests or its importance. Also, although it is rough, reliability and validity of the tests would be overviewed by their retest and education materials. This would contribute, in the future, to setting up for the standard of upgrading or integrating the tests.

• 한국운동역학회지
• /
• 제16권1호
• /
• pp.31-41
• /
• 2006

The primary purpose of a TKA is to restore normal knee function Therefore, ideally, a TKA should: (a) maintain the natural leverage of the knee joint muscles to ensure generating adequate knee muscle moments to accomplish daily tasks such as rising from climbing stairs; (b) provide adequate knee joint stability. A 16-channel MyoResearch XP EMG system was used to collect the differential input surface electromyography signals VM, VL, RF, BF, ST during climbing/descending stair tests. A Peak Motion Measurement System was used to collect the kinematic and kinetic data. AKIN-COM Ill isokinetic dynamometer was used for EMG of VM, VL, RF, BF and ST during maximal voluntary contraction. I Quadriceps EMG results for the VM of the passed 1year group limb demonstrated significant less RMS EMG than that of the passed 3year group limb $60^{\circ}-15^{\circ}$ of knee flexion(p<0.05). The VL of the passed 1year group limb also demonstrated significants less RMS EMG than that of the passed 3year group limb from $60^{\circ}-45^{\circ}$ of knee flexion(p<0.05). Similar to the VM and VL, the RF of the passed 1year group limb showed less RMS EMG than that of the passed 3year group limb from $60^{\circ}-30^{\circ}$ do knee flexion(p<0.05). Hamstring EMG results for the BF of the passed 1year group limb demonstrated less RMS EMG than that of the passed 3year group limb from $75^{\circ}-15^{\circ}$ of knee flexion(p<0.05). The passed 1year group limb tended to have less ADD displacement(p<0.071) than that of the passed 3year group limb. There was no significant difference of the ABD displacement between the passed 1year group and the passed 3year group limbs(p<0.73). The passed 3year group used compensatory adaptation movement strategies to compensate for the strength deficit of passed 3year group limbs. The passed 3year group limb also increased the quadriceps muscle activation level to produce more knee extension moment to compensate for the short quadriceps moment arm. The passe 3year group limb might have an unstable knee joint in the medio-Iateral direction during the climbing/descending by showing a tendency of more ADD displacement and greater hamming co-activation EMG than the passed 1year group limbs. The TKA design was not able to help the knee joint to produce adequate knee extension moment with less quadriceps muscle effort. I think that old man needs continuous exercise for muscle strength.

• Safety and Health at Work
• /
• 제10권3호
• /
• pp.370-376
• /
• 2019

Background: Respirator fit testing is a method to assess if the respirator provides an adequate face seal for the worker. Methods: Workers from four Norwegian smelters were invited to participate in the study, and 701 respirator fit tests were performed on 127 workers. Fourteen respirator models were included: one FFABE1P3 and 11 FFP3 respirator models produced in one size and two silicone half masks with P3 filters available in three sizes. The workers performed a quantitative fit test according to Health and Safety Executive 282/28 with 5-6 different respirator models, and they rated the respirators based on comfort. Predictors of overall fit factors were explored. Results: The pass rate for all fit tests was 62%, 56% for women, and 63% for men. The silicone respirators had the highest percentage of passed tests (92-100%). The pass rate for the FFP3 models varied from 19-89%, whereas the FFABE1P3 respirator had a pass rate of 36%. Five workers did not pass with any respirators, and 14 passed with all the respirators tested. Only 63% passed the test with the respirator they normally used. The mean comfort score on the scale from 1 to 5 was 3.2. The respirator model was the strongest predictor of the overall fit factor. The other predictors (age, sex, and comfort score) did not improve the fit of the model. Conclusion: There were large differences in how well the different respirator models fitted the Norwegian smelter workers. The results can be useful when choosing which respirators to include in respirator fit testing programs in similar populations.

• Environmental Analysis Health and Toxicology
• /
• 제16권4호
• /
• pp.205-209
• /
• 2001

Lemna gibba was newly cultured and provided for toxicity tests. In this study, the chromate toxicity tests for Lemna gibba were performed according to the OECD Lemna growth inhibition test guideline. The test species was Lemna gibba, and the tests were repeated 5 times. To evaluate the toxicity test results, the average specific growth rate, EC50, 95％ confidential limit, and variances were calculated. The test performance was analyzed by the doubling time and test statistics. The average values of EC50 data determined by logistic and linear interpolation curves were 25.9 ppm and 35.4 ppm respectively (by chromate concentration). The doubling time of all controls were below 2.5 day, so all tests passed the criteria for the test performance. This study introduced a new test method, Lemna growth inhibition test, which is provided for the hazard assessment of aquatic environment.

• Transactions on Electrical and Electronic Materials
• /
• 제10권5호
• /
• pp.161-164
• /
• 2009

Forest fire simulation tests were performed with polymer and porcelain insulators at GOCHANG Power Testing Center. These tests consisted of open flames causing a temperature rise of up to $600{\sim}800^{\circ}C$ measured at the insulator surfaces. Mechanical and electrical characteristics such as the specific mechanical load, the low frequency dry flashover voltage and the impulse flashover voltage were analyzed for the polymer insulators before, during and after the simulation tests and then compared to the porcelain insulators. At the end of the fire simulation tests, there was no detrimental deterioration of any of the insulators. All the insulators passed the KEPCO specification criteria. This study showed that the forest fire simulation had no impact on the polymer insulators.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2008년도 제39회 하계학술대회
• /
• pp.460-461
• /
• 2008

The forest fire simulation tests were performed with polymer and porcelain insulators at Gochang testing center. These tests consisted of energizing 90 kV at line-to-ground voltage of 154 kV lines and open flame rising up to $600-630^{\circ}C$ as being measured at insulator surface. Mechanical and electrical characteristics such as specific mechanical load, leakage current, low frequency dry flashover voltage and impulse flashover voltage were analyzed for the polymer insulators before, during and after simulation tests compared with porcelain insulators. At the end of fire simulation tests, there was no detrimental deterioration of any insulators. All insulators passed the criteria of KEPCO specification. This study showed that forest fire simulation had no impact on polymer insulators.

• 한국철도학회논문집
• /
• 제12권2호
• /
• pp.219-229
• /
• 2009

철도안전법에 의해서 2006년 7월 1일부터 차량운전 및 신호기 등 취급자에 대해서 시행중인 적성검사의 구성체계, 신뢰도 및 적합성을 검증해 보고 향후 적성검사의 방향을 모색하는데 목적이 있다.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2005년도 봄학술 발표회 논문집(II)
• /
• pp.69-72
• /
• 2005

In this study, it is contents to application on AE water reducing admixture for high early strength, which reduce to construction period for cost down in construction. In experiment result on the kinds of AE water reducing admixture for concrete strength promotion, when passed 60 minutes, while it was happened on lignin and naphthalene system about $30\∼35\%$ that loss related to slump, slump flow and air, but happened about $8\∼10\%$ on polycarboxylic system. And the result of compressive strength tests, when 32 hours passed in polycarboxylic system than lignin and naphthalene system, was showing an increase of 10$\%$. Accordingly, concrete properties was measured to condition change by the addition amount and curing temperature of polycarboxylic system. The required curing temperature to gain 5MPa of compressive strength, which is capable of side form stripping, must keep more than smallest 12. 5$^{circ}C$ when polycarboxylic system is used. As a result, AE water reducing admixture of polycarboxylic system may apply effectively to high early strength concrete

• 한국건설순환자원학회논문집
• /
• 제8권4호
• /
• pp.520-527
• /
• 2020

황토는 국내 토양의 약 15.0%를 차지하는 풍부한 자원이며, 고온소성 후 급랭하여 활성화시키면 포졸란 특성을 갖는 콘크리트 결합재로서 사용할 수 있다. 본 연구에서는 시중에서 판매되는 경계석 배합을 기반으로 하여 활성 황토 혼입 모르타르 경계석 시편을 제작하였다. 활성 황토의 혼입율은 10.0% 및 25.0%를 고려하였으며, 시험 항목으로는 압축 및 휨 강도 시험, 동결융해 저항 성능 평가, 촉진 탄산화 시험, 촉진 염화물 확산 시험을 설정하였다. 역학적 성능 평가 결과 OPC 배합에서 가장 높은 강도가 평가되었으며, 재령일의 증가에 따른 강도 증가가 적게 나타났는데 이는 3일간 증기 양생을 통해 대부분의 강도가 발현되었기 때문으로 사료된다. 재령 28일에 해당하는 시편을 대상으로 동결융해 저항성능 평가 결과, 모든 배합에서 85.0% 이상의 강도 저하율을 나타내어 제시된 기준에 만족하였다. 촉진 탄산화 시험은 재령 28일 시편을 대상으로 수행되었으며 활성 황토 혼입 배합에서 OPC 배합 대비 다소 저하된 탄산화 저항성능을 나타내었다. 재령 28일 및 91일에 ASTM C 1202에 준하여 각 배합의 통과 전하량을 평가하였다. OPC 배합의 경우 "Low" 등급을, 활성 황토 혼입 배합의 경우 "Moderate" 등급을 나타내어 활성 황토 혼입 배합에서도 적절한 염해 저항성능을 나타내는 것으로 보인다.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 1999년도 학회창립 10주년 기념 1999년도 가을 학술발표회 논문집
• /
• pp.341-344
• /
• 1999

In the case of the offshore concrete structures like the anchorage block of a suspension bridge of Kwangan Grand Road, there is a need of the concrete which has low heat of hydration and good resistance for sea-water attack. In this study, the blended super low heat cement which satisfies that requirement was developed and several tests were carried out. The concrete using the blended super low heat cement showed lower adiabatic temperature rise than 3$0^{\circ}C$ and good early strength. Also, its passed charge(coulomb) to resist chloride ion penetration was very low.