• Journal of the Korean Society of Safety
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• v.27 no.3
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• pp.9-14
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• 2012

The objectives of this study were to compare the results of HSL (Health and Safety Laboratory) ramp test with perceived sense of slip onto the several different floor surfaces under contaminated conditions. There are a variety of approaches from biomechanical measurements to psychophysical test and human perception. However, controversies over these approaches still remain. Some widely accepted methods need to be improved. AHP (Analytic Hierarchy Process) was used to evaluate the perception of slipperiness of seven different floor surfaces under the contaminated condition with glycerol solution. Twelve subjects worn same footwear and walked with self-selected step and cadence along the test floors. The angle of inclination obtained for water wet condition using 5 l/min with HSL ramp test was compared to perception of slipperiness. The surface roughness ($R_z$) related very well both AHP (r=0.95) and ramp test (r=0.92). The high significant correlation (r=0.90) was found between AHP and HSL ramp test.The HSL ramp test values (Coefficient of Friction, COF) according to subjective evaluation were divided into two categories. There were high correlations between test results (subjective evaluation, HSL ramp test) and surface roughness in Rz. Perception rating obtained with AHP showed a high correlation with COF obtained with HSL ramp test.

• Proceedings of the ESK Conference
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• 1996.10a
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• pp.33-40
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• 1996

본 연구의 목적은 작업생리학적 접근방법(physiological approach)을 이용하여 생리학적 작업 능력(PWC; physiological work capacity)을 추정할 경우 작업형태와 작업방법에 따른 차이점을 비교분석해 보고자 함이다. 작업유형으로는 자전거 에르고미터(cycle ergometer)와 트레드밀 (treadmill)을 사용하였고, 작업방법으로는 각각의 작업유형에 대하여 램프 테스트(ramp test 와 인크리멘탈 테스트(increemntal test)의 차이점을 비교하였다. 또한 외국인들의 생리학적 작업능력(PWC)과 한국인들의 생리학적 작업능력(PWC)을 비교,검토하여 NIOSH(National Institute of Safety and Healty)기준치를 사용하는데 문제점이 없는가를 검토해 보고자 하였다. 작업방법 에 따른 차이점은 자전거 에르고미터의 경우 램프 테스트(ramp test )253.63 ml/min로서 인크리 멘탈 테스트(increemental test) 2859.74ml/min 의 87.70 % 정도로 나타났으며, 트레드 밑의 경우 ramp test 2859.22ml/min로서 incremental test 289.46ml/min의 98.77%정도로 나타났다. 작업유형 에 따른 결과는 자전거 에르고미터의 ramp test 트레드밀의 ramp test 는 ramp test는 트레드밀의 ramp test의 88.72% 정도로 나타났으며, 자전거 에르고미터의 incremental tests는 트레이드밀 작 업의 98.% 정도로 나타났다.

• Journal of the Ergonomics Society of Korea
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• v.15 no.2
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• pp.89-98
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• 1996

The objective of this study was to make comparison of the physical work capacities with different types and methods of tasks. To produce standard work loads, a bicycle ergometer and a treadmill were used for the purpose of two different types of tasks. Maximal oxygen uptake measurement tests are usually performen (1) continuously - with no rest between work load increments, or (2) discontinuously - with the subjects resting several minutes between work periods. Continuous test protocol with two different methods of work load increments, (1) ramp test- with 3 to 5 minutes of work period for each work load, and (2) incremental test - where exercise intensity was increased progressively in 2 minutes interval, were used. Predicted physicala work capacities (PWCs) were compared with the one by Kim(1990), and Lee(1995), and the NIOSH physiological criteria. For ergometer test, the PWC based on the ramp test was 89.65% of the one based on the incremental test. The PWC values were 2553.88 ml/min for the ramp test and 2848.82 ml/min for the incremental test. For treadmill test, the PWC based on the ramp test was 97.54% of the one based on the incremental test. The PWC values were 2786.89 ml/min for the ramp test and 2857.24 ml/min for the incremental test. The PWC obtained with a bicycle ergometer was 91.64% of the one obtained with a treadmill for the ramp test, and 99.71% for the incremental test.

• Nuclear Engineering and Technology
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• v.41 no.2
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• pp.187-198
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• 2009

In this paper, three power ramp tests performed on high burn-up Re-crystallized Zircaloy2 - UO2 BWR fuel rods (56 to 63 MWd/kgU) within the SCIP project are simulated with METEOR and ALCYONE 3D. Two of the ramp tests are of staircase type up to Linear Heat Rates of 420 and 520 W/cm and with long holding periods. Failure of the 420 W/cm fuel rod was observed after 40 minutes. The third ramp test consisted of a more standard ramp test with a constant power rate of 80 W/cm/min up to 410 W/cm with a short holding time. The tests were first simulated with the METEOR 1D fuel rod code, which gave accurate results in terms of profilometry and fission gas releases. The behaviour of a fuel pellet fragment and of the cladding piece on top of it was then investigated with ALCYONE 3D. The size and the main characteristics of the ridges after base irradiation and power ramp testing were recovered. Finally, the failure criteria validated for PWR conditions and fuel rods with low-to-medium burn-ups were used to analyze the failure probability of the KKL rodlets during ramp testing.

• Clean Technology
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• v.21 no.3
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• pp.184-190
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• 2015

Most of LNT catalysts use noble metals such as Pt for low temperature NO_x oxidation but there is an economic weakness. For the purpose of overcoming this, this study is to develop DeNO_x catalyst for LNT excluding PGM (platinum group metal) such as Pt, Pd, Rh, etc. To do so, Al/Co/Ni catalyst selected as a preliminary test is used to study fundamental property and NO_x’s conversion according to calcined temperature. Ultimately, that is, Al/Co/Ni mixed metal oxide which does not use PGM is selected and physicochemical characterization is performed by way of XRD, EDS, SEM, BET and ramp test and NO_x conversion is also analyzed. This study shows that all samples consist of mixed oxides of spinel structure of Co₂AlO₄ and NiAl₂O₄ and have enough pore volume and size for redox. But as a result of NH₃-TPD test, it is desired that calcined temperature needs to be maintained at 700 ℃ or lower. Also only samples which are processed under 500 ℃ satisfied NO and NO_x conversion simultaneously through ramp test. Based on this study’s results, optimum calcined temperature for Al/Co/Ni=1.0/2.5/0.3 mixed metal oxide catalyst is 500 ℃.

• Nuclear Engineering and Technology
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• v.38 no.5
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• pp.417-422
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• 2006

The present paper describes the 45 MW High Flux Reactor (HFR) which is located in Petten, The Netherlands. This paper focuses on selected technical aspects of this reactor and on nuclear fuel irradiation experiments. These fuel experiments are mainly experiments on Light Water Reactor (LWR) and Very/High Temperature Reactor (V/HTR) fuels, but also on Fast Reactor (FR) fuels, transmutation fuels and Material Test Reactor (MTR) fuels.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.16 no.2
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• pp.145-151
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• 2006

Because of the limitations of maximal load tests for $VO_2max$, submaximal tests using cycle ergometer are used for field study in general. This study was conducted to evaluate validity of various submaximal tests using cycle ergometer. This study had been conducted during May to June 2005, which subjects were 15 males and 15 females in twenties. Experiment was performed with restrictive conditions which regulated ambient temperature, noise, and entrance restriction. Submaximal load test protocols including YMCA Protocol (YP), ${\AA}strand$-Rhyming Protocol (ARP), Relative heart ratio Protocol (RP), and Ramp test Protocol (RP) were compared with maximal load test which used gas mask analyser using Bruce Protocol. All submaximal load tests were highly related with maximal load test (Spearman's correlation coefficient > 0.60) with statistical significancy. The highest correlation coefficient with maximal test was found in RP. Three submaximal test results except RP were significantly different with maximal test results (Wilcoxon rank test). All submaximal tests had high validity. The reason why RP had highest validity might be that it represents Korean physical strength and individual differences better than the others. RP using cycle ergometer would make easy to study for physical capacity evaluation and field workload estimation.

• Journal of the Ergonomics Society of Korea
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• v.18 no.2
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• pp.71-79
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• 1999

An experiment was conducted to study the PWC(Physical work capacity) of Korean females. A submaximal technique using the Ramp test protocol was used to measure the PWC. A cycle ergometer and a treadmill were used to assess the workload. The estimated PWCs of Korean females in terms of maximum oxygen consumption(${\dot{V}}o_2Max$) from the experiment were 1818.79ml/min in cycle ergometer test and 2076.33ml/min in treadmill test, respectively. The PWCs of Korean females were compared with those of western and oriental females. The PWCs of Korean females were about 2/3 of Korean males, 72%-82% of western females, and about 118% of South-east Asian females after applying age correction factor.

• The Korean Journal of Applied Statistics
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• v.12 no.2
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• pp.463-478
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• 1999

가속수명시험은 제품의 사용조건 보다 높은 스트레스 수준에서 시험하여 제품의 신뢰수명을 추정하는 것으로써 스트레스 수준을 일정하게 유지하는 일정형 시험이 일반적이다. 그러나 경우에 따라서는 시험절차의 편리와 시험기간의 단축을 위해서 스트레스를 시간에 따라 선형적으로 증가시키는 램프(ramp)형 시험을 사용하기도 한다. 이 논문에서는 일정스트레 s에서 제품의 수명이 모수 $\Theta$(s), $\beta$인 와이블분포를 따르고 수명과 스트레스의 관계가 역거듭제곱모형인 경우에 스트레스를 사용조건에서 가하고, 스트레스 수준의 최대 한계가 주어져 있는 램프시험 하에서 시험제품이 갖는 수명분포를 유도하고, 정시관측중단시험의 경우에 대해서 수명분포의 최우추정량과 추정량의 점근분포를 구하며, 최우추정치를 구하는 알고리즘을 제안한다.

• Journal of the Korean Society of Safety
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• v.5 no.3
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• pp.51-55
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• 1990

This study describes the engineering approach adopted to investigate sprinkler head during the early stage of a fire when they are subjected to convective heating and low gas velocities. Comparions are made between the parameters derived using basic methods, ie. ramp test, for evaluating sprinkler parameters(time constant, response time index) is illustrated. Evidence is presented that the propotion of heat loss by conduction from a sprinkler element may very typically employed in the rate of rise test. This fact alone may justfy the precautionary need to perform a limited number of rate of rise tests to confirm a sprinklers capacity to function correctly in reasonably unfavourable yet realistic conditions. The work is aimed primarily at meeting the needs of sprinkler industry.