• International Journal of Advanced Culture Technology
• /
• v.3 no.2
• /
• pp.34-41
• /
• 2015

Bonding strength of a thermal sprayed coating is difficult to measure using a conventional pull-off test method. Scratch test is a potential alternative testing method. An adhesive and a cohesive bond strength of the coating can be measured by the pull-off test while the scratch test performed on the cross-section of the thermal sprayed coating can only demonstrate the cohesive bond strength of the coating. Nevertheless, it is still beneficial to perform the scratch testing on the cross-section of the coating for the sake of comparison thus providing an alternative to the pull-off test. The scratch test method can reduce testing time and cost in the long run due to a significant cost reduction in consumables and energy and time saving from the curing step of the glue used in the pull-off test. This research investigates the possibility of using the scratch test to measure the cohesive bond strength of Mo/NiCrBSi composite coating. The results from the pull-off test and the scratch test indicate that the cohesive bond strengths of the Mo composite coating show similar trend and that the cohesive bond strength are increased when increasing NiCrBSi content.

• Korean Journal of Applied Biomechanics
• /
• v.17 no.2
• /
• pp.61-73
• /
• 2007

The purpose of this study was to investigate the influence of the muscular endurance on the kinematic factors during a prolonged run. Subjects, 12 males, who were divided into three groups(lower group, general group, and in higher group) after measuring the lower limb's muscular endurance previously. They were asked toe run on the treadmill at 7.4km/h of speed. To analyze the kinematics parameters of the trunk during running, the ProReflex MCU Camera(Qualisys, Sweden) were used. All parameters were sampled from 5 minute, 40 minute, and 60 minute moments during running. An ANOVA with Repeated Measure was used to test the statistic significance between and within groups for all parameters determined with SPSS 11.0. Significance was defined as p<.05. The conclusions were as follows; There was significantly difference within(lapse of running time) groups in the take-off and minimum knee angle event of swing phase of the trunk flexion and extension. In conclusion, the muscular endurance affected on movement of the trunk during a prolonged run. In addition, it showed that there was significant difference in the energy consumption by lapse of running time. Therefore, it seems to be relationships between the muscular endurance and running efficiency.

• 한국신재생에너지학회:학술대회논문집
• /
• 2011.11a
• /
• pp.152.1-152.1
• /
• 2011

This study analyzes transitions to a green path in transportation system in South Korea. We develop transportation system model with four new technology options, green cars; Hybrid electric vehicle, plug-in hybrid vehicle, electric vehicle and fuel cell vehicle. Among those technologies fuel cell vehicle is the best option assuming no GHG emissions when driving. We use MESSAGE model to get an optimal solution of pathway for high deployment of fuel cell vehicles under the Korea BAU transportation model. Among hydrogen production sources, off gas hydrogen is most economic since it is hardly used to other chemical sources or emits in South Korea. According to off gas hydrogen projection it can run 1.8 million fuel cell vehicles in 2040 which corresponds to 10% of all passenger cars expected in Korea in 2040. However, there are concerns associated with technology maturity, cost uncertainty which has contradictions. But clean pathway with off gas and renewable sources may provide a strong driving force for energy transition in transportation in South Korea.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2001.04a
• /
• pp.229-233
• /
• 2001

In this paper, we propose a remote controller for robot manipulator using local area network(LAN) and internet. To do this, we develope a server-client system as used in the network field. The client system is in any computer in remote place for the user to log-in the server and manage the remote factory. the server system is a computer which controls the manipulator and waits for a access from client. The server system consists of several control algorithms which is needed to drive the manipulator and networking system to transfer images that shows states of the work place, and to receive a Tmp data to run the manipulator. The client system consists of 3D(dimension) graphic user interface for teaching and off-line task like simulation, external hardware interface which makes it easier for the user to teach. Using this server-client system, the user who is on remote place can edit the work schedule of manipulator, then run the machine after it is transferred and monitor the results of the task.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.20 no.5
• /
• pp.457-462
• /
• 1987

Stochastic stability criterias for ocean wave analysis add simulation are studied using the data simulated by the linear superposition method. To clarify the criterias, the effects of the simulation parameters on the variance of stochastic properties of ocean waves are investigated, and the stable conditions of the parameters are estimated through the comparative study on the stochastic properties of simulated waves and well-known ocean waves. The simulation parameters considered are high frequency cut-off, data length, and number and phase angle of component waves. Statistical characteristics analysed are wave height, period and steepness, and the formation of groups of higher waves, resonance periods, steeper higher waves and extreme run-length of the run.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.20 no.3
• /
• pp.123-146
• /
• 1995

Several quality control schemes have been extensively compared using multivariate normal data sets simulated with various correlation structures. They include multiple univariate CUSUM charts, multivariate EWMA charts, multivariate CUSUM charts and Shewhart T$^{3}$ chart. This paper considers a new approach of the multivariate EWMA chart, in which the smoothing matrix has full elements instead of only diagonal elements. Performance of the schemes is measured by avaerage run length (ARL), coefficient of variation of run length (CVRL) and rank in order of signaling of off-target shifts in the process mean vector. The schemes are also compared by noncentrality parameter. The multiple univariate CUSUM charts are generally affected by the correlation structure. The multivariate EWMA charts provide better ARL performance. Especially, the new EWMA chart shows remarkable results in small shifts.

• Journal of Powder Materials
• /
• v.29 no.2
• /
• pp.123-131
• /
• 2022

The purpose of this study is to improve the mechanical properties and develop manufacturing technology through self-soluble alloy powder flame spray coating on the surface of a run-out table roller for hot rolling. The roller surface of the run-out table should maintain high hardness at high temperatures and possess high wear, corrosion, and heat resistances. In addition, sufficient bonding strength between the thermal spray coating layer and base material, which would prevent the peel-off of the coating layer, is also an important factor. In this study, the most suitable powder and process for roll manufacturing technology are determined through the initial selection of commercial alloy powder for roll manufacturing, hardness, component analysis, and bond strength analysis of the powder and thermal spray coating layer according to the powder.

• Journal of Korean Society of Forest Science
• /
• v.54 no.1
• /
• pp.60-67
• /
• 1981

The run-off experiment plots had been established for eight sets of plot comprising four treatments with two replications on $20^{\circ}$ slope land having the Wait-A-Bit Clay soil(locally known), at the Olive River Soil Conservation Centre, Trelawny in Jamaica. The location of plots was about 820 metres m.s.l. and sloped north-west. Each plot size was determined as $40m^2$ having 2.7 m wide and 15.8 m long along slope. All of the run-off soil and water were collected by using the receiving tanks through the collection troughs and conveyance pipes. These run-off materials were measured and sampled, dried and computed for determination of the soil loss from each treatment of plots. During the first period of experiment for about 10 month which was one crop-year cycle of yam crop, total amount of 1,295 mm rainfall received. The heaviest daily rainfall was recorded as 116.2 mm on August 5 followed by 100.4 mm on August 6, 1980. The soil sediment had been collected and analysed for eleven times during this experiment. Total amounts of soil sediment as over-dried weight by the treatment plot were estimated as 182 ton/ha from treatment I, 105 tons/ha from treatment II, 50 tons/ha from treatment III, 43 tons/ha from treatment IV respectively. It is recommendable at present that the treatment III and IV measure which treated with contour mounds with the hillside ditch and grass buffer strip should be adopt4ed for hillside farming particularly with yam cultivation in Jamaica.

• The Korean Journal of Pesticide Science
• /
• v.12 no.1
• /
• pp.24-33
• /
• 2008

In this study, the mobility of seven pesticides from soil in different slopes was investigated by simulated rainfall under field conditions. Simulated rainfall subjected to $22\;mm\;hr^{-1}$ was treated using rainfall simulator after 12 hr of pesticide treatment. Amounts of the pesticides were measured in run-off water samples. The soil samples collected before and after rainfall from upper, middle and lower parts and three different depths of sloped-plot were also analyzed. At result, the order of the amount of pesticide residues was $0{\sim}15$ > $15{\sim}30$ > $30{\sim}45\;cm$ of soil depth and no pattern was shown in upper, middle and lower, and different slopes in soil samples. all pesticides from the run-off water samples collected from soils were detected maximum 96% within 60 minutes after first collection except carbendazim and cypermethrin which have the lowest water solubilities. These results revealed that mobility of pesticides can be dependant mainly on soil textures and physicochemical properties of pesticides. Therefore, it can be suggested that selection of pesticides should be considered for properties of pesticide in the alpine and sloped-land.

• Korean Journal of Soil Science and Fertilizer
• /
• v.29 no.4
• /
• pp.336-341
• /
• 1996

This study was conducted to investigate the effects of compost application on the soil loss and physico-chemical properties at the slope land from 1990 to 1991. Lysimeters with 15% slope. 5m slope length. 2m width and 1.2m depth were constructed in 1984 and filled with sandy loam, loam, clay loam. and clay soils. Treatments were bare soil, compost(1.5ton/10a) and non-compost with soybean-barley cropping system from 1984. Losses of soil were increased with the order of sandy loam, clay, loam and clay loam. Run-off was increased with the order of sandy loam, loam, clay loam and clay, but leachate was decreased with the same order. Compost treatments decreased 33.6-44.6% of soil loss and 17.0-24.0% of run-off but increased 17.1-33.7.% of leachate as compared with the non-compost treatments. The amount of soil loss was positively correlated with the amount of run-off by Y = 12.125+0.063X (r=$0.970^{**}$)and negatively correlated with the leachate by Y=43.425-0.096X(r=$-0.917^{**}$). The application of compost increased soil pH, OM, CEC and extractable cations. Application of compost decreased bulk density but increased porosity, water stable aggregate and available water. These results provide that the compost application plays an important role in conserving soil and water, and improving soil physico-chemical properties.