• Computers and Concrete
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• v.32 no.5
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• pp.499-511
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• 2023

Anchor channels are commonly used for façade, tunnel, and structural connections. These connections encounter various types of loadings during their service life, including high rate or impact loading. For anchor channels that are placed close and parallel to an edge and loaded in shear perpendicular to and towards the edge, the failure is often governed by concrete edge breakout. This study investigates the transverse shear behavior of the anchor channels under quasi-static and high rate loadings using a numerical approach (3D finite element analysis) utilizing a rate-sensitive microplane model for concrete as constitutive law. Following the validation of the numerical model against a test performed under quasi-static loading, the rate-sensitive static, and rate-sensitive dynamic analyses are performed for various displacement loading rates varying from moderately high to impact. The increment in resistance due to the high loading rate is evaluated using the dynamic increase factor (DIF). Furthermore, it is shown that the failure mode of the anchor channel changes from global concrete edge failure to local concrete crushing due to the activation of structural inertia at high displacement loading rates. The research outcomes could be valuable for application in various types of connection systems where a high rate of loading is expected.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.3
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• pp.444-454
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• 2016

This study was designed to examine the characteristics of sawdust and cocopeat bedding materials, including physicochemical properties (Exp. I) and on-farm trial (Exp. II). In Exp. I, the proportion of particle size was in the order of sawdust>cocopeat India>cocopeat Vietnam (p<0.05), and cocopeat contained higher proportion of small particles ($250{\mu}m$+below $250{\mu}m$) than sawdust, causing a dust production problem. Bulk density was cocopeat India>cocopeat Vietnam>sawdust (p<0.05), thus cocopeat treatments showed 4.4 times higher bedding cost than sawdust. The water absorption rates were 702.0% in cocopeat India, 678.3% in cocopeat Vietnam, and 444.0% in sawdust, showing cocopeat had approximately 1.5 times higher water absorption rate than sawdust. Moisture evaporation rates after 12 h of air blowing (2.00 m/s) were higher (p<0.05) in cocopeat Vietnam (80.4%) than sawdust (71.2%) and cocopeat India (72.8%). In vitro ammonia emissions were higher (p<0.05) in sawdust ($2.71mg/m^2/h$) than cocopeat India ($1.59mg/m^2/h$) and Vietnam ($1.22mg/m^2/h$), and total ammonia emissions were higher (p<0.05) in sawdust ($37.02mg/m^2$) than cocopeat India ($22.51mg/m^2$) and Vietnam ($13.60mg/m^2$). In Exp. II, an on-farm trial was conducted with 48 Hanwoo cattle in 16 pens using the same bedding materials as in Exp. I, with fan (blowing 2.00 m/s) and no fan treatments, and feed bunk side (FB) and water supply side (WS) within a pen (4.5 m, $width{\times}9.0m$, length). Beddings were replaced with fresh bedding materials when moisture concentrations were over 65%. No interactions among treatments were detected for moisture concentration and increment rates, and ammonia concentrations, but a significant effect was observed (p<0.01) for each of the treatments. Both concentrations and increment rate of moisture were higher (p<0.01) in the beddings without fan than with fan. Moisture concentrations and increment rate within a pen were also higher (p<0.01) in FB than WS. Thus, the whole no-fan-FB and sawdust-fan-FB were replaced with fresh bedding material between 4 to 5 experimental weeks. The ammonia concentrations and pH of beddings were not significantly different among treatments. Therefore, using cocopeat bedding with a blowing fan can extend twice the bedding utilization period, and WS within a pen showed twice the bedding-life compared to FB. Despite the outstanding characteristics of cocopeat compared with sawdust, using cocopeat as an alternative for sawdust bedding is not recommended for cattle management, considering it has 4.4 times higher bedding cost and a dust production problem.

• Journal of the Korean Society of Propulsion Engineers
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• v.10 no.3
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• pp.60-66
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• 2006

Notable are the burning rate characteristics of solid propellant burning at extremely high pressure(10000-20000 psia). The burning rate test using closed bomb shows the discontinuous increment around 4000 psia so that the exponent of burning rate(n) is almost double, from 0.4 to 0.8. The pressure-increasing rate of the test motor is about 300 times as high as that of the motor operating at the conventional pressure, less than 2000 psia, is, therefor the burning rate is augmented about 5-50 times. The performance prediction reflecting the pressure-change-rate effect are fairly comparable with the test data at various test conditions.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.9
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• pp.2086-2097
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• 2012

A terminal-based dynamic clustering algorithm is proposed in a multi-cell scenario, where the user could select the cooperative BSs from the predetermined static base stations (BSs) set based on dynamic channel condition. First, the user transmission rate is derived based on linear precoding and per-cell feedback scheme. Then, the dynamic clustering algorithm can be implemented based on two criteria: (a) the transmission rate should meet the user requirement for quality of service (QoS); (b) the rate increment exceeds the predetermined constant threshold. By adopting random vector quantization (RVQ), the optimized number of cooperative BSs and the corresponding channel conditions are presented respectively. Numerical results are given and show that the performance of the proposed method can improve the system resources utilization effectively.

• Applied Biological Chemistry
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• v.29 no.1
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• pp.29-35
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• 1986

Viscosity development pattern, in aqueous sodium hydroxide, of rice starches isolated from various hydration groups of milled rice was investigated. The maximum viscosity and viscosity development rate of Japonica rice starches at a given alkali concentration were loswer than those of J/Indica counterparts. The difference in the viscosity development rate of starches by increment of 0.1N (0.02 meq/g) was greater in J/Indica rice starches in comparison with Japonica ones. Viscosity of rice starch was not correlated to that of rice flour and to hydration rate of milled rice.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.2 no.3
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• pp.62-68
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• 2003

In this study, an experimental work was performed to mold tensile specimens by using the injection molding machine. Melt temperature, mold temperature and the mixed rate of recycled resin were selected as processing parameters for studing the effect of those condition on the shrinkage and weight of molded parts. As a result, the shrinkage was increased with the higher mold and melt temperature and It was more senstive to the change of mold temperature. On the other hand, the weight of molded parts was decreased with the increment of mold and melt temperature.

• Proceedings of the Safety Management and Science Conference
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• 2001.11a
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• pp.37-42
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• 2001

Utilization rate for the restrictive gate and required time and walking distance to board are to be a measure for the gate management and passenger's convenience estimation. So, the main purpose of the gate management are maximization of utilization rate and increment of airport terminal user's convenience through the efficient gate management. This study intends to maximize the utilization rate on usable gates by concerning about layout, terminal configuration, local passenger of the airport and development of gate assignment algorithm and DSS which maximize the gate utilization and minimize the passenger's walking distance.

• Journal of the Korea Safety Management & Science
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• v.4 no.4
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• pp.129-136
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• 2002

Utilization rate for the restrictive gate and required time and walking distance to board are to be a measure for the gate management and passenger's convenience estimation. So, the main purpose of the gate management are maximization of utilization rate and increment of airport terminal user's convenience through the efficient gate management. This study intends to maximize the utilization rate on usable gates and minimize the passenger's working distance in terminal by concerning about layout, terminal configuration, local passenger of the airport and formulate the gate assignment problem with integer linear programming problem. Then we obtained solution using optimization software LINGO and analyzed that maximize the number of assignment flights and minimize the passenger's walking distance.

• Journal of Korean society of Dental Hygiene
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• v.2 no.1
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• pp.1-19
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• 2002

This study has been conducted with continuous dental sanitary education for primary school pupils for five years from 1997 through 2001, based on data obtained from a 97' survey on primary school pupils' recognition on dental hygiene education and their permanent dental health capacity. Following results were drawn through comparative analysis of data obtained during the survey period. Approx 70.77% of the examinees have experienced decay missing feeling (DMF) in the year 2001, suggesting a good effectiveness of dental hygiene education compared with 92.1 % of DMF rate in 1997. It has been found that pupils' knowledge and recognition on dental hygiene and management, etc were improved, as well as their eating habits and consciousness were changed. Comparative analysis of annual DMF showed that DMF rate, DMFT index, and DT rate were found to decrease every year, suggesting a improved dental health capacity. Grade level analysis revealed that DMFT index and DT rate were found to decrease every year during the survey period, suggesting pupils' dental management and consciousness were improved and changed. It has been found that DMF rate more significantly increased in a higher grade in 2001 than 1997. There was no difference in DMF rate between grades of primary school in 1997. However, in the year 2001 increment of approx 10% of DMF rate were observed in a higher grade.

• Tribology and Lubricants
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• v.21 no.4
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• pp.159-164
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• 2005

An experimental study was conducted to evaluate characteristic variation of diluted engine oils in which contains diesel fuels and its tribological effects on engine components. In this study, diluted engine oils with $10\%,\;15\%,\;and\;20\%$ of initial fuel content rate have been used for measuring the viscosity reduction rate, blow-by gas increment rate, main gallery pressure reduction rate, and fuel content rate in engine oils. These parameters are strongly related to the tribological characteristics of key engine components. The kinematic viscosity of engine oils in which is contained by diesel fuels from $10\%\;to\;20\%$ in oils is decreasing to approximately $54\%$ of initial diluted fuel-oil volume ratios. The experimental results show that the distillated engine oil decrease the viscosity of engine oil and its oil film stiffness, and increase the wear rate of rubbing parts of engine components. Thus we recommend that the containing volume rate of fuels in engine oils should be restricted to $3\~4\%$ for a sophisticated Diesel engine and $5\~7\%$ for a standard one.