• Asian-Australasian Journal of Animal Sciences
• /
• v.16 no.3
• /
• pp.380-383
• /
• 2003

The gas dilution technique was used to evaluate the possibility of estimating the volume of gaseous phase in the rumen from its composition in sheep given rice whole crop silage (RWS) or dent corn silage (DCS) at a level of maintenance (M) or 2 M, and in the course of fasting. The rumen gas composition was determined at 2 and 7.5 h after morning feeding. Nitrogen gas was injected by using an airtight syringe into the rumen immediately after collecting the rumen gas sample as a control. Then rumen gas samples were collected at 5, 10, 20, 40 and 60 min. after injection. Dry-matter intakes were $42g/kg^{0.75}$ and $57g/kg^{0.75}$ for DCS, and $36g/kg^{0.75}$ and $59g/kg^{0.75}$ for RWS, at 1 M and 2 M levels, respectively. Animals ingested both silages about 20% less than expected at 2 M level. The rumen gas composition did not differ significantly between 2 h and 7.5 h after feeding except for $N_2$. Content of $CO_2$ in gas composition was significantly higher at 2 M level than at 1 M (p<0.05) for both RWS and DCS, whereas $CH_4$ showed no significant difference between feeding levels. At both feeding levels, $CO_2$ showed a higher (p<0.05) percentage in DCS than RWS. A dilution technique by using $N_2$ injection is not appropriate for the determination of gas production in vivo, unless the rate of rumen gas turnover is considered. Changes in composition at fasting indicate that the rumen fermentation may reach the lowest level after 72 h fasting for sheep given silage as their sole diet.

• Korean Journal of Cognitive Science
• /
• v.24 no.4
• /
• pp.323-338
• /
• 2013

There are multiple process mechanism in causal reasoning, which is estimation of the causal strength between cause and result. Further, because these mechanisms operate on different time phase during causal reasoning, it is highly possible that different individual difference factors are related to individual mechanisms of causal reasoning. Especially, the phenomena of conditionalization and discounting reflect attention to multiple potential causes when people infer the relationship between cause and effect. In this study, we manipulated self-construal which is an individual difference factor that reflects context sensitivity in cognition. As results, no difference was observed in conditionalization between individuals with an independent self-construal and those with an interdependent self-construal. However, independent self-construal group was observed to be lower in discounting than the interdependent self-construal group. The results indicate that conditionalization and discounting are independent cognitive process in human causal reasoning.

• Land and Housing Review
• /
• v.8 no.4
• /
• pp.257-266
• /
• 2017

LH has been using ultra high strength reinforcing bars (SD500 and SD600), since 2011. Such a change requires an adjustment of the old extra rates of bar splice to reflect use of ultra high strength reinforcing bars, as these rates had been set based on SD400 bars. It is particularly difficult to calculate precisely rebar lap-splice locations for large areas, such as those in apartment buildings. This research aims to adjust the extra rates of bar splice to reflect a reasonable rate; the rebar lap-splice length is not an exact estimation, but instead, an extra rates of bar splice is set and the rebar lap-splice length is increased by 2% (D 10) - 7% (025) depending on the bar size. The subjects of this study are LH apartments undergoing frame construction. We studied the quantity estimations from the design drawings, and analyzed the settlement quantities of construction field. The results of the study revealed that, when each of the quantities are analyzed, consider adjusting the extra rates of bar splice of some rebar to 1% - 3.5%. This was caused by an overuse of reinforcing bars in onsite construction and the use of supporting bars that have not been reflected in the documents, among other reasons. Based on the results of our study, an improvement plan for the current extra rates of bar splice seems to be necessary, cutting or raising the rate depending on the analysis of the data. Through this study, we expect to contribute to the calculation of reasonable construction costs, improvements in the quality of rebar work, and improvements in the capacity of design techniques for apartment buildings.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.6 no.2
• /
• pp.115-124
• /
• 2001

In this paper, authors propose a new nonlinear rotor flux observer for rotor field oriented control of an induction motor which is designed based on the extended Luenberger Observer theory. Extended Luenberger Observer requires minimal solution of nonlinear partial differential equation on its coordinate transformation and linearization needed on a nonlinear observer design in general. The proposed rotor flux observer is derived from the 2 phase model of induction motor on the orthogonal coordination and it has the reduce gain matrix. Simulation and experimentation were performed under the conventional indirect vector control and direct vector control with the proposed observer at different rotor resistance. Simulation results show that the convergence of the proposed observer is influenced by the chosen eigenvalues. Experimentation results on load operation show the direct vector control with the proposed observer is better than the indirect vector control to maintain the characteristics of the vector control.

• The Transactions of the Korea Information Processing Society
• /
• v.6 no.6
• /
• pp.1468-1480
• /
• 1999

In database systems, join operations are the most complex and time consuming ones which limit performance of such system. Many parallel join algorithms have been proposed for the systems. However, they did not consider data skew, such as attribute value skew (AVS) and join product skew (JPS). In the skewness environments, performance of framework for a uniform load distribution and an efficient parallel join algorithm using the framework to handle AVS and JPS. In our algorithm, we estimate data distributions of input and output relations of join operations using the sampling methodology and evaluate join cost for the estimated data distributions. Finally, using the histogram equalization method we distribute data among nodes to achieve good load balancing among nodes in the local joining phase. For performance comparison, we present simulation model of our algorithm and other join algorithms and present the result of some simulation experiments. The results indicate that our algorithm outperforms other algorithms in the skewed case.

• KSBB Journal
• /
• v.5 no.3
• /
• pp.235-240
• /
• 1990

A quantitative physiological approach has been employed to estimate the metabolic parameters such as specific uptake rates of nutrients and specific production rate in continuous culture of Pseudomonas elodea for gellan gum production. The estimated values of metabolic parameters are used for process improvement. During the exponential growth phase, the specific growth rate was 0.16hr-1 in batch culture. The gellan gum concentration increased up to 0.7g dry weight/100g broth and the apparent viscosity of the culture broth was about 4,500 cp.(72hrs culture). The ratio of specific uptake rate of carbon to that of nitrogen were found to be optimum at about 3.0mg-carbon/mg-nitro-gen. With the improved medium, the maximum gellan production rate, 0.6g dry weight/1/hr, was obtained at D=0.14 hr-1. The shear stresses of culture broth were fairly well correlated with shear rates by using Casson equation and at highly viscous culture broth, oxygen transfer coefficient was greatly reduced.

• Journal of KIISE:Software and Applications
• /
• v.34 no.8
• /
• pp.689-696
• /
• 2007

It is important issue for software architects to estimate performance of software in the early phase of the development process due to the need to verify non-functional requirements and estimation of performance in various stages of architectural design. In order to analyze performance of software, there are many approaches to translate software architecture represented by Unified Modeling Language, into analytical models. However, in the development of agent-based systems, these approaches ignore or simplify the crucial details of the underlying performance of the agent platform. In this paper, we propose performance prediction methodology for agent based system using formal semantic descriptions, and then, we transform the descriptions into queuing network model which model reflects performance of hardware and software platform. We prove the accuracy of proposed methodology using prototype implementation. The accuracy is summarized at 80%.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.23 no.5
• /
• pp.369-382
• /
• 2011

This study investigated the tsunami force acting on onshore structures using a numerical program, three-dimensional one-field model for immiscible multi-phase flows, which is based on Navier-Stokes solver. In this paper, the characteristics of tsunami of oil storage tank and house structures studied to the distance between the seawall and structure. In addition, the study compared and analyzed the tsunami forces determined by considering drag force only and considering both drag and inertia forces. These numerical results were compared with the design standard. As a results, the case of considering the both forces is more close to numerical result than that of considering the drag force only.

• Analytical Science and Technology
• /
• v.25 no.1
• /
• pp.14-18
• /
• 2012

Rn-222 was used as a natural radioactive isotope tracer to evaluate non-aqueous phase liquid(NAPL) contaminated soil and aquifer. In the case of soil sample, Rn-222 concentration was inversely decreased with diesel concentration in the granite soil sample and it was decreased about 30% at the 13% diesel contaminated soil. For evaluating trichloroethylene (TCE) contaminated aquifer, the natural radioisotope Rn-222 was used as naturally occurring partitioning tracer for the approximate localization and semiquantitative assessment of the TCE source zone. Rn-222 was analyzed for the estimation of TCE contamination ranges of the acquifer in the contaminated site at Wonju in Korea.

• Proceedings of the KWS Conference
• /
• 2009.11a
• /
• pp.68-68
• /
• 2009

Recently, resistance spot welding using Inverter DC is applied to improve the weldability of high strength steel for the auto-body fabrication. In this study, inverter DC spot welding machine, which is developed in the domestic, was evaluated weldability of the galvanized and cold rolled dual-phase steel(tensile strength : 590MPa). The welding conditions (welding time, current and force) were decided by tensile-shear test, and welding strength and nugget size were analyzed by statistical analysis methods which involved dynamic resistance and indentation. The results of the statistical analysis was utilized for real-time estimation of the invisible nugget size and tensile strength. Moreover, it can be achieved without the conventional destructive testing of welds.