• Computers and Concrete
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• v.19 no.3
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• pp.275-282
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• 2017

The aim of this study is to build Machine Learning models to evaluate the effect of blast furnace slag (BFS) and waste tire rubber powder (WTRP) on the compressive strength of cement mortars. In order to develop these models, 12 different mixes with 288 specimens of the 2, 7, 28, and 90 days compressive strength experimental results of cement mortars containing BFS, WTRP and BFS+WTRP were used in training and testing by Random Forest, Ada Boost, SVM and Bayes classifier machine learning models, which implement standard cement tests. The machine learning models were trained with 288 data that acquired from experimental results. The models had four input parameters that cover the amount of Portland cement, BFS, WTRP and sample ages. Furthermore, it had one output parameter which is compressive strength of cement mortars. Experimental observations from compressive strength tests were compared with predictions of machine learning methods. In order to do predictive experimentation, we exploit R programming language and corresponding packages. During experimentation on the dataset, Random Forest, Ada Boost and SVM models have produced notable good outputs with higher coefficients of determination of R2, RMS and MAPE. Among the machine learning algorithms, Ada Boost presented the best R2, RMS and MAPE values, which are 0.9831, 5.2425 and 0.1105, respectively. As a result, in the model, the testing results indicated that experimental data can be estimated to a notable close extent by the model.

• The Journal of Korean Academy of Prosthodontics
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• v.42 no.5
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• pp.583-596
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• 2004

Statement of problem : Stress concentration on the neck bone affects the bone resorption, and finally the implant survival. Purpose: In order to examine the stress distribution on the neck bone and prosthesis abutment for implants, decreasing abutment sizes were used. Material and methods : Axisymmetric models were used to obtain the data required. These models were composed of 4mm implants with 3.4mm and 4mm abutments, 5mm implants with 3.4mm and 5mm abutments and 6mm implants with 3.4mm and 6mm abutments. All abutments were designed to received a 10mm high by 10mm diameter gold crown. Functional element analysis was used to obtain these results using data that consisted of 50 N vertical and 45 degree inclination forces. Results : 1. Changing the diameter of the abutment on the implant affects the effect of the inclination forces more than the effect of the vortical forces. 2. Changing the diameter of the abutment on the implant affect the effect of the inclination forces more than the effect of the vertical forces. 3. Experimentation showed that the larger diameter implants provided a decreased neck bone stress, whereas a larger diameter abutment provided a decrease marginal abutment stress. 4. Experimentation showed that the neck bone and abutment received more stress from inclination forces than vertical forces, Conclusions: By decreasing the size of the abutment on the implant we were able to diminishneck bone stress.

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

• Journal of KIISE:Information Networking
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• v.41 no.4
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• pp.167-176
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• 2014

In this paper, we discuss the implementation and experimentations of a new future Internet architecture for mobile-oriented environments, named Mobile Oriented Future Internet (MOFI). The MOFI architecture is featured by the host identifier and local locator for identifier-locator separation, Query-First Data Delivery (QFDD), and Distributed Mapping System (DMS) for identifier-locator mapping control. In the existing study on MOFI, we examined the intra-domain mobility control, the implementation of MOFI over Linux platform, and the performance analysis over the small-scale testbed. In this paper, we describe how to implement the MOFI architecture for inter-domain mobility control by using the OpenFlow and Click Modular Router platform. From the experimentations over the KOREN testbed, we can see that the MOFI scheme can give better performance than the existing Proxy Mobile IP scheme.

• Journal of Internet Computing and Services
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• v.12 no.6
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• pp.63-71
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• 2011

Cardiac disorder data are generally tested using the classifier and QRS-Complex and R-R interval which is used in this experiment are often extracted by ECG(Electrocardiogram) signals. The experimentation of ECG data with classifier is generally performed with SVM(Support Vector Machine) and MLP(Multilayer Perceptron) classifier, but this study experimented with Best-First Decision Tree(B-F Tree) derived from the Dicision Tree among Random Forest classifier algorithms to improve accuracy. To compare and analyze accuracy, experimentation of SVM, MLP, RBF(Radial Basic Function) Network and Decision Tree classifiers are performed and also compared the result of announced papers carried out under same interval and data. Comparing the accuracy of Random Forest classifier with above four ones, Random Forest is the best in accuracy. As though R-R interval was extracted using Band-pass filter in pre-processing of this experiment, in future, more filter study is needed to extract accurate interval.

• Journal of KIISE:Information Networking
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• v.32 no.6
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• pp.723-731
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• 2005

Wide spread deployment of infrastructure WLANs has made Wi Fi an integral part of today's Internet access technology. Despite its crucial role in affecting end to end performance, past research has focused on MAC protocol enhancement, analysis and simulation based performance evaluation without sufficient consideration for modeling inaccuracies stemming from inter layer dependencies, including physical layer diversity, that significantly impact performance. We take a fresh look at IEEE 802.11 WLANs, and using experiment, simulation, and analysis demonstrate its surprisingly agile performance traits. Contention based MAC throughput degrades gracefully under congested conditions, enabled by physical layer channel diversity that reduces the effective level of MAC contention. In contrast, fairness and jitter significantly degrade at a critical offered load. This duality obviates the need for link layer flow control for throughput improvement but necessitates traffic control for fairness and QoS. We use experimentation and simulation in a complementary fashion, pointing out performance characteristics where they agree and differ.

• Journal of Korean Society of societal Security
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• v.1 no.1
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• pp.81-87
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• 2008

The cigarette holds more than 10 percents of the entire fire accidents despite the number of smokers rapidly decreases every year. The purpose of this study is to examine the ignition characteristics of cigarette by experimentation. This study analyzed the cases of fires inferred that they were caused by cigarette in Incheon during 2006. As the representative ignition materials, corrugated board, gasoline, lacquer thinner, tarpaulin, flexible PVC sheet, and poly ethylene were tested. In this experimentation, the corrugated board was ignited by cigarette. However gasoline, lacquer thinner, tarpaulin, flexible PVC sheet, and poly ethylene were seldom ignited. Meanwhile most fire investigators have argued that oils and tents were ignited by cigarette, but this study experimentally proved that such an argument might be ungrounded.

• The Korean Journal of Physiology
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• v.17 no.1
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• pp.29-35
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• 1983

The most popular way to get the animal to be co-operative for the animal experimentation is by using some kinds of general anesthetic agents. One of the most important point to take care of is, however, whether the agent(s) to be used is hinder the experimentation itself. There have been many contradictory reports of the general anesthetic agents on the renal function. Moreover, little information on the changes of the renal function by anesthesia has been available. We have done experiments to clarify and compare the effects of anesthesia induced by several general anesthetic agents on renal function in unanesthetized rabbits. Nembutal anesthesia(30 mg/kg, iv.) caused a decrease in free-water clearance, and increase in sodium and chloride excretion without significance. Thiopental anesthesia$(20{\sim}30\;mg/kg,\;iv.)$ suppressed all renal parameters tested. Chloralose(50 mg/kg, iv.) and chloral hydrate(75 mg/kg, iv.) did not change renal functions except for glomerular filtration rate, which parameter was suppressed only for a short period just after agent administration. Urethane(1 g/kg), administered by the route of either subcutaneously or intraperitoneally, suppressed renal functions lasted for the duration of experimental anesthesia. The above data suggest that it is very important to chose an appropriate anesthetic agents for a given experiment, especially experiment involved with renal function, and to interprete the data obtained from the anesthetized animal model for the expected results.

• Journal of the Korean earth science society
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• v.25 no.3
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• pp.160-175
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• 2004

This study examined the knowledge and practices of scientific inquiry displayed by three student teachers and two beginning teachers at secondary levels. Observations using the instrument of OTOP designed by the research team of OCEPT (Oregon Collaborative for Excellent in the Preparation of Teachers) generalized similar teaching strategies of scientific inquiry between student and beginning teachers, such as using group work for students' first hand experience, using concrete materials for experimentation or visual tools for demonstration, using questions for factual knowledge mainly without opportunities to understand how scientific knowledge is constructed. Those scientific inquiry activities were very confirmative ones to follow the steps without opportunities of understanding nature of science or nature of scientific inquiry. However, all participants in this study hold knowledge of scientific inquiry envisioned by the National Science Education Standards [NSES] (NRC, 1996), where students identify their hypothesis, use critical and logical thinking, and consider alternative explanations through argumentation as well as experimentation. An inconsistent relationship between participating teachers knowledge and practices about scientific inquiry resulted from their lack of pedagogy skills of implementing it in the classroom. Providing opportunities for these teachers to reflect on their beliefs and practices about scientific inquiry was recommended for the future study. Furthermore, increasing college faculty interest in new teaching approaches for upgrading the content knowledge of student teachers and beginning teachers was recommended as a solution, since those teachers showed evidence of influence by college faculties at universities in their pedagogy skills.

• Journal of the Korean earth science society
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• v.25 no.3
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• pp.194-204
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• 2004

The purpose of this literature review is to investigate what kinds of research have been done about scientific inquiry in terms of scientific argumentation in the classroom context from the upper elementary to the high school levels. First, science educators argued that there had not been differentiation between authentic scientific inquiry by scientists and school scientific inquiry by students in the classroom. This uncertainty of goals or definition of scientific inquiry has led to the problem or limitation of implementing scientific inquiry in the classroom. It was also pointed out that students' learning science as inquiry has been done without opportunities of argumentation to understand how scientific knowledge is constructed. Second, what is scientific argumentation, then? Researchers stated that scientific inquiry in the classroom cannot be guaranteed only through hands-on experimentation. Students can understand how scientific knowledge is constructed through their reasoning skills using opportunities of argumentation based on their procedural skills using opportunities of experimentation. Third, many researchers emphasized the social practices of small or whole group work for enhancing students' scientific reasoning skills through argumentations. Different role of leadership in groups and existence of teachers' roles are found to have potential in enhancing students' scientific reasoning skills to understand science as inquiry. Fourth, what is scientific reasoning? Scientific reasoning is defined as an ability to differentiate evidence or data from theory and coordinate them to construct their scientific knowledge based on their collection of data (Kuhn, 1989, 1992; Dunbar & Klahr, 1988, 1989; Reif & Larkin, 1991). Those researchers found that students skills in scientific reasoning are different from scientists. Fifth, for the purpose of enhancing students' scientific reasoning skills to understand how scientific knowledge is constructed, other researchers suggested that teachers' roles in scaffolding could help students develop those skills. Based on this literature review, it is important to find what kinds of generalizable teaching strategies teachers use for students scientific reasoning skills through scientific argumentation and investigate teachers' knowledge of scientific argumentation in the context of scientific inquiry. The relationship between teachers' knowledge and their teaching strategies and between teachers teaching strategies and students scientific reasoning skills can be found out if there is any.