• Environmental and Resource Economics Review
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• v.20 no.3
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• pp.419-457
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• 2011

This study aims at understanding the characteristics of global economic models, which are widely used for climate change policy analysis. A literature review study was conducted in order to derive general features of top-down models such as CGE and bottom-up/hybrid models such as GTEM. Furthermore, a structural analysis was carried out by applying parameter and structural components from other models to a particular model to observe the potential differences in outcomes. Literature review shows that bottom-up or hybrid models generally have higher level of reduction potentials than top-down models in the long run. This contradicts the conclusion presented by IPCC, and raises the need for more rigorous investigation through structural analysis. Structural analysis of EPPA model indicates that the structural component of the energy sector in a particular model is the most influential factor in predicting baseline emissions and reduction potentials. This includes the structure among energy, capital, and labor inputs, and the substitution elasticities within the energy bundle. Technology bundle can establish the conclusions from literature review, and change in Armington elasticities do not significantly affect the outcome in aggregate.

• Asia pacific journal of information systems
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• v.7 no.2
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• pp.163-183
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• 1997

As object models and hybrid knowledge are increasingly used in current information systems development, Is-a structures need to be more formally defined, and subsequently subsumption related anomalies need to be detected with minimal declaration of meta knowledge. This paper extends a metagraph in the hybrid environments and demonstrates its utilities for detecting such anomalies that can occur from semantics and dynamics unique to the hybrid knowledge and data structure.

• Journal of Electrical Engineering and Technology
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• v.12 no.3
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• pp.1219-1226
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• 2017

This paper presents the hybrid stepping machine for linear oscillating generators. The focus of the work is the suggestion of the improved model through the comparison of proposed models ; new flux concentrating PMs mover of the hybrid stepping generator is proposed based on the symmetrical and non-symmetrical stator cores of the surface mounted PMs mover, and non-slanted PMs and slanted PMs of the flux concentrating PMs mover. It is achieved using equivalent magnetic circuit considering leakage elements. Finally, this study suggests new hybrid stepping structure of linear oscillating generator.

• Structural Engineering and Mechanics
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• v.65 no.5
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• pp.535-546
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• 2018

The objective of this study is to understand the behaviour of hollow core slabs strengthened with FRP and hybrid techniques through numerical and analytical studies. Different strengthening techniques considered in this study are (i) External Bonding (EB) of Carbon Fiber Reinforced Polymer (CFRP) laminates, (ii) Near Surface Mounting (NSM) of CFRP laminates, (iii) Bonded Overlay (BO) using concrete layer, and (iv) hybrid strengthening which is a combination of bonded overlay and NSM or EB. In the numerical studies, three-dimensional Finite Element (FE) models of hollow core slabs were developed considering material and geometrical nonlinearities, and a phased nonlinear analysis was carried out. The analytical calculations were carried out using Response-2000 program which is based on Modified Compression Field Theory (MCFT). Both the numerical and analytical models predicted the behaviour in agreement with experimental results. Parametric studies indicated that increase in the bonded overlay thickness increases the peak load capacity without reducing the displacement ductility. The increase in FRP strengthening ratio increased the capacity but reduced the displacement ductility. The hybrid strengthening technique was found to increase the capacity of the hollow core slabs by more than 100% without compromise in ductility when compared to their individual strengthening schemes.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.1
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• pp.8-19
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• 2001

A number of atomization and droplet breakup models have been developed and used to predict the diesel spray characteristic. Most of these models could not provide reasonable computational result of the diesel spray characteristic because they have only considered the primary breakup. A hybrid model is, therefore, required to develop by considering the primary and secondary breakup of liquid jet. according to this approach, wave breakup(WB) model was used compute the primary breakup of the liquid jet and droplet deformation and breakup(DDB) model was used for the secondary breakup of droplet. Development of hybrid model by using KIVA-II code was performed by comparing with the experimental data of spray tip penetration and SMD from the literature. A hybrid model developed in this study could provide the good agreement with the experimental data of spray tip penetration. The prediction results of SMD were in good agreement between 0.5 and 1.0 ms after the start of injection. Numerical results obtained by the present hybrid model have the good agreement with the experimental data with the breakup time constant in WB model of 30, and DDB model constant Ck of 1.0 when the droplet becomes less than 95% of maximum droplet diameter injected.

• Korean Journal of Materials Research
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• v.21 no.2
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• pp.100-105
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• 2011

The relative viscosity was measured at different filler loadings for a cycloaliphatic epoxy resin and hexahydro-4-methylphthalic anhydride hardener system filled with micro/nano hybrid silica. Various empirical models were fitted to the experimental data and a fitting parameter such as critical filler fractions (${\phi}_{max}$) was estimated. Among the models, the Zhang-Evans model gave the best fit to the viscosity data. For all the silica loadings used, ln (relative viscosity) varied linearly with filler loadings. Using the Zhang-Evans model and the linearity characteristics of the viscosity change, simple methods to predict the relative viscosity below ${\phi}_{max}$ are presented in this work. The predicted viscosity values from the two methods at hybrid silica fractions of $\phi$ = 0.086 and 0.1506 were confirmed for a micro:nano = 1:1 hybrid filler. As a result, the difference between measured and predicted values was less than 11%, indicating that the proposed predicting methods are in good agreement with the experiment.

• Journal of the Korea Society for Simulation
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• v.15 no.1
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• pp.69-75
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• 2006

P2P services occupy more then 50% of the internet traffics. A huge number of query packets are generated since pure P2P based models rely on message flooding for their query mechanisms. In this study, the numbers of query messages generated in the pure P2P and hybrid P2P model are analyzed. The results show that hybrid P2P models also could suffer from message flooding. To reduce the message flooding, this study proposes an interest based clustering mechanism for hybrid P2P services. By applying this clustering algorithm, it could reduce 99.998% of the message flooding. The proposed algorithm also reduces the cost of the joining operations by storing previous supernodes.

• Journal of the Korean earth science society
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• v.27 no.1
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• pp.6-14
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• 2006

The study investigates mental models of scientifically gifted, middle school students when it comes to tides. This was done by analyzing facet of conceptual types for two contexts. We carried out two performance tasks of tide with different context. A large number of students showed different conceptual types by context. As a result of analyzing facet of conceptual types by context, there was a slight difference in content-specific facet, but a remarkable one in strategic facet. We classified four mental models about tide by configuring facets of conceptual types: (1) Tide model (2) Force model (3) Phase model (4) Hybrid model. The Tide model is scientifically accepted model, but Force model and Phase model are incorrect models, and Hybrid model is mixed model. In cases of Force model and Phase model, conceptual types concur with each other, but these types of students comprehend tides as a result of joined forces of Moon & Sun and phase change of Moon, respectively. Arranging low mental models in proportional order, Tide model (45.0%), Hybrid model (30.0%), Force model (12.5%), and Phase model (7.5%).

• Journal of the Korea Convergence Society
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• v.12 no.6
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• pp.9-16
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• 2021

In the past, there have been various studies on predicting the stock market by machine learning techniques using stock price data and financial big data. As stock index ETFs that can be traded through HTS and MTS are created, research on predicting stock indices has recently attracted attention. In this paper, machine learning models for KOSPI's up and down predictions are implemented separately. These models are optimized through a grid search of their control parameters. In addition, a hybrid machine learning model that combines individual models is proposed to improve the precision and increase the ETF trading return. The performance of the predictiion models is evaluated by the accuracy and the precision that determines the ETF trading return. The accuracy and precision of the hybrid up prediction model are 72.1 % and 63.8 %, and those of the down prediction model are 79.8% and 64.3%. The precision of the hybrid down prediction model is improved by at least 14.3 % and at most 20.5 %. The hybrid up and down prediction models show an ETF trading return of 10.49%, and 25.91%, respectively. Trading inverse×2 and leverage ETF can increase the return by 1.5 to 2 times. Further research on a down prediction machine learning model is expected to increase the rate of return.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.12
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• pp.1014-1022
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• 2002

An objective of Automated Highway Systems (AHS) is to increase the safety and throughput of the existing highway infrastructure by introducing traffic automation. AHS is an example of a large scale, multiagent complex dynamical system and is ideally suited for a hierarchical hybrid controller. We discuss a design issue of efficient hybrid controllers for the platoon maneuvers on AHS. For the modeling of a hybrid system including the merge and split operations, a safety distance policy is introduced for the merge and split operations. After that, the platoon system will be modeled by a hybrid system In addition, a hybrid controller for the proposed merge and split operation models is presented. Finally, the performance of the proposed hybrid control scheme is demonstrated via scenarios for platoon maneuvers.