• Journal of The Korean Society of Agricultural Engineers
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• v.59 no.3
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• pp.97-110
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• 2017

This study investigates the efficiencies of machine learning models, including artificial neural network (ANN), generalized regression neural network (GRNN), adaptive neuro-fuzzy inference system (ANFIS) and random forest (RF), for reservoir water level forecasting in the Chungju Dam, South Korea. The models' efficiencies are assessed based on model efficiency indices and graphical comparison. The forecasting results of the models are dependent on lead times and the combination of input variables. For lead time t = 1 day, ANFIS1 and ANN6 models yield superior forecasting results to RF6 and GRNN6 models. For lead time t = 5 days, ANN1 and RF6 models produce better forecasting results than ANFIS1 and GRNN3 models. For lead time t = 10 days, ANN3 and RF1 models perform better than ANFIS3 and GRNN3 models. It is found that ANN model yields the best performance for all lead times, in terms of model efficiency and graphical comparison. These results indicate that the optimal combination of input variables and forecasting models depending on lead times should be applied in reservoir water level forecasting, instead of the single combination of input variables and forecasting models for all lead times.

• Journal of the Semiconductor & Display Technology
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• v.12 no.1
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• pp.1-7
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• 2013

Grey-level statistical models have been widely used in many applications for object location and identification. However, conventional models yield some problems in model refinement when training images are not properly aligned, and have difficulties for real-time recognition of arbitrarily rotated models. This paper presents improved grey-level statistical models that align training images using image or feature matching to overcome problems in model refinement of conventional models, and that enable real-time recognition of arbitrarily rotated objects using efficient hierarchical search methods. Edges or features extracted from a mean training image are used for accurate alignment of models in the search image. On the aligned position and orientation, fitness measure based on grey-level statistical models is computed for object recognition. It is demonstrated in various experiments in PCB inspection that proposed methods are superior to conventional methods in recognition accuracy and speed.

• JSTS:Journal of Semiconductor Technology and Science
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• v.10 no.1
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• pp.20-27
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• 2010

Modeling is essential to simulate the operation of integrated circuit (IC) before its fabrication. Seeing a large number of Metal-Oxide-Silicon Field-Effect-Transistor (MOSFET) models available, it has become important to understand them and compare them for their pros and cons. The task becomes equally difficult when the complexity of these models becomes very high. The paper reviews the mainstream models with their physical relevance and their comparisons. Major short-channel and quantum effects in the models are outlined. Emphasis is set upon the latest compact models like BSIM, MOS Models 9/11, EKV, SP etc.

• Wind and Structures
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• v.32 no.3
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• pp.219-225
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• 2021

Wind tunnel test models for super tall buildings mainly include synchronized pressure models, high-frequency force balance models, forced vibration models and aeroelastic models. Aeroelastic models, especially MDOF aeroelastic models, are relatively accurate, and designing MDOF model is an important step in aero-model wind tunnel tests. In this paper, the authors propose a simple and accurate design method for MDOF model. The purpose of this paper is to make it easier to design MDOF models without unnecessary experimentation, which is of great significance for the use of the aero-model for tall buildings.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.72-77
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• 2000

In order to estimate strength of concrete, many attempts have been made. However, it is difficult to estimate concrete strength with ages. In this study, the factors influencing the strength of concrete such as w/c ratio and curing temperature, were investigated and results predicted by the established strength models were compared to measured strength data. It is found that in general the estimated values are approximate to the test results. In order to accurately predict the concrete strength curing temperature factor should be employed in the strength models.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.5 no.3
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• pp.260-265
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• 2004

In order to analyze the shaped drawing process, it is necessary that the friction boundary condition between dies and blanks should be worked out the accurate numerical friction models. But, the existing numerical models of the drawing may be large different from the actual conditions. In this paper, accurate analysis of the drawing process should be subjected. It is to develop accuracy of the numerical friction models and potentialize to apply for the high speed forming work in the drawing process. Therefore, the results should improve the accuracy, cause the energy saving for the drawing process and finally expand the applying areas of the results.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.995-999
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• 2009

Before a contractor embarks on exporting its services, it needs to know if it is likely to succeed. This research developed two prediction models to help contractors in Singapore predict the number of projects (Y1) and the contract values (Y2) that they are likely to secure from overseas. Detailed characteristics of 60 contractors who export their services (exporters) were obtained from the database of registered contractors in Singapore. Multiple linear regression models were developed and tests showed that Y1 is a robust model. A contractor's chance of winning more overseas projects may be predicted by the number of projects it acted as a subcontractor; the variety of projects it undertakes; the total contract value in the domestic market; and the number of countries it exported its services to. It is recommended that contractors who are planning to export their services be flexible instead of adopt a focused policy of undertaking only one or two project types in a few selected countries.

• Journal of Families and Better Life
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• v.13 no.4
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• pp.1-14
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• 1995

Various theoretical models have developed io both a family research area and family therapy field on he basis of several family theories and social theories in order to understand the family life and its function. These theoretical models have give rise to provide not only a framework for family therapy bt also opportunities for the development of family studies. Regardless of the devotion of these theoretical models to a family therapy however some family therapy professions have suggested the disvergence between these models and practice because the models tend to confuse therapists in their actual practices Other family therapists on the other hand have claimed the convergence between these models and practice. One of the reasons for the issues of convergence and disvergence in the family therapy study would be that various theoretical models have different sometimes contradicatable definitions and explanations for same concept. Therefore the purpose of this paper is to investigate the extent of similarities and differences among these theoretical models of practice in a way of examining family models to compare Olson's circumplex model to the Beavers systems model. Both models were based on the general systems theory. This paper consists of the explanation of Olson's circumplex model and Beavers systems model in general respectively. Then it will investigate similarities and differences between these two models in terms of the relationship between family functioning and family adaptability.

• Proceedings of the Korea Society for Simulation Conference
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• 2002.05a
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• pp.253-258
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• 2002

This paper proposes a methodology for development of protocol models. The methodology attempts to employ two modeling environments in models development, NS2 and DEVSim++, which will interoperate during simulation. NS2 is a widely used network simulator in protocol research, which employs an informal modeling approach. Within the approach time and state information of protocol models are not explicitly described, thus being hard to validate model. On the other hand the DEVS formalism is a mathematical framework for modeling a discrete event system in a hierarchical, modular manner. In DEVS, model's time and state information is described explicitly, By using DEVS formalism, models can easily be validated and errors in the modeling stage can be reduced. However, the DEVS simulator, DEVSim++, supports a small amount of models library which are required to build simulation models of general communication network. Although NS2 employs an informal modeling approach and models validation is difficult, it supports abundant models library validated by experimental users. Thus, combination of DEVS models and NS2 models may be an effective solution for network modeling. Such combination requires interoperation between DEVSim++ simulator and NS2 simulator. This paper develops an environment for such interoperation. Correctness and effectiveness of the implemented interoperation environment have been validated by simulation of UDP and TCP models.

• Journal of The Korean Association For Science Education
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• v.16 no.1
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• pp.13-34
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• 1996

The purpose of this study is to develop appropriate science teaching models which can be applied effectively to relevant situations. Five science teaching models; cognitive conflict teaching models, generative teaching model, learning cycle teaching model, hypothesis verification teaching model and discovery teaching model, were identified from the existing models. The teaching models were modified and in primary and secondary students using a nonequivalent pretest-posttest control group design. Major findings of this study were as follows: 1. For teaching science concepts, three teaching models were found more effective; cognitive conflict teaching model, generative teaching model and discovery teaching model. 2. For teaching inquiry skills, two teaching models were found more effective; learning cycle teaching model and hypothesis verification teaching model. 3. For teaching scientific attitudes, two teaching models were found more effective; learning cycle teaching models and discovery teaching model. Each teaching model requires specific learning environment. It is strongly suggested that teachers should select a suitable teaching model carefully after evaluating the learning environment including teacher and student variables, learning objectives and curricular materials.