• School Mathematics
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• v.18 no.2
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• pp.277-300
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• 2016

In school mathematics, the definition and concept of a differentiation has been dealt with as a formula. Because of this reason, the learners' fundamental knowledge of the concept is insufficient, and furthermore the learners are familiar with solving routine, typical problems than doing non-routine, unfamiliar problems. Preceding studies have been more focused on dealing with the issues of learner's fallacy, textbook construction, teaching methodology rather than conducting the more concrete and efficient research through experiment-based lessons. Considering that most studies have been conducted in such a way so far, this study was to create a lesson plan including teaching resources to guide the understanding of differential coefficients and derivatives. Particularly, on the basis of the theory of Historical Genetic Process Principle, this study was to accomplish the its goal while utilizing a technological device such as GeoGebra. The experiment-based lessons were done and analyzed with 68 first graders in S high school located in G city, using Posttest Only Control Group Design. The methods of the examination consisted of 'learning comprehension' and 'learning satisfaction' using 'SPSS 21.0 Ver' to analyze students' post examination. Ultimately, this study was to suggest teaching methods to increase the understanding of the definition of differentials.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.1 s.256
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• pp.26-35
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• 2007

The vehicle of urban transit is a complex system that consists of various electric, electronic, and mechanical equipments, and the maintenance cost of this complex and large-scale system generally occupies sixty percent of the LCC (Life Cycle Cost). For reasonable establishing of maintenance strategies, safety security and cost limitation must be considered at the same time. The concept of system reliability has been introduced and optimized as the key of reasonable maintenance strategies. For optimization, three preceding studies were accomplished; standardizing a maintenance classification, constructing RBD (Reliability Block Diagram) of VVVF (Variable Voltage Variable Frequency) urban transit, and developing a web based reliability evaluation system. Historical maintenance data in terms of reliability index can be derived from the web based reliability evaluation system. In this paper, we propose applying inverse problem analysis method and hybrid neuro-genetic algorithm to system reliability optimization for using historical maintenance data in database of web based system. Feed-forward multi-layer neural networks trained by back propagation are used to find out the relationship between several component reliability (input) and system reliability (output) of structural system. The inverse problem can be formulated by using neural network. One of the neural network training algorithms, the back propagation algorithm, can attain stable and quick convergence during training process. Genetic algorithm is used to find the minimum square error.

• Korean Institute of Interior Design Journal
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• v.19 no.2
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• pp.99-106
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• 2010

This study is about Foucault's conceptual and methodological relevance for structural analysis of Korean traditional space design history. By Foucault's Theory, regionalism is product of the instrumentality of space, power, knowledge and provide the basis for making the operation of power both spatial and temporal. The purpose of this study is to establish topographical map of historical progress and to shed new light on the forming of identity in Korean traditional space design on the poststructural-archaeological aspect. The process of this study is illustrated as follows: At first, it suggests Foucault's 'Theory of archaeology'. It mentions 'historical apriori' and archive, collateral space and general grammar as theoretical background of archaeological logic. Secondly, it clarifies 'statements' depending on the conditions that is 'episteme' in which they emerge and exist within a field of discourse. And it discuss Korean traditional space design concept as a social product on the situated character of interaction in time-space. Finally, it studies genetic variation process of Korean traditional space design based on the social progress in Korean society. And it analyses practical actions of 'Statements' in terms of general grammar and textuality.

• Journal of Educational Research in Mathematics
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• v.17 no.1
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• pp.1-31
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• 2007

Negative numbers have been one of the most difficult mathematical concepts, and it was only 200 years ago that they were recognized as a real object of mathematics by mathematicians. It was because it took more than 1500 years for human beings to overcome the quantitative notion of numbers and recognize the formality in negative numbers. Understanding negative numbers as formal ones resulted from the Copernican conversion in mathematical way of thinking. we first investigated the historic and the genetic process of the concept of negative numbers. Second, we analyzed the conceptual fields of negative numbers in the aspect of the additive and multiplicative structure. Third, we inquired into the levels of thinking on the concept of negative numbers on the basis of the historical and the psychological analysis in order to understand the formal concept of negative numbers. Fourth, we analyzed Korean mathematics textbooks on the basis of the thinking levels of the concept of negative numbers. Fifth, we investigated and analysed the levels of students' understanding of the concept of negative numbers. Sixth, we analyzed the symbolizing process in the development of mathematical concept. Futhermore, we tried to show a concrete way to teach the formality of the negative numbers concepts on the basis of such theoretical analyses.

• The KIPS Transactions:PartD
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• v.12D no.1 s.97
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• pp.51-62
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• 2005

After figuring out the function of an amino acid sequence, we can infer the function of the other amino acids that have similar sequence composition. Besides, it is possible that we alter protein whose function we know, into useful protein using genetic engineering method. In this process. an original protein amino sequence produces various protein sequences that have different sequence composition. Here, a systematic technique is needed to manage protein version sequences and reference data of those sequences. Thus, in this paper we proposed a technique of managing protein version sequences based on local sequence alignment and a technique of managing protein historical reference data using Trigger This method automatically determines the similarity between an original sequence and each version sequence while the protein version sequences are stored into database. When this technique is employed, the storage space that stores protein sequences is also reduced. After storing the historical information of protein and analyzing the change of protein sequence, we expect that a new useful protein and drug are able to be discovered based on analysis of version sequence.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.676-684
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• 2009

Decision making at the early stages of a construction project has a significant impact on the project, and various scenarios created based on the owner's requirements should be considered for the decision making. At the early stages of a construction project, the information regarding the project is usually limited and uncertain. As such, it is difficult to plan and manage the project (especially cost planning). Thus, in this study, a cost model that could be varied according to the owner's requirements was developed. The cost model that was developed in this study is based on the case-based reasoning (CBR) methodology. The model suggests cost estimation with the most similar historical case as a basis for the estimation. In this study, the optimization process was also conducted, using genetic algorithms that reflect the changes in the number of project characteristics and in the database in the model according to the owner's decision making. Two optimization parameters were established: (1) the minimum criteria for scoring attribute similarity (MCAS); and (2) the range of attribute weights (RAW). The cost model proposed in this study can help building owners and managers estimate the project budget at the business planning stage.

• Korean Journal of Biological Psychiatry
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• v.21 no.4
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• pp.118-127
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• 2014

Along with language, socialization is a unique feature of the human being. There is a continuous debate regarding whether the development of socialization is innate, and conducted by the environment in the growing process, or the result of the interaction of both aspects. If socialization is the result of the interaction with the environment or is an acquired developmental process, the following question rises. "Is there a 'critical period' for the development of socialization?" Although there are a huge number of studies seeking for treatment and solutions for developmental delay or deficits of socialization, it is very complicated question to answer. Historical figures such as 'Hugh Blair' of Borgue in England, and 'the wild boy of Aveyron' in France, seem to have innate socialization deficits. Nowadays patients with non-verbal learning disorder, social communication disorder, or autism spectrum disorder seem to have genetic defects. On the other hand, Harry Harlow's monkey experiments, hikikomori of Japan, Romanian orphans and patients with reactive attachment disorder seem to display social deficits due to environmental factors. However, it is not easy to clearly draw a line between innate or acquired factors. Therefore, rather than subdividing the diseases for etiological and pathophysiological approach to heterogenous groups with the common denominator of social deficit, and for the research of pathophysiology and treatment development, the authors suggest a comprehensive concept of "social dysfunction spectrum."

• Korean Journal of Construction Engineering and Management
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• v.12 no.1
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• pp.53-61
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• 2011

For construction projects, the importance of early cost estimates is highly recognized by the project team and sponsoring organization because early cost estimates are frequently a foundation of business decisions as well as a basis for identifying any changes as the project progresses from design to construction. However, it is difficult to accurately estimate construction cost in the early stage of a project due to various uncertainties in construction. To deal with these uncertainties, cost estimates should be made several times over the course of the project. In particular, early cost estimates are essential process for successful project management. For accurate construction cost estimates, it is necessary to compare cost estimates with actual costs based on historical project data. In this context, case-based reasoning (CBR), which is the process of solving new problems based on the solutions of similar past problems, can be considered as an effective method for cost estimating. To obtain this, it is also required to define the attribute similarities and the attribute weights. However, no existing method is capable of determining attribute weights of qualitative variables. Consequently, it has been a well-known barrier of accurate early cost estimates. Using Genetic Algorithms (GA), this research suggests the method of determining the attribute weight of qualitative variables. Based on building project case studies, the proposed methodology was validated.

• Journal of Korean Society of Transportation
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• v.32 no.5
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• pp.522-530
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• 2014

Spatio-temporal congestion evolution pattern can be reproduced using the VDS(Vehicle Detection System) historic speed dataset in the TMC(Traffic Management Center)s. Such dataset provides a pool of spatio-temporally experienced traffic conditions. Traffic flow pattern is known as spatio-temporally recurred, and even non-recurrent congestion caused by incidents has patterns according to the incident conditions. These imply that the information should be useful for traffic prediction and traffic management. Traffic flow predictions are generally performed using black-box approaches such as neural network, genetic algorithm, and etc. Black-box approaches are not designed to provide an explanation of their modeling and reasoning process and not to estimate the benefits and the risks of the implementation of such a solution. TMCs are reluctant to employ the black-box approaches even though there are numerous valuable articles. This research proposes a more readily understandable and intuitively appealing data-driven approach and developes an algorithm for identifying congestion patterns for recurrent and non-recurrent congestion management and information provision.

• Journal of Korean Elementary Science Education
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• v.24 no.2
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• pp.145-159
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• 2005

Students' alternative concepts of evolution are similar to misconcepts and disputes which scientists had in science history. The aims of this study are to analyze the elementary children's concept in evolution based on science history. Lee (2004)'s two tests were applied to 6th grade to investigate the children's evolution concepts and genetic concepts related to the historical development of the evolution concepts. The test results were analyzed in accordance with 4 stages of science history based on Lee (2004)'s method. These stages are divided to stage 1 (Before Lamarck), stage 2 (Lamarck), stage 3 (Darwin), stage 4 (After Darwin). The major results are as follows. Most of elementary school children are fixed to the stage 2. They usually do not show the consistency of evolution concepts in the three dimensional aspects such as mechanism, time, and subjects. Many children do not have concrete meaning of gene, inheritance, sexual reproduction, mutation and could not connect these concetps and process of evolution. Also, they believe the inheritance of acquired traits and spontaneous generation. Therefore it is confirmed that they still have similar misconcepts and disputes which scientists had in transition time between stage 2 and 3 and most of children already have strong Lamarckian thought acquired from daily life experience before learning about natural selection and evolution.