• Journal of The Korean Association For Science Education
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• v.29 no.8
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• pp.990-1010
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• 2009

To derive brain-based evolutionary educational principles, this study examined the studies on the structural and functional characteristics of human brain, the biological evolution occurring between- and within-organism, and the evolutionary attributes embedded in science itself and individual scientist's scientific activities. On the basis of the core characteristics of human brain and the framework of universal Darwinism or universal selectionism consisted of generation-test-retention (g-t-r) processes, a Model of Brain-based Evolutionary Scientific Teaching for Learning (BEST-L) was developed. The model consists of three components, three steps, and assessment part. The three components are the affective (A), behavioral (B), and cognitive (C) components. Each component consists of three steps of Diversifying $\rightarrow$ Emulating (Executing, Estimating, Evaluating) $\rightarrow$ Furthering (ABC-DEF). The model is 'brain-based' in the aspect of consecutive incorporation of the affective component which is based on limbic system of human brain associated with emotions, the behavioral component which is associated with the occipital lobes performing visual processing, temporal lobes performing functions of language generation and understanding, and parietal lobes, which receive and process sensory information and execute motor activities of the body, and the cognitive component which is based on the prefrontal lobes involved in thinking, planning, judging, and problem solving. On the other hand, the model is 'evolutionary' in the aspect of proceeding according to the processes of the diversifying step to generate variants in each component, the emulating step to test and select useful or valuable things among the variants, and the furthering step to extend or apply the selected things. For three components of ABC, to reflect the importance of emotional factors as a starting point in scientific activity as well as the dominant role of limbic system relative to cortex of brain, the model emphasizes the DARWIN (Driving Affective Realm for Whole Intellectual Network) approach.

• Journal of the Korean Chemical Society
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• v.46 no.4
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• pp.353-363
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• 2002

In this study, characteristics of the problem solving process of the balancing redox equations was ana-lyzed by mental capacity and problem solving methods, and the pertinent teaching and learning guidance for oxidation-reduction unit was suggested. Participants were 79 senior high school students and 57 science high school students. Tests were conducted to measure the mental capacity, the understanding of the oxidation-reduction concepts and the com-pletion of the balancing redox equations. The framework was made to find the patterns of failure and success. As the analysis of the influence on the performance of mental capacity,understanding of the oxidation-reduction concepts, and problem solving methods, students who had lower understanding of oxidation-reduction concepts selected the trial and error method, and their performance were influenced by mental capacity. The students that had higher understanding of the oxidation-reduction concepts had good performance by using oxidation number method regardless of their mental capacity. As the results of analysis for the patterns, the success patterns of solving the problems, those of mostly the sci-ence high school students, were the cases of using oxidation number method well and lessening problem solving steps. The patterns of failure in solving problems by using trial and error method showed that students had mistakes in cal-culating, errors in making unknown equations, no consideration for all variables, or stopped solving the complicated problems. The patterns of failure in solving problems by using oxidation number method showed that many students had wrong oxidation number or no consideration for mass and charge balance.

• The Korean Journal of Applied Statistics
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• v.34 no.2
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• pp.239-254
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• 2021

This paper studies time series analysis with estimation and forecasting for Korean COVID-19 confirmed cases, based on the approach of a heterogeneous autoregressive (HAR) model with two-piece t (TP-T) distributed errors. We consider HAR-TP-T time series models and suggest a step-by-step method to estimate HAR coefficients as well as TP-T distribution parameters. In our proposed step-by-step estimation, the ordinary least squares method is utilized to estimate the HAR coefficients while the maximum likelihood estimation (MLE) method is adopted to estimate the TP-T error parameters. A simulation study on the step-by-step method is conducted and it shows a good performance. For the empirical analysis on the Korean COVID-19 confirmed cases, estimates in the HAR-TP-T models of order p = 2, 3, 4 are computed along with a couple of selected lags, which include the optimal lags chosen by minimizing the mean squares errors of the models. The estimation results by our proposed method and the solely MLE are compared with some criteria rules. Our proposed step-by-step method outperforms the MLE in two aspects: mean squares error of the HAR model and mean squares difference between the TP-T residuals and their densities. Moreover, forecasting for the Korean COVID-19 confirmed cases is discussed with the optimally selected HAR-TP-T model. Mean absolute percentage error of one-step ahead out-of-sample forecasts is evaluated as 0.0953% in the proposed model. We conclude that our proposed HAR-TP-T time series model with optimally selected lags and its step-by-step estimation provide an accurate forecasting performance for the Korean COVID-19 confirmed cases.

• Resources Recycling
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• v.8 no.1
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• pp.18-22
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• 1999

In order to utilize incineration fly ash of industrial wastes as resources, we present the recovery and separation of metals included in the fly ash by leaching with aqueous solution A great quantity of Cu, Pb, and Zn as well as a small amount oftoxic heavy metals are contained in the leach liquor of the fly ash, and the concentration of the ingredients of the fly ash depends on the industrial wastes which are fed into incinerators. In this paper, sequential Ieachiog operations are conducted using $H_2O$, $H_2SO_4$, $(NH_4)_2CO_3$ and NaOH as Icachants. Water soluble copper salt was leached by $H_2O$, Zn and Pb were separated by the NaOH leach liquor, and water insoluble copper was selectively leached as chelate ion with the $(NH_4)_2CO_3$ leach liquor of the third Ieaehant. Results show that the reduction percent of the fly ash in the leaching steps using $H_2O$, $H_2SO_4$, and $(NH_4)_2CO_3$ is 77%, and the other leaching procedures lose the weight of fly ash by above 60%.

• Journal of Technology Innovation
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• v.18 no.2
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• pp.221-252
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• 2010

This study presents a concept of technology trade network and management, and proposes a procedural method for optimally selecting the technology transferor when a technology transferee needs to buy a specific technology. We develop a technology trade network where technology supplier, technology marketer, and technology transferee are informatively linked. And a technology trade management consists of three step of estimating technology, trading technology, and commercialization technology. Technology transferees could import the best appropriate technology which they want through these technology network method and cost optimization method. And we hope that these methodologies can be used in selecting new technology. A methodology can be classified into an estimating technology process and a choice of technology supplier process. In an estimating technology process, we calculate the technology similarity quantitatively through developing method of estimating technology which is focused on its technological characteristics. After defining the related cost of technology introduction, we suggest goal programming model to find a solution which can be acceptable both maximizing the technology similarity and minimizing the cost of technology. And suggested model is verified with a supplier selection problem of next generation tanks.

• The Journal of the Acoustical Society of Korea
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• v.22 no.4
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• pp.315-322
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• 2003

We propose a channel-attentive Mel frequency cepstral coefficient (CAMFCC) extraction method to improve the recognition performance of speech that is partially corrupted in the frequency domain. This method introduces weighting terms both at the filter bank analysis step and at the output probability calculation of decoding step. The weights are obtained for each frequency channel of filter bank such that the more reliable channel is emphasized by a higher weight value. Experimental results on TIDIGITS database corrupted by various frequency-selective noises indicated that the proposed CAMFCC method utilizes the uncorrupted speech information well, improving the recognition performance by 11.2% on average in comparison to a multi-band speech recognition system.

• Korean Journal of Food Science and Technology
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• v.45 no.3
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• pp.285-292
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• 2013

This study was carried out to validate the safety of ametoctradin residues in agricultural commodities by developing an official analysis method. An analytical method was developed and validated using HPLC-PDA detectors. The samples were extracted with methanol, subsequently partitioned with dichloromethane and purified with florisil column chromatograph using acetone/hexane (30/70, v/v) as solvent. The method was validated by using grape, hulled rice, mandarin, and potato spiked with ametoctradin at 0.05 and 5.0 mg/kg, and pepper at 0.05 and 2.0 mg/kg. Average recoveries were 76-114.8% with relative standard deviation less than 10%, and the limit of detection and limit of quantification were 0.0125 and 0.05 mg/kg, respectively. The result of recoveries and overall coefficient of variation of the laboratory results from Gwangju regional Food and Drug Administration (FDA) and Daejeon regional FDA was accorded with Codex Alimentarius Commission Guideline (CAC/GL 40). Based on these results, this method was found to be appropriate for ametoctradin residue determination and can be used as the official method of analysis.

• 한국벤처창업학회:학술대회논문집
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• 2022.04a
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• pp.51-56
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• 2022

오늘날의 4차산업혁명시대에서는 전통적인 대기업보다는 신속하게 사업을 추진하는 스타트업이 혁신을 주도하고 있다. 스타트업은 문제 해결에 도전하는 활동을 수행하는 프로젝트 조직으로서, 개인사업자 또는 법인 등 법적으로 인정되는 기업을 설립하는 단계인 창업과는 분명히 구분되어야 한다. 다시 말해, 스타트업 활동을 통해 일정 수준 이상의 사업성을 검증하는 준비 단계의 창업 전 스타트업과 그 결과로 창업 과정을 거친 창업 후 스타트업으로 구분해야 한다. 또한, 현재 대부분의 대학교에서는 다양한 창업 교육교과/비교과 프로그램들을 진행하고 있는데, 실제 대학생 졸업 후 취업률 대비 창업률은 비율이 극히 낮은 실정이다. 이를 감안할 때 대학생에게 창업을 목표로 하기 보다는, 도전적인 창업가 정신을 함양하고 스타트업 활동 중심의 교육을 통해 자신의 진로 적성을 찾고, 그 분야의 스타트업에의 취업을 우선 목표로 하는 교육이 스타트업의 인력난 문제를 해결한다는 측면에서 볼 때 스타트업 생태계 발전에 보다 바람직하다. 본 연구에서는 먼저 캠퍼스 스타트업 문화 확산을 위한 교육 방향으로 스타트업 관련한 '경험 확대 - 진로 선택 - 실무 체험 - 진로 실행' 단계별 지원을 제안한다. 다음으로 실제 대학교에서 개설하고 운영한 일련의 교육 프로그램으로서 진로 지도, 스타트업 활동 이해, 스타트업 활동용 디지털 리터러시, 스타트업 협력 프로젝트, 스타트업 인턴 준비 교육 과정 및 결과들을 사례로 소개한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.10C
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• pp.614-620
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• 2011

RSA, the most commonly used public-key cryptosystem, is based on the difficulty of factoring very large integers. The fastest known factoring algorithm is the Number Field Sieve(NFS). NFS first chooses two polynomials having common root modulo N and consists of the following four major steps; 1. Polynomial Selection 2. Sieving 3. Matrix 4. Square Root, of which the most time consuming step is the Sieving step. However, in recent years, the importance of the Polynomial Selection step has been studied widely, because one can save a lot of time and memory in sieving and matrix step if one chooses optimal polynomial for NFS. One of the ideal ways of choosing sieving polynomial is to choose two polynomials with same degree. Montgomery proposed the method of selecting two (nonlinear) quadratic sieving polynomials. We proposed two cubic polynomials using 5-term geometric progression.

• Journal of the Korea Convergence Society
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• v.10 no.11
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• pp.71-77
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• 2019

This paper defines a multi-selection knapsack problem and presents an algorithm for seeking its optimal solution. Multi-selection means that all members of the particular group be selected or excluded. Our branch-and-bound algorithm introduces a simplex containing the feasible region of the original problem to exploit the fact that the most tightly underestimating function on the simplex is linear. In bounding operation, the subproblem defined over the candidate simplex is minimized. During the branching process the candidate simplex is splitted into two one-less dimensional subsimplices by being projected onto two hyperplanes. The approach of this paper can be applied to solving the global minimization problems under various types of the knapsack constraints.