• 제목/요약/키워드: 개념변화모형

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The Prediction of Currency Crises through Artificial Neural Network (인공신경망을 이용한 경제 위기 예측)

  • Lee, Hyoung Yong;Park, Jung Min
    • Journal of Intelligence and Information Systems
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    • v.22 no.4
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    • pp.19-43
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    • 2016
  • This study examines the causes of the Asian exchange rate crisis and compares it to the European Monetary System crisis. In 1997, emerging countries in Asia experienced financial crises. Previously in 1992, currencies in the European Monetary System had undergone the same experience. This was followed by Mexico in 1994. The objective of this paper lies in the generation of useful insights from these crises. This research presents a comparison of South Korea, United Kingdom and Mexico, and then compares three different models for prediction. Previous studies of economic crisis focused largely on the manual construction of causal models using linear techniques. However, the weakness of such models stems from the prevalence of nonlinear factors in reality. This paper uses a structural equation model to analyze the causes, followed by a neural network model to circumvent the linear model's weaknesses. The models are examined in the context of predicting exchange rates In this paper, data were quarterly ones, and Consumer Price Index, Gross Domestic Product, Interest Rate, Stock Index, Current Account, Foreign Reserves were independent variables for the prediction. However, time periods of each country's data are different. Lisrel is an emerging method and as such requires a fresh approach to financial crisis prediction model design, along with the flexibility to accommodate unexpected change. This paper indicates the neural network model has the greater prediction performance in Korea, Mexico, and United Kingdom. However, in Korea, the multiple regression shows the better performance. In Mexico, the multiple regression is almost indifferent to the Lisrel. Although Lisrel doesn't show the significant performance, the refined model is expected to show the better result. The structural model in this paper should contain the psychological factor and other invisible areas in the future work. The reason of the low hit ratio is that the alternative model in this paper uses only the financial market data. Thus, we cannot consider the other important part. Korea's hit ratio is lower than that of United Kingdom. So, there must be the other construct that affects the financial market. So does Mexico. However, the United Kingdom's financial market is more influenced and explained by the financial factors than Korea and Mexico.

Suggesting Strategies of Integrating Science Based on Worldview: Climate Change (세계관을 바탕으로 통합과학 교육전략 제안: 기후변화를 중심으로)

  • Oh, Jun-Young;Son, Yeon-A
    • Journal of the Korean Society of Earth Science Education
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    • v.11 no.1
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    • pp.1-20
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    • 2018
  • The purpose of this study is to suggest some strategies for integrated science. It also suggests educational strategies through worldview. The directions of most educational policy are based on the deficit model. It is assumed that learners are always lacking in knowledge, and as a result they do not understand properly. However, it is difficult for the public and students to change their attitudes because they do not feel much lacking. For example, the world view of climate change coexists with an optimistic mechanical worldview and an organic and entropy worldview. This study is characterized by the process of expanding awareness of living and fulfillment of knowledge rather than the existing deprivation model. Unconnected knowledge has problems in diversity. It is neither sustainable nor flexible. It is not about eliminating interdisciplinarity but about lowering it. We go into another area with your deep expertise, but we must have a purpose. As a result, not only problem solving but also dynamic feedback of mutual feedback between other domains increases the quality and quantity of knowledge.

Research for The Environmental Optimization of Dose and Image quality in Digital Radiography (디지털 방사선촬영 환경에서 선량의 최적화 및 영상품질에 대한 연구)

  • Lee, Kwang Jae;Kim, MinGi;Lee, Jong Woong;Kim, Ho Cheol
    • Journal of the Institute of Electronics and Information Engineers
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    • v.50 no.2
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    • pp.203-209
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    • 2013
  • Digital Radiography (DR) has improved a quality of resolution based on a wide dynamic range, high detective quantum efficiency (DQE), and modulation transfer function (MTF), compared with film/screen(F/s). Unlike expectation that a low level of radiation can be used in examination, high level of signal to noise ratio(SNR) due to over-exposure caused increase of exposed dose to patients. Also, the auto exposure control (AEC) using Kilovolage(kVp) in F/S can cause over-exposure. Hence, in this study, we proposed a proper method for using DR, in which effect of tubing Kilovolage on device's image, DR MTF measurement with changes of tubing current (mA), and the quantitative evaluation of skull phantom captured images' PSNR were evaluated. Changes of contrast with tubing Kilovolage can be improved by retouching, and MTF changes according to tubing current(1.41~1.39 lp/mm in 50% area, and 3.19~2.8 lp/mm in 10% area) does not influence on resolution of image. As a result, high tubing Kilovoltage, and tubing current will be suitable to use of DR.

A Study on the Effects of Design Thinking Process and Maker Education on University Students' Start-Up Activities (디자인사고방법 활용 메이커교육이 대학생 창업역량에 미치는 영향에 관한 탐색 연구)

  • Kim, Tae-Ywan
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.16 no.6
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    • pp.177-196
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    • 2021
  • In the era of the 4th industrial revolution, high technology is causing many changes in modern society and economy. Among them, changes in industries and jobs require new competencies of future human resources. As an educational alternative to these changes, maker education and design thinking methods are spreading around the world, and it is necessary to actively apply such education in university curriculum. Therefore, this study examines the effects of the maker education using the design thinking method on the learners' competencies required as future human resources and, relationship between the development of university students' entrepreneurial competencies and learners' competencies. And the purpose of this study is to contribute to the vitalization of entrepreneurship education for university students by suggesting an educational model. For this purpose, this study investigated the prior research on maker education/environment and design thinking methods to examine concepts and characteristics, and analyzed the influences between maker education/environment and design thinking methods and the development of learners' personal, social and technological capabilities. In addition, this study analyzed the relationship between learners' developed capabilities and university students' entrepreneurial capabilities, and based on the results, suggested directions and conceptual models for education that combine maker education/environment and design thinking methods. In conclusion, maker education/environment and design thinking methods in university education have a positive effect on the cognitive, social, and technological development of learners, and this has a significant relationship with the factors of personal, social, and technological dimensions of university students' entrepreneurial competency. It is analyzed that it has a positive effect on the promotion of entrepreneurship activities of university students. Therefore, it is judged that university's interest and support should be given to the vitalization of maker education using the design thinking method for university student entrepreneurship education and future human resources nurturing.

Estimation of Groundwater Recharge by Considering Runoff Process and Groundwater Level Variation in Watershed (유역 유출과정과 지하수위 변동을 고려한 분포형 지하수 함양량 산정방안)

  • Chung, Il-Moon;Kim, Nam-Won;Lee, Jeong-Woo
    • Journal of Soil and Groundwater Environment
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    • v.12 no.5
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    • pp.19-32
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    • 2007
  • In Korea, there have been various methods of estimating groundwater recharge which generally can be subdivided into three types: baseflow separation method by means of groundwater recession curve, water budget analysis based on lumped conceptual model in watershed, and water table fluctuation method (WTF) by using the data from groundwater monitoring wells. However, groundwater recharge rate shows the spatial-temporal variability due to climatic condition, land use and hydrogeological heterogeneity, so these methods have various limits to deal with these characteristics. To overcome these limitations, we present a new method of estimating recharge based on water balance components from the SWAT-MODFLOW which is an integrated surface-ground water model. Groundwater levels in the interest area close to the stream have dynamics similar to stream flow, whereas levels further upslope respond to precipitation with a delay. As these behaviours are related to the physical process of recharge, it is needed to account for the time delay in aquifer recharge once the water exits the soil profile to represent these features. In SWAT, a single linear reservoir storage module with an exponential decay weighting function is used to compute the recharge from soil to aquifer on a given day. However, this module has some limitations expressing recharge variation when the delay time is too long and transient recharge trend does not match to the groundwater table time series, the multi-reservoir storage routing module which represents more realistic time delay through vadose zone is newly suggested in this study. In this module, the parameter related to the delay time should be optimized by checking the correlation between simulated recharge and observed groundwater levels. The final step of this procedure is to compare simulated groundwater table with observed one as well as to compare simulated watershed runoff with observed one. This method is applied to Mihocheon watershed in Korea for the purpose of testing the procedure of proper estimation of spatio-temporal groundwater recharge distribution. As the newly suggested method of estimating recharge has the advantages of effectiveness of watershed model as well as the accuracy of WTF method, the estimated daily recharge rate would be an advanced quantity reflecting the heterogeneity of hydrogeology, climatic condition, land use as well as physical behaviour of water in soil layers and aquifers.

Development of Highway Safety Evaluation Considering Design Consistency using Acceleration (가속도를 고려한 도로의 설계일관성 평가기법에 관한 연구)

  • 하태준;박제진;김유철
    • Journal of Korean Society of Transportation
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    • v.21 no.1
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    • pp.127-136
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    • 2003
  • Road safety is defined under the minimum design standard and design examination process is consisted of the standard according to current road design. However, road safety in practical way is correlative to not only all element of roads but also road shape, such as, between straight line and curved line and between curved lines. Also. it is related to alignments such as horizontal alignment and vertical alignment, and cross section. That is, the practical road design should be examined in both sides of 3 dimension and consecutiveness (consistency) as the actual road is a 3 - dimensional successive object. The paper presents a concept for acceleration to evaluate consistency of road considering actual road shape on 3-dimension. Acceleration of vehicle is influential to road consistency based on running state of vehicles and state of drivers. The magnitude of acceleration. especially, is a quite influential element to drivers. Based on above, the acceleration on each point on 3-D road can be calculated and then displacement can be done. Computation of acceleration means total calculation on each axis. Speed profile refers to “Development of a safety evaluation model for highway horizontal alignment based on running speed(Jeong, Jun-Hwa, 2001)” and then acceleration can be calculated by using the speed pronto. According to literature review, definition of acceleration on 3-D and g-g-g diagram are established. For example, as a result of the evaluation, if the acceleration is out of range, the road is out of consistency. The paper shows calculation for change of acceleration on imaginary road under minimum design standard and the change tried to be applied to consistency. However accurate acceleration is not shown because the speed forecasting model is limited and the paper did not consider state of vehicles (suspension, tires and model of vehicles). If speed pronto is defined exactly, acceleration is calculated on all road shapes, such as. compound curve and clothoid curve. and then it is appled to consistency evaluation. Unfortunately, speed forecasting model on 3 -D road and on compound curves have rarely presented. Speed forecasting model and speed profile model need to be established and standard of consistency evaluation need to developed and verified by experimental vehicles.

Development and Application of a Conceptual Change Model for Effective Laboratory Teaching (효과적인 실험 수업을 위한 개념 변화 수업모형의 개발 및 적용)

  • Noh, Tae-Hee;Kang, Suk-Jin;Kim, Hye-Kyung;Chae, Woo-Ki;Noh, Suk-Goo
    • Journal of The Korean Association For Science Education
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    • v.17 no.2
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    • pp.179-189
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    • 1997
  • In this study, a conceptual change model for effective laboratories was developed and its instructional effect on students' achievement, the acquisition of scientific conceptions, and the attitudes toward science was investigated. Considering several conceptual change models in literature and Korean educational situations, the conceptual change model was developed. The model consists of 5 stages; preliminary, prediction, exploration, consolidation and reconstruction, and application. The treatment and control groups (2 classes) were selected from a middle school in Seoul, and taught about the changes of states, density, and dissolution for three weeks. Prior to instruction, the Group Assessment of Logical Thinking and the Learning Approach Questionnaire were administered, and their scores were used as covariate and / or blocking variable. To examine students' alternative conceptions before the instructions, a pre-conceptions test was also administered. After the instructions, students' achievement, the acquisition of scientific conceptions, and the attitudes toward science were measured with a researcher-made achievement test, a post-conceptions test, and the subtests of the Test of Science-Related Attitudes, respectively. The results indicated that the score of the treatment group was significantly higher than that of the control group in the post-conceptions test. The students in the treatment group had also less alternative conceptions than those in the control group. However, there were no significant differences for the achievement and the attitudes toward science. Educational implications are discussed.

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An Exploratory Study on Paradigms, Policies in the Digital Convergence Era (디지털 컨버전스 시대의 특징 : 그 패러다임과 정책 방향)

  • Han, Hak-Soo
    • Journal of Digital Convergence
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    • v.10 no.1
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    • pp.455-461
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    • 2012
  • The paper explores the relationship among paradigms, ecosystem which need to establish broadcasting, information and communications industry as the core of national competitiveness in the digital convergence era, and proposes the future progressing strategies and policies directions that consider environmental factors which all mass media converged on Internet. This paper makes an attempt to contribute innovative & integrated perspectives in the industry.

Analysis on the groundwater usage in Pyoseon area by using the integrated SWAT-MODFLOW model (SWAT-MODFLOW모형을 이용한 표선 지역 지하수 이용량 분석)

  • Kim, Nam-Won;Chung, Il-Moon;Yoo, Sang-Yeon;Lee, Jeong-Woo
    • Proceedings of the Korea Water Resources Association Conference
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    • 2009.05a
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    • pp.1939-1944
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    • 2009
  • 우리나라의 대표적인 도서지역인 제주도는 일반 내륙지역과 달리 지표수-지하수에 대한 연구가 지하수계에 대한 연구에 비해 미미한 실정이다. 제주도의 경우 내륙과 달리 대부분의 하천이 평상시 건천의 형태로 유지되며, 일정한 강우가 도달해야만 지표유출이 발생하는 경우가 많다. 이와 같은 하천특성은 내륙과 매우 상이하여 일반적으로 사용되는 유역 수문해석 방법으로는 수문성분의 정확한 산정을 기대하기 어렵고 이로 인해 지하수 해석에 있어서도 불확실성이 크게 증가하는 요인이 된다. 따라서 지표수의 정확한 거동과 지하수 해석의 불확실성을 줄이기 위해 유역개념의 물순환을 해석할 수 있는 지표수-지하수 연계 해석기술이 필요한 실정이다. 본 연구에서는 '삼다수 먹는샘물 환경영향조사'가 수행되어 비교적 정확한 지하수위 관측 자료가 확보되어 있고, 매우 제한적이기는 하나 하천의 유출량 조사가 수행된 바 있는 제주 표선 유역에 완전연동형 지표수-지하수 해석 프로그램인 SWAT-MODFLOW을 이용하여 지표수 유출성분과 지하수 유동변화를 동시에 고려한 분석을 수행하였다. 특히 MODFLOW의 Well 패키지와 SWAT의 물이동 옵션을 결합하여 표선유역의 198개 관측공의 양수를 동시에 모의하였다. 모의결과 지하수위는 비교적 양수에 비해 안정되게 유지되는 것을 알 수 있었고 이를 통해 현재 삼다수 공장의 양수량은 현재로서는 과다양수가 아닌 것으로 판단되었다. 현재의 양수량의 10배를 가정하여 모의를 한 결과, 지하수위는 함양에 의해 다시 회복되는 결과를 보이고 있어 이 지역의 실제 개발가능량에 대한 보다 심도있는 논의가 필요한 것으로 판단되었다. 나아가 이와 같은 분석을 통해 제주 지역의 전체의 지하수 개발가능량을 산정할 경우 제주지역의 지하수 관리방안이 새롭게 제시될 수 있을 것으로 기대된다.

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Empirical Analysis on the Stress Test Using Credit Migration Matrix (신용등급 전이행렬을 활용한 위기상황분석에 관한 실증분석)

  • Kim, Woo-Hwan
    • The Korean Journal of Applied Statistics
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    • v.24 no.2
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    • pp.253-268
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    • 2011
  • In this paper, we estimate systematic risk from credit migration (or transition) matrices under "Asymptotic Single Risk Factor" model. We analyzed transition matrices issued by KR(Korea Ratings) and concluded that systematic risk implied on credit migration somewhat coincide with the real economic cycle. Especially, we found that systematic risk implied on credit migration is better than that implied on the default rate. We also emphasize how to conduct a stress test using systematic risk extracted from transition migration. We argue that the proposed method in this paper is better than the usual method that is only considered for the conditional probability of default(PD). We found that the expected loss critically increased when we explicitly consider the change of credit quality in a given portfolio, compared to the method considering only PD.