• Title/Summary/Keyword: mathematics

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A Study about the Logical Thinking Ability and the Metacognition of Economically Disadvantaged Gifted Students (소외 영재의 논리적 사고력과 상위인지에 대한 연구)

  • Lee, Mi-Soon;Cho, Seok-Hee;Lee, Hyun-Joo
    • Journal of Gifted/Talented Education
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    • v.16 no.2
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    • pp.167-191
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    • 2006
  • The purpose of this study was to explore logical thinking abilities and metacognitive characteristics by student's giftedness and grade level. Furthermore, this study sought to present the practical basis for the promotion of students' abilities in self-driven learning as well as cognition. Average-ability students(n=199), economically disadvantage gifted students(n=133), and gifted students(n=111), who were sampled by two-step sampling procedures, responded the logical thinking ability test(Cho et al, 2006) and the questionnaire asking self-perception for 'metacognitive knowledge' and 'metacognitive control' abilities(Cho & Han, 2004). As the results, average-ability students showed less logical thinking abilities(in language, mathematics, and space) than gifted students. The logical thinking abilities had affected by giftedness, grade level and these interaction. And gifted students showed higher metacognitive control abilities in planning, monitoring, priority, and strategies of learning than average-ability students. However, there were no significant differences in metacognitive knowledge and metacognitive control abilities between economically disadvantaged gifted students and gifted students.

Probable Volcanic Flood of the Cheonji Caldera Lake Triggered by Volcanic Eruption of Mt. Baekdusan (백두산 화산분화로 인해 천지에서 발생 가능한 화산홍수)

  • Lee, Khil-Ha;Kim, Sung-Wook;Yoo, Soon-Young;Kim, Sang-Hyun
    • Journal of the Korean earth science society
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    • v.34 no.6
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    • pp.492-506
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    • 2013
  • The historical accounts and materials about the eruption of Mt. Baekdusan as observed by the geological survey is now showing some signs of waking from a long slumber. As a response of the volcanic eruption of Mt. Baekdusan, water release may occur from the stored water in Lake Cheonjii caldera. The volcanic flood is crucial in that it has huge potential energy that can destruct all kinds of man-made structures and that its velocity can reach up to 100 km $hr^{-1}$ to cover hundreds of kilometers of downstream of Lake Cheonji. The ultimate goal of the study is to estimate the level of damage caused by the volcanic flood of Lake Cheon-Ji caldera. As a preliminary study a scenario-based numerical analysis is performed to build hydrographs as a function of time. The analysis is performed for each scenario (breach, magma uplift, combination of uplift and breach, formation of precipitation etc.) and the parameters to require a model structure is chosen on the basis of the historic records of other volcanos. This study only considers the amount of water at the rim site as a function of time for the estimation whereas the downstream routing process is not considered in this study.

Damage and Socio-Economic Impact of Volcanic Ash (화산재 양에 따른 피해와 사회 · 경제적 영향 분석)

  • Jiang, Zhuhua;Yu, Soonyoung;Yoon, Seong-Min;Choi, Ki-Hong
    • Journal of the Korean earth science society
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    • v.34 no.6
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    • pp.536-549
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    • 2013
  • This study investigates the damages of and analyzes the social and economic impacts of volcanic ash eruptions in the world in order to estimate the potential volcanic ash impacts in South Korea when Mt. Baekdusan volcano erupts in the future. First, we build a comparison chart called "the impact of volcanic ash" on each economic and social sector by using major volcanic eruptions and we compare the damage with respect to volcanic ash thickness/weights. Secondly, we analyze the social and economic impact from volcanic ash. The economic damage is not likely to occur in South Korea, unless Mt. Baekdusan erupts in winter. However, the potential damage should not be overlooked because the volcanic ash may have a global impact around the world. If Mt. Baekdusan volcano erupts when the wind blows from north or northeast, the volcanic ash may then significantly affect South Korea of which economy is highly dependent on exports. Particularly when the volcanic ash moves to the densely populated metropolitan areas or agricultural areas, the damage can be significant. In preparation for the potential volcanic disasters, the volcanic ash forecast table suitable for South Korea should be prepared. In addition, building a Korean volcanic ash hazard map in advance will have a strategic significance.

A Study for Automotive Lamp Manufacturing System Control Composing Ultra melting Process (초음파 접합 공정을 합성한 자동차용 램프 생산시스템 제어에 관한 연구)

  • Lee, Il-Kwon;Kook, Chang-Ho;Kim, Seung-Chul;Kim, Ki-Jin;Han, Ki-Bong
    • Journal of the Korean Institute of Gas
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    • v.18 no.1
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    • pp.46-51
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    • 2014
  • The purpose of this paper is to study of the vehicle lamp manufacturing system composing ultrasonic waves connection process. Making lamp assembly plant, it was produced in the separate process as the injection molding, ultrasonic waves bonding, annealing in the constant temperature, lamp assembling and packing. But the improvement method producing the lamp was added with one-step process by one automation technique. As a result, welding with ultrasonic waves process, the method decreased the energy consumption and noise during ultrasonic waves welding. Therefore, this method used the mathematics modeling for checking validity, it selected the stability and suitable controller using transfer function of plant and bode chart. In this study, the $180^{\circ}$ revolution control system to turn injection part upside down was $M_{eq}\;lcos{\theta}(t)$ because of gravity influence. It effected to unstable condition a system. For solving this problem, it aimed the linearization and stabilization of system by elimination $M_{eq}\;lcos{\theta}(t)$ as applying Free-forward control technique.

The Landscape Characteristics of Village Located in the Meander cut-off Area;The Case of Samji Village (곡류단절지에 입지한 마을의 경관특성;삼지마을을 사례로)

  • 임의제;최기수
    • Journal of the Korean Institute of Landscape Architecture
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    • v.28 no.2
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    • pp.109-109
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    • 2000
  • This study seeks what kind of factors influence to locate dwellings and to establish scenic spots in nature by a case study focused on a meandering stream. The study specially concentrates on the interrelationship between both residences and beautiful sceneries and a meander cut-off-area that reveals a special topographical characteristics, located at Samji village in Youngyang-eup, Youngyang-gun, Koungsangbuk-do. The meander cut-off area, developed at the middle or upper reaches of a river, often makes up specific landscapes such as precipitous cliffs, sheer cliffs and caves. And the area where is specially created by sudden change of flow due to erosion perceived by the cut surface to be the most beautiful scenic spot. These beautiful landscapes were used to be called as Dae, Dam or Gul and managed by Confucian scholars who enjoy refined taste and devote themselves to the study in nature. Moreover, the Ku-Hado-literary means the area of ex-flow-made the scholars' lving with a well prepared basis for agriculture where supplied a cornucopia of organic matters and water. The merit of agriculture made it possible that the scholars became economically independent, and the fact might be the essential point why the meander cut-off area took noticed. Actually, Cho-family has been in Smaji Village for generations, producing a large number of scholars and keeping the actual power of the region. The physical shape of the meander cut-off area, cozily surrounded by mountains, is considered as a good place for the dwelling due to the influence of traditional sight of view for location and P'ungsuchiri which is known as Feng Shui in China and geomancy in the western world. It is a fruit in it own way that we could find the ancestors' discernment and wisdom from this study, who have lived their lives adapting themselves to the given natural environment and also utilizing the nature wisely. But this is a current-argued study on the meander cut-off area. Follow-up studies have to be continued about the landscapes of the meander streams and the meander cut-off areas scattered all over the country except Samji Village and draw the characteristics from the comparative analysis.

Comparative Study on Monetary Estimates of the Preservation Value of Recreational Forests through Contingent Valuation Methods (자연휴양림 보존가치 측정을 위한 조건부가치측정법(CVM) 추정액 비교)

  • Kang, Kee-Rae
    • Journal of the Korean Institute of Landscape Architecture
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    • v.38 no.2
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    • pp.25-36
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    • 2010
  • The generally known important functions of forests include air purification and the health benefits that humans can receive when relaxing and enjoying recreation in the forests. In recent years, people have appreciated the value of the natural environment but it is not easy to answer the question how much monetary value a natural environment has. Because environmental property is public property, which is not traded on the market, market prices cannot be established, so it is not easy to assess the currency value. Methods for estimating environmental property value have been studied by economists. The representative method for measuring environmental property value is a contingent valuation method, or CVM. Various methods have been researched and attempted along with the development and fusion of mathematics, statistics, and economics. Representative methods of CVM are single-bound and double-bound logit and probit methods. This study has been carried out to compare four estimates. Estimates are as follows: the lowest estimate is derived from a single-bound logit WTPmedian while the highest estimate is from double-bound probit WTPmean. While there are some preceding studies on price estimation and methods of measurement through CVM, they offer only partial comparisons. This study suggests four analytic methods and prices through 1,123 questionnaires. The results can be used for the subsequent comparison of estimate prices and the methods of measurement

A Comparative Analysis of Body Composition, Physical Fitness, and Physical Self-Concept between Gifted Students in Math and Science and Non-Gifted Students (과학영재 학생들과 일반학생들의 신체조성, 체력 및 신체적 자아개념 비교 분석)

  • Song, Kang-Young;Ahn, Jeong-Deok
    • The Journal of the Korea Contents Association
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    • v.14 no.11
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    • pp.450-466
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    • 2014
  • This study compared and analyzed body composition, physical fitness, and physical self-concept between gifted students in mathematics and science attending Korea Science Academy (KSA) and non-gifted students attending traditional high schools. The KSA students were 117 males who entered the school in 2009. As a control group, a total of 117 non-gifted students were randomly selected from 5 cities. The results of covariate analysis taken 2 year interval, pretest (2009) and posttest (2010), indicated that gifted students were significantly taller (p<.05) than non-gifted students, and were lower in BMI (p<.05) and PBF (p<.001). There was no significant difference in physical fitness between gifted and non-gifted students. But non-gifted students have a significantly higher self-concept in physical appearance (p<.05) and physical strength (p<.05). The internal/external frame of reference model and the Big Fish Little Pond Effect (BFLPE) theory were supported. Especially, gifted students were significantly higher (p<.01) in endurance self-concept than non-gifted students. We have discussion this result as the future research subject whether it come from the characteristics of the gifted's tenacity at high level tasks.

A Case Study On Digital Media Design Of Education In Foreign Countries (디지털 교육매체 디자인에 관한 국외 사례 연구)

  • Kim, Jung-Hee
    • Cartoon and Animation Studies
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    • s.27
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    • pp.177-198
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    • 2012
  • Development of digital media and interest in education bring big progress at digital device of education globally. UK which is advanced country of education is using digital education devices such as digital chalkboards, digital desks etc. and Japan plan digital text book's through the state. At 2011, Korea which is advanced country of internet adopted digital text book 2007 with mathematics, through science and English digital text book through the state. Korea's digital textbook is in a transition period, that needs case-study of advanced country of education for setting design guide and educational effect to Digital text book plan. All researches are based on LG europe design center at London, UK and target countries are UK and Sweden which is advanced country of education and a welfare state. Analysis by using FGI, KJ, survey of questionnaire, heuristic method, concentration observation. Through analytical researches prefer using digital text book with paper text book to using solo that can offer each advantage to user and teacher. Especially Interactive GUI design of digital text book to easy to access for teacher whom not friendly with digital device. When plan Digital text book content and design needs methodical design guide for target who students and teachers an in-depth study of the appraisal and method. The results of the research are introduce the design plan as a basic research and giving useful design plan to make digital text book and digital educational media in industrial aspect.

Reactive transport modeling of the $CO_2-H_2O$-cement reaction in a $CO_2$ injection well for $CO_2$ geological storage ($CO_2$ 지중저장 주입정에서의 $CO_2-H_2O$-시멘트 반응 운송 모델링)

  • Jo, Min-Ki;Chae, Gi-Tak;Choi, Byoung-Young;Yu, Soon-Young;Kim, Tae-Hee;Kim, Jeong-Chan
    • The Journal of Engineering Geology
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    • v.20 no.4
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    • pp.359-370
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    • 2010
  • $CO_2$ leakage from a geological formation utilized for $CO_2$ storage could result in failure of the facility and threaten the environment, as well as human safety and health. A reactive transport model of a $CO_2-H_2O$-cement reaction was constructed to understand chemical changes in the case of $CO_2$ leakage through a cement crack in an injection well, which is the most probable leakage pathway during geological storage. The model results showed the dissolution of portlandite and CSH (calcium silicate hydrate) within the cement paste, and the precipitation of secondary CSH and calcite as the $CO_2$ plume migrated along the crack. Calcite occupied most of the crack after 3 year of reaction, which could be maintained until 30 years after crack development. The present results could be applied in the development of technology to prevent $CO_2$ leakage and to enhance the integrity of wells constructed for $CO_2$ geological storage.

A Study on a Multiresolution Filtering Algorithm based on a Physical Model of SPECT Lesion Detectability (SPECT 이상조직 검출능 모델에 근거한 다해상도 필터링 기법 연구)

  • Kim, Jeong-Hui;Kim, Gwang-Ik
    • Journal of Biomedical Engineering Research
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    • v.19 no.6
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    • pp.551-562
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    • 1998
  • Amultiresolution filtering algorithm based on the physical SPECT lesion detachability provides and optimal solution for SPECT reconstruction problem. Related to the previous study, we estimated the SPECT lesion detection capability by m minimum detectable lesion sizes (MDLSs), and generated m reconstruction filters which are designed to maximize the smoothing effect at a fixed MDLS-dependent resolution level $\frac{MDLS}{4\sqrt{2In2}}$. The proposed multiresolution filtering algorithm used a coarse-to-fine approach for the m-level resolution filter images obtained from these m filters for a given projection image. First, the local homogeneity is determined for every pixel of the filter images, by comparing the local variance value computed in a window centered at the pixel and the mode determined from the distribution of the local variances. Based on the local homogeneity, the pixels declared as homogeneous are chosen from the filter image of the lowest resolution, and for the other pixels the same process is repeated for the higher resolution filter images. For the non-homogeneous pixels after this pixels after this repetition process ends, the pixel values of the highest resolution filter image are substituted. From the results of the simulated experiments, the proposed multiresolution filtering algorithm showed a strong smoothing effect in the homogeneous regions and a significant resolution improvement near the edge regions of the projection images, and so produced good adaptability effects in the reconstructed images.

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