• Title/Summary/Keyword: Moon's Phase change

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An Analysis of 'The Phase Changes of the Moon', the Contents in Science Textbook of the 9th Grade

  • Chae, Dong-Hyun
    • 한국지구과학회:학술대회논문집
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    • 2010.04a
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    • pp.73-73
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    • 2010
  • The purpose of this study is to analyze illustrations, contents, and experiment in 6 kinds of science textbook from the 9th grade covering the phase change of the Moon (on the phase change of the Moon in six 9th grade science textbook) and to suggest coherent and effective contents and frame of the science textbook. Hence, the researcher decided the study problem. The study problems are as follows; 'Are the illustrations in the science textbook presented to help understand the phase change of the Moon depending on the position of the observer?', 'Does the contents of the book clearly mention the phase change of the Moon?', 'Can students understand the phase change of the Moon through the experiments in the science textbook?', 'Do illustrations, contents, and experiment of the science textbook consistently explain phase change of the Moon?'. 10 persons (9graduate students including the researcher) took part in this study. All things unanimously agreed upon by all participants were reflected in the results. The results are as follows. First, the universe observer's view point is mixed with the earth observer's view in illustration of these science textbook regarding the phase change of the Moon. Moreover, illustrations of some textbooks are presented with such words as 'sunrise', 'midnight' and consequently contain too much contents. Second, the contents of the science textbook concerning the phase change of the Moon is not described clearly. In addition, they don't give clear and detailed explanations for the reason of the phase change of the Moon. Third, all of the textbooks, except one textbook, describe the experiment regarding the phase change of the Moon with the earth observer's view point but don't specifically mention that the view point is that of the earth observer's view point. Fourth, illustrations, contents, and experiments in the science textbook don't coherently explain the phase change of the Moon. In addition, it is confirmed through the process of the result analysis that the described contents in the science curriculum is not well constructed or logical.

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Elementary School 5th Students' Understanding of the Illustrations on the Phase change of the Moon in Science Textbook of 2007 and 2009 Revised National Curriculum (2007과 2009 개정 과학교과서에 제시된 달의 위상 변화 삽화에 대한 초등학교 5학년 학생들의 이해)

  • Yang, Il-Ho;Kim, Jung-Yun;Lim, Sung-Man
    • Journal of the Korean Society of Earth Science Education
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    • v.8 no.1
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    • pp.56-65
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    • 2015
  • The purpose of this study is to investigate how elementary school student understands or students understand the illustrations on the phase change of the Moon in science textbook and to find out how textbook illustration helps students form the conception of the phase change of the Moon. To identify this purpose, we selected illustrations on the phase change of the Moon in the science textbook revised in 2007 and 2009 revised science textbook. For this study we selected and interviewed 20 students in the fifth grade. We integrated all data collected through interviews and created a transcription and a protocol and then, confirmed scientific conceptions related to the phase change of the Moon in students' illustration reading. The result are as followings: First, students read more scientific conceptions related to the phase change of the Moon in illustration of the 2009 revised science textbook which is presented with the universal observer's view point and the earth observer's view point. Second, students who find meaning in the various elements of the illustration and interpret with the integration of the various elements, get a lot of relevant information from illustration. All students have no differences recognizing the elements presented in illustration. But there are differences of contents of illustration reading depending on how students interpret the illustrations with integration of the various elements and if students cannot figure out the four scientific concepts needed to understand the phase change of the Moon, they ignore the information provided by illustration or analysis in their own way according to information provided by illustration. So misconception appears in this process.

Vibration and Noise Characteristics of SRM with Hybrid Excitation (하이브리드 여자방식 SRM의 진동.소음 저감 특성)

  • Kim, C.S.;Moon, J.W.;Oh, S.G.;Ahn, J.W.;Hwang, Y.M.
    • Proceedings of the KIEE Conference
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    • 2000.07b
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    • pp.638-640
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    • 2000
  • The main source of vibration in SRM drive is generated by rapid change of radial force when phase current is extinguished by commutation action. In this paper a hybrid excitation method is proposed to reduce vibration and acoustic noise of SRM. The hybrid excitation has 2-phase excitation by long dwell angle as well as conventional 1-phase excitation. The vibration and acoustic noise are reduced because the scheme reduces abrupt change of excitation level by distributed and balanced excitation.

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The Development and Application of the New Model of Moon Phases (새로운 달 위상 모형의 개발과 그 적용)

  • Chae, Dong-Hyun
    • Journal of Korean Elementary Science Education
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    • v.27 no.4
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    • pp.385-398
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    • 2008
  • The purpose of this study is to understand the effect of The Model of Phases of the Moon on conception changes for preservice teachers. The researcher interviewed two preservice teachers under the agreement with them on their participation in the research just before he performed a class using The New Model of Phases of the Moon. The post-interview with the same content as the pre-interview was preformed one month later. The main content of the interview is as follows; 'Explain the shape of the Moon by drawing it.', 'Explain the relative different position among the Sun, Earth, and Moon depending on phases of the Moon by drawing them.', 'What do you think of the cause of phases of the Moon?', 'Draw a picture to explain why we always see only one side of the moon.' The results of the research are as follows. First, the class with New Model of Phases of the Moon was able to perceive the relationship of Sun, Earth, and Moon in three-dimensions rather than in two-dimensions and it helped to change their misconception that the Moon's shadow causes the Moon's shape. Secondly, the class with New Model of Phases of the Moon helped preservice teachers understand better the different positional relationships among the Sun, Earth, and Moon depending on the Moon shapes. Third, the class adopting the New Model of Phases of the Moon help preservice teachers form scientific conceptions on the causes of phase change of the Moon. Fourth, the class with the New Model of Phases of the Moon is not appropriate for explaining the reason why only one face of the Moon is seen. Based upon the results above, the researcher realized the limitation of this model and suggested that this model would help learners understand phase change of the Moon and increase space perception ability.

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A CBR-BASED COST PREDICTION MODEL FOR THE DESIGN PHASE OF PUBLIC MULTI-FAMILY HOUSING CONSTRUCTION PROJECTS

  • TaeHoon Hong;ChangTaek Hyun;HyunSeok Moon
    • International conference on construction engineering and project management
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    • 2009.05a
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    • pp.203-211
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    • 2009
  • Korean public owners who order public multi-family housing construction projects have yet to gain access to a model for predicting construction cost. For this reason, their construction cost prediction is mainly dependent upon historic data and experience. In this paper, a cost-prediction model based on Case-Based Reasoning (CBR) in the design phase of public multi-family housing construction projects was developed. The developed model can determine the total construction cost by estimating the different Building, Civil, Mechanical, Electronic and Telecommunication, and Landscaping work costs. Model validation showed an accuracy of 97.56%, confirming the model's excellent viability. The developed model can thus be used to predict the construction cost to be shouldered by public owners before the design is completed. Moreover, any change orders during the design phase can be immediately applied to the model, and various construction costs by design alternative can be verified using this model. Therefore, it is expected that public owners can exercise effective design management by using the developed cost prediction model. The use of such an effective cost prediction model can enable the owners to accurately determine in advance the construction cost and prevent increase or decrease in cost arising from the design changes in the design phase, such as change order. The model can also prevent the untoward increase in the duration of the design phase as it can effectively control unnecessary change orders.

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Development of Cost Management Process during Design Phase based on Design to Cost (DTC(Design to Cost)기반의 설계단계 사업비관리 프로세스 개발)

  • Park, So-Hyun;Moon, Hyun-Seok;Hyun, Chang-Teak
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2009.11a
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    • pp.209-212
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    • 2009
  • The Development of Cost Management is embossed efficiently to use the budget for the construction industry. The government is exploring every efforts and polices to control increasing the budget for the construction industry. However, despite of the government's efforts, researches are insufficient for a cost management of development. Also, the changed cost of construction by frequent plan change is caused of decline in quality etc during an accomplishing project. Therefore, in this study, analyzed about principal official phase of design phase to solve the problem. In order to define clearly the target cost concepts in the planning phase apply to the DTC(Design To Cost) concept and technique at the development of cost management process which will be able to manage the enterprise expense. It's process is expected with the fact that will be the possibility efficiently of fixing target cost in the planning phase by the construction client and designer.

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The Differences in Eye Movement of Pre-service Teachers and Elementary School Students in SBF Question about a Visual Material of the Change on the Lunar Phases (달 위상 변화의 시각화 자료에서 SBF 질문에 따른 예비교사와 초등학생의 시선 이동 차이)

  • Ko, Minseok;Yang, Ilho;Kim, Obeom;Lim, Sungman
    • Journal of Korean Elementary Science Education
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    • v.33 no.2
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    • pp.273-285
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    • 2014
  • Purpose of this study is to analyze eye movements of pre-service teachers and elementary students about a visual material of the change on the lunar phases. Eye-Tracker was used for analysis for eye-fixation time and eye movement at the structure, behavior, function question on the visual material. The Results were as follows. First, the pre-service teacher checked the visual materials from a holistic perspective depending on the function questions and fixed eye-fixation on the moon of the behavior question concerned. On the contrary, elementary school student only checked function of the moon located in the upper part and eye-fixation focus was spread here and there regardless of the questions. Second, the pre-service teacher gazed at the sun, earth and moon in a consecutive order depending on the questions to identify their spatial relations and checked location of the moon related to the question. On the contrary, the elementary school student did not view relations between earth, sun and moon from a spatial perspective. These findings indicate that the pre-service teacher conjures up the mechanism of the change on the lunar phases and confirms it in visual materials by visualizing change on the lunar phase model from earth's point of view while the elementary school student fails to take advantage of visual materials to visualize it from earth's point of view.

A Case Study on the Cultural Innovation and Change in Performance of the Railway Construction Authority (철도건설기관의 조직문화혁신과 성과변화에 관한 사례연구)

  • Ryu, Keun-Ok;Moon, Dae-Sup;Kim, Young-Woo
    • Journal of the Korean Society for Railway
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    • v.10 no.1 s.38
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    • pp.29-33
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    • 2007
  • This paper considers the case study of the change management and business innovation of the rail construction agency fer overcoming the crisis it faced in early stage. It will provide the suitable innovation techniques of each change stage. Also, each phase it evaluated the change degree of organization culture especially by the six box model of Weisbord and the Quinn's model. For the Period of Change, organization culture will grow about 10% and harmonize with 4 competitive organization culture; community, innovation, hierarchy, product. Only, it discovered that the difference of the current culture and rho organizer' wish is considerable by the Quinn's model. It wilt be able to describe the innovation fatigue which the organizers feel in the change of organization culture. For the successful innovation, it wilt have to be managed properly and the new innovation technique will have to be developed for solving.

Study on the Change of Nuclear Energy Policy: Before and After Fukushima Nuclear Accident (원자력 정책 변동에 관한 연구: 후쿠시마 원전 사고 전후를 중심으로)

  • Park, Soo-Kyung;Jang, Dong-Hyun
    • The Journal of the Korea Contents Association
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    • v.19 no.6
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    • pp.222-235
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    • 2019
  • Since Fukushima nuclear disaster occurred in 2011, the nuclear energy policy of the international society has been in recession. However, In Korea, the nuclear-friendly policy had remained and even expanded over the last 60 years until the Park Geun-hye government. In other words, there was the path dependence of nuclear energy policy. Since the Moon Jae-in government that pledged to perform nuclear phase-out policy in 2017 was inaugurated, the nuclear-friendly policy began to swerve from the course of path dependence. Based on the mai logic of historical institutionalism, this study looked into the change of Korean nuclear policy by before and after the Fukushima nuclear accident. As the result of this research, the external situation of Fukushima Nuclear Accident became a critical turning point and led to a change in the government's policy on nuclear power. From an institutional perspective, it influenced the paradigm of nuclear power policy, policy decision structure, and laws of nuclear power. From a doer's perspective, it influenced political idea and social acceptability. Since Moon Jae-in government was inaugurated in 2017, nuclear phase-out policy has secured its institutional foundation and nuclear power policy has basically changed from nuclear-friendly policy to nuclear phase-out policy. Therefore, the energy policy of Moon Jae-in government gets out of the nuclear power based path dependency that previous governments pursued, keeps punctuated equilibrium, and changes to renewable energy oriented policy.

Baseline Refinement for Topographic Phase Estimation using External DEM

  • Lee, Chang-Won;Moon, Wooil-M.
    • Proceedings of the KSRS Conference
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    • 2002.10a
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    • pp.460-464
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    • 2002
  • Multitemporal interferometric SAR has became an useful geodetic tool for monitoring Earth's surface deformation, generation of precise DEM, and land cover classification even though there still exist certain constraints such as temporal and spatial decorrelation effects, atmospheric artifacts and inaccurate orbit information. The Korea where nearly all areas are heavily vegetated, JERS-1 SAR has advantages in monitoring surface deformations and environmental changes in that it uses 4-times longer wavelength than ERS-l/2 or RADARSAT SAR system. For generating differential SAR interferogram and differential coherence image fer deformation mapping and temporal change detection, respectively, topographic phase removal process is required utilizing a reference inteferogram or external DEM simulation. Because the SAR antenna baseline parameter for JERS-1 is less accurate than those of ERS-l/2, one can not estimate topographic phases from an external DEM and the residual phase appears in differential interferogram. In this paper, we examined topographic phase retrieval method utilizing an external DEM. The baseline refinement is carried out by minimizing the differences between the measured unwrapped phase and the reference points of the DEM.

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