• Title/Summary/Keyword: limited observation

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An efficient numerical modeling approach for coupled electrical cabinets in nuclear power plants

  • Sudeep Das Turja;Md. Rajibul Islam;Dong Van Nguyen;Dookie Kim
    • Nuclear Engineering and Technology
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    • v.56 no.9
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    • pp.3512-3527
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    • 2024
  • Seismic quantification of nonstructural components like electrical cabinets is essential to ensure the uninterrupted operation of nuclear facilities during earthquake events. This process requires experimental tests, which can be expensive, time-consuming, and limited by safety concerns and precision. As an alternative to that, numerical simulations should be done in such a way that they are capable of capturing the global dynamic behavior with minimum computational efforts. However, in the case of complex interconnected cabinets, the simplification of numerical models often poses difficulties in illustrating the real-time behavior of combined cabinet systems. On the other hand, detailed three-dimensional (3D) numerical models require lengthy time and sophisticated computational setup, indicating their expensive computational efforts. To resolve this issue, a simplified and efficient 3D modeling approach has been proposed in this study. The accuracy of the results from the new model showed an excellent match with that obtained from the responses of the experimental test. After the validation and observation of the numerical efficiency, a practical application is implemented by considering the impacts of earthquake frequency contents on the behavior of cabinet systems. From the outcomes, it is evident that this proposed modeling methodology has the potential to replace the complex combined nuclear cabinet models for earthquake evaluation.

A Study on Domestic Applicability for the Korean Cosmic-Ray Soil Moisture Observing System (한국형 코즈믹 레이 토양수분 관측 시스템을 위한 국내 적용성 연구)

  • Jaehwan Jeong;Seongkeun Cho;Seulchan Lee;Kiyoung Kim;Yongjun Lee;Chung Dae Lee;Sinjae Lee;Minha Choi
    • Korean Journal of Remote Sensing
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    • v.39 no.2
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    • pp.233-246
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    • 2023
  • In terms of understanding the water cycle and efficient water resource management, the importance of soil moisture has been highlighted. However, in Korea, the lack of qualified in-situ soil moisture data results in very limited utility. Even if satellite-based data are applied, the absence of ground reference data makes objective evaluation and correction difficult. The cosmic-ray neutron probe (CRNP) can play a key role in producing data for satellite data calibration. The installation of CRNP is non-invasive, minimizing damage to the soil and vegetation environment, and has the advantage of having a spatial representative for the intermediate scale. These characteristics are advantageous to establish an observation network in Korea which has lots of mountainous areas with dense vegetation. Therefore, this study was conducted to evaluate the applicability of the CRNP soil moisture observatory in Korea as part of the establishment of a Korean cOsmic-ray Soil Moisture Observing System (KOSMOS). The CRNP observation station was installed with the Gunup-ri observation station, considering the ease of securing power and installation sites and the efficient use of other hydro-meteorological factors. In order to evaluate the CRNP soil moisture data, 12 additional in-situ soil moisture sensors were installed, and spatial representativeness was evaluated through a temporal stability analysis. The neutrons generated by CRNP were found to be about 1,087 counts per hour on average, which was lower than that of the Solmacheon observation station, indicating that the Hongcheon observation station has a more humid environment. Soil moisture was estimated through neutron correction and early-stage calibration of the observed neutron data. The CRNP soil moisture data showed a high correlation with r=0.82 and high accuracy with root mean square error=0.02 m3/m3 in validation with in-situ data, even in a short calibration period. It is expected that higher quality soil moisture data production with greater accuracy will be possible after recalibration with the accumulation of annual data reflecting seasonal patterns. These results, together with previous studies that verified the excellence of CRNP soil moisture data, suggest that high-quality soil moisture data can be produced when constructing KOSMOS.

Simulation Approach for the Tracing the Marine Pollution Using Multi-Remote Sensing Data (다중 원격탐사 자료를 활용한 해양 오염 추적 모의 실험 방안에 대한 연구)

  • Kim, Keunyong;Kim, Euihyun;Choi, Jun Myoung;Shin, Jisun;Kim, Wonkook;Lee, Kwang-Jae;Son, Young Baek;Ryu, Joo-Hyung
    • Korean Journal of Remote Sensing
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    • v.36 no.2_2
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    • pp.249-261
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    • 2020
  • Coastal monitoring using multiple platforms/sensors is a very important tools for accurately understanding the changes in offshore marine environment and disaster with high temporal and spatial resolutions. However, integrated observation studies using multiple platforms and sensors are insufficient, and none of them have been evaluated for efficiency and limitation of convergence. In this study, we aimed to suggest an integrated observation method with multi-remote sensing platform and sensors, and to diagnose the utility and limitation. Integrated in situ surveys were conducted using Rhodamine WT fluorescent dye to simulate various marine disasters. In September 2019, the distribution and movement of RWT dye patches were detected using satellite (Kompsat-2/3/3A, Landsat-8 OLI, Sentinel-3 OLCI and GOCI), unmanned aircraft (Mavic 2 pro and Inspire 2), and manned aircraft platforms after injecting fluorescent dye into the waters of the South Sea-Yeosu Sea. The initial patch size of the RWT dye was 2,600 ㎡ and spread to 62,000 ㎡ about 138 minutes later. The RWT patches gradually moved southwestward from the point where they were first released,similar to the pattern of tidal current flowing southwest as the tides gradually decreased. Unmanned Aerial Vehicles (UAVs) image showed highest resolution in terms of spatial and time resolution, but the coverage area was the narrowest. In the case of satellite images, the coverage area was wide, but there were some limitations compared to other platforms in terms of operability due to the long cycle of revisiting. For Sentinel-3 OLCI and GOCI, the spectral resolution and signal-to-noise ratio (SNR) were the highest, but small fluorescent dye detection was limited in terms of spatial resolution. In the case of hyperspectral sensor mounted on manned aircraft, the spectral resolution was the highest, but this was also somewhat limited in terms of operability. From this simulation approach, multi-platform integrated observation was able to confirm that time,space and spectral resolution could be significantly improved. In the future, if this study results are linked to coastal numerical models, it will be possible to predict the transport and diffusion of contaminants, and it is expected that it can contribute to improving model accuracy by using them as input and verification data of the numerical models.

A Study on Industries's Leading at the Stock Market in Korea - Gradual Diffusion of Information and Cross-Asset Return Predictability- (산업의 주식시장 선행성에 관한 실증분석 - 자산간 수익률 예측 가능성 -)

  • Kim Jong-Kwon
    • Proceedings of the Safety Management and Science Conference
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    • 2004.11a
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    • pp.355-380
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    • 2004
  • I test the hypothesis that the gradual diffusion of information across asset markets leads to cross-asset return predictability in Korea. Using thirty-six industry portfolios and the broad market index as our test assets, I establish several key results. First, a number of industries such as semiconductor, electronics, metal, and petroleum lead the stock market by up to one month. In contrast, the market, which is widely followed, only leads a few industries. Importantly, an industry's ability to lead the market is correlated with its propensity to forecast various indicators of economic activity such as industrial production growth. Consistent with our hypothesis, these findings indicate that the market reacts with a delay to information in industry returns about its fundamentals because information diffuses only gradually across asset markets. Traditional theories of asset pricing assume that investors have unlimited information-processing capacity. However, this assumption does not hold for many traders, even the most sophisticated ones. Many economists recognize that investors are better characterized as being only boundedly rational(see Shiller(2000), Sims(2201)). Even from casual observation, few traders can pay attention to all sources of information much less understand their impact on the prices of assets that they trade. Indeed, a large literature in psychology documents the extent to which even attention is a precious cognitive resource(see, eg., Kahneman(1973), Nisbett and Ross(1980), Fiske and Taylor(1991)). A number of papers have explored the implications of limited information- processing capacity for asset prices. I will review this literature in Section II. For instance, Merton(1987) develops a static model of multiple stocks in which investors only have information about a limited number of stocks and only trade those that they have information about. Related models of limited market participation include brennan(1975) and Allen and Gale(1994). As a result, stocks that are less recognized by investors have a smaller investor base(neglected stocks) and trade at a greater discount because of limited risk sharing. More recently, Hong and Stein(1999) develop a dynamic model of a single asset in which information gradually diffuses across the investment public and investors are unable to perform the rational expectations trick of extracting information from prices. Hong and Stein(1999). My hypothesis is that the gradual diffusion of information across asset markets leads to cross-asset return predictability. This hypothesis relies on two key assumptions. The first is that valuable information that originates in one asset reaches investors in other markets only with a lag, i.e. news travels slowly across markets. The second assumption is that because of limited information-processing capacity, many (though not necessarily all) investors may not pay attention or be able to extract the information from the asset prices of markets that they do not participate in. These two assumptions taken together leads to cross-asset return predictability. My hypothesis would appear to be a very plausible one for a few reasons. To begin with, as pointed out by Merton(1987) and the subsequent literature on segmented markets and limited market participation, few investors trade all assets. Put another way, limited participation is a pervasive feature of financial markets. Indeed, even among equity money managers, there is specialization along industries such as sector or market timing funds. Some reasons for this limited market participation include tax, regulatory or liquidity constraints. More plausibly, investors have to specialize because they have their hands full trying to understand the markets that they do participate in

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Effects of the Feeding Methods on Body Growth and Sexual Maturity in Broiler Breed Male (육용종웅계(肉用種雄鷄)의 사양방법(飼養方法)이 체성장(體成長) 및 성성숙(性成熟)에 미치는 영향(影響))

  • Yeon, Seong Heum;Park, Chang Sik;Kim, Young Mook
    • Korean Journal of Agricultural Science
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    • v.13 no.1
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    • pp.68-81
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    • 1986
  • This experiment was conducted to find out the effects of the six different feeding methods on the development of body weight, testis, comb and pituitary gland, and the sexual maturity of White Plymouth Rock cockerels. From hatching to 22 weeks of age, the weights of whole body, testis, comb and pituitary gland, and the histological changes of testis and the semen characteristics were checked every other week. The results obtained in this expeniment were as follows: 1. The growth rates of the self-feeding groups were faster than those of the limited feeding groups (70 percent of the self-feeding) by about 2 weeks. The weights of testis and comb showed the most marked increase at 20 weeks of age in the self-feeding groups and at 22 weeks of age in the limited feeding groups, respectively. 2. The weights of pituitary gland from hatching to 22 weeks of age at all observation weeks were not recognized significantly among the compared groups except 4, 14 and 16 weeks of age. 3. Correlations between week of age, body weight, testis, comb and pituitary gland, in the course of 22 weeks, were highly significant. 4. The diameters of lumina and tubules in the seminiferous tubules increased very slowly until 10 weeks of age. They showed the most marked increase at 12 weeks of age in the self-feeding groups and at 14 weeks of age in the limited feeding groups, and then continueously increased until 22 weeks of age. 5. Primary spermatocytes appeared at first at 8 weeks in the all treatment groups. Secondary spermatocytes appeared at first at 10 weeks in the self-feeding groups and at 12 weeks in the limited feeding groups. At 14 weeks of age spermatids and spermatozoa were found at first in the self-feeding groups but spermatids were found in the limited feeding groups. 6. Age of the first ejaculation was between 14 and 16 weeks of age in the all treatment groups. The average semen volume and sperm concentration ranged from $0.1{\sim}0.2m{\ell}/ejaculate$ and $5.6{\sim}9.8{\times}10^8sperm/m{\ell}$ at the age of the first ejaculation but $0.30{\sim}0.35m{\ell}/ejaculate$ and $22.4{\sim}42.7{\times}10^8sperm/m{\ell}$ at the 20 weeks of age in the all treatment groups.

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A Study on the Retrievals of Downward Solar Radiation at the Surface based on the Observations from Multiple Geostationary Satellites (정지궤도 위성자료를 이용한 지표면 도달 태양복사량 연구)

  • Jee, Joon-Bum;Zo, Il-Sung;Lee, Kyu-Tae
    • Korean Journal of Remote Sensing
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    • v.29 no.1
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    • pp.123-135
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    • 2013
  • The reflectance observed in the visible channels of a geostationary meteorological satellite can be used to calculate the amount of cloud by comparing the reflectance with the observed solar radiation data at the ground. Using this, the solar radiation arriving at the surface can be estimated. This study used the Meteorological Imager (MI) reflectance observed at a wavelength of 675 nm and the Geostationary Ocean Color Imager (GOCI) reflectance observed at similar wavelengths of 660 and 680 nm. Cloudy days during a typhoon and sunny days with little cloud cover were compared using observation data from the geostationary satellite. Pixels that had more than 40% reflectance in the satellite images showed less than 0.3 of the cloud index and blocked more than 70% of the solar energy. Pixels that showed less than 15% reflectance showed more than 0.9 of the cloud index and let through more than 90% of the solar energy to the surface. The calculated daily accumulated solar radiation was compared with the observed daily accumulated solar radiation in 22 observatories of the Korean Meteorological Administration. The values calculated for the COMS and MTSAT MI sensors were smaller than the observation and showed low correlations of 0.94 and 0.93, respectively, which were smaller than the 0.96 correlation coefficient calculated for the GOCI sensor. The RMSEs of MTSAT, COMS MI and GOCI calculation results showed 2.21, 2.09, 2.02 MJ/$m^2$ in order. Comparison of the calculated daily accumulated results from the GOCI sensor with the observed data on the ground gave correlations and RMSEs for cloudy and sunny days of 0.96 and 0.86, and 1.82 MJ/$m^2$ and 2.27 MJ/$m^2$, respectively, indicating a slightly higher correlation for cloudy days. Compared to the meteorological imager, the geostationary ocean color imager in the COMS satellite has limited observation time and observation is not continuous. However, it has the advantage of providing high resolution so that it too can be useful for solar energy analysis.

Studies on the mechanism in the induced to unfertilized eggs(male sterility of Silkworm) by protected environment during pupae period (용기의 보호환경에 따른 불수정란(웅성불임잠)의 유발기구에 관한 조사연구)

  • 윤종관;오준식
    • Journal of Sericultural and Entomological Science
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    • v.15 no.2
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    • pp.9-14
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    • 1973
  • In order to find out effects of the generative power of silk worm moth which have been brought up in the high temperature accommodation at their pupa stage. For this specific study, 9 different kinds of male silk worms have been selected as specimen. All those specimen were brought up in the normal temperature at their larvae stage and after the pupation period they have been accommodated in the condition of high temperature for a certain length in accordance with the study programme. Afterwards, those mlae specimen were copulated with Suwon jam 103${\times}$104 which were all brought up in normal conditions. This study was carried out to find the copulation function as well as the ratio of unfertilized eggs(male sterility test). Results of study have been revealed as follows: 1) Although some differences were observed, male pura which have been brought up in the condition of high temperature shown the low rate of unfertilized eggs rather than those were brought up in the normal conpition. 2) In this group the eclosion(emergency) has been found to be poor rather, than those specimen brought up in normal conditions. 3) The copulation function of Moran, Daedong, J124 and C108 specimen were found to be poor than those of Suwon jam. 4) Fertility rate of Moran, Daedong, J124 and C108 was found to be around 65%. This figure is rather lower than what we normally expect. 5) Unfertilized egg ratio of Moran, Daedong and C108 were found to be around 20% if they were brought up in the condition of high temperature for one day from the time of pupation: 40% at 2 days, and 70% at 3 days duration. More than 3 days treatment has shown no progress in the unfertilized egg ratio. 6) One day's treatment for the pupa at the later stage has shown the unfertilized egg ratio of about 10%; 20% at 2 day's treatment, 35% at 3 day's treatment, 40-60% at 4 day's treatment, more than 60% at 5 day's treatment, and the 70% of fertilized egg ratio was only observed when the treatment days come to 7 days. It was understood that the unfertilized egg ratio was high at the antepupa stage rather than that of post-pupa stage. 7) According to the result of observation the sperm in copulatory pouch and seminal receptacle out of the normal female silk worm which have been copulated with the male brought up in the condition of high temperature at their moth stage. The reproduction system found in the control zone has been found to be normal and the sperm is amountful and active in motion while the sperm found in the treatment to be limited in amount and slow in motion. The observation was made within 5 hours from the copulation. 8) According to the result of observation of sperm of seminal receptacles of the female silkworm moth, and according to that observation of sperm in the seminal receptacle in female silkworm moth, the amount of sperm and mobility in the female moth brought up in high temperature were poor comparing that were brought up in normal temperature zone. Some of them are even found to be no trace of such. 9) Appearance and mosle of the copulatory organ of the male silkworm moth was found to be no anatomical change. 10) Testis of the later pupa stage which was brought up in the high temperature was found to be almost net developed to anucleate sperm and they are degenerated at stage of between maturation division and sperm abnormal stage. Mean time at control zone, the formation of anucleate sperm was already observed.

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A Study on the Environment for Lowbirth Weight Infants in Neonatal Intensive Care Unit in the United States (신생아집중간호단위 환경과 저체중출생아의 반응에 대한 연구)

  • Han Kyung Ja
    • Child Health Nursing Research
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    • v.4 no.2
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    • pp.159-176
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    • 1998
  • In effort to conduct comparative study on the caregiving environment of Neonatal Intensive Care Unit(NICU) in both U. S and Korea, this study was been conducted first in the U.S. Purpose : The purpose of this study is to identify the physical environment and direct caregiving practices to lowbirth weight infants in NICU in the US. It also aims to examine the NICU outcome status and behavioral reponses of lowbirth weight infants. Methods : A study design using descriptive and inferential statistics was been conducted through an observational, field method. A sample of 15 preform infants admitted to NICU were recruited for the study. The subjects were those with birth weight between 1,000 gm to 1,500 gm, born at the gestation period of 27 to 33 weeks, and without any chromosomal or other genetic anomalies, major congenital infections, or maternal illness. Thirty minutes observation(three times of ten minutes of continuous observation)of the infant's behavior and physiological status, and an four-hour observation of the physical environment and direct care giving procedures were been conducted on the 3rd and 10th day after birth, and on the day of discharge from the NICU or at 34weeks postconception. The data to be collected were in four areas : the demograghic characteristics of the infants, the physical environment and care giving procedures, the frequency of the infant's designated behavior and physiological response, and NICU outcome variables. A descriptive analysis and Kruskal-Wallis, Pearson r were been applied according to variable characteristics. Results : 1. Mother's mean age was 29.47. The sample consisted of 6 males and 9 females. Mean gestational ages were 29.17 weeks. Mean birth weight was 1236.33g. Mean Apgar scores at one minute were 6.6, and 7.8 at five minutes. 2. The location for the incubator was in the distance from the light, X-ray screens and nursing station, in proximity to side-lamp, telephone and faucet on the third day after birth. The location for the incubator was in the distance from the light and radio on the tenth day and in proximity to nursing station on the day of dischage from the NICU or at 34weeks postconception. 3. Nesting was the most applying aids to the infants. And foot roll, shielding and plastic frame were frequently using by nurses for facilitating well modulated restful posture. 4. There were statistically significant changes in the patterns of physical environment included locating the infant's incubator and bedding, specific aids to self regulation on the 3rd and 10th day after birth, and on the day of discharge from the NICU or at 34weeks postconception. 5. Statistically significant changes were not appeared in the patterns of direct caregiving procedure to the infants included stress inducing or reducing manipulations on the 3rd and 10th day after birth, and on the day of discharge from the NICU or at 34weeks postconception. 6. The stress response of the infants in NICU were significantly reduced as the infants grow older. 7. There were not statistically significant correlation between the physical envronment and the stress responses of the infants in NICU. 8. There were statistically significant correlation between the direct caregiving procedure to the infants and the stress response of the infants in NICU in the second and third observation on the day three. 9. Average weight gain per day from birth to discharge was 38.73g, number of days in the hospital was 42.60, number of days before bottle feeding was 3.6. Postconception age starting bottle feed ing was 31/sup +5/ weeks. Number of days on mechanical ventilator was average 7.64, 11.42 was an average number of days of oxygen need. Conclusion : It, thus, appears that to minimize the sensorymotor stimulation for the low birthweight preterm infant in NICU, manipulation of care giving practices to the babies whatever the stress inducing or reducing procedures, have to be limited in the immediate early stage after birth. And it needed to be reexamine to identify the appropriate and specific physical environment and the patterns of direct caregiving to the low birthweight preform infant as the infants grow older in NICU.

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Rational Spirit for Painting Theory of the Song Dynasty (宋代画论中的理性精神)

  • Chen, Gu Xiang
    • (The)Study of the Eastern Classic
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    • no.59
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    • pp.405-428
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    • 2015
  • Painting theorists in Song dynasty often spoke 'Li' when they talked about paintings. But 'Li' of the song dynasty is not limited to the 'ethics'. First, it includes visible 'natural's truth', such as the differences of 'geography' and 'physics' between the depicted objects. Second, it also includes 'common sense' which was based on both the observation and the thinking. The theorists thought if the 'common sense' was improper in the painting, the whole work was invalid. Thirdly, it also includes 'the reasonable sense in special situation', which requires great imagination ability and elaborative faculty. For example, when playing wind instruments and stringed instruments in the same time at the same concert, the painter should accurately draw the different gestures of musicians according to that the wind instrument is 'sound when the finger lift' and the stringed instrument is 'sound after the finger have left' in that moment. Fourthly, it includes 'art reason', theorists call it as 'ShenLi' or 'MiaoLi'. 'ShenLi' or 'MiaoLi' require the creator to join the spiritual concept besides his observation and thinking. For example, 'banana in snow' is neither observed available nor thought of available, but is the result of spiritual concept of creators for seeking everlasting. And at last, it certainly includes 'the principle of ethics'. Painters often highlighted the ethical relations of the feudal nation and the value of individual gentleman through the allegory story of figure painting and even the sudden composition in the landscape painting. 'Geography', 'physical', and 'common sense' are required the meticulous observation and the rational thinking for the painted object. And 'the reasonable sense in special situation', 'the art reason', 'the principle of ethics' are required enhancing painting style in the painting artistic conception and realm of life based on the nuanced observation, making 'technology' into the 'Tao'. This is the six reasonable increasing requirements for the painting work. Therefore, 'seeking the final reason' is the fundamental spirit of painting theory of Song Dynasty.

The Importance of Reflection on the Middle School Science Experiment Class for Teaching the Nature of Science (과학의 본성 지도를 위한 중학교 과학 실험수업에서 '반성'의 중요성)

  • Do, Songhee;Hwang, Yohan;Park, Jongseok
    • Journal of Science Education
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    • v.33 no.2
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    • pp.184-192
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    • 2009
  • Understanding about the Nature of Science (NOS) is element of scientific literacy. Its importance is emphasized, especially understanding about NOS was presented as goal of science education on the fifth curriculum in Korea. Attempt of teaching NOS has been continuous in school, that was limited by method of using History of Science. Except method of using History of Science, Experimenting is appropriate for method of teaching NOS. We expected that is effective to apply reflective approach method for understanding the NOS and composite lesson to emphasize reflection and discussion to general experiment class in the school. We applied experiment class to emphasize reflection and discussion to second grade students in the middle school and researched whether positive reflection and discussion is helpful understanding the NOS in science experiment class or not, through questionnaire about NOS and analysis of observation and interview. As a result, experiment class to emphasize reflection and discussion was effective for scientific inquiry skills and sociality of scientific inquiry, particularly for relation observation with deduction and possibility of variable analysis to experiment result. Therefore, experiment class to emphasize reflection and discussion is effective for understanding the NOS.

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