• Title/Summary/Keyword: 기(에너지)

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Recontextualizing geography curriculum:society;student and discipline of geography (地理 敎育課程의 再脈絡化)

  • Seo, Tae Yeol
    • Journal of the Korean Geographical Society
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    • v.29 no.4
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    • pp.438-449
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    • 1994
  • This paper focuses on recontextualizing geography curriculum, i.e. examining recent changing aspects in three geography curriculum locators-society, student and discipline of geography-and searching future directions of geography curriculum in light of such changes. For conciliation and reflection of changing aspects of each locators, this paper dealt with social issues and societal changes in terms of locator of society, increased concern to student and development of cognitive science in terms of students, and challenging views on science and the meaning of epistemological changes in geography in terms of discipline. As a result, three future directions in geography curriculum are searched : issue-based geography curriculum, thinking geography curriculum, geography curriculum toward equity and accessbility.

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Association of the RORA Gene Polymorphism and Seasonal Variations in Mood and Behavior (RORA 유전자 다형성과 기분 및 행동의 계절성 변동의 연관성)

  • Kim, Hae-In;So, Soo-Jung;Yang, Hee Jung;Song, Hyun Mi;Moon, Joung Ho;Yoon, Ho-Kyoung;Kang, Seung-Gul;Park, Young-Min;Lee, Seung-Hwan;Kim, Leen;Lee, Heon-Jeong
    • Sleep Medicine and Psychophysiology
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    • v.20 no.2
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    • pp.63-68
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    • 2013
  • Objectives: Several evidence has been suggested that the circadian gene variants contribute to the pathogenesis of seasonal affective disorder. In this study, we aimed to investigate the polymorphism in RORA (Retinoid-related orphan receptor A) gene in relation to seasonal variations among healthy young adults in Seoul, Korea. Methods: A total of 507 young healthy adult subjects were recruited by advertisement. Seasonal variations were assessed by the Seasonality Pattern Assessment Questionnaire (SPAQ). Single-nucleotide polymorphism in the RORA rs11071547 gene was genotyped by PCR in 507 individuals. Considering summer type as confounding factor, we conducted analysis 478 subjects except 29 subjects of summer type. The Chi-square test was conducted to compare differences between groups of seasonals and non-seasonals. Association between genotypes and Global Seasonality Score (GSS) were tested using ANCOVA (Analysis of covariance). Results: In this sample, the prevalence of SAD was 12.1% (winter type 9.3%, summer type 2.8%). There is no significant difference in genotyping distribution of RORA rs11071547 between groups of seasonals and non-seasonals. Global seasonality score (GSS) and scores of all subscales except body weight and appetite were not significantly different between the group with C allele homozygote and the group with T allele homozygote and heterozygote (p-value 0.138). Scores of body weight and appetite were significantly higher in group with C allele homozygotes. Conclusion: These results suggest that RORA gene polymorphism play a role in seasonal variations in appetite and body weight and is associated with susceptibility to seasonal affective disorder in some degree in the population studied.

Infrared Characteristics of Some Flash Light Sources (섬광의 적외선 특성 연구)

  • Lim, Sang-Yeon;Park, Seung-Man
    • Korean Journal of Optics and Photonics
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    • v.27 no.1
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    • pp.18-24
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    • 2016
  • To effectively utilize a flash and predict its effects on an infrared device, it is essential to know the infrared characteristics of the flash source. In this paper, a study of the IR characteristics of flash light sources is carried out. The IR characteristics of three flash sources, of which two are combustive and the other is explosive, are measured with an IR characteristic measurement system over the middle- and long-wavelength infrared ranges. From the measurements, the radiances over the two IR ranges and the radiative temperatures of the flashes are extracted. The IR radiance of flash A is found to be the strongest among the three, followed by those of sources C and B. It is also shown that the IR radiance of flash A is about 10 times stronger than that of flash B, even though these two sources are the same type of flash with the same powder. This means that the IR radiance intensity of a combustive flash source depends only on the amount of powder, not on the characteristics of the powder. From the measured radiance over MWIR and LWIR ranges for each flashes, the radiative temperatures of the flashes are extracted by fitting the measured data to blackbody radiance. The best-fit radiative temperatures (equivalent to black-body temperatures) of the three flash sources A, B, and C are 3300, 1120, and 1640 K respectively. From the radiance measurements and radiative temperatures of the three flash sources, it is shown that a combustive source radiates more IR energy than an explosive one; this mean, in turn, that the effects of a combustive flash on an IR device are more profound than those of an explosive flash source. The measured IR radiances and radiative temperatures of the flash sources in this study can be used to estimate the effects of flashes on various IR devices, and play a critical role for the modeling and simulation of the effects of a flash source on various IR devices.

Effects of Corn Distiller's Dried Grains with Solubles on Production Performance in Laying Hens (옥수수주정박의 급여가 산란계 생산성에 미치는 효과)

  • Cheon, Yeoung-Ju;Lee, Hak-Lim;Shin, Myung-Ho;Lee, Soo-Kee;Lee, Bong-Duk;Son, Chan-Ku
    • Korean Journal of Agricultural Science
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    • v.34 no.1
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    • pp.53-60
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    • 2007
  • A layer feeding trial was conducted for 10 weeks to investigate the effects of the addition of corn distillers dried grains with solubles (DDGS) to layer diets on the laying performance, egg qualities, and yolk fatty acid composition. Nine hundred Hyline Brown layers, 24 weeks of age,were randomly allotted to 20 replicate laying cages, 45 birds per replicate. There were four diet treatments (0, 10, 15, and 20% DDGS), and five replicates per treatment. All experimental diets were prepared to contain iso-protein (17%) and iso-calorie (TMEn 2,780 kcal/kg). The use of DDGS up to 20% level in layer diets did not exert any influence on feed intake, laying rate, total egg mass, mean egg weight, and feed conversion ratio. DDGS did not exert any influence in weight of egg, breaking strength, and color of eggshell. The albumen height and Haugh unit was not influenced by DDGS addition. The yolk color was significantly increased by DDGS supplementation. As the DDGS level increased, the oleic acid content decreased, and the linoleic acid increased (P<0.05). The degree of saturation of yolk fatty acids was not affected by dietary DDGS. The inclusion of DDGS up to 20% in layer diets resulted in the decrease of feed cost per kg without any effect in the laying performance. In conclusion, the use of DDGS up to 20% level in layer diets could replace corn and soybean meal without any harmful effect on the laying performances.

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Lessons from Cross-Scale Studies of Water and Carbon Cycles in the Gwangneung Forest Catchment in a Complex Landscape of Monsoon Korea (몬순기후와 복잡지형의 특성을 갖는 광릉 산림유역의 물과 탄소순환에 대한 교차규모 연구로부터의 교훈)

  • Lee, Dong-Ho;Kim, Joon;Kim, Su-Jin;Moon, Sang-Ki;Lee, Jae-Seok;Lim, Jong-Hwan;Son, Yow-Han;Kang, Sin-Kyu;Kim, Sang-Hyun;Kim, Kyong-Ha;Woo, Nam-Chil;Lee, Bu-Yong;Kim, Sung
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.9 no.2
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    • pp.149-160
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    • 2007
  • KoFlux Gwangneung Supersite comprises complex topography and diverse vegetation types (and structures), which necessitate complementary multi-disciplinary measurements to understand energy and matter exchange. Here, we report the results of this ongoing research with special focuses on carbon/water budgets in Gwangneung forest, implications of inter-dependency between water and carbon cycles, and the importance of hydrology in carbon cycling under monsoon climate. Comprehensive biometric and chamber measurements indicated the mean annual net ecosystem productivity (NEP) of this forest to be ${\sim}2.6\;t\;C\;ha^{-1}y^{-1}$. In conjunction with the tower flux measurement, the preliminary carbon budget suggests the Gwangneung forest to be an important sink for atmospheric $CO_2$. The catchment scale water budget indicated that $30\sim40%$ of annual precipitation was apportioned to evapotranspiration (ET). The growing season average of the water use efficiency (WUE), determined from leaf carbon isotope ratios of representative tree species, was about $12{\mu}mol\;CO_2/mmol\;H_2O$ with noticeable seasonal variations. Such information on ET and WUE can be used to constrain the catchment scale carbon uptake. Inter-annual variations in tree ring growth and soil respiration rates correlated with the magnitude and the pattern of precipitation during the growing season, which requires further investigation of the effect of a monsoon climate on the catchment carbon cycle. Additionally, we examine whether structural and functional units exist in this catchment by characterizing the spatial heterogeneity of the study site, which will provide the linkage between different spatial and temporal scale measurements.

Effect of 'Breakfast Club Program' on Dietary Behaviors and School Life in High School Students Residing in Seoul Metropolitan Areas (서울지역 고등학생 대상 '아침밥 클럽'의 식생활 및 학교생활 개선 효과)

  • Yang, Seung Ju;Kim, Kirang;Hwang, Ji-Yun
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.44 no.7
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    • pp.1000-1006
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    • 2015
  • The adolescent period, during which physical, spiritual, and physiological growth and development occurs, is important for the development of healthy dietary habits. Particularly, eating a regular breakfast improves eating habits and school life in adolescents but few studies have investigated the effects of eating breakfast on these outcomes. Therefore, this research was performed to investigate the effects of eating a regular breakfast provided by the 'Breakfast Club Program' on eating behaviors and school life. A total of 315 high school students were recruited for the program from 10 high schools in nine districts among 25 districts in Seoul during August to December of 2013. The average age was $17.8{\pm}0.8$ years and 38.1% of students were females. Based on 315 subjects, 38.3%, 35.7%, and 17.1% increased their intakes of breakfast (P=0.001), fruit (P=0.033), and milk (P<0.001) up to 5~7 times per week, respectively. The intake frequency of fruit (P<0.001) and eating breakfast (P<0.001) increased noticeably after program participation. Based on 64 students performing dietary record, intakes of cereals (P<0.001), mushrooms (P=0.027), and fruits (P=0.002) increased while intakes of eggs (P=0.001) and fat and oils (P=0.019) decreased after the program. Consumption of energy (P=0.004), plant protein (P=0.012), carbohydrates (P<0.001), dietary fiber (P=0.026), iron from plant sources (P=0.009), potassium (P=0.043), zinc (P=0.013), vitamin $B_1$ (P=0.043), and vitamin C (P<0.001) increased whereas intake of cholesterol (P=0.002) decreased. Regarding school life, the score for 'comfortable and cheerful starting of a day' (P=0.001) and 'healthy starting of a day' (P<0.001) increased significantly. This study indicates that a regular 'Breakfast Club Program' may establish healthy eating habits and school life in teenagers.

International Legal Regulation on Commercial Space Activity (상업적 우주활동의 국제법적 규제)

  • Lee, Young-Jin
    • The Korean Journal of Air & Space Law and Policy
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    • v.28 no.2
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    • pp.183-221
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    • 2013
  • While in the early stages of space activities only a few states engaged in the use of outer space, as is well known, commercial space activities have grown dramatically in recent years. Both states, state institutions, and international governmental organizations as well as many private enterprises are engaged in such commercial use of outer space by now. This development is not reflected in the present state of space law. The existing international instruments of space law were developed and finalized before this development and thus only provide very few and sometimes unfitting provisions for the commercial use of outer space and particularly the use by private enterprises. Law formulated in an era when the word "privatization" had not even been coined cannot contain potential problems caused by the increasing commercialization of outer space. For the promotion and further development of such commercial use of outer space it is necessary to clarify and establish the legal framework for such use, because participants will need this information for their future investments in this field. The purpose of this paper is to research and make an analysis of the contents and international regulation of international space commerce, which is rapidly proliferating and to review the process of improvement on national legislations relating to the commercialization of outer space in a few main space advanced countries to make the sustainable progress of commercial space activities project in international society. The legal implications of matters such as international commercial launch services, the liability aspects of such services, intellectual property rights, insurance, product liability insurance and materials processing could one day will be subject to regulated by international space law as well as domestic law. In fact, the question of commercialization is linked to the question of sharing benefits of space activities, and this currently is an agenda item in the Legal Subcommittee of UN COPUOS. Most of developed countries have enacted the national legislation for commercial space activities relating to the development of our space as follows : The National Aeronautic and Space Act of 1958 and the Commercial Space Act of 1998 in the United States, Outer Space Act of 1986 in England, Establishment Act of National Space Center of 1961 in France, Canadian Space Agency Act of 1990 in Canada, Space Basic Act of 2008 in Japan, and Law on Space Activity of 1993 in Russia. Becides there are currently three national legislations relating to space development and commercial space activities in Korea as follows : Aerospace Industry Development Promotion Act of 1987, Outer Space Development Promotion Act of 2005, Outer Space Damage Compensation Act of 2008. Commercial space great promise for the utilization and expansion of human outer space activities but aspring commercial actors must recognize that foreign policy, as well as obligations to the international community as a whole, ensure that commercial space activities will not operate in a legal and regulatory vacuum. As commercial space matures the law and accompanying regulation will most certainly evolve and choose to become participants in the inevitable evolution of law and regulation.

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Practical Output Dosimetry with Undefined $N_{dw}{^{Co-60}}$ of Cylindrical Ionization Chamber for High Energy Photon Beams of Linear Accelerator ($N_{dw}{^{Co-60}}$이 정의되지 않은 원통형 이온전리함을 이용한 고에너지 광자선의 임상적 출력선량 결정)

  • Oh, Young-Kee;Choi, Tae-Jin;Song, Ju-Young
    • Progress in Medical Physics
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    • v.23 no.2
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    • pp.114-122
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    • 2012
  • For the determination of absorbed dose to water from a linear accelerator photon beams, it needs a exposure calibration factor $N_x$ or air kerma calibration factor $N_k$ of air ionization chamber. We used the exposure calibration factor $N_x$ to find the absorbed dose calibration factors of water in a reference source through the TG-21 and TRS-277 protocol. TG-21 used for determine the absorbed dose in accuracy, but it required complex calculations including the chamber dependent factors. The authors obtained the absorbed dose calibration factor $N_{dw}{^{Co-60}}$ for reduce the complex calculations with unknown $N_{dw}$ only with $N_x$ or $N_k$ calibration factor in a TM31010 (S/N 1055, 1057) ionization chambers. The results showed the uncertainty of calculated $N_{dw}$ of IC-15 which was known the $N_x$ and $N_{dw}$ is within -0.6% in TG-21, but 1.0% in TRS-277. and TM31010 was compared the $N_{dw}$ of SSDL to that of PSDL as shown the 0.4%, -2.8% uncertainty, respectively. The authors experimented with good agreement the calculated $N_{dw}$ is reliable for cross check the discrepancy of the calibration factor with unknown that of TM31010 and IC-15 chamber.

Carbon Fiber as Material for Radiation Fixation on Device : A comparative study with acrylic (고정기구 재질로써 탄소 섬유와 아크릴의 방사선량 감쇄 영향 비교)

  • Chie, Eui-Kyu;Park, Jang-Pil;Huh, Soon-Nyung;Hong, Se-Mie;Park, Suk-Won;Kim, In-Ah;Wu, Hong-Gyun;Kim, Jae-Sung;Kang, Wee-Saing;Kim, Il-Han;Ha, Sung-Whan;Park, Charn-Il
    • Journal of Radiation Protection and Research
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    • v.30 no.1
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    • pp.1-7
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    • 2005
  • Radiation absorption parameters of carbon fiber panel were measured in comparison to acrylic panel. $30{\times}30cm$ sized 2mm thick carbon fiber panel and identical sized 6mm thick acrylic panel were placed in tray holder position and 0cm, 5cm, 10cm from surface of phantom. Radiation field size was $10{\times}10cm$. 50MU of 4MV photon was irradiated to the phantom with dose rate of 300MU/min. Source-to-phantom distance was 120cm. Radiation dose was measured with 0.6cc Farmer-type ionization chamber with 1cm build-up. Measurement was repeated thrice and normalization was done to the dose of the open field. Radiation transmission rate of carbon fiber panel is approximately 1% lower than acrylic panel of equivalent thickness. However, considering the strength of the material, transmission rate is higher for carbon fiber panel. Although carbon fiber panel increases the radiation dose when attached to the surface for about 2%, it normalizes the radiation dose to 97-99% of irradiated dose which could have been lowered to as much as 5-7.5% with acrylic panel. As carbon fiber panel is stronger than acrylic panel, radiation fixation device could be made thinner and thus lighter and furthermore, with increased radiation transmission. This in turn makes carbon fiber more ideal material for radiation fixation device over conventionally used acrylic.

Studies on the Utilization of Plant Pigments -II. Stability of Anthocyanin Pigments in Ganges Amaranth- (식물성(植物性) 색소(色素)의 이용(利用)에 관(關)한 연구(硏究) -II. 꽃잎맨드라미(Amaranthus tricolor L.) Anthocyanin색소(色素)의 안정성(安定性)-)

  • Kim, Kwang-Soo;Lee, Sang-Jik;Yoon, Tai-Heon
    • Korean Journal of Food Science and Technology
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    • v.11 no.1
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    • pp.42-49
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    • 1979
  • In order to evaluate the utility of the anthocyanins of Amaranthys tricolor L. as an edible pigment, the present study was undertaken to investigate the effects of pH. temperature, ascorbic acid, sugars and their degradation products, quercetin, thiourea, sodium pyrophosphate and metal ions on the stability of the anthocyanins in the model systems. The results obtained from this study were as follows. 1. The degradation of total anthocyanins was retarded as the pH levels decreased from 8.0 to 1.0. At pH 1.0, however. the initial degradation reaction proceeded faster than at pH 2.0 to 3.0 2. On heating in buffered aqueous solution at $80^{\circ}C$, the total anthocyanin content was higher at pH 2.0 than other pH levels. Increasing the storage temperature accelerated greatly the pigment degradation. In darkness at $40^{\circ}C$, after 10 days, only 19% of the original amount was left, while at $2^{\circ}C$, under the same conditions of storage, approximately 90% of the pigment was retained. The half-life of the pigment, 63.0 days at $2^{\circ}C$, shortened to 1. 7 days at $40^{\circ}C$. 3. An increase in ascorbic arid concentration from 0. 15 to 0.50 mg/ml lowered the anthocyanin retention. 4. There was no significant difference between glucose and fructose in anthocyanin degradation effect. Furfural was more effective than other sugar degradation products, formic acid or levulinic acid in accelerating anthocyanin breakdown. 5. Neither quercetin nor sodium pyrophosphate had a protective effect on the anthocyanins in the presence of ascorbic acid, while, in the systems 0.5 or 1 mg/ml of thiourea with $150{\;}{\mu}g/ml$ of ascorbic acid, the loss of anthocyanins was significantly reduced. 6. Both mercuric and cupric ions in 30 ppm greatly accelerated anthocyanin degradation.

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