• 제목/요약/키워드: 순환영역

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Numerical Simulation of Local Atmospheric Circulations in the Valley of Gwangneung KoFlux Sites (광릉 KoFlux 관측지 계곡에서의 국지순환 수치모의)

  • Lee, Seung-Jae;Kim, Joon;Kang, Minseok;Malla-Thakuri, Bindu
    • Korean Journal of Agricultural and Forest Meteorology
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    • 제16권3호
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    • pp.246-260
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    • 2014
  • A 90-m horizontal-resolution numerical model was configured to study the micrometeorological features of local winds in the valley of Gwangneung KoFlux (Korea Flux network) Sites (GDK: Gwangneung Deciduous forest site in Korea, GCK: Gwangneung Coniferous forest site in Korea) during summer days. The U. S. Geological Survey (USGS) Shuttle Radar Topography Mission (SRTM) data were employed for high-resolution model terrain height. Model performance was evaluated by comparing observed and simulated near-surface temperature and winds. Detailed qualitative analysis of the model-simulated wind field was carried out for two selected cases which are a clear day (Case I) and a cloudy day (Case II). Observed winds exhibited that GDK and GCK, as well as Case I and Case II, had differences in timing, duration and strength of daytime and nighttime wind direction and speeds. The model simulation results strongly supported the existence of the drainage flow in the valley of the KoFlux tower sites. Overall, the simulated model fields realistically presented the diurnal cycle of local winds in and around the valley, including the morning drainage-upslope transition and the evening reversal of upslope wind. Also, they indicated the complexity of local winds interactions by presenting that daytime westerly winds in the valley were not always pure mountain winds and were often coupled with larger-scale wind systems, such as synoptic-scale winds or mesoscale sea breezes blowing from the west coast of the peninsula.

Exploring Practical Methods On Agriculture Technology Education of the Practical Arts for Sustainable Development (실과교과 농업 생명 기술 영역에서의 지속가능발전을 위한 실천 방안 탐색)

  • Kang, Kyoung-Kyoon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • 제19권5호
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    • pp.509-518
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    • 2018
  • The purpose of this study was to explore practical methods of practical arts education for sustainable development in agriculture technology. To archive this purpose, a case-study involving the specialized 'P school' was undertaken. Results of the study were as follows: First, this study estimated value to not only the concept of environmental-friendly agriculture, but also integrated social, disciplinary, generation, intra-generation, and economic perspectives. Second, elementary school students suggested plans for practical activities featuring which was all-rounded growth in circulating between education and the nature of the life. This study concludes that educational programs based on the integration of agriculture, technology, and education, as well as hands-on activities are most effective.

Numerical study of a conical MILD combustor with varing the fuel flow rate (연료유량 변화에 따른 원추형 MILD 연소로의 수치적 해석)

  • Kim, Tae Kwon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • 제15권6호
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    • pp.3370-3375
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    • 2014
  • MILD combustion is a highly favored technology for solving the trade-off relation between high thermal efficiency and low pollutant emissions. The system has low NOx concentration in high temperature combustion by recirculating the combustion gas, as well as improving the thermal efficiency by making the internal temperature in a combustion furnace uniform. This study describes the combustion characteristics of a conical MILD combustor in a laboratory-scale furnace by adjusting the equivalence ratio with the fuel gas flow rate while maintaining a constant air flow rate of the furnace. The MILD regime in the furnace is well characterized and the in-furnace temperature and emissions were predicted, respectively, for the range of equivalence of 0.69 - 0.83. For the range of equivalence ratios, this study confirmed the existence of a stable flame region that has an approximately $300^{\circ}C$ temperature difference between the maximum flame temperature region and main reaction region.

Analysis of Face Region Color According to the Heart Reflex Point Acupressure Foot (심장 반사점 발 지압에 따른 얼굴 영역 색상 분석)

  • Lim, Soon-Yong;Yean, Yong-Hem;Min, Ji-Seon;Song, Han-Sol;Lim, Sung-Su;Kim, Bong-Hyun;Ka, Min-Kyoung;Cho, Dong-Uk;Bae, Young-Lae J.
    • Annual Conference of KIPS
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    • 한국정보처리학회 2011년도 춘계학술발표대회
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    • pp.1086-1089
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    • 2011
  • 현대 사회의 의학기술과 대체의학은 IT 기술과의 융합적 개발로 점차 발전하고 있다. 동양의학 이론을 통해 인체 중 손, 발, 얼굴 등이 오장육부와 관련이 있다는 학설이 널리 알려져 있다. 이 중 발은 '제2의 심장'이라고까지 불려지고 있다. 즉, 발이 건강해야 전신 건강을 유지할 수 있다는 의미도 있지만 실제로 혈액 순환에도 중요하다는 의미도 있다. 따라서, 본 논문에서는 심장과 관련된 발 영역인 왼쪽발바닥 네번째와 다섯 번째 발가락 사이에서 3cm정도 내려간 부위를 지압하여 심장 관련 얼굴 영역의 색상 변화를 측정하는 실험을 수행하였다. 지압에 쓰이는 지압봉은 일반 가정용으로 사용되는 150x10mm 크기의 지압봉이며 지압법으로는 뒤꿈치 방향에서 심장 지압점까지 누르면서하는 방법을 사용하였다. 이와 같은 발지압법을 수행한 후 심장과 관련된 얼굴 영역인 천정과 입술 부위의 붉은 정도를 Lab색체계로 측정하여 a*값 색상의 변화를 분석하였다.

Influence of Fish Habitats by Change of Flow Patterns with Squr Dikes (수제로 인한 흐름변화가 어류서식처에 미치는 영향 검토)

  • Chanjin Jeong;Yong Jun Kwon;Dong Hyun Kim;Hyung Suk Kim;Seung Oh Lee
    • Journal of Korean Society of Disaster and Security
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    • 제16권4호
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    • pp.109-121
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    • 2023
  • Squr dikes in rivers can enhance various ecological environments, contributing to the improvement of the river's environmental functions. However, the alterations in flow caused by squr dikes not only enhance environmental functions but can also have adverse effects. Therefore, this study aimed to analyze the flow changes induced by the installation of squr dikes through flume experiments and assess their impact on fish habitats. Key factors in the fish habitat environment include flow velocity, turbulence kinetic energy, and recirculation zones. Among these, particular emphasis was placed on examining turbulence kinetic energy and recirculation zones. Experimental conditions were set by varying the interval and submergence of the squr dikes, resulting in a total of eight experimental cases. The results revealed that shorter interval and lower submergence of the squr dikes led to increased turbulence kinetic energy and recirculation zone sizes, significantly impacting fish habitats.

A Study on the Virtuous Cycle Structure of the Archival Ecosystem (기록관리 생태계의 선순환 구조에 관한 단상(斷想))

  • Kim, Jang-hwan
    • The Korean Journal of Archival Studies
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    • 제79호
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    • pp.83-120
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    • 2024
  • This paper covers the current status and problems of the archival ecosystem. Since the enactment of the Records Management Act, the archival ecosystem has grown rapidly, but in retrospect, the discipline of archival science has stagnated, records management practice is overly concentrated in the public sector, the records management infrastructure in the private sector is weak, and the industry is failing. In recent years, the archival community has continued to discuss these issues, but mostly in the context of public records management, especially in the field. In this article, we look at the archival community as a whole, including the problems of archival academia and universities, the professionalism and qualification system of archivists, the Records Management Act limited to the public domain, and the difficulties of the industry, and propose alternatives in terms of professionalism and localization.

A STUDY ON THE IONOSPHERE AND THERMOSPHERE INTERACTION BASED ON NCAR-TIEGCM: DEPENDENCE OF THE INTERPLANETARY MAGNETIC FIELD (IMF) ON THE MOMENTUM FORCING IN THE HIGH-LATITUDE LOWER THERMOSPHERE (NCAR-TIEGCM을 이용한 이온권과 열권의 상호작용 연구: 행성간 자기장(IMF)에 따른 고위도 하부 열권의 운동량 강제에 대한 연구)

  • Kwak, Young-Sil;Richmond, Arthur D.;Ahn, Byung-Ho;Won, Young-In
    • Journal of Astronomy and Space Sciences
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    • 제22권2호
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    • pp.147-174
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    • 2005
  • To understand the physical processes that control the high-latitude lower thermospheric dynamics, we quantify the forces that are mainly responsible for maintaining the high-latitude lower thermospheric wind system with the aid of the National Center for Atmospheric Research Thermosphere-Ionosphere Electrodynamics General Circulation Model (NCAR-TIEGCM). Momentum forcing is statistically analyzed in magnetic coordinates, and its behavior with respect to the magnitude and orientation of the interplanetary magnetic field (IMF) is further examined. By subtracting the values with zero IMF from those with non-zero IMF, we obtained the difference winds and forces in the high-latitude 1ower thermosphere(<180 km). They show a simple structure over the polar cap and auroral regions for positive($B_y$ > 0.8|$\overline{B}_z$ |) or negative($B_y$ < -0.8|$\overline{B}_z$|) IMF-$\overline{B}_y$ conditions, with maximum values appearing around -80$^{\circ}$ magnetic latitude. Difference winds and difference forces for negative and positive $\overline{B}_y$ have an opposite sign and similar strength each other. For positive($B_z$ > 0.3125|$\overline{B}_y$|) or negative($B_z$ < -0.3125|$\overline{B}_y$|) IMF-$\overline{B}_z$ conditions the difference winds and difference forces are noted to subauroral latitudes. Difference winds and difference forces for negative $\overline{B}_z$ have an opposite sign to positive $\overline{B}_z$ condition. Those for negative $\overline{B}_z$ are stronger than those for positive indicating that negative $\overline{B}_z$ has a stronger effect on the winds and momentum forces than does positive $\overline{B}_z$ At higher altitudes(>125 km) the primary forces that determine the variations of tile neutral winds are the pressure gradient, Coriolis and rotational Pedersen ion drag forces; however, at various locations and times significant contributions can be made by the horizontal advection force. On the other hand, at lower altitudes(108-125 km) the pressure gradient, Coriolis and non-rotational Hall ion drag forces determine the variations of the neutral winds. At lower altitudes(<108 km) it tends to generate a geostrophic motion with the balance between the pressure gradient and Coriolis forces. The northward component of IMF By-dependent average momentum forces act more significantly on the neutral motion except for the ion drag. At lower altitudes(108-425 km) for negative IMF-$\overline{B}_y$ condition the ion drag force tends to generate a warm clockwise circulation with downward vertical motion associated with the adiabatic compress heating in the polar cap region. For positive IMF-$\overline{B}_y$ condition it tends to generate a cold anticlockwise circulation with upward vertical motion associated with the adiabatic expansion cooling in the polar cap region. For negative IMF-$\overline{B}_z$ the ion drag force tends to generate a cold anticlockwise circulation with upward vertical motion in the dawn sector. For positive IMF-$\overline{B}_z$ it tends to generate a warm clockwise circulation with downward vertical motion in the dawn sector.

The Theoretical Review of the Feature and Application of Science Teaching Models (과학 교수 모형의 특징과 적용에 대한 이론적 고찰)

  • Cho, Hee-Hyung;Kim, Hee-Kyung;Yoon, Hee-Sook;Lee, Ki-Young
    • Journal of The Korean Association For Science Education
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    • 제30권5호
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    • pp.557-575
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    • 2010
  • The purpose of the study was to suggest the characteristics and goals of the science teaching model for use as criteria in selecting the appropriate teaching model for science in secondary schools. These characteristics and the goals have been organized based on the analyses of the literature on the teaching and/or instructional model. The teaching models have been classified into four areas, and the characteristics and goals of each area have been summarized as follows: $\cdot$ Traditional models: teaching of scientific knowledge through lectures, acquisition of scientific knowledge through discovery, acquisition of inquiry process skills through inquiry-based teaching/learning $\cdot$ Transitional models: demonstration and discovery as teaching strategies, acquisition of inquiry process skills through inquiry approach, acquisition and change of scientific knowledge $\cdot$ Modernistic model - conceptual change models: differentiation of scientific knowledge, exchange of misconceptions for scientific concepts - learning cycle models: conceptual differentiation, exchange of misconceptions, acquisition of science process skills Also described in this paper are the model's characteristics and goals that can be used as the criteria for selecting the appropriate teaching model for the subject that will be taught.

Geochemistry and Isotope Studies of the Shinchon $CO_2$ -rich Waters in the Gyeongsang Province (경상지역 신촌 탄산약수의 지화학적 및 동위원소 특성)

  • 김건영;고용권;배대석;김천수;박맹언
    • Economic and Environmental Geology
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    • 제34권1호
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    • pp.71-88
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    • 2001
  • The Geochemica] and isotope studies on the $CO_2$-rich water from the Shinchon area were carried out. The Shinchon $CO_2$-rich water belongs to Ca(Na)-$HCO_3$ type showing very high $P_{CO_{2}}$ ( $10^{-0.35}$ ~ $10^{0.29}$ atm) and TDS (835-3,144 mg/L). The results of geochemical and isotope analysis indicate that $CO_2$ gas is originated from the deep seated source such as mantle or magmatic gases. The $CO_2$-rich water was evolved by interaction with deep-seated granite and major water-rock interaction was dissolution of p]agioclase resulting high Na content of $CO_2$-rich water. Precipitation and dissolution of secondary calcite might be accompanied with the dissolution of plagioclase maintaining Na/Ca ratio. High contents of K and $SO_4$ indicate that the geochemical characteristics of $CO_2$-rich water were partially affected by interaction with upper sedimentary rock during uprising to surface. N03 and tritium contents suggest that the $CO_2$-rich water was mixed with low $CO_2$ groundwater at some locations. The oxygen-hydrogen isotopes show that all water samples were derived from meteoric waters and the $CO_2$-rich water was isotopically re-equilibrated with lighter $CO_2$ gas. Although some carbon isotope data show isotopically heavy values, carbon isotope data indicate that the $CO_2$ gas was possib]y derived by deep source.

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Numerical Simulation of Flow Characteristics behind a Circular Patch of Vegetation using a Two-Dimensional Numerical Model (2차원 수치모형을 이용한 원형군락 하류의 흐름특성 수치모의)

  • Kim, Hyung Suk;Park, Moonhyeong
    • Journal of Korea Water Resources Association
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    • 제48권11호
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    • pp.891-903
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    • 2015
  • This paper presents numerical simulations of flow around a circular patch of vegetation using a depth-averaged two-dimensional numerical model which is capable of simulating flow structure in vegetated open channel. In order to account for vegetation effect, drag force terms are included in governing equations. Numerical simulations are conducted with various solid volume fractions (SVF). Flow passes through a circular patch and low velocity region, which is called wake region, is formed downstream of the patch. When SVF is larger than 0.08, a recirculation is observed. The location of the recirculation is moved further downstream as SVF decreases. Von-$K{\acute{a}}rm{\acute{a}}n$ vortex street is developed beyond the wake region due to interaction between two shear layers induced by a circular patch of vegetation. The vortex is developed as SVF is larger than 0.08, and the location of the vortex is consistent with the maximum of turbulence kinetic energy. The location of the peak of turbulence kinetic energy is moved further downstream as SVF decreases.