• Title/Summary/Keyword: Circulation change

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A Study of Selecting Sequential Viewpoint and Examining the Effectiveness of Omni-directional Angle Image Information in Grasping the Characteristics of Landscape (경관 특성 파악에 있어서의 시퀀스적 시점장 선정과 전방위 화상정보의 유효성 검증에 관한 연구)

  • Kim, Heung Man;Lee, In Hee
    • KIEAE Journal
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    • v.9 no.2
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    • pp.81-90
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    • 2009
  • Relating to grasping sequential landscape characteristics in consideration of the behavioral characteristics of the subject experiencing visual perception, this study was made on the subject of main walking line section for visitors of three treasures of Buddhist temples. Especially, as a method of obtaining data for grasping sequential visual perception landscape, the researcher employed [momentum sequential viewpoint setup] according to [the interval of pointers arbitrarily] and fisheye-lens-camera photography using the obtained omni-directional angle visual perception information. As a result, in terms of viewpoint selection, factors like approach road form, change in circulation axis, change in the ground surface level, appearance of objects, etc. were verified to make effect, and among these, approach road form and circulation axis change turned out to be the greatest influences. In addition, as a result of reviewing the effectiveness via the subjects, for the sake of qualitative evaluation of landscape components using the VR picture image obtained in the process of acquiring omni-directional angle visual perception information, a positive result over certain values was earned in terms of panoramic vision, scene reproduction, three-dimensional perspective, etc. This convinces us of the possibility to activate the qualitative evaluation of omni-directional angle picture information and the study of landscape through it henceforth.

Responses of the Ross Sea to the Climate Change: Importance of observations in the Ross Sea, Antarctica (기후변화에 따른 남극 로스해 반응에 관한 고찰: 남극 로스해 관측의 중요성)

  • Yoon, Seung-Tae
    • Ocean and Polar Research
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    • v.44 no.1
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    • pp.69-82
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    • 2022
  • The Ross Sea, Antarctica plays an important role in the formation of Antarctic Bottom Water (AABW) which is the densest water mass in global thermohaline circulation. Of the AABW, 25% is formed in the Ross Sea, and sea ice formation at the polynya (ice-free area) developed in front of ice shelves of the Ross Sea is considered as a pivotal mechanism for AABW production. For this reason, monitoring the Ross Sea variations is very important to understand changes of global thermohaline circulation influenced by climate change. In addition, the Ross Sea is also regarded as a natural laboratory in investigating ice-ocean interactions owing to the development of the polynya. In this article, I introduce characteristics of the Ross Sea described in previous observational studies, and investigate variations that have occurred in the Ross Sea in the past and those taking place in the present. Furthermore, based on these observational results, I outline variations or changes that can be anticipated in the Ross Sea in the future, and make an appeal to researchers regarding the importance and necessity of continuous observations in the Ross Sea.

The Study of Vascular Dynamics for the Effect of a Compress Pack on Pain Relief using Magnetic Resonance Angiography (자기공명영상을 이용한 찜질 자극에 의한 통증 완화 효과에 대한 혈류 영상학적 고찰)

  • Baek, Ji-Won;Lim, Young-Khi
    • Journal of Radiation Protection and Research
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    • v.40 no.4
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    • pp.277-282
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    • 2015
  • This study was to investigate the effects of the hot compress pack on alleviating local muscular discomfort, stiffness in limbs as well as the chronic pains such as migraine in terms of hemodynamics. In this study, the hot compress band was put on the neck and the local physiological change on the stimulation site and the cranial blood circulation change were examined. We recruited healthy volunteers (n=8, mean age: 32.13 (4.61)), who participated in the magnetic resonance imaging (MRI) study. Local skin color and temperature were measured for the local effect of the hot compress band and the changes of intra-cranial and extra-cranial blood vessels were examined with MR angiography (MRA) images. The skin temperature increased from $36.4^{\circ}C$ at the rest condition to $36.7^{\circ}C$ and $37.1^{\circ}C$ after 15 min and 30 min stimulation, respectively. The change of the extra-cranial blood vessels between pre-stimulation and post-stimulation of 30 min was significantly increased (+38.8%), while the change of the intra-cranial blood vessels was negligible. In this study, we demonstrated that the hot compress band on the neck yielded the increase of local skin temperature on the stimulation site and it made an effect on the extracranial circulation. In conclusion, the stimulation with a hot compress could facilitate the blood circulation, causing to relieve the muscular discomfort, stiffness in limbs as well as the chronic pains such as migraine.

An Analysis of Students' Conceptions on Blood Circulation as Components: A Cross-sectional Study (혈액 순환 요소별 학생들의 개념 분석 : 횡단적 연구)

  • Kim, Mi-Young;Kim, Heui-Baik
    • Journal of The Korean Association For Science Education
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    • v.26 no.6
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    • pp.753-764
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    • 2006
  • The concept of blood circulation is so complex, dynamic and abstract that students have difficulty in understanding it and students' preconceptions hardly change into scientific concepts even after the lessons. The purpose of this study is to examine middle school, high school, and undergraduate students' understanding of blood circulation and to find the reason why the lack of deep understanding is displayed in students' explanations for the blood circulation. The study consists of three parts. First, the test was designed to investigate students' ideas for blood circulation as components of the structure, the function, the behavior and the mechanism. Second, the test was applied to 7th, 10th and 13th graders to investigate the students' understanding of blood circulation and categorize the types of students' blood circulation model according to their academic level. Finally, the concepts the students had little understanding of were analyzed to decide which ontological category they fell into and further to inquire the characteristics of each concept. The results showed that many students comprehend the structure and the function of blood circulation components well, and there was no significant difference in students' understanding according to the academic level. In contrast, understanding the behavior and the mechanism of circulatory components has remarkably improved in high school students and undergraduates majoring in science and engineering. Also, students' blood circulation models were classified into seven different types. High school students and undergraduates majoring in science and engineering demonstrated a significantly higher percentage on the type of double-loop-branch compared to other academic levels. In addition, it was found that the lack of deep understanding was caused by students' misconceiving the 'equilibrium' category as 'event' category.

Coastal Circulation and Bottom Change due to Ocean Resort Complex Development

  • Kim, Pill-Sung;Lee, Joong-Woo;Kim, Jeong-Seok
    • Journal of Navigation and Port Research
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    • v.36 no.7
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    • pp.585-590
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    • 2012
  • On the basis of the potentials for the growth of local economy and the result of investigation of the ocean space development status, an ocean resort complex was proposed at the small harbor with a parallel beach in the east coast of Korea. As the development plan needs to reclaim the noticeable amount of coastal water area together with the applied shore facilities, it is necessary to analyze their impacts. Here, it was intended to analyze the coastal environment change such as water circulation and bottom change because of the development plan. A horizontal two-dimensional numerical model was applied to represent the combined impact of wind waves and tidal currents to sediment transport in that coastal region. Based on the result of 30 days tidal current simulations considering major four tidal components of $M_2$,$S_2$,$K_1$ and $O_1$ for the upper and lower boundaries and wind field data, bottom change was discussed. Flow velocities were not changed much at outer breakwater of Yangpo harbor. Bottom was eroded by maximum 1.7m after construction but some locations such as lee side of outer breakwater and some islets near the entrance shows isolated accretions. Although it needs more field observations for bottom change in the period of construction, the numerical calculation shows that there exist small impacts near the entrance area and coastal boundaries because of the development.

Analysis of Precipitation Characteristics of Regional Climate Model for Climate Change Impacts on Water Resources (기후변화에 따른 수자원 영향 평가를 위한 Regional Climate Model 강수 계열의 특성 분석)

  • Kwon, Hyun-Han;Kim, Byung-Sik;Kim, Bo-Kyung
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.5B
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    • pp.525-533
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    • 2008
  • Global circulation models (GCMs) have been used to study impact of climate change on water resources for hydrologic models as inputs. Recently, regional circulation models (RCMs) have been used widely for climate change study, but the RCMs have been rarely used in the climate change impacts on water resources in Korea. Therefore, this study is intended to use a set of climate scenarios derived by RegCM3 RCM ($27km{\times}27km$), which is operated by Korea Meteorological Administration. To begin with, the RCM precipitation data surrounding major rainfall stations are extracted to assess validation of the scenarios in terms of reproducing low frequency behavior. A comprehensive comparison between observation and precipitation scenario is performed through statistical analysis, wavelet transform analysis and EOF analysis. Overall analysis confirmed that the precipitation data driven by RegCM3 shows capabilities in simulating hydrological low frequency behavior and reproducing spatio-temporal patterns. However, it is found that spatio-temporal patterns are slightly biased and amplitudes (variances) from the RCMs precipitation tend to be lower than the observations. Therefore, a bias correction scheme to correct the systematic bias needs to be considered in case the RCMs are applied to water resources assessment under climate change.

Modeling of Grade Change Operations in Paper Mills

  • Ko, Jun-Seok;Yeo, Yeong-Koo;Ha, Seong-Mun;Lim, Jung-Woo;Ko, Du-Seok;Hong Kang
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.35 no.5
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    • pp.46-52
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    • 2003
  • In this work we developed the closed-loop model of a paper machine during grade change with the intention to provide a reliable dynamic model to be used in the model-based grade change control scheme. During the grade change, chemical and physical characteristics of paper process change with time. It is very difficult to represent these characteristics on-line by using physical process models. In this work, the wet circulation part and the drying section were considered as a single process and closed-loop identification technique was used to develop the grade change model. Comparison of the results of numerical simulations with mill operation data demonstrates the effectiveness of the model identified.

A Study of Literature on the Ying Qi and Wei Qi (영(營).위기(衛氣)에 대(對)한 문헌적(文獻的) 고찰(考察))

  • Hong Seung-Won;Um Jeong-Hun;Lee Sang-Yong
    • Korean Journal of Acupuncture
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    • v.19 no.2
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    • pp.87-96
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    • 2002
  • Objective : To study of Literature on the Ying Qi and Wei Qi One of thing that is among basis theory of Oriental medicine is Vital Essence, Vitality, Qi and Blood(精神氣血) justly. Results : Physiological special quality of Ying Qi(營氣) first, flows within Blood Circulation and the temper is mild and second, transform blood and grow up whole body, and follow through Pectoral Qi(宗氣). Wei Qi(衛氣) means running regeneration of material that do guard action of human body as refined nutritious substances transformed in food. Physiological special quality of Wei Qi(衛氣) first, nature is fast, smooth, and sharp. And it flows outside Blood Circulation. Second, go on muscslar gap without following through Pectoral Qi(宗氣). Ying blood(營血) flows within Blood Circulation means living body ingredient which thing reveals by circulation of the blood change phenomenon. Ying Qi(營氣) is Ying(營) in meaning which go on meridians, therefore meridians as wandering living body reaction route mean. This Ying Qi(營氣)'s physiology transform blood and grows up whole body and flows within Blood Circulation. It becomes most important ingredient of composition of blood, Wei Qi(衛氣) transforms and becomes nutrition constantly by running regeneration of material which transform in Jungcho(中焦) and spread by spreading action of upper chest exhaust in lower belly above the blader of apriority, Kidney-yang.

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Conceptual Design and Feasibility Study on 0.5 MWth Pressurized Chemical Looping Combustor (0.5 MWth 가압 케미컬루핑 연소기 개념설계 및 구현 가능성 조사)

  • RYU, HOJUNG;LEE, DONGHO;JANG, MYOUNGSOO;KIM, JUNGHWAN;BAEK, JEOM-IN
    • Transactions of the Korean hydrogen and new energy society
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    • v.27 no.2
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    • pp.201-210
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    • 2016
  • To develop a pressurized chemical looping combustor, conceptual design of 0.5 MWth chemical looping combustor was performed by means of mass and energy balance calculations. Based on the conceptual design, reactivity of oxygen carrier and solid circulation rate were selected as key parameters. Sensitivity analysis of those key parameters were conducted with the change of oxygen carrier utilization percent from 5 to 50% and proper solid circulation rate and solid conversion rate to meet 98% of $CO_2$ selectivity were confirmed. Feasibility of 0.5 MWth pressurized chemical looping combustor was confirmed by experimental studies to find real solid circulation rate and $CO_2$ selectivity within the operating conditions based on the conceptual design. We could varied very wide range of solid circulation rate in two interconnected fluidized bed system. We also got enough $CO_2$ selectivity more than 98% in semi-continuous chemical looping combustor using OCN717 oxygen carrier. Consequently, feasibility of 0.5 MWth pressurized chemical looping combustor was confirmed.

Decadal Change in Rainfall During the Changma Period in Early-2000s (2000년대 초반 우리나라 장마기간 강수량의 십년 변화 특성)

  • Woo, Sung-Ho;Yim, So-Young;Kwon, Min-Ho;Kim, Dong-Joon
    • Atmosphere
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    • v.27 no.3
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    • pp.345-358
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    • 2017
  • The decadal change in rainfall for Changma period over the South Korea in early-2000s is detected in this study. The Changma rainfall in P1 (1992~2002) decade is remarkably less than in P2 (2003~2013) decade. The much rainfall in P2 decade is associated with the increase of rainy day frequency during Changma period, including the frequent occurrences of rainy day with a intensity of 30 mm/day or more in P2 decade. This decadal change in the Changma rainfall is due to the decadal change of atmospheric circulation around the Korean Peninsula which affects the intensity and location of Changma rainfall. During P2 decade, the anomalous anti-cyclone over the south of the Korean Peninsula, which represents the expansion of the North Pacific high with warm and wet air mass toward East Asia, is stronger than in P1 decade. In addition, the upper level zonal wind and meridional gradient of low-level equivalent potential temperature in P2 decade is relatively strengthened over the northern part of the Korean Peninsula than in P1 decade, which corresponds with the intensification of meridional gradient between air mass related to the East Asian summer monsoon nearby the Korean Peninsula in P2 decade. The enhanced meridional gradient of atir mass during P2 decade is favorable condition for the intensification of Changma rainfall band and more Changma rainfall. The atmospheric conditions related to enhanced Changma rainfall during P2 decade is likely to be influenced by the teleconnection linked to the suppressed convection anomaly over the southern part of China and South China Sea in P2 decade.