• Title/Summary/Keyword: Stagnation point

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Aerodynamic properties of a streamlined bridge-girder under the interference of trains

  • Li, Huan;He, Xuhui;Hu, Liang;Wei, Xiaojun
    • Wind and Structures
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    • v.35 no.3
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    • pp.177-191
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    • 2022
  • Trains emerging on a streamlined bridge-girder may have salient interference effects on the aerodynamic properties of the bridge. The present paper aims at investigating these interferences by wind tunnel measurements, covering surface pressure distributions, near wake profiles, and flow visualizations. Experimental results show that the above interferences can be categorized into two primary effects, i.e., an additional angle of attack (AoA) and an enhancement in flow separation. The additional AoA effect is demonstrated by the upward-moved stagnation point of the oncoming flow, the up-shifted global symmetrical axis of flow around the bridge-girder, and the clockwise-deflected orientation of flow approaching the bridge-girder. Due to this additional AoA effect, the two critical AoAs, where flow around the bridge-girder transits from trailing-edge vortex shedding (TEVS) to impinging leading-edge vortices (ILEV) and from ILEV to leading-edge vortex shedding (LEVS) of the bridge-girder are increased by 4° with respect to the same bridge-girder without trains. On the other hand, the underlying flow physics of the enhancement in flow separation is the large-scale vortices shedding from trains instead of TEVS, ILEV, and LEVS governed the upper half bridge-girder without trains in different ranges of AoA. Because of this enhancement, the mean lift and moment force coefficients, all the three fluctuating force coefficients (drag, lift, and moment), and the aerodynamic span-wise correlation of the bridge-girder are more significant than those without trains.

A Study On the Theory of 'Pungent and Sweet becoming Yang' and 'Sour and Sweet becoming Yin' (신감화양(辛甘化陽), 산감화음(酸甘化陰)의 이론에 대한 고찰)

  • Yun, Ki-ryoung
    • Journal of Korean Medical classics
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    • v.35 no.2
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    • pp.33-49
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    • 2022
  • Objectives : This paper aims to investigate the role of the sweet flavor within the contexts of 'pungent and sweet becoming Yang' and 'sour and sweet becoming Yin' and the meaning of the two concepts. Methods : Related contents in databases including the Siqu Quanshu were searched with 'pungent and sweet becoming Yang' and 'sour and sweet becoming Yin', whose understanding and application were examined. Results & Conclusions : The theories of 'pungent and sweet becoming Yang' and 'sour and sweet becoming Yin' originate from Cheng Wuji's comparison of the Gancaoqianjiangtang and Shaoyaogancaotang in the 29th verse of the Shanghanlun. The two terms first appeared in the Qing period among the Wenbing school. In other medical texts, the combination with sweet flavors could be found with salty, bitter and bland flavors other than with pungent and sour. The role of the sweet flavor in 'pungent and sweet becoming Yang' and 'sour and sweet becoming Yin' is to accomplish the dispersing and converging action slowly and effectively, by supplying energy in small amounts preventing it from happening too quickly, corresponding to its Earth nature of the Five Elements which harmonizes the Yin and Yang. While 'becoming Yin' and 'becoming Yang' could be understood as tonifying Yin and Yang, it could also be understood as 'doing Yin' and 'doing Yang', The specific actions differ according to herb and mixture. The point of distinction between the aforementioned tonification and that of medicinals that have Yin and Yang tonifying properties is that due to the other flavor that is matched with the sweet flavor, Qi is given motility which allows for tonification without stagnation.

Inquiry on Post Surgery Induced Consumption in HyungSang Medicine View (각종 수술 후 유발되는 허로(虛勞)의 형상의학적 고찰)

  • Kim, Jong-Won;Ji, Gyu-Yong;Kim, Kyung-Chul;Lee, In-Sun;Kim, Hyung-Gyu;Lee, Yong-Tae
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.22 no.4
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    • pp.930-942
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    • 2008
  • Following conclusions were derived from researching various consumption caused after surgical operation. The meaning of surgery in HyungSang medical point of view is a big flaw of the original configuration. Therefore meaning, the loss of container to store something. Changes of the body after surgery can be formation of stagnated blood and abnormal cyst of the removed part and entangled undigested food and stagnant blood. After surgery when the symptoms become chronic or the patients develop side effects as they age, consumption and aging process begins. HyungSang medical treatments of consumption caused after surgery are the followings. We should prevent aging of the framework by using appropriate medication to make up for faults in Gall Bladder, Bladder type and six meridian type by considering its form, color, pulse and symptoms. Stability of emotion that can endure various mental stimulation is needed. Prevent stagnation, indigestion, obstruction and numbness by smoothing up the constructive energy and the defensive energy in the operated part. The Heart and Kidney should be under control and Stomach and Spleen should be reinforced so that food intake is accelerated and produce vital substances and Ki and blood. Eum blood and Yang Ki should circulate around the body well. Examine daily life and if small changes in skin complexion, appetite, sleep and excretion occur, also difference in adaptation of external stimulation and mental health occurs immediate treatment and care is necessary. Treatment of side-effects caused from both aging process and post-surgery in HyungSang's view point is considered better than other ways of treatment and will contribute in expanding the field of medical science.

A Study on the Development Strategy of Offshore Oil Resource in China (중국의 해외 석유자원 개발 전략에 관한 연구)

  • Lee, Choong-Bae;Noh, Jin-Ho
    • International Commerce and Information Review
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    • v.13 no.3
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    • pp.119-142
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    • 2011
  • Competitions for secure oil are intense around the world due to the limited oil reserves. The situations are becoming more serious as China has participated in the competition. This paper aims to investigate China's offshore oil development strategies to balance the supply and demand of oil and then suggest its policy implications. A surging increase of oil demand due to the rapid economic growth as well as the stagnation in domestic oil output has turned China into a net oil importer since 1993. Therefore, China has placed a significant priority on securing long-term stability of its offshore oil to cope with the rapid growing demand. It has taken a variety of strategies to secure stable oil resource such as development of offshore oil resource, increasing the number of oil importing countries. China with the highest foreign exchange reserve of approximately $3 trillion as of 2010, has considered to employ foreign exchange reserves while making a huge amount of investment to secure oil resource. China has pursued several policies such as loan to oil production country for securing oil, foreign direct investment on offshore oil development, M&A of oil exploration and production companies and geographical diversification of oil importing countries. China has promoted offensive strategies for securing oil resource rather than cooperation with other countries. Thus, China should find a trade-off point for recovering relationship with international society while developing and investing renewable energy for long-term future. It will also address some implications for Korea, which has to prepare new strategies of overseas oil development.

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Icing Wind Tunnel Tests to Improve the Surface Roughness Model for Icing Simulations (착빙 해석의 표면 거칠기 모델 개선을 위한 착빙 풍동시험 연구)

  • Son, Chankyu;Min, Seungin;Kim, Taeseong;Kim, Sun-Tae;Yee, Kwanjung
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.46 no.8
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    • pp.611-620
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    • 2018
  • For the past decades, the analytic model for distributed surface roughness has been developed to improve the accuracy of the icing simulation code. However, it remains limitations to validate the developed model and determine the empirical parameters due to the absence of the quantitative experimental data which were focused on the surface state. To this end, the experimental study conducted to analyze the ice covered surface state from a micro-perspective. Above all, the tendency of the smooth zone width which occurs near the stagnation point has been quantitatively analyzed. It is observed that the smooth zone width is increased as growing the ambient temperature and freestream velocity. Next, the characteristics of the ice covered surface under rime and glaze ice have been analyzed. For rime ice conditions, ice elements are developed as the opaque circular corn in the opposite direction of freestream. The height and interval of each circular corn are increased as rising the ambient temperature. For glaze ice conditions, numerous lumps of translucent ice can be observed. This is because the beads formed by gravity concentrate and froze on the lower surface.

Colonial Tourism and Modernism in Korean Modern Architecture - Focused on Railroad Station during Japanese Ruling Era - (한국근대건축에서 식민지관광주의와 모더니즘에 관한 연구 - 일제강점기 철도역사 건축을 중심으로 -)

  • Ahn, Chang-Mo
    • Journal of architectural history
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    • v.11 no.2 s.30
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    • pp.7-22
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    • 2002
  • Architectural style is said to be product reflecting political, social and cultural condition. Especially, in colony, architectural style is strongly related to political condition or policy. After colonization in 1910, public buildings with western historical architectural style in Japanese version were widely built by Japanese colonial government in Korea. And in the late 1920s, modernism style in architecture became dominant in Korea as like other countries. In this situation, curious buildings in strange architectural styles came out. One example is railroad station buildings with traditional Korean architectural style and timber house station having a steep roof which is widely used in North Europe such as Alps area with good sights and mountains. Generally, the colonizer says that colonization is the only way to save the colony at crisis defined by colonizer and they insist that they can help the colony modernize. To justify colonization, the colonizer attributes the colonization to the characteristics of the nation and stagnation of the traditional culture etc.. Accordingly, the colonizer tries to depreciate colony's traditional value and culture. In case of colony which has similar cultural background historically (in this case, economical exploitation is less important than other Asian colony by European power), this depreciation of traditional value and culture in Korea was done more strongly than others. At this time, we should understand special relation between Korea and Japan historically. Even though, colony's locality is adopted by the colonizer in public fields, which is based on political purpose or exotic taste etc.. In early days of Japanese ruling period, Japan never use the Korean traditional facts in public. Therefore there is no use of Korean traditional architectural style in public field. In late 1920s, some railroad station buildings were constructed in new styles without precedence in modern Korea. One is railroad station buildings in Korean traditional architectural style, the other is railroad station buildings in timber house stations having a steep roof which is different form western historical architectural style. It was mystery that Japan had constructed railroad stations in Korean traditional style which Japan had tried to destroy together with Western style railroad station buildings. This paper is made to solve the mystery why the colonizer(Japan) constructed entirely different types of railroad stations at the same time in the late 1920s and 1930s. The key point to solve this mystery is tourism. In this paper, to solve this mystery, I try to use terminology' 'Colonial Tourism' in architecture why colonial power had constructed railroad stations with colony's traditional architectural style and Western style having a steep roof which can be seen north European region.

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An Ethnography of the Concept of Illness by the Elderly (노인의 질병 관념에 관한 문화기술적 연구)

  • Cho, Myoung Ok
    • Korean Journal of Adult Nursing
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    • v.12 no.4
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    • pp.690-705
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    • 2000
  • This ethnography was based on Kleinman's explanatory model of a health care system. It is conducted to make thick discription of illness conception of the elderly in a sociocultural context. The basic assumptions were as follows. 1) A health care system is a cultural system, and as with any other cultural system, it is a system of symbolic meanings anchored in a particular arrangement of social institutions and patterns of interpersonal relationships; 2) In all societies health care activities are more or less interrelated. Therefore, they need to be in a holistic manner as socially organized responses to disease that constitute a special cultural system; health care system; 3) Health and illness experiences are the natural process of disease. Individuals who recognized a for state of health, their family, neighbors, and communities define the state, search for causes of the health problems, and response to it. According by, they proceed to search for healing stratagies. So, understanding of the illness experience is the starting point for health care. The study participants were 12 elders aged 60 or more. The fieldwork was conducted in an agricultural clan village of Namwon city. The data collection and analysis were cyclic, from descriptive observation, domain analysis, focused observation, taxanomic analysis, selected observation, componential analysis, and finally cultural themes were all analysed. Proxemic and text analysis techniques were used according to the characteristics of the data. The data of sociocultural context and descriptive data were collected from 1990 to 1992. Informations on illness concepts were collected during 1994 using focused observation. Data confirming and contrast observations were conducted from 1997 and 1999. Illness concepts of the elderly were taxonomized supernatural cause, non-supernatural cause, immediate cause, and ultimate cause. The supernatural ones were ancestors, god of home, god of village, and ghost such as 'sal(evil force of dead man)' and 'gagqui(ghost of begger)'. The non-supernatural ones were Ki, natural phenomenones, natural objects, foods, human and human behaviors. Immediate ones were insufficiency and overflows, discretion and consolidation, disorder and out of order, cloudness and contamination, and fluctuation and stagnation of supernatural cause and non-supernatural ones. Ultimate causes were intrusion and loss of supernatural and nonsupernatural ones. The cultural themes of illness concepts of the elderly are: 1) illness concepts are not based on causality principle, but on reciprocal principle; 2) illness concepts are affected by social level and charicteristics of the patients; 3) the causes of disease are recognized as imposed both positive and negative effects on health based on interpretation of the indiviuals; 4) illness concepts reflects on principles of everyday life of the society members such as hierachial structure and group cohesiveness; 5) illness concepts are ruled on principle of reciprocity and spread; 6) illness concepts are interrelated with physical environment of the participants. It can be concluded that the illness concepts of the elderly in a traditional clan village are a component of health care system as a cultural system based on these results. The these results can be a useful basis for gerontological nursing practice and education.

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A Case Study on Big Data Analysis of Performing Arts Consumer for Audience Development (관객개발을 위한 공연예술 소비자 빅데이터 분석 사례 고찰)

  • Kim, Sun-Young;Yi, Eui-Shin
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.12
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    • pp.286-299
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    • 2017
  • The Korean performing arts has been facing stagnation due to oversupply, lack of effective distribution system, and insufficient business models. In order to overcome these difficulties, it is necessary to improve the efficiency and accuracy of marketing by using more objective market data, and to secure audience development and loyalty. This study considers the viewpoint that 'Big Data' could provide more general and accurate statistics and could ultimately promote tailoring services for performances. We examine the first case of Big Data analysis conducted by a credit card company as well as Big Data's characteristics, analytical techniques, and the theoretical background of performing arts consumer analysis. The purpose of this study is to identify the meaning and limitations of the analysis case on performing arts by Big Data and to overcome these limitations. As a result of the case study, incompleteness of credit card data for performance buyers, limits of verification of existing theory, low utilization, consumer propensity and limit of analysis of purchase driver were derived. In addition, as a solution to overcome these problems, it is possible to identify genre and performances, and to collect qualitative information, such as prospectors information, that can identify trends and purchase factors.combination with surveys, and purchase motives through mashups with social data. This research is ultimately the starting point of how the study of performing arts consumers should be done in the Big Data era and what changes should be sought. Based on our research results, we expect more concrete qualitative analysis cases for the development of audiences, and continue developing solutions for Big Data analysis and processing that accurately represent the performing arts market.

Inquiry on Post Surgery Induced Consumption in HyungSang Medicine View (우울증(憂鬱症)에 대한 형상의학적 고찰)

  • Kim, Jong-Won;Jj, Gyu-Yong;Kim, Kyung-Chul;Lee, In-Sun;Eun, Jong-Won;Kim, Kyu-Kon;Lee, Yong-Tae
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.22 no.5
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    • pp.1035-1046
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    • 2008
  • I looked into hypochondria, an increasing social problem, in psychological and Korean medical aspects and these conclusions were made through 16 clinical cases based on HyungSang medicine. Hypochondria is a disorder that is caused when feeble minded person could not fight the reality. It is caused by deficiency and stagnation of Ki which connects body and mind. In Korean medical view point mind and body is the same. Particularly, in HyungSang medicine believes that everyone's way of life and how to deal with situation differs according to the characteristics and traits. HyungSang medical treatment in hypochondria Mind and body is in line with each other, so manifestation of mental activity is caused by deficiency of combining action of vital Ki. Medication that helps combining force of vital Ki is needed. As the way people handle situation is different, according to characteristics and trait it is valid to differ counselling and treatment according to the criteria. Looking at 16 case studies of hypochondria patients, in gender wise, woman with astriction quality and engaging in much mental activities are more vulnerable. In view of vital substances, more cases were found in Jung type and Ki type. In animal type, bird and reptile type were, and in six meridian type, Tae yang, Yang Myong, Tae Eum and Kwolum type were more susceptible. Especially, cases of Indang being stagnant was noticeable. Moreover, the pulse activated parallel with the Heart which is a leading organ that manifests mental activity and controls seven emotions, so many cases were found that was far from Heart-Small intestine and Heart-Gall Bladder relationship.

Experimental analysis on the characteristics of enthalpy probe immersed in arc plasma flow (아크 플라즈마 유동에 삽입된 엔탈피 탐침의 동작특성 실험)

  • Seo, Jun-Ho;Nam, Jun-Seok;Choi, Seong-Man;Hong, Bong-Gun;Hong, Sang-Hee
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.38 no.12
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    • pp.1240-1246
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    • 2010
  • Enthalpy probe with the inner and outer diameters of 1.5 mm and 4.8 mm, respectively, is designed and used to measure the temperatures and velocities along the centerline of Ar arc plasma flow until the probe was destroyed. For this purpose, Ar arc plasma flow is generated by non-transferred type DC arc heater with the power level of 17 kW. From this experiment, it is shown that the designed enthalpy probe can measure the temperature and velocity of arc plasma flow up to 12,000 K and 600 m/s, respectively, without destroy of probe tip. In this extreme case, the arc plasma flow is calculated to transfer the heat flux of ${\sim}5{\times}10^7\;W/m^2$ to the probe based on the heat and thermal boundary equations near the forward stagnation point of a body immersed in arc plasma flow. Consequently, the designed enthalpy probe can measure the wide ranges of plasma temperatures, velocities and concentrations simultaneously, which are generated by various types of arc heaters within the heat flux ranges of $0{\sim}5{\times}10^7\;W/m^2$ on the probe tip.