• 한국전산유체공학회:학술대회논문집
• /
• 2008.10a
• /
• pp.251-255
• /
• 2008

Flow field around helicopter involves incompressible flow near the blade root and compressible flow at the blade tip. A problem occurs for low Mach number flow due to the stiffness of the governing equations. Time-derivative preconditioning techniques have been incorporated to reduce the stiffness that occurs at low speed region. The preconditioned form of the compressible Navier-Stokes and Euler equations is used. Computations are performed for the Caradonna-Tung's hovering and non-lifting forward flight case. Computational results are in good agreement with the experimental data.

• Restorative Dentistry and Endodontics
• /
• v.11 no.1
• /
• pp.7-10
• /
• 1985

Coccal form of microorganism (staphylococcus) isolated from infected root canal was inoculated on the thioglycolate agar and paper discs (5mm in diameter) immersed with 0.1ml of 10% Formaldehyde, Thymol, Eugenol Phenol (90%) and 5% Silver nitrate were placed on the media. The thioglycolate plate was incubated at $37^{\circ}C$ for 48 hours. Inhibition zone was measured as follow: The greatest value was 3.9mm at Formaldehyde, next followed Thymol 3.6mm, Eugenol 3.5mm and Phenol 3.4mm. The least value, 3.0mm was found at Silver nitrate.

• Journal of Chest Surgery
• /
• v.33 no.9
• /
• pp.748-751
• /
• 2000

The diffuse form of supravalvar aortic stenosis represents a surgical challenge when the ascending aorta, aortic arch, proximal descending thoracic aorta and arch arteries are involved. It can be treated by a variety of surgical approaches. We report a case of severe diffuse supravalvar aortic stenosis combined with an aortic valve anomaly and occlusion of the right coronary artery ostium in a 14-year-old boy with Williams syndrome. We enlarged the aortic root(Nick's procedure), ascending aorta, aortic arch, proximal descending thoracic aorta, and innominate artery with patches and replaced aortic valve with 19 mm St. Jude valve. Deep hypothermic circulatory arrest and retrograde cerebral perfusion were used during repair of the arch and arch artery.

• Journal of Korean Society for Atmospheric Environment
• /
• v.12 no.1
• /
• pp.67-77
• /
• 1996

Total suspended particulate matters (TSP) were collected based on a size segregation method by a cascade impactor for 6 consecutive years (form Dec. 1989 to sep. 1994) in the Kyung Hee University-Suwon Campus, and 6 trace metals (Ca, Si, Fe, Pb, Cu, Zn) were determined by an x-ray fluorescence spectroscopy. Total number of samples collected during the study are 118 sets and each set of sample comsists of 9 filters. The levels of TSP and 6 trace metals were then used to examine seasonal and annual variations with respects to their size distributions. For statistical analyses, raw data were initially transformed by both logarithmic and root transformating to approximately normalize them, and then size distribution functions for each trace element were separately developed season-to-season by a regression analysis in order to obtain maximum amount of physical information, Subsequently, each developed model was verified by comparing with supervised data collected on 1994. The result showed that each prediction model was in good agreement except the fall, partly due to lack of the data collected on fall, 1994.

• Journal of Institute of Control, Robotics and Systems
• /
• v.4 no.2
• /
• pp.226-234
• /
• 1998

The concept of dynamic tracking line is proposed as the feasible tracking region for a robot in a robot-conveyor system, which takes the conveyor speed into consideration. This paper presents an effective method to identify the dynamic tracking line in a robotic workcell. The maximum line speed of a robot is derived in an analytic form using the parameterized dynamics and kinematics of the manipulator, and some of its properties are established mathematically. The identification problem of the dynamic tracking line is then formulated as a root-solving problem for a single-variable equation, and solved by using a simple numerical technique. Finally, numerical examples are presented to demonstrate the methodology and its applications in workspace specification.

• Communications of Mathematical Education
• /
• v.22 no.4
• /
• pp.505-514
• /
• 2008

In this paper we study on derivation of formulas for roots of quadratic equation, cubic equation, and quartic equation through method analogy. Our argument is based on the norm form of polynomial. We also present some mathematical content knowledge related with main discussion of this article.

• Design & Manufacturing
• /
• v.9 no.2
• /
• pp.6-9
• /
• 2015

The objective of manufacturing knowledge sharing platform is to convert the production experience like a worker's know-how into quantitative values, to construct database of the process technologies and to share the technologies systematically via web portal service. In addition, the knowledge sharing platform contains the total production processes of automobile and mobile products such as information of experts, facilities, and cutting-edge R&D outputs. Automobile, telecommunication mobile, and semiconductors account for a large amount of Korea's export industry rate. These industries need production technology which is a result of converting worker's know-how and R&D. Manufacturing knowledge portal aims to enable transforming production experience such as worker's know-how into standardized form for constructing database and sharing technologies systematically. Manufacturing knowledge portal can contribute to small and mid-sized manufacturing companies with further improvements.

• Proceedings of the Ginseng society Conference
• /
• 2002.10a
• /
• pp.145-158
• /
• 2002

Since immemorial time Panax ginseng has been known as therapeutic, tonic, prophylactic and restorative agent in ancient Korea, China and Tibet and at present time is also used as a food supplement by Western societies (6). Various ginseng preparations in a form of powders, teas, tinctures or extracts, very often mixed with other substances are recommended for attenuation of degenerative processes caused by aging or fatigue, as well as for treatment of various disorders and diseases in several organs (e.g. circulatory and nervous system, liver, kidney). One of the most commonly known properties of ginseng is its possibly positive influence on physical and mental performance and general well being. Because of these adaptogenic properties promoting vitality and resistance to stress ginseng is considered as an ergogenic aid. During almost 40 years in many laboratories attempts have been made to find out whether ginseng can be 'a remedy for today's problems'. The present work is focused on the results obtained in human studies and concerning an influence of ginseng root extracts on exercise and mental performance.

• East Asian Economic Review
• /
• v.23 no.2
• /
• pp.149-168
• /
• 2019

Public information arrivals and their immediate incorporation in asset price is a key component of semi-strong form of the Efficient Market Hypothesis. In this study, we explore the impact of public information arrivals on cryptocurrency market via Twitter posts. The empirical analysis was conducted through various methods including Kapetanios unit root test, Maki cointegration analysis and Markov regime switching regression analysis. Results indicate that while in bull market positive public information arrivals have a positive influence on Ripple's value; in bear market, however, even if the company releases good news, it does not divert out the Ripple from downward trend.

• Journal of Information Science Theory and Practice
• /
• v.8 no.4
• /
• pp.29-39
• /
• 2020

The diverse set of phenomena, concepts, and activities existing in academic disciplines could be studied from multiple perspectives. One of the promising approaches to explore phenomena is hermeneutics, especially in the form of hermeneutic phenomenology, which has been formed as a consequence of postmodern movements. Hermeneutic phenomenology has taken root in the original ideas of philosophers like Husserl, Heidegger, and Gadamer, and has become one of the fruitful research methodologies over time. After a brief review of the foundations of hermeneutic and phenomenological methodologies, the role of the hermeneutic phenomenology approach in supporting research and information services is discussed. The present article seeks to describe narratively the use of hermeneutic phenomenology in such issues as information technology, information behavior, knowledge organization, and librarians' roles as related to Information Science.