• Journal of The Korean Astronomical Society
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• v.35 no.1
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• pp.59-65
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• 2002

Solar observations support that magnetic reconnect ion ubiquitously occurs in the chromosphere as well as in the corona. It is now widely accepted that coronal magnetic reconnect ion is fast reconnect ion of the Petschek type, and is the main driver of solar flares. On the other hand, it has been thought that the traditional Sweet-Parker model may describe chromospheric reconnect ion without difficulty, since the electric conductivity in the chromoshphere is much lower than that in the corona. However, recent observations of cancelling magnetic features have suggested that chromospheric reconnect ion might proceed at a faster rate than the Sweet-Parker model predicts. We have applied the Sweet-Parker model and Petschek model to a well-observed cancelling magnetic feature. As a result, we found that the inflow speed of the Sweet-Parker reconnect ion is too small to explain the observed converging speed of the feature. On the other hand, the inflow speeds and outflow speeds of the Petschek reconnect ion are well compatible with observations. Moreover, we found that the Sweet-Parker type current sheet is subject to the ion-acoustic instability in the chromosphere, implying the Petschek mechanism may operate there. Our results strongly suggest that chromospheric reconnect ion is of the Petschek type.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2006.05a
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• pp.189-192
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• 2006

The development of digital technology makes our life more convenient in our lives and its calmness promotes the qualify of our life. Digital-home-automation system lets indoor-living more free, safe and clear so that it really has come true our life style that considers our mind and healthy to be important. Moreover, LED light source that combines the semiconductor with the digital technology has been tried as a current indoor illumination. Also the introduction of the light which has a high technology, like LED light, has been required in living space. It shows that it is very important to have an illuminated- plan which is accepted as well-developed technology. This study deals with the investigation into the user satisfaction of the existing residential area illumination and the investigation into the user satisfaction of the LED illumination being supplied for commercial area now. In the result, the fact is investigated that the user wants the introduction of the digital technology In the illumination because of a backward the residental area illumination in the circumstances being digital gradually. The inconvenience of the illumination used now should be minimized and the development of the LED illumination is a way satisfying the desire. The intended illumination project of the residential area should be accomplished according to the lifestyle of a changing residence.

• Korean Institute of Interior Design Journal
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• v.15 no.6 s.59
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• pp.11-18
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• 2006

Ceaseless studies and efforts to verify today's Korean nature that has advanced into digital era of 21C are continued. At this point of time, it is required to look back our heritage in diverse points of view free from theoretical and formal studies on our traditional spaces. Phenomenology, which is rising as the important theme in recent modem Western philosophy, suggests interesting analyses from this standpoint. This study is intended to analyze Korea's traditional residents 'Dok Rak Dang' based on Marleau-Ponty's phenomenology, and explore phenomenological spatial principle and new point of view implied in it. Particularly, Marleau-Ponty's phenomenology is the philosophy that shows intersubjective and involved relations between space and human, and intended to accept coincidental incidents occurred by human's action truthfully as they are. With three spatial concepts of direction, depth, and movement in Ponty's phenomenology, and placement nature of the earth that intercombine with human's body who is subject of these three concepts as analyze tool, Korea's traditional residents, 'Dok Rak Dang' has been analyzed. More segmentalized analyses have been deduced, and principle of phenomenology, that perceptions such as direction, depth, movement, etc are working synthetically to be accepted as essence of experiences could also be found in Dok Rak Dang.

• Journal of Astronomy and Space Sciences
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• v.36 no.2
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• pp.45-60
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• 2019

The Earth's outer radiation belt has long received considerable attention mainly because the MeV electron flux in the belt varies often dramatically and at various time scales. It is now widely accepted that the wave-particle interaction is one of the major mechanisms responsible for such flux variations. The wave-particle interaction can accelerate electrons to MeV energies, explaining the observed flux increase events, and can also scatter the electrons' motion into the loss cone, resulting in atmospheric precipitation and thus contributing to flux dropouts. In this paper, we provide a review of the current state of research on relativistic electron scattering and precipitation due to the interaction with electromagnetic ion cyclotron (EMIC) waves in the inner magnetosphere. The review is intended to cover progress made over the last ~15 years in the theory and simulations of various issues, including quasilinear resonance diffusion, nonlinear interactions, nonresonant interactions, effects of finite normal angle on pitch angle scattering, effects due to rising tone emission, and ways to scatter near-equatorial pitch angle electrons. The review concludes with suggestions of a few promising topics for future research.

• Journal of the Chungcheong Mathematical Society
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• v.34 no.1
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• pp.37-53
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• 2021

In this paper we define scaled visual curvature and visual Frenet frame that can be visually accepted for discrete space curves. Scaled visual curvature is relatively simple compared to multi-scale visual curvature and easy to control the influence of noise. We adopt scaled minimizing directions of height functions on each neighborhood. Minimizing direction at a point of a curve is a direction that makes the point a local minimum. Minimizing direction can be given by a small noise around the point. To reduce this kind of influence of noise we exmine the direction whether it makes the point minimum in a neighborhood of some size. If this happens we call the direction scaled minimizing direction of C at p ∈ C in a neighborhood Br(p). Normal vector of a space curve is a second derivative of the curve but we characterize the normal vector of a curve by an integration of minimizing directions. Since integration is more robust to noise, we can find more robust definition of discrete normal vector, visual normal vector. On the other hand, the set of minimizing directions span the normal plane in the case of smooth curve. So we can find the tangent vector from minimizing directions. This lead to the definition of visual tangent vector which is orthogonal to the visual normal vector. By the cross product of visual tangent vector and visual normal vector, we can define visual binormal vector and form a Frenet frame. We examine these concepts to some discrete curve with noise and can see that the scaled visual curvature and visual Frenet frame approximate the original geometric invariants.

• Journal of Oral Medicine and Pain
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• v.21 no.1
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• pp.197-206
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• 1996

This study ws performed to investigate the relationship between cervical curvature and the spatial position of the posterior part of the atlas imaged in the lateral cephalograph. Sixty six patients with temporomandibular disorders(TMD) and twenty dental students were selected for patients group and control group, respectively. The average age of patients group was 26.3 years, and 24.9 years in control group. Measured variables were cervical depth, upper space between the atlas and the base of the occiput, lower space between the atlas and the spinous process of the axis, rea of the posterior part of the atlas imaged in the lateral cephalograph, and the cervical curvature passing through the uppermost point in dorsal side of Dens of the Axis to the lowermost and rearmost point of the 5th cervical vertebra. The reliability of the method used for measuring cervical curvature with curved ruler was also tested. The results obtained were as follows : 1. Cervical depth of patients group was 122.9mm and significantly shorter than that of control group, in which cervical depth was 131.9mm, and cervical depth was significantly correlated with other variables in all subjects. 2. Upper space was greater in patients group, but total space including upper and lower space showed no difference between the two groups. The average value of total space was 26.5mm. 3. Area of the posterior part of the atlas was 168.2$\textrm{mm}^2$ in patients group, and 186.5$\textrm{mm}^2$ in control group with significant difference between the two groups. 4. Average range of radius of cervical curvature were 33-40cm and there was no difference between the two groups. 5. There was no significant correlation between the cervical curvature and the area of the posterior arch of the atlas. 6. The method using curved ruler for measuring cervical curvature could be accepted as a reliable method.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.2
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• pp.54.1-54.1
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• 2016

Stellar wind and radiation pressure from massive stars can trigger the formation of new generation of stars. The sequential age distribution of stars, the morphology of cometary globules, and bright-rimmed clouds have been accepted as evidence of triggered star formation. However, these characteristics do not necessarily suggest that new generation of stars are formed by the feedback of massive stars. In order to search for any physical connection between star forming events, we have initiated a study of gas and stellar kinematics in NGC 1893, where two prominent cometary nebulae are facing toward O-type stars. The spectra of gas and stars in optical and near-infrared (NIR) wavelength are obtained with Hectochelle on the 6.5m MMT and Immersion GRating INfrared Spectrograph on the 2.7m Harlan J. Smith Telescope at McDonald observatory. In this study, the radial velocity field of gas across the cluster is investigated using $H{\alpha}$ and [N II] ${\lambda}$ 6584 emission lines, and that of the cometary nebula Sim 130 is also probed using 1-0 S(1) transition line of $H_2$. We report a distinctive velocity field of the cometary nebulae and many ro-vibrational transitions of $H_2$ even at high energy levels in the NIR spectra. These properties indicate the interaction between the cometary nebulae and O-type stars, and this fact can be a clue to triggered star formation in NGC 1893.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.33 no.2
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• pp.180-184
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• 2011

The mucocele is a mucus extravasation cyst arising from the salivary gland. Although it is a common?lesion of the minor salivary gland, it is uncommon when it originated from the submandibular gland. The ranula is a form of mucocele which specifically occurs in the floor of the mouth and the sublingual gland is generally accepted as the origin of ranula. They can be classified into two types based on extent: simple ranula are confined to the sublingual space and plunging ranula extend into the adjacent space. It is difficult to differentiate the submandibular gland mucocele from the plunging ranula because both of them can occupy the submandibular space. A 37-year old male visited our clinic with the chief complaint of left facial swelling. The patient's history revealed that he had suffered from a cystic lesion on the left side of the floor of the mouth 10 months previously. He supposed the cystic lesion had come from trauma at other dental clinics. Using CT and MRI, we diagnosed a simple ranula on the sublingual space and a submandibular gland mucocele. We then excised the mucocele with the submandibular gland by an extraoral approach and the sublingual gland by an intraoral approach under general anesthesia. We report a rare case of an enormous submandibular gland mucocele which extended into the pterygoid plate and parapharyngeal space with good surgical results.

• Korea Science and Art Forum
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• v.19
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• pp.515-525
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• 2015

Along with a rapid increase in the number of 1-person households where the concept of 1-person consumption and 1-person economy is emphasized, the proportion of 1-person household in Korea occupies a 25.3% at present, and the number is expected to grow continuously. And this rapid increase will bring about a host of problems such as housing shortage in the metropolitan area, egoism, loneliness felt by individuals, and other social problems such as crime. As an alternate movement to this phenomenon, concern on and interest in community, community culture, and sharing of space are on the rise, together with concern on and preference for sharehouse culture. In news media as well, articles on life shared with members of a sharehouse often appear. This sharehouse, which is widely spread and well received in Japan, not only reduces economic burden but also creates their own community and promotes their own culture. In this sense, it is a new way of life that represents benefits of sharing, well beyond just economic interests. Accordingly, In this research, an attempt was made tp examine the circumstances in the use of space based on existing studies on sharehouse characteristics in order to shed new lights on the meaning that non-characteristic space concept of the traditional residential space has as the concept of sharehouse space by considering it in connection with the non-characteristic space concept of the Korean traditional residential space where diverse circumstances occur centered on communal life and which were accepted by all naturally.

• The Journal of Art Theory & Practice
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• no.1
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• pp.49-70
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• 2003

What is an exhibition? Is it of the system which is designed to serve Art Works in their representation, or is it a place where the artistic presentation could be considered as art work itself? After modernist era, the role of exhibitional space might have been shifted from those two principle raison d'$\^{e}$tre of exhibitional space into another, a new one. What Deleuze would call it as he borrowed the term from Spinozian philosophy : the Affectional Space. This new type of exhibitional space has been announced since 1969 when a Harald Szeeman, young independent curator and art critic from Swiss, has organized his brilliant exhibition "When Attitudes become Form" in Bern. For sure, these intensities in curatorial practices have been existing before like some early 20th century exhibitional efforts by Marcel Duchamp, El Lissitzky, Yve Klein, etc. It has influenced much on many of, otherwise most of contemporary art exhibiting practices. And now it seems to be necessary to give it a conceptual idea which could enlighten better the new paradigm of exhibitional practices that we try to clarify. I would propose the idea of that new exhibitional space as "space of non-organic becoming". This idea is inspired by Deleuze's ever famous philosophical work Thousand Plateaus, which, with Folds by the same author, has contributed to many contemporary and aesthetical debating issues. What is "affect"? Explaining about Spinoza's principle concepts, Deleuze defines it as a kind of durations or variations which are constituted by different levels of perfection. One perfection is precedented or followed by certain perfection bigger or lesser through lived transitions or passages. So each time it actualizes and reflects the state of All as a cut of Reality while each state of affections, images or ideas can not be separated from the duration which binds it to the precedent state and extends it to following one. Affect is also a term of changes. One affects at the same time it is affected. Exhibitional space as affect (or affectional space) is distinguished from representational and presentational space in the way it attributes movement, produces arrangements and generates new factors of artistic creation including those which are outside of ever accepted artistic elements. The concepts of affectional space are used especially to enlighten contemporary situation of artistic and curatorial processes. Art is no more limited to be seen as mere objects of aesthetical admiration, nor as art vis-$\`{a}$-vis art relationship apart from the whole. It includes possibilities and virtuality that appear in the imperceptible and undescribable manners if delimited in given language. As once noticed by Kuhn, we might be living in a paradigmatically shifting world, not only in Art but also in Life. And we need to express it more with Art as moving and affectional nods than as just a clean window or a distinct manual book.