1,667 research outputs found
Symmetrical Aspects of Urban Regeneration in Seoul
Korea has developed very rapidly since 1980s highlighted with Seoul olympic, and urbanization necessarily incurred. Population grew with increasing housing demands, but old towns could not provide enough land. The old town was already congested, and living conditions fell off. Therefore, new towns outside the old town were planned and built through three sequential phases. This suburbanization brought about heavy load on commuter transportation and air pollution. At the same time, improper infrastructure and amenities turned new towns into bedtowns. To escape from bedtowns, people returned to the old town, and urban remodeling was needed to accommodate adequate living conditions. In doing so, local characteristics were lost. Urban regeneration aroused as a countermeasure to this mishap. In this study, urban regeneration reinforced with smart technologies is suggested to revive lost placeness, communal connectivity, and urban orientation. Gentrification is another important issue to be resolved for the sustainable urbanization. This study focused on symmetrical aspects of the successful urban regeneration
Behavior of Connections Between SHS Columns & W-section Beams
Connections between SHS (Square Hollow Section) columns and W-section beams are generally fabricated by welding with or without endplates in the factory. These welded connections possess some finite degree of rotational stiffness which falls between fully rigid and ideally pinned joints. The influence of partially restrained connections on structural response not only changes the moment distribution but also increases frame drift. In this paper, a series of connection tests joining SHS column and W-section beam were executed and the test results compared with theoretical values. A method to utilize nonlinear moment-rotation relations of beam-to-column connections in steel framed structures is proposed. For the problem of contact in endplate-type connections, a simple and efficient method is also introduced
Toward an Evaluation Model of User Experiences on Virtual Reality Indoor Bikes
This paper deals with deriving a model or framework to evaluate user experiences (UX) of virtual reality (VR) systems, especially, VR indoor bikes which are under construction. Recently, VR is one of the most appealing areas attracting peopleâs interests around the world. Many products armed with it increasingly emerge on the market, and it is expected that the use of VR systems will continue to increase sharply in the future. However, UX of such products cannot be evaluated appropriately at the moment due to a lack of proper evaluation models. In a broad sense, UX that may stem from human machine interface in ergonomics covers affect, usability, and user value in spite of some differences in definition among the researchers. While evaluations of UX on the products without VR have been overall justifiably performed, UX has been evaluated neither systematically nor strictly on the products with VR. Through the analyses of expert reviews, we newly identify an additional component and its elements, and modify some elements of the three existing components for evaluating UX on the VR systems. As a result, we propose a comprehensive evaluation model of UX, which consists of four factors: usability, affect, user value, and presence feeling. In addition, we determine the components and their elements for specific VR indoor bikes similarly through the analyses of expert surveys and focus-group discussions, which results in developing a questionnaire for users. Finally, along with the questionnaire, we propose a specific evaluation model for VR indoor bikes
Epileptic nystagmus: A case report and systematic review
AbstractPurposeWe aimed to define the characteristics of epileptic nystagmus and correlate those with other clinical findings in a large number of patients.MethodsWe report a patient with epileptic nystagmus and additionally reviewed the reported clinical features of 36 more patients through a systematic literature search. We analyzed the characteristics of epileptic nystagmus and attempted correlations of those with alertness of the patients and epileptic foci on EEG.ResultsAll 33 patients with unilateral horizontal nystagmus showed nystagmus beating away from the side of ictal discharges. Epileptic nystagmus was preceded by gaze deviation in 21 patients, with contraversive in 19 and ipsiversive in 2. Seizures associated with epileptic nystagmus were mostly focal (25/29, 86.2%) with or without loss of awareness. Ictal discharges originated from the occipital (n=16), parietal (n=9), temporo-occipital (n=6), frontal (n=4), and temporal (n=3) areas, and two patients had multiple epileptic foci. Seizures were usually symptomatic (24/37, 64.9%). The presence of preceding gaze deviation and midline crossing of the nystagmus did not correlate with the ictal onset zone or alertness of the patients. Recording of epileptic nystagmus was available only in 6 patients, and the epileptic nystagmus could be localized to the saccadic areas in two and to the smooth pursuit areas in another two. Two patients showed the features of epileptic nystagmus from both areas.ConclusionEven though the localizing value of epileptic nystagmus seems limited in previous reports, the fast phase of epileptic nystagmus was almost always directed away from the epileptic focus that mostly arose from the posterior part of the cerebral hemisphere
Far-Ultraviolet Cooling Features of the Antlia Supernova Remnant
We present far-ultraviolet observations of the Antlia supernova remnant
obtained with Far-ultraviolet IMaging Spectrograph (FIMS, also called SPEAR).
The strongest lines observed are C IV 1548,1551 and C III 977. The C IV
emission of this mixed-morphology supernova remnant shows a clumpy
distribution, and the line intensity is nearly constant with radius. The C III
977 line, though too weak to be mapped over the whole remnant, is shown to vary
radially. The line intensity peaks at about half the radius, and drops at the
edge of the remnant. Both the clumpy distribution of C IV and the rise in the C
IV to C III ratio towards the edge suggest that central emission is from
evaporating cloudlets rather than thermal conduction in a more uniform, dense
medium.Comment: 9 pages, 4 figures, will be published in ApJ December 1, 2007, v670n2
issue. see http://astro.snu.ac.kr/~jhshinn/ms.pd
Vertigo Induced During Coitus
Objectives: The aim of this study was to describe the clinical features of vertigo developed during sexual intercourse.Methods: We retrospectively reviewed the clinical and laboratory findings of seven patients who reported recurrent vertigo during sexual intercourse.Results: All the patients reported spinning sensation for a few minutes to 1 h, which developed during the coitus. Most patients (6/7, 86%) reported associated auditory symptoms including tinnitus (n = 4), ear fullness (n = 2), autophony (n = 1), hearing impairment (n = 1), or hyperacusis (n = 1). Four patients reported the vertigo to occur exclusively during sexual intercourse or masturbation while the other three patients also experienced vertigo during other physical activities. Underlying disorders included Meniere's disease (n = 3), superior canal dehiscence (n = 1), and high jugular bulb anomaly (n = 1) while the remaining two patients had no identifiable causes.Conclusions: Various disorders may cause coital vertigo probably due to disruption of the mechanism that normally refrains the increased intracranial pressure from being directly transferred to the peripheral vestibular organs
Analysis On Runoff Characteristics Of Decentralized Rainwater Management System Using XP-SWMM Simulation
In recent years, impervious areas are increasing in residential zone as well as unsettled area with rapid urbanization and land use. Consequently, this phenomenon influences weak urban environmental compositions about climate change including urban flooding accidents. Therefore, a new paradigm on rainwater management is needed for sound and sustainable restoration of hydrological circulation. Recently, a novel rainwater management system has been developed and recommended for irrigation and flood control in Korea. Especially, P city is now planning a new rainwater management system adopting LID (Low Impact Development) techniques on a small scale development area. In this study, XP-SWMM was used to simulate effects on runoff characteristics by installation of 8 kinds of rainwater management facilities on small scale development area (4.2 ha) of P city in Korea. Also, flood control safety analysis under the condition of localized torrential downpour event was carried out and effects of rainwater recycling facility was evaluated to measure annual water resource amount and water cost reduction. Peak rate runoff was reduced 11.8% and 36.4% in restrict A and B, respectively. Total amount of annual water source substitution was estimated 3,000ăĄ/yr with LID adoption in land use planning. Acknowledgement : This research was supported by a grant (12-TI-C01) from Advanced Water Management Research Program funded by Ministry of Land , Infrastructure, and Transport of Korean government
Microlensing Detections of Planets in Binary Stellar Systems
We demonstrate that microlensing can be used for detecting planets in binary
stellar systems. This is possible because in the geometry of planetary binary
systems where the planet orbits one of the binary component and the other
binary star is located at a large distance, both planet and secondary companion
produce perturbations at a common region around the planet-hosting binary star
and thus the signatures of both planet and binary companion can be detected in
the light curves of high-magnification lensing events. We find that identifying
planets in binary systems is optimized when the secondary is located in a
certain range which depends on the type of the planet. The proposed method can
detect planets with masses down to one tenth of the Jupiter mass in binaries
with separations <~ 100 AU. These ranges of planet mass and binary separation
are not covered by other methods and thus microlensing would be able to make
the planetary binary sample richer.Comment: 5 pages, two figures in JPG forma
Limits of Binaries That Can Be Characterized by Gravitational Microlensing
Due to the high efficiency of planet detections, current microlensing planet
searches focus on high-magnification events. High-magnification events are
sensitive to remote binary companions as well and thus a sample of
wide-separation binaries are expected to be collected as a byproduct. In this
paper, we show that characterizing binaries for a portion of this sample will
be difficult due to the degeneracy of the binary-lensing parameters. This
degeneracy arises because the perturbation induced by the binary companion is
well approximated by the Chang-Refsdal lensing for binaries with separations
greater than a certain limit. For binaries composed of equal mass lenses, we
find that the lens binarity can be noticed up to the separations of
times of the Einstein radius corresponding to the mass of each lens. Among
these binaries, however, we find that the lensing parameters can be determined
only for a portion of binaries with separations less than times of
the Einstein radius.Comment: 5 pages, 3 figures, 1 tabl
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