88,390 research outputs found
Classifying inhibitory synapses in the cortex: beyond cell types
No full textSeung-Hee Lee describes findings published in 2000 that gave us insight into the principles by which different types of GABAergic synapses are organized in cortical networks.11Nsciescopu
Lee, Chang-rae : interview; May 12th, 2006
No full textContents:
Interview Jim Schiff interviews Chang-rae LeeDescription on cassette : Chang-rae Lee - Interview w/Jim Schiff
May 12, 2006Digital Projects SAN: Folder and disc location for wav file: 20121005/Disc 1. Folder and disc location for mp3 file: 20121005/Disc 6/mp3
Seung-Taek Lee
No full textAs one of the first generation of South Korean artists to embrace radical experimentation in art, Seung-Taek Lee has been at the forefront of Korean avant-garde art since the 1950s. Through his diverse and highly individualistic practice, Lee questions established political, social and artistic values, thereby consistently pushing the boundaries of art and culture. While Lee’s artistic experiments range from soft sculpture and site-specific installation to land art and performances, he is best known for his conceptualisation of ‘non- sculpture’ which not only signifies a rejection of values traditionally attributed to sculpture, but also of existing ideas or orders. The works shown in Lee’s first-ever European solo exhibition at MOT International are mainly from the period between late 1950s and early 1970s, which is regarded as the artist’s most experimental phase, resulting in works such as Wind from East (1971) and Fire Ceremony (1964).
Lee often works in series, at times by repeatedly using same materials and at others by revisiting similar motives or concepts: both Godret Stone (1957) and Paper Tree (1970) belong to Lee’s early binding and wind series respectively. Inspired by the stones traditionally used in tying knots when plating handcrafts mats, Lee created Godret Stone by binding bifurcated stones along the flat and horizontal wooden bar with a cord. Precisely through this practice of binding an object (or combining disparate objects) using a rope, scarf or an iron cord, Lee subverts the natural material properties of the object, challenging the established notion of physical materiality. The precariously hanging stones of Godret Stone appear malleable and ‘squeezable,’ having lost their solid materiality. This effect is heightened to a greater extent in Soft Rock, which is one the largest and most ambitious works from Lee’s binding series. While the subversion of the inherent material qualities serves as a strategy of questioning existing mode of perception, it also expressively visualises a power relationship between the enveloping material and the one being enveloped.
In the 1960s Lee began to experiment with the concept of dematerialisation, extensively working with transient materials such as wind, water, smoke and fire. Paper Tree (1970) and Wind-Folk Amusement (1971) are Lee’s signature works from the wind series, for which the artist used everyday materials such as cloths, papers and vinyl to visualise the sheer force of the wind. Arranged specifically for the space at MOT International, the Paper Tree installation derives from a series of Lee’s early outdoor installations where strips of clothes were tied along the tree branches to flutter and billow in the wind, thereby giving form to the transience of nature. The photographic documentation of Wind Folk Amusement dramatically captures the energetic movement of the wind which is visualised by the unravelling and fluttering of an enormous 80 meter long scarlet cloth in the sky. Natural landscape is not only used as a backdrop to his performances and outdoor installations, but nature itself acts as an artistic medium.
What this highly eclectic and experimental body of works have in common is their references to Korean traditions and folk sensibilities. Working in the aftermath of the Korean War, Lee actively responded to (or reacted against) the rapid social, political, economic and cultural changes that he witnessed and experienced. With an increasing influx of foreign cultural influences, which has been facilitated by globalisation, Lee sought to introduce art that reflects modernity and cultural identity specific to Korea. One of the ways in which he achieved this was by incorporating traditional objects, rituals and materials that are imbued with the unique history and culture of the nation. For his land art and performance works, Lee even purposely chose historical landmarks such as burial mounds or Han River, the sites which are symbolic of the historical past of Korea as well as the current socio-political situation of the divided nation.
On the other hand, the dense strips of white mulberry papers of Paper Tree which seem to grow out from the broken tree branches, recalls shamanistic rituals which traditionally take place in remote areas near mountains. In fact, Lee’s interest in shamanism and its status as a marginalised folk belief in Korea appears frequently throughout his oeuvre. Lee’s Wind-Folk Amusement performance is yet another example which has a visual reference to Korean folk festivals where colourful flags similar to the scarlet cloths used in Lee’s performance are hung on the trees.
This exhibition thus presents works of an artist who is currently being re-evaluated by the international art scene as arguably one of the most radical and experimental artists in the East Asia region in the 20th century. The show not only brings together Lee’s signature works, but for the first time, it also introduces the Untitled series (1968) which are abstract self-portraits of the artist. While Lee’s artworks provide an insight into understanding his experimental artistic practice, they also offer an alternative perspective to the rich and diverse avant-garde art scene in East Asia.
Seung-Taek Lee was born Kowon, North Korea, 1932 and lives and works in Seoul. Selected exhibitions include Seung-Taek Lee, Sungkok Art Museum, Seoul (2012); Modern Art of Korea & Australia 1976-2011, National Museum of Contemporary Art, Gwacheon (2011); Gwangju Biennale, Gwangju (2010); Beginning of New Era, National Museum of Modern Art, Seoul (2009); Lines the Space, Gyeonggi Art Museum, Ansan, Korea (2007); New Acquisition Exhibition, National Museum of Contemporary Art, Gwacheon, Korea (2006); Art-60s-70s Experiment, National Museum of Contemporary Art, Gwacheon, Korea (2001). Lee participated in the 6th Paris Biennial (1969) and 3rd Sao Paolo Biennial (1970). In 2009 he was awarded the Nam June Paik Art Center Prize
Debris flow susceptibility assessment based on an empirical approach in the central region of South Korea
No full textMany debris flow spreading analyses have been conducted during recent decades to prevent damage from debris flows. An empirical approach that has been used in various studies on debris flow spreading has advantages such as simple data acquisition and good applicability for large areas. In this study, a GIS-based empirical model that was developed at the University of Lausanne (Switzerland) is used to assess the debris flow susceptibility. Study sites are classified based on the types of soil texture or geological conditions, which can indirectly consider geotechnical or rheological properties, to supplement the weaknesses of Flow-R which neglects local controlling factors. The mean travel angle for each classification is calculated from a debris flow inventory map. The debris flow susceptibility is assessed based on changes in the flow-direction algorithm, an inertial function with a 5-m DEM resolution. A simplified friction-limited model was applied to the runout distance analysis by using the appropriate travel angle for the corresponding classification with a velocity limit of 28 m/s. The most appropriate algorithm combinations that derived the highest average of efficiency and sensitivity for each classification are finally determined by applying a confusion matrix with the efficiency and the sensitivity to the results of the susceptibility assessment. The proposed schemes can be useful for debris flow susceptibility assessment in both the study area and the central region of Korea, which has similar environmental factors such as geological conditions, topography and rainfall characteristics to the study area. (C) 2018 Elsevier B.V. All rights reserved.
Development of a Citywide Real-time Landslide Warning System in Busan, Korea
No full textRainfall-induced landslides have been one of major disasters in Korea where 70% of territory is covered by mountainous regions. As magnitude and frequency of extreme rainfall events has increased due to the global climate change, the number of landslide has significantly enlarged that results in casualties and property damages. In order to mitigate the landslide risk and to provide with an effective tool for public officials to manage the landside disasters, a citywide real-time landslide warning system has been developed by taking into account for situations in Busan, the second largest metropolitan city in Korea, as an application target area. The system provides with warning information based on five-alert levels that are classified as Normal, Attention, Watch, Alert, and Emergency. The warning level is determined by applying several thresholds developed by statistical, and physically-based as well as direct measurement-based approaches using forecasted/observed rainfall data or data obtained from a ground monitoring system. As a first step, the target area at ‘normal’ state is upgraded to an ‘attention’ state if the statistical thresholds are exceeded. Subsequently, the area delineated in the previous step can be updated to the next warning levels (watch and alert) by applying an infiltration-slope stability analysis when the safety factor of slope failure is less than 1.3 and 1.0, respectively. Finally, the ‘emergency’ state is determined by applying a debris-flow mobilization criterion and the subsequent potential debris-flow risk at specific local-scale areas are evaluated by conducting runout analyses. In order to validate the system applicability, landslide historical data and previous rainfall data during rainy seasons from 2009 to 2016 have been used. The system performance demonstrates a good agreement with the past landslide events. The developed system, therefore, will serve as a powerful tool to decision makers for landslide disaster preparedness
Prediction of long-term pore pressure dissipation behavior by short-term piezocone dissipation test
No full textThe coefficient of consolidation determined from piezocone dissipation test and common interpretation methods makes the predicted dissipation curve match only at 50% degree of dissipation of the measured dissipation curve. It makes it difficult to predict the long-term pore pressure dissipation behavior of in-situ soft deposits. Therefore, based on the authors' previous result [Kim YS, Lee SR, Kim YT. Application of an optimization design technique for determining the coefficient of consolidation by using piezocone test data. Computers and Geotechnics 1997;21(4): 77-93] in which an optimized coefficient of consolidation reflects well the measured dissipation trend over the input degree of dissipation range, a systematic way of predicting a more realistic pore pressure dissipation behavior at high degree of dissipation with the optimized coefficient of consolidation is proposed. It was found that, relatively over the wide range of dissipation, the optimized coefficient of consolidation is more consistent than those determined by other researchers' methods. Applied to some real examples, it is also shown that the dissipation behavior of pore water pressure at a high degree of the dissipation range can be predicted well if the coefficient of consolidation is determined using the optimization technique with the data up to around 50% dissipation. Thus, it is expected that the proposed method saves time and expenses in conducting dissipation tests in the held. (C) 2000 Published by Elsevier Science Ltd. All rights reserved
An Improved Search Strategy for the Critical Slip Surface using Finite Element Stress Fields
No full textThe finite element method can be used to advantage in slope stability problems. This paper proposes a technique to search for the critical slip surface as well as to define and calculate the factor of safety for the slope, when the finite element method is used to model its formation. First, stresses are estimated at each Gaussian point from the finite element analysis. Then, the global stress smoothing method is applied to get a continuous stress field. Based on this stress field, the factor of safety is calculated for a specified slip surface by a stress integration scheme. An improved search strategy is proposed for a noncircular critical surface which starts with a search method for a circular critical surface. During the search process, points defining a trial slip surface can freely move in the finite element mesh subject to some kinematical constraints. This method can be applied to both the limit equilibrium method and the finite element method. Effects of the slope stress history and soil parameters on the resulting critical surface are investigated. (C) 1998 Elsevier Science Ltd. All rights reserved
Formulation of implicit stress integration and consistent tangent modulus for an anisotropic hardening constitutive model
No full textAn anisotropic hardening constitutive model based on the generalized isotropic hardening (GIH) rule was implemented into the nonlinear finite element method. The GIH rule describes discrete formation of homology centers and simultaneous hardening of both inner and outer yield surfaces. Consequently, yielding in the field of reverse loading can be accurately modeled by this rule. In order to preserve the accuracy of nonlinear finite element analysis, an implicit stress integration technique employing the generalized trapezoidal rule was applied to the GIH constitutive equation. Furthermore, the consistent tangent modulus was formulated and coded into a nonlinear FEA program, which has the advantage of the quadratic rate of convergence in Newton's iteration. Accuracy and convergence were successfully verified through examples, and thus the anisotropic hardening constitutive model could assess the plastic straining mobilized in overconsolidated state and versatile loading sequences. (C) 2001 Elsevier Science B.V. All rights reserved
Long-term settlement behaviour of MSW landfills with various fill ages
No full textMSW landfill settlement characteristics are peculiar because a considerable amount of settlement occurs due to the decomposition of waste organic solids for very long duration. The total amount of settlement that occurs due to this decomposition in a MSW landfill is mainly dependent upon the amount of biodegradable solid waste and hence the fill age of the MSW landfill. The settlement stabilisation period is also dependent upon the decomposition condition. In order to investigate the settlement characteristics of MSW landfills, a mathematical model was proposed and applied to settlement data of MSW landfills which have various fill ages. A data bank of model parameters were obtained and the trends were analysed. The long-term settlement behaviour of MSW landfills can be fairly well estimated by the proposed model. It is supposed that the total remaining amount of settlement might be predicted on the basis of the fill age with two appropriate design parameters
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