Close Range Photogrammetric analysis of Earthen Buildings under Seismic Loading

Building Materials/Materials Testing (301.3)The digital Cuny Archive was made available in part through funding assistance from USAID.This paper describes an' INTERTECT project to demonstrate the feasibility of a new analytical technique for evaluating the performance of earthen buildings and other non-instrumentable structures subjected to earthquake-induced loads. Close range photogrammetrie equipment will be linked to, and triggered by, seismographic instrumentation to observe and record the performance of buildings during actual loading. If successful, the technique will provide a tool for observing adobe and other earthen buildings during seismic events. Successful development of this technique will give researchers and scientists a new tool for earthquake engineering research and will open numerous types of buildings and other structures such as earthen dams to observation, which have not previously been subject to complete analytical examination under actual or simulated loading conditions

The New Control and Interlock System for the SPS Main Power Converters

The Control and Interlock System (CIS) of the SPS main power converters was designed in the mid-70s and became increasingly difficult to maintain. A new system based on Programmable Logic Controllers has been developed by an external contractor in close collaboration with CERN. The system is now operational and fully integrated in the SPS/LEP control infrastructure. The CIS is the first major contracted industrial solution used to control accelerator equipment directly involved in the production of particle beams at CERN. This paper gives an overview of the SPS main power converter installation and describes both the contractual and technical solution adopted for the CIS. It first explains how the system was specified and how the contractual relationship was defined to respect CERNs purchasing rules and the operational requirements of the SPS accelerator. The architectural design of the new system is presented with special emphasis on how the conflict between safety and availability has been addressed

Control and interlock system for the SPS main power converters

The control and interlock system of the main power converters was 20 years old and needed to be replaced. In order to face the shrinking resources of CERN, it was decided to adopt, as far as possible, standard industrial solutions and to contract out the development of the new system to industry. A tender was sent to European firms and the contract was awarded to GTD, a Spanish Engineering Firm, in May 1997. The SPS accelerator restarted in March 98 with the new Control and Interlock System

Oblique Convergence in the Himalayas of Western Nepal Deduced from Preliminary Results of GPS Measurements

A GPS network consisting of 29 sites was installed in central and western Nepal, with measurements taken in 1995 and partial remeasurements in 1997. Data suggest 15 +/−5 mm/yr of N180° convergence between the Higher Himalayas and India, a result that is consistent with N‐S shortening across the arcuate shape of the Nepalese Himalayas and an oblique underthrusting of the Indian crust below the High Himalayas of western Nepal. A 4 +/−3 mm/year E‐W extension and deviation of the principal shortening axes are inferred east of 83°E, where Quaternary faults (Darma‐Bari Gad fault system and Thakkhola graben) delineate a crustal wedge. This wedge is located on the SE projection of the Karakorum fault and may segment the Himalayan thrust belt. The convergence between the outer belt of western Nepal and India is less than 3 mm/yr, an attenuation consistent with creep on a dislocation locked beneath the Lesser Himalayas. A preliminary model suggests that this N 120°E striking dislocation is affected by a 19 mm/yr thrust component and a 7 mm/yr right lateral component

Direct exoplanet detection and characterization using the ANDROMEDA method: Performance on VLT/NaCo data

Context. The direct detection of exoplanets with high-contrast imaging requires advanced data processing methods to disentangle potential planetary signals from bright quasi-static speckles. Among them, angular differential imaging (ADI) permits potential planetary signals with a known rotation rate to be separated from instrumental speckles that are either statics or slowly variable. The method presented in this paper, called ANDROMEDA for ANgular Differential OptiMal Exoplanet Detection Algorithm is based on a maximum likelihood approach to ADI and is used to estimate the position and the flux of any point source present in the field of view. Aims. In order to optimize and experimentally validate this previously proposed method, we applied ANDROMEDA to real VLT/NaCo data. In addition to its pure detection capability, we investigated the possibility of defining simple and efficient criteria for automatic point source extraction able to support the processing of large surveys. Methods. To assess the performance of the method, we applied ANDROMEDA on VLT/NaCo data of TYC-8979-1683-1 which is surrounded by numerous bright stars and on which we added synthetic planets of known position and flux in the field. In order to accommodate the real data properties, it was necessary to develop additional pre-processing and post-processing steps to the initially proposed algorithm. We then investigated its skill in the challenging case of a well-known target, $\beta$ Pictoris, whose companion is close to the detection limit and we compared our results to those obtained by another method based on principal component analysis (PCA). Results. Application on VLT/NaCo data demonstrates the ability of ANDROMEDA to automatically detect and characterize point sources present in the image field. We end up with a robust method bringing consistent results with a sensitivity similar to the recently published algorithms, with only two parameters to be fine tuned. Moreover, the companion flux estimates are not biased by the algorithm parameters and do not require a posteriori corrections. Conclusions. ANDROMEDA is an attractive alternative to current standard image processing methods that can be readily applied to on-sky data

Close Range Photogrammetric analysis of Earthen Buildings under Seismic Loading

Building Materials/Materials Testing (301.3)The digital Cuny Archive was made available in part through funding assistance from USAID.This paper describes an' INTERTECT project to demonstrate the feasibility of a new analytical technique for evaluating the performance of earthen buildings and other non-instrumentable structures subjected to earthquake-induced loads. Close range photogrammetrie equipment will be linked to, and triggered by, seismographic instrumentation to observe and record the performance of buildings during actual loading. If successful, the technique will provide a tool for observing adobe and other earthen buildings during seismic events. Successful development of this technique will give researchers and scientists a new tool for earthquake engineering research and will open numerous types of buildings and other structures such as earthen dams to observation, which have not previously been subject to complete analytical examination under actual or simulated loading conditions

Basic conceptual structures theory

Although the theory of Conceptual Structures is over 10 years old, basic notions (like canonical graphs) are far from settled and are subject to constant extensions and reformulations. However, most of these are done in an informal way, which doesn't help in clarifying the issues involved. It is our hope that this paper will provide a first step towards the complete and rigorous account of Conceptual Structures (CS) Theory, which is needed for ongoing standardization and implementation efforts. Towards that goal, we present formal definitions of some of the central notions of CS theory (type, referent, concept, relation, conceptual graph, canonical formation rules, canon, and canonical graph) in its simplest form, i.e. no contexts nor coreference links are allowed and referents must be individuals. We thereby introduce higher-order types in order to enable the use of conceptual graphs at the metalevel, the restriction operation of the canonical formation rules is extended to make use of the relation hierarchy, we show the relationship between denotation and conformity relation, and we give a rigorous meaning to the canonical basis, among other things

Elaboration and characterization of Fe1–xO thin films sputter deposited from magnetite target

Majority of the authors report elaboration of iron oxide thin films by reactive magnetron sputtering from an iron target with Ar–O2 gas mixture. Instead of using the reactive sputtering of a metallic target we report here the preparation of Fe1–xOthin films, directly sputtered froma magnetite target in a pure argon gas flow with a bias power applied. This oxide is generally obtained at very low partial oxygen pressure and high temperature.We showed that bias sputtering which can be controlled very easily can lead to reducing conditions during deposition of oxide thin film on simple glass substrates. The proportion of wustite was directly adjusted bymodifying the power of the substrate polarization. Atomic force microscopy was used to observe these nanostructured layers. Mössbauer measurements and electrical properties versus bias polarization and annealing temperature are also reported

An inexpensive nonlinear medium for intense ultrabroadband pulse characterization

The ability of pellets made up of compressed iron iodate nanocrystals to frequency-double the whole visible spectrum is demonstrated. We suggest their use for complete characterization of intense ultrabroadband laser pulse