Users, technology and space in libraries in the digital age

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Architecture, 2005.Includes bibliographical references (leaves 60-62).This thesis is a user research study of emerging issues in the use of libraries as public spaces and as information repositories in the digital age. Till recently strong physicality was attached to the library with the only access to its information resources being visiting the library premises. The availability of the Internet, digital documents and wi-fi has brought about unprecedented changes in the function, use and operation of libraries today. The environment of evolving technologies is bringing about a variety of new user practices that creates ambiguity for the future of the library as an institution as well as an architectural space. This study attempts to identify various issues in the use of library spaces today through the means of qualitative and quantitative data collection methods. Four libraries differing in the technology and quality of space provided have been chosen as case studies. The shifting physical form and meaning of the library's architectural space and its implications for the design of future libraries will be examined. A set of recommendations for better user experience in present and future library spaces will be part of the research.by Tripti G-Chandorkar.S.M

Using gradient boosting regression to improve ambient solar wind model predictions

Studying the ambient solar wind, a continuous pressure‐driven plasma flow emanating from our Sun, is an important component of space weather research. The ambient solar wind flows in interplanetary space determine how solar storms evolve through the heliosphere before reaching Earth, and especially during solar minimum are themselves a driver of activity in the Earth’s magnetic field. Accurately forecasting the ambient solar wind flow is therefore imperative to space weather awareness. Here we present a machine learning approach in which solutions from magnetic models of the solar corona are used to output the solar wind conditions near the Earth. The results are compared to observations and existing models in a comprehensive validation analysis, and the new model outperforms existing models in almost all measures. In addition, this approach offers a new perspective to discuss the role of different input data to ambient solar wind modeling, and what this tells us about the underlying physical processes. The final model discussed here represents an extremely fast, well‐validated and open‐source approach to the forecasting of ambient solar wind at Earth

E-Nose: Multichannel Analog Signal Conditioning Circuit with Pattern Recognition for Explosive Sensing

This paper presents E-Nose, a novel cost-effective, field-deployable portable system that constitutes a 4-channel signal conditioning circuit and multi-coated piezo-resistive micro-cantilever sensors for explosive sensing. E-Nose also features an embedded PCA and K-means based pattern recognition (PR) algorithm for the classification of explosives from non-explosives. The 4-channel configuration is a stack of two 2-channel circuits that are capable of measuring the change in the sensor resistance or capacitance in four optional modes of � R - � R, � R - � C , � C- � R , and � C - � C by using time multiplexing. The circuit uses a bidirectional AC current excitation method to drive the sensor bridge for significant reduction of DC offset errors, 1/f noise, line noise, and DC drifts. The proposed signal conditioning circuit uses the phase-sensitive synchronous rectification (PSSR) method for AC-to-DC conversion by using balanced demodulation. The circuit can measure a wide range of resistors that range from 100 Ω to 4 MΩ , with a sensitivity of 0.4mV/ppm and the worst relative error of 2.6. The capacitive measurement range is from 100pF to 100 μF with the worst relative error of 3.3. The entire data processing and the PR algorithms run on Raspberry Pi (R-Pi), which is integrated into the E-Nose system. The system performance is tested with MEMS cantilevers for the detection of explosive compounds, such as TNT and its derivatives, RDX and PETN in a controlled environment at a concentration that was as low as 16ppb TNT, 56ppb RDX and 134ppb of PETN. Measurements show that the E-Nose can detect explosives with 77 as true positive results without considering the environmental and mixed vapor effects

IVC Filters-Trends in Placement and Indications, a Study of 2 Populations.

Inferior vena cava filter (IVCF) placement appears to be expanding over time despite absence of clear directing evidence.Two populations were studied. The first population included patients who received an IVCF between January 2005 and August 2013 at our community hospital center. Demographic information, indications for placement, and retrieval rate was recorded among other variables. The second population comprised of patients receiving an IVCF from 2005 to 2012 according to the Nationwide Inpatient Sample (NIS) using ICD-9CM coding. Patients were divided into 2 groups based on the year of admission for comparison, that is, first group from 2005 to 2008 and the second from 2009 to 2012. In addition, we analyzed annual trends in filter placement, acute venothromboembolic events (VTE) and several underlying comorbidities within this population.At our center, 802 IVCFs were placed (55.2% retrievable); 34% for absolute, 61% for relative, and 5% for prophylactic indications. Major bleeding (27.5%), minor self-limited bleeding (13.7%), and fall history (11.2%) were the commonest indications. Periprocedural complication rate was 0.7%, and filter retrieval rate was 7%. The NIS population (811,487 filters) saw a decline in IVCF placement after year 2009, following an initial uptrend (Ptrend \u3c 0.01). IVCF use among patients with neither acute VTE nor bleeding among prior VTE saw a 3-fold absolute reduction from 2005 to 2012 (33,075-11,655; Ptrend \u3c 0.01). Patients from 2009 to 2012 were more likely to be male and had higher rates of acute VTE, thrombolytic use, cancer, bleeding, hypotension, acute cardiorespiratory failure, shock, prior falls, blood product transfusion, hospital mortality including higher Charlson comorbidity scores. The patients were younger, had shorter length of stay, and were less likely to be associated with strokes including hemorrhagic or require ventilator support. Prior falls (adjusted odds ratio-aOR 2.8), thrombolytic use (aOR 1.76), and shock (aOR 1.45) were most predictive of IVCF placement between 2009 and 2012 on regression analysis.Recent trends suggest that a higher proportion of patients receive temporary IVCF, for predominantly relative indications. Nationally, the number of filters being placed is decreasing, especially among those who did not experience acute VTE or bleeding events. Prior falls, thrombolytic therapy, and shock were most predictive of IVCF placement in latter half of the study period