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The growing amount of openly available, meter-scale geospatial vertical aerial imagery and the need of the OpenStreetMap (OSM) project for continuous updates bring the opportunity to use the former to help with the latter, e.g., by leveraging the latest remote sensing data in combination with state-of-the-art computer vision methods to assist the OSM community in labeling work. This article reports our progress to utilize artificial neural networks (ANN) for change detection of OSM data to update the map. Furthermore, we aim at identifying geospatial regions where mappers need to focus on completing the global OSM dataset. Our approach is technically backed by the big geospatial data platform Physical Analytics Integrated Repository and Services (PAIRS). We employ supervised training of deep ANNs from vertical aerial imagery to segment scenes based on OSM map tiles to evaluate the technique quantitatively and qualitatively.
Conrad M. Albrecht; Rui Zhang; Xiaodong Cui; Marcus Freitag; Hendrik F. Hamann; Levente J. Klein; Ulrich Finkler; Fernando Marianno; Johannes Schmude; Norman Bobroff; Wei Zhang; Carlo Siebenschuh; Siyuan Lu. Change Detection from Remote Sensing to Guide OpenStreetMap Labeling. ISPRS International Journal of Geo-Information 2020, 9, 427 .
AMA StyleConrad M. Albrecht, Rui Zhang, Xiaodong Cui, Marcus Freitag, Hendrik F. Hamann, Levente J. Klein, Ulrich Finkler, Fernando Marianno, Johannes Schmude, Norman Bobroff, Wei Zhang, Carlo Siebenschuh, Siyuan Lu. Change Detection from Remote Sensing to Guide OpenStreetMap Labeling. ISPRS International Journal of Geo-Information. 2020; 9 (7):427.
Chicago/Turabian StyleConrad M. Albrecht; Rui Zhang; Xiaodong Cui; Marcus Freitag; Hendrik F. Hamann; Levente J. Klein; Ulrich Finkler; Fernando Marianno; Johannes Schmude; Norman Bobroff; Wei Zhang; Carlo Siebenschuh; Siyuan Lu. 2020. "Change Detection from Remote Sensing to Guide OpenStreetMap Labeling." ISPRS International Journal of Geo-Information 9, no. 7: 427.
C. M. Albrecht; B. Elmegreen; O. Gunawan; H. F. Hamann; L. J. Klein; S. Lu; F. Mariano; C. Siebenschuh; J. Schmude. Next-generation geospatial-temporal information technologies for disaster management. IBM Journal of Research and Development 2020, 64, 5:1 -5:12.
AMA StyleC. M. Albrecht, B. Elmegreen, O. Gunawan, H. F. Hamann, L. J. Klein, S. Lu, F. Mariano, C. Siebenschuh, J. Schmude. Next-generation geospatial-temporal information technologies for disaster management. IBM Journal of Research and Development. 2020; 64 (1/2):5:1-5:12.
Chicago/Turabian StyleC. M. Albrecht; B. Elmegreen; O. Gunawan; H. F. Hamann; L. J. Klein; S. Lu; F. Mariano; C. Siebenschuh; J. Schmude. 2020. "Next-generation geospatial-temporal information technologies for disaster management." IBM Journal of Research and Development 64, no. 1/2: 5:1-5:12.
We present field deployment results of a portable optical absorption spectrometer for localization and quantification of fugitive methane (CH4) emissions. Our near-infrared sensor targets the 2ν3 R(4) CH4 transition at 6057.1 cm−1 (1651 nm) via line-scanned tunable diode-laser absorption spectroscopy (TDLAS), with Allan deviation analysis yielding a normalized 2.0 ppmv∙Hz−1/2 sensitivity (4.5 × 10−6 Hz−1/2 noise-equivalent absorption) over 5 cm open-path length. Controlled CH4 leak experiments are performed at the METEC CSU engineering facility, where concurrent deployment of our TDLAS and a customized volatile organic compound (VOC) sensor demonstrates good linear correlation (R2 = 0.74) over high-flow (>60 SCFH) CH4 releases spanning 4.4 h. In conjunction with simultaneous wind velocity measurements, the leak angle-of-arrival (AOA) is ascertained via correlation of CH4 concentration and wind angle, demonstrating the efficacy of single-sensor line-of-sight (LOS) determination of leak sources. Source magnitude estimation based on a Gaussian plume model is demonstrated, with good correspondence (R2 = 0.74) between calculated and measured release rates.
Eric J. Zhang; Chu C. Teng; Theodore G. Van Kessel; Levente Klein; Ramachandran Muralidhar; Gerard Wysocki; William M. J. Green. Field Deployment of a Portable Optical Spectrometer for Methane Fugitive Emissions Monitoring on Oil and Gas Well Pads. Sensors 2019, 19, 2707 .
AMA StyleEric J. Zhang, Chu C. Teng, Theodore G. Van Kessel, Levente Klein, Ramachandran Muralidhar, Gerard Wysocki, William M. J. Green. Field Deployment of a Portable Optical Spectrometer for Methane Fugitive Emissions Monitoring on Oil and Gas Well Pads. Sensors. 2019; 19 (12):2707.
Chicago/Turabian StyleEric J. Zhang; Chu C. Teng; Theodore G. Van Kessel; Levente Klein; Ramachandran Muralidhar; Gerard Wysocki; William M. J. Green. 2019. "Field Deployment of a Portable Optical Spectrometer for Methane Fugitive Emissions Monitoring on Oil and Gas Well Pads." Sensors 19, no. 12: 2707.
Oil and gas operations contribute on the order of 31% (according to EPA) to the portion of methane emissions due to human activities. Identifying and localizing these emission sources requires continued development of better sensing modalities. We present a sensor network and cloud based methods for detecting, localizing, and quantifying methane leaks with a focus on natural gas fracking sites. The sensor network is designed for year round remote autonomous operation and includes methane and wind sensing abilities.
Theodore G. Van Kessel; Muralidhar Ramachandran; Levente J. Klein; Dhruv Nair; Nigel Hinds; Hendrik Hamann; Norma E. Sosa. Methane Leak Detection and Localization Using Wireless Sensor Networks for Remote Oil and Gas Operations. 2018 IEEE Sensors Applications Symposium (SAS) 2018, 1 -4.
AMA StyleTheodore G. Van Kessel, Muralidhar Ramachandran, Levente J. Klein, Dhruv Nair, Nigel Hinds, Hendrik Hamann, Norma E. Sosa. Methane Leak Detection and Localization Using Wireless Sensor Networks for Remote Oil and Gas Operations. 2018 IEEE Sensors Applications Symposium (SAS). 2018; ():1-4.
Chicago/Turabian StyleTheodore G. Van Kessel; Muralidhar Ramachandran; Levente J. Klein; Dhruv Nair; Nigel Hinds; Hendrik Hamann; Norma E. Sosa. 2018. "Methane Leak Detection and Localization Using Wireless Sensor Networks for Remote Oil and Gas Operations." 2018 IEEE Sensors Applications Symposium (SAS) , no. : 1-4.
A closed loop irrigation system is demonstrated that fully automates the delivery of irrigation water and calculates in real time the water requirement from satellite images. The system optimizes water delivery for 140 cells located across four hectares of land based on two independent objectives (e.g., maximizing yield and/or increasing water efficiency) and is continuously adapting irrigation scheduling to the local spatial-temporal variability of the vegetation across the growing season. Irrigation is controlled by a central computer that issues commands to 693 control nodes to start irrigation based on analytics extracted from satellite images. The control nodes are grouped to create 15 m by 15 m cells and each cell can be addressed independently and can irrigate differentially. After two years of operation, this digital drip irrigation approach resulted in a 26% yield increase in the second year and an average increase of 16% in water use efficiency. This study demonstrates that combining closed loop automation and analytics can improve water use efficiency and increase yield on existing agricultural lands.
Levente J. Klein; Hendrik F. Hamann; Nigel Hinds; Supratik Guha; Luis A. Sanchez; Brent Sams; Nick K. Dokoozlian. Closed Loop Controlled Precision Irrigation Sensor Network. IEEE Internet of Things Journal 2018, 5, 4580 -4588.
AMA StyleLevente J. Klein, Hendrik F. Hamann, Nigel Hinds, Supratik Guha, Luis A. Sanchez, Brent Sams, Nick K. Dokoozlian. Closed Loop Controlled Precision Irrigation Sensor Network. IEEE Internet of Things Journal. 2018; 5 (6):4580-4588.
Chicago/Turabian StyleLevente J. Klein; Hendrik F. Hamann; Nigel Hinds; Supratik Guha; Luis A. Sanchez; Brent Sams; Nick K. Dokoozlian. 2018. "Closed Loop Controlled Precision Irrigation Sensor Network." IEEE Internet of Things Journal 5, no. 6: 4580-4588.
Results from three years of continuous monitoring of environmental conditions using a wireless sensor platform installed at The Cloisters, the medieval branch of the New York Metropolitan Museum of Art, are presented. The platform comprises more than 200 sensors that were distributed in five galleries to assess temperature and air flow and to quantify microclimate changes using physics-based and statistical models. The wireless sensor network data shows a very stable environment within the galleries, while the dense monitoring enables localized monitoring of subtle changes in air quality trends and impact of visitors on the microclimate conditions. The high spatial and temporal resolution data serves as a baseline study to understand the impact of visitors and building operations on the long-term preservation of art objects.
Levente J. Klein; Sergio A. Bermudez; Alejandro G. Schrott; Masahiko Tsukada; Paolo Dionisi-Vici; Lucretia Kargere; Fernando Marianno; Hendrik F. Hamann; Vanessa López; Marco Leona. Wireless Sensor Platform for Cultural Heritage Monitoring and Modeling System. Sensors 2017, 17, 1998 .
AMA StyleLevente J. Klein, Sergio A. Bermudez, Alejandro G. Schrott, Masahiko Tsukada, Paolo Dionisi-Vici, Lucretia Kargere, Fernando Marianno, Hendrik F. Hamann, Vanessa López, Marco Leona. Wireless Sensor Platform for Cultural Heritage Monitoring and Modeling System. Sensors. 2017; 17 (9):1998.
Chicago/Turabian StyleLevente J. Klein; Sergio A. Bermudez; Alejandro G. Schrott; Masahiko Tsukada; Paolo Dionisi-Vici; Lucretia Kargere; Fernando Marianno; Hendrik F. Hamann; Vanessa López; Marco Leona. 2017. "Wireless Sensor Platform for Cultural Heritage Monitoring and Modeling System." Sensors 17, no. 9: 1998.
Identifying fugitive methane leaks can improve predictive maintenance of the extraction process, can extend gas extraction equipment lifetime, and eliminate hazardous work conditions. We demonstrate a wireless sensor network based on cost effective and robust chemi-resistive methane sensors combined with real time analytics to identify leaks from 2 scfh to 1000 scfh. The chemi-resistive sensors were validated to have a sensitivity better than 1 ppm in methane plume detection. The real time chemical sensor and wind data is integrated into an inversion models to identify the location and the magnitude of the methane leak. This integrated sensing and analytics solution can be deployed in outdoor environment for long term monitoring of accidental methane plume emissions, generate recommendations about fixing them, and ensure compliance with local government regulations.
Levente J. Klein; Ted Van Kessel; Dhruv Nair; Ramachandran Muralidhar; Hendrik Hamann; Norma Sosa. Monitoring Fugitive Methane Gas Emission From Natural Gas Pads. ASME 2017 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems 2017, 1 .
AMA StyleLevente J. Klein, Ted Van Kessel, Dhruv Nair, Ramachandran Muralidhar, Hendrik Hamann, Norma Sosa. Monitoring Fugitive Methane Gas Emission From Natural Gas Pads. ASME 2017 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems. 2017; ():1.
Chicago/Turabian StyleLevente J. Klein; Ted Van Kessel; Dhruv Nair; Ramachandran Muralidhar; Hendrik Hamann; Norma Sosa. 2017. "Monitoring Fugitive Methane Gas Emission From Natural Gas Pads." ASME 2017 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems , no. : 1.
Interpreting sensor data requires knowledge of sensor placement and the contextual environment surrounding the sensor. For a single sensor measurement, it is easy to document the context usually by visual observation. However, for millions of sensors reporting data back to a server, the contextual information needs to be automatically extracted from either data analysis or leveraging complimentary data sources. Data layers that overlap spatially or temporally with sensor locations, can be used to extract the context and validate the measurement. The second challenge is to minimize the amount of sensor data transmitted through the internet while preserving signal information content. Here we demonstrate two methods for communication bandwidth reduction: computation at the edge and compressed sensing. We validate the above methods on wind and chemical sensor data to: (1) eliminate redundant measurement from wind sensors and (2) extract peak value of a chemical sensor measuring a methane plume. We present a general cloud based framework to validate sensor data based on statistical and physical modeling and contextual data extracted from geospatial data.
Lavanya Turlapati; Nigel Hinds; Dhruv Nair; Levente J. Klein. Edge Computing and Contextual Information for the Internet of Things Sensors. ASME 2017 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems 2017, 1 .
AMA StyleLavanya Turlapati, Nigel Hinds, Dhruv Nair, Levente J. Klein. Edge Computing and Contextual Information for the Internet of Things Sensors. ASME 2017 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems. 2017; ():1.
Chicago/Turabian StyleLavanya Turlapati; Nigel Hinds; Dhruv Nair; Levente J. Klein. 2017. "Edge Computing and Contextual Information for the Internet of Things Sensors." ASME 2017 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems , no. : 1.
Urban air quality affects health and well-being of more than half of the world's population. Measurement, modeling and real time action on pollution sources can alleviate their impact. A preliminary study for drone-based image acquisition and processing steps required for 3D reconstruction of potential pollution sources is presented. The 3D surface terrain models combined with sensor data are inputs into air pollution models for visualization, understanding and potential mitigation of methane plumes. Scaling these technologies across large areas requires the integration of big geospatial data with modeling, machine learning, and image processing.
Jason D. Renwick; Levente J. Klein; Hendrik F. Hamann. Drone-based reconstruction for 3D geospatial data processing. 2016 IEEE 3rd World Forum on Internet of Things (WF-IoT) 2017, 729 -734.
AMA StyleJason D. Renwick, Levente J. Klein, Hendrik F. Hamann. Drone-based reconstruction for 3D geospatial data processing. 2016 IEEE 3rd World Forum on Internet of Things (WF-IoT). 2017; ():729-734.
Chicago/Turabian StyleJason D. Renwick; Levente J. Klein; Hendrik F. Hamann. 2017. "Drone-based reconstruction for 3D geospatial data processing." 2016 IEEE 3rd World Forum on Internet of Things (WF-IoT) , no. : 729-734.
IBM's Physical Analytics Integrated Data Repository and Services (PAIRS) is a geospatial Big Data service. PAIRS contains a massive amount of curated geospatial (or more precisely spatio-temporal) data from a large number of public and private data resources, and also supports user contributed data layers. PAIRS offers an easy-to-use platform for both rapid assembly and retrieval of geospatial datasets or performing complex analytics, lowering time-to-discovery significantly by reducing the data curation and management burden. In this paper, we review recent progress with PAIRS and showcase a few exemplary analytical applications which the authors are able to build with relative ease leveraging this technology.
Siyuan Lu; Xiaoyan Shao; Marcus Freitag; Levente J. Klein; Jason Renwick; Fernando J. Marianno; Conrad Albrecht; Hendrik F. Hamann. IBM PAIRS curated big data service for accelerated geospatial data analytics and discovery. 2016 IEEE International Conference on Big Data (Big Data) 2016, 2672 -2675.
AMA StyleSiyuan Lu, Xiaoyan Shao, Marcus Freitag, Levente J. Klein, Jason Renwick, Fernando J. Marianno, Conrad Albrecht, Hendrik F. Hamann. IBM PAIRS curated big data service for accelerated geospatial data analytics and discovery. 2016 IEEE International Conference on Big Data (Big Data). 2016; ():2672-2675.
Chicago/Turabian StyleSiyuan Lu; Xiaoyan Shao; Marcus Freitag; Levente J. Klein; Jason Renwick; Fernando J. Marianno; Conrad Albrecht; Hendrik F. Hamann. 2016. "IBM PAIRS curated big data service for accelerated geospatial data analytics and discovery." 2016 IEEE International Conference on Big Data (Big Data) , no. : 2672-2675.
Air side economization minimizes the usage of Air Conditioning Units (ACU) and water chiller when outside temperature falls below the operating set point of data centers. In many data centers, the relative humidity is less controlled compared to temperature; humidification or de-humidification are used only when upper (80%) or lower limits (10%) thresholds are exceeded. We present a case study of a data center where high humidity combined with abrupt cooling leads to condensation. Since servers racks cannot respond to instant decrease in temperature, the thermal lag time to reach equilibrium can create a transient condition when condensation can appear in locations where the temperature of the servers falls below the dew point within the data center. A new control algorithm is discussed based on dew point control to improve Information Technology (IT) equipment safety by minimizing corrosion and/or reducing condensation risks.
Levente Klein; Fernando J. Marianno; Hendrik F. Hamman; Alan Claassen. Condensation risk in a partially air side economized data center. 2016 15th IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm) 2016, 1306 -1311.
AMA StyleLevente Klein, Fernando J. Marianno, Hendrik F. Hamman, Alan Claassen. Condensation risk in a partially air side economized data center. 2016 15th IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm). 2016; ():1306-1311.
Chicago/Turabian StyleLevente Klein; Fernando J. Marianno; Hendrik F. Hamman; Alan Claassen. 2016. "Condensation risk in a partially air side economized data center." 2016 15th IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm) , no. : 1306-1311.
For redundancy, almost all mission-critical facilities such as data centers are fitted with more air condition units than required. These units are most of the time heavily underutilized, where the fans within the units are still consuming energy circulating air without actually providing cooling. In more modern facilities such fans are equipped with variable frequency drives, which can reduce substantially the energy consumption if proper controls are implemented. While there have several solutions for controlling and optimizing such variable frequency drive operated air conditioning units, control systems without variable frequency drives (discrete on/off ACU controls) have not been addressed thoroughly. In this paper, we present a practical, distributed and automatic control method for such discrete air conditioning units. The technique includes several safety features and is based on dense environmental sensing and events like hotspots or device failures. We discuss this approach by way of example of a case study.
Sergio A. Bermudez; Hendrik F. Hamann; Levente J. Klein; Fernando J. Marianno; Alan C. Claassen. Discrete Control of Air Conditioning Units in Mission Critical Facilities. Volume 2: Advanced Electronics and Photonics, Packaging Materials and Processing; Advanced Electronics and Photonics: Packaging, Interconnect and Reliability; Fundamentals of Thermal and Fluid Transport in Nano, Micro, and Mini Scales 2015, 1 .
AMA StyleSergio A. Bermudez, Hendrik F. Hamann, Levente J. Klein, Fernando J. Marianno, Alan C. Claassen. Discrete Control of Air Conditioning Units in Mission Critical Facilities. Volume 2: Advanced Electronics and Photonics, Packaging Materials and Processing; Advanced Electronics and Photonics: Packaging, Interconnect and Reliability; Fundamentals of Thermal and Fluid Transport in Nano, Micro, and Mini Scales. 2015; ():1.
Chicago/Turabian StyleSergio A. Bermudez; Hendrik F. Hamann; Levente J. Klein; Fernando J. Marianno; Alan C. Claassen. 2015. "Discrete Control of Air Conditioning Units in Mission Critical Facilities." Volume 2: Advanced Electronics and Photonics, Packaging Materials and Processing; Advanced Electronics and Photonics: Packaging, Interconnect and Reliability; Fundamentals of Thermal and Fluid Transport in Nano, Micro, and Mini Scales , no. : 1.
The energy used by information technology (IT) equipment and the supporting data center equipment keeps rising as data center proliferation continues unabated. In order to contain the rising computing costs, data center administrators are resorting to cost cutting measures such as not tightly controlling the temperature and humidity levels and in many cases installing air side economizers with the associated risk of introducing particulate and gaseous contaminations into their data centers. The ASHRAE TC9.9 subcommittee, on Mission Critical Facilities, Data Centers, Technology Spaces, and Electronic Equipment, has accommodated the data center administrators by allowing short period excursions outside the recommended temperature-humidity range, into allowable classes A1-A3. Under worst case conditions, the ASHRAE A3 envelope allows electronic equipment to operate at temperature and humidity as high as 24°C and 85% relative humidity for short, but undefined periods of time. This paper addresses the IT equipment reliability issues arising from operation in high humidity and high temperature conditions, with particular attention paid to the question of whether it is possible to determine the all-encompassing x-factors that can capture the effects of temperature and relative humidity on equipment reliability. The role of particulate and gaseous contamination and the aggravating effects of high temperature and high relative humidity will be presented and discussed. A method to determine the temperature and humidity x-factors, based on testing in experimental data centers located in polluted geographies, will be proposed.
Prabjit Singh; Levente Klein; Dereje Agonafer; Jimil M. Shah; Kanan D. Pujara. Effect of Relative Humidity, Temperature and Gaseous and Particulate Contaminations on Information Technology Equipment Reliability. Volume 2: Advanced Electronics and Photonics, Packaging Materials and Processing; Advanced Electronics and Photonics: Packaging, Interconnect and Reliability; Fundamentals of Thermal and Fluid Transport in Nano, Micro, and Mini Scales 2015, 1 .
AMA StylePrabjit Singh, Levente Klein, Dereje Agonafer, Jimil M. Shah, Kanan D. Pujara. Effect of Relative Humidity, Temperature and Gaseous and Particulate Contaminations on Information Technology Equipment Reliability. Volume 2: Advanced Electronics and Photonics, Packaging Materials and Processing; Advanced Electronics and Photonics: Packaging, Interconnect and Reliability; Fundamentals of Thermal and Fluid Transport in Nano, Micro, and Mini Scales. 2015; ():1.
Chicago/Turabian StylePrabjit Singh; Levente Klein; Dereje Agonafer; Jimil M. Shah; Kanan D. Pujara. 2015. "Effect of Relative Humidity, Temperature and Gaseous and Particulate Contaminations on Information Technology Equipment Reliability." Volume 2: Advanced Electronics and Photonics, Packaging Materials and Processing; Advanced Electronics and Photonics: Packaging, Interconnect and Reliability; Fundamentals of Thermal and Fluid Transport in Nano, Micro, and Mini Scales , no. : 1.
Many data center operators are considering the option to convert from mechanical to free air cooling to improve energy efficiency. The main advantage of free air cooling is the elimination of chiller and Air Conditioning Unit operation when outdoor temperature falls below the data center temperature setpoint. Accidental introduction of gaseous pollutants in the data center along the fresh air and potential latency in response of control infrastructure to extreme events are some of the main concerns for adopting outside air cooling in data centers. Recent developments of ultra-high sensitivity corrosion sensors enable the real time monitoring of air quality and thus allow a better understanding of how airflow, relative humidity, and temperature fluctuations affect corrosion rates. Both the sensitivity of sensors and wireless networks ability to detect and react rapidly to any contamination event make them reliable tools to prevent corrosion related failures. A feasibility study is presented for eight legacy data centers that are evaluated to implement free air cooling.
Levente J. Klein; Sergio A. Bermudez; Fernando J. Marianno; Hendrik F. Hamann; Prabjit Singh. Energy Efficiency and Air Quality Considerations in Airside Economized Data Centers. Volume 2: Advanced Electronics and Photonics, Packaging Materials and Processing; Advanced Electronics and Photonics: Packaging, Interconnect and Reliability; Fundamentals of Thermal and Fluid Transport in Nano, Micro, and Mini Scales 2015, 1 .
AMA StyleLevente J. Klein, Sergio A. Bermudez, Fernando J. Marianno, Hendrik F. Hamann, Prabjit Singh. Energy Efficiency and Air Quality Considerations in Airside Economized Data Centers. Volume 2: Advanced Electronics and Photonics, Packaging Materials and Processing; Advanced Electronics and Photonics: Packaging, Interconnect and Reliability; Fundamentals of Thermal and Fluid Transport in Nano, Micro, and Mini Scales. 2015; ():1.
Chicago/Turabian StyleLevente J. Klein; Sergio A. Bermudez; Fernando J. Marianno; Hendrik F. Hamann; Prabjit Singh. 2015. "Energy Efficiency and Air Quality Considerations in Airside Economized Data Centers." Volume 2: Advanced Electronics and Photonics, Packaging Materials and Processing; Advanced Electronics and Photonics: Packaging, Interconnect and Reliability; Fundamentals of Thermal and Fluid Transport in Nano, Micro, and Mini Scales , no. : 1.
A novel method to measure strain without mediation of stress has been developed to assess relative displacements in art objects responding to environmental fluctuations. The method uses a chip with a variable resistor composed of a Giant Magnetic Resistance (GMR) material. In a case study, the dimensional changes of wooden test vehicles subjected to sudden humidity changes at constant temperature inside a controlled environmental chamber were measured. Furthermore, an optimized sensor deployment and converging algorithm to increase the accuracy of the measurements was developed and applied.
Joseph Sloan; Levente Klein; Sergio A. Bermudez Rodriguez; Hendrik F. Hamann; A. G. Schrott. Concealable strain sensing method for art preservation. Applied Physics A 2013, 115, 829 -836.
AMA StyleJoseph Sloan, Levente Klein, Sergio A. Bermudez Rodriguez, Hendrik F. Hamann, A. G. Schrott. Concealable strain sensing method for art preservation. Applied Physics A. 2013; 115 (3):829-836.
Chicago/Turabian StyleJoseph Sloan; Levente Klein; Sergio A. Bermudez Rodriguez; Hendrik F. Hamann; A. G. Schrott. 2013. "Concealable strain sensing method for art preservation." Applied Physics A 115, no. 3: 829-836.
Environmental conditions in data centers determine the reliability of the IT equipment and operational uptimes. Due to continuous increase in energy usage and a trend towards sustainability, leads many data center operators to lean towards implementing energy efficiency measures. Many of today's data center are operated in a narrow temperature and relative humidity band, however these may change as ASHRAE recently expanded the limits of the temperature and relative humidity. These expansions are triggered by recent interest to implement air side economizer based cooling in data centers. For air side economized data centers besides pollutants that can be introduced unintentionally, the daily variation of temperature and relative humidity could possibly lead to condensation or corrosion. The variation of the corrosion rate due to daily changes of the indoor pollutant concentrations combined with temperature and humidity cycling are presented for a data center.
Levente Klein; Michael A Schappert; Hendrik F. Hamann. Corrosion risk management in IT facilities. 13th InterSociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems 2012, 353 -357.
AMA StyleLevente Klein, Michael A Schappert, Hendrik F. Hamann. Corrosion risk management in IT facilities. 13th InterSociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems. 2012; ():353-357.
Chicago/Turabian StyleLevente Klein; Michael A Schappert; Hendrik F. Hamann. 2012. "Corrosion risk management in IT facilities." 13th InterSociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems , no. : 353-357.
The energy consumption of data centers (DCs) has dramatically increased in recent years, primarily due to the massive computing demands driven by communications, banking, online retail, and entertainment services. In today's data centers, the cooling and infrastructure operations require almost the same energy as the IT operations. The large energy consumption in data centers prompted government agencies, industries, professional organizations, and academic institutions to investigate sustainable growth paths. We discuss such scenarios based on current trends and projections and propose the required innovations to achieve a 10 fold increase in “performance per Watt” of IT operations. We discuss three possible technology components that would improve the operational performance of data centers: (1) integration of renewable energy sources (2) increasing energy efficiency through IT consolidation and workload optimization, and (3) multifunctional sensor networks for better cooling and infrastructure management. We discuss the key requirements and how these technologies can be combined to achieve a sustainable path.
Levente Klein; Sergio A Bermudez; Hans-Dieter Wehle; Stephan Barabasi; Hendrik F. Hamann. Sustainable data centers powered by renewable energy. 2012 28th Annual IEEE Semiconductor Thermal Measurement and Management Symposium (SEMI-THERM) 2012, 362 -367.
AMA StyleLevente Klein, Sergio A Bermudez, Hans-Dieter Wehle, Stephan Barabasi, Hendrik F. Hamann. Sustainable data centers powered by renewable energy. 2012 28th Annual IEEE Semiconductor Thermal Measurement and Management Symposium (SEMI-THERM). 2012; ():362-367.
Chicago/Turabian StyleLevente Klein; Sergio A Bermudez; Hans-Dieter Wehle; Stephan Barabasi; Hendrik F. Hamann. 2012. "Sustainable data centers powered by renewable energy." 2012 28th Annual IEEE Semiconductor Thermal Measurement and Management Symposium (SEMI-THERM) , no. : 362-367.
We present novel nanoscale bolometers made of lithographically defined platinum wires. The cores of our structures are narrow wires with fixed width of 300 nm and length ranging from 300 nm to 17 μm. Some are significantly smaller in size than the wavelengths they are exposed to from a 1200 K blackbody source. The response of the wire's resistance to the external radiation reflects its temperature and can be monitored in real-time. Previously, we have reported a steep rise in responsivity and detectivity with decreasing wire length under such infrared exposure, for a constant Joule power dissipation in the wire (drive power). In this work, we aim to enhance the performance of the bolometers by changing physical and driving parameters, i.e. the insulating layer thickness or the external bias. We find that after such optimization, structures can reach a responsivity R of 4.5x105 V/W and a detectivity D* of 2.3x1010 cmHz1/2/W. With a reduced size and a high performance, these devices could improve the infrared sensors technology.
Pauline Renoux; Alice Beauny; Levente Klein; Hendrik F. Hamann; Snorri Ingvarsson. Thin-film platinum nanowires as sub-wavelength bolometers. SPIE OPTO 2012, 82610I -82610I-8.
AMA StylePauline Renoux, Alice Beauny, Levente Klein, Hendrik F. Hamann, Snorri Ingvarsson. Thin-film platinum nanowires as sub-wavelength bolometers. SPIE OPTO. 2012; ():82610I-82610I-8.
Chicago/Turabian StylePauline Renoux; Alice Beauny; Levente Klein; Hendrik F. Hamann; Snorri Ingvarsson. 2012. "Thin-film platinum nanowires as sub-wavelength bolometers." SPIE OPTO , no. : 82610I-82610I-8.
We present characterization results of microscopic platinum wires as bolometers. The wire lengths range from 16 μm down to 300 nm. Thus they are in many cases significantly smaller in size than the wavelength of the radiation from the 1200 K blackbody source they were exposed to. We observe a steep rise in both responsivity ℜ and detectivity D★ with decreasing wire size, reaching ℜ = 3.1×104 V/W and D★ = 2.7×109 cmHz1/2/W at room temperature for a 300×300 nm2 device. Two significant advantages of such small wires as bolometers are their low power requirement and fast response time. Our numerical estimations suggest response times in the order of nanoseconds for the smallest samples. They could help improve resolution and response of thermal imaging devices, for example. We believe the performance may be further improved by optimizing the design and operating parameters.
Pauline Renoux; Sigurdur Aegir Jónsson; Levente J. Klein; Hendrik F. Hamann; Snorri Ingvarsson. Sub-wavelength bolometers: Uncooled platinum wires as infrared sensors. Optics Express 2011, 19, 8721 -8727.
AMA StylePauline Renoux, Sigurdur Aegir Jónsson, Levente J. Klein, Hendrik F. Hamann, Snorri Ingvarsson. Sub-wavelength bolometers: Uncooled platinum wires as infrared sensors. Optics Express. 2011; 19 (9):8721-8727.
Chicago/Turabian StylePauline Renoux; Sigurdur Aegir Jónsson; Levente J. Klein; Hendrik F. Hamann; Snorri Ingvarsson. 2011. "Sub-wavelength bolometers: Uncooled platinum wires as infrared sensors." Optics Express 19, no. 9: 8721-8727.
Humidity control in buildings is important for several reasons ranging from ensuring comfort of the occupants to mold control. While the optimum humidity range can be different depending on the function of a particular facility, data centers require especially tight control of humidity and dew point. For example, at low humidity (electro-static discharge) ESD might impose a significant risk to the computing equipment while at high humidity levels hardware failures are more probable due to the growth of conductive filaments or corrosion of circuit boards. In this paper we present a detailed comparison of data centers from several geographical locations, where we have measured humidity and temperature distributions over extended periods of time. The data are analyzed in terms of spatial and temporal dew point variations. We derive detailed dew point “maps” of the respective data center and the impact on reliability and energy efficiency is being discussed.
Levente J. Klein; Hendrik F. Hamann. Humidity Control and Dew Point Management. ASME 2011 Pacific Rim Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Systems, MEMS and NEMS: Volume 1 2011, 629 -635.
AMA StyleLevente J. Klein, Hendrik F. Hamann. Humidity Control and Dew Point Management. ASME 2011 Pacific Rim Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Systems, MEMS and NEMS: Volume 1. 2011; ():629-635.
Chicago/Turabian StyleLevente J. Klein; Hendrik F. Hamann. 2011. "Humidity Control and Dew Point Management." ASME 2011 Pacific Rim Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Systems, MEMS and NEMS: Volume 1 , no. : 629-635.