Performance of the CMS Level-1 Trigger

The first level trigger of the CMS experiment is comprised of custom electronics that process data from the electromagnetic and hadron calorimeters and three technologies of muon detectors in order to select the most interesting events from LHC collisions, such as those consistent with the production and decay of the Higgs boson. The rate of events selected by this Level-1 trigger must be reduced from the beam crossing frequency to no more than 100 kHz further processing can occur, a major challenge since the LHC instantaneous luminosity has increased by six orders of magnitude since the start of operations to more than 6E33 cm-2s-1 today. The performance of the Level-1 trigger, in terms of rates and efficiencies of the main objects and trigger algorithms, as measured from LHC proton collisions at 7 and 8 TeV center-of-mass energies is presented here.Comment: Presented at 36th International Conference on High Energy Physics, July 4-11, 2012, Melbourne, Australi

Century scale persistence in longitude distribution: in the Sun and in silico

Using Greenwich sunspot data for 120 years it was recently observed that activity regions on the Sun's surface tend to lie along smoothly changing longitude strips 180 degrees apart from each other. However, numerical experiments with random input data show that most, if not all, of the observed longitude discrimination can be looked upon as an artifact of the analysis method.Comment: 4 pages, 12 figures, accepted for publication in Astronomy and Astrophysic

The Value of User-Visible Internet Cryptography

Cryptographic mechanisms are used in a wide range of applications, including email clients, web browsers, document and asset management systems, where typical users are not cryptography experts. A number of empirical studies have demonstrated that explicit, user-visible cryptographic mechanisms are not widely used by non-expert users, and as a result arguments have been made that cryptographic mechanisms need to be better hidden or embedded in end-user processes and tools. Other mechanisms, such as HTTPS, have cryptography built-in and only become visible to the user when a dialogue appears due to a (potential) problem. This paper surveys deployed and potential technologies in use, examines the social and legal context of broad classes of users, and from there, assesses the value and issues for those users

Explicit constructions of infinite families of MSTD sets

We explicitly construct infinite families of MSTD (more sums than differences) sets. There are enough of these sets to prove that there exists a constant C such that at least C / r^4 of the 2^r subsets of {1,...,r} are MSTD sets; thus our family is significantly denser than previous constructions (whose densities are at most f(r)/2^{r/2} for some polynomial f(r)). We conclude by generalizing our method to compare linear forms epsilon_1 A + ... + epsilon_n A with epsilon_i in {-1,1}.Comment: Version 2: 14 pages, 1 figure. Includes extensions to ternary forms and a conjecture for general combinations of the form Sum_i epsilon_i A with epsilon_i in {-1,1} (would be a theorem if we could find a set to start the induction in general

Curriculum Innovation: Incorporating the Kern Engineering Entrepreneurial Network (KEEN) Framework into Online Discussions

The purpose of this study was to respond to the following research question: How does the Kern Engineering Entrepreneurial Network (KEEN) framework build interest in technical topic areas, impact student learning outcomes, and develop the entrepreneurial mindset when applied to the engineering classroom? The KEEN framework was developed to combine the entrepreneurial mindset with engineering education to produce a more valuable, strategically prepared engineer, rather than simply an “obedient engineer”. The framework proposes that the entrepreneurial mindset of students is increased by promoting curiosity, encouraging connections, and creating value. The results from this work provide insight into the impact and implications resulting from applying the KEEN framework to the engineering classroom via online discussions

Triclosan Adsorption Using Wastewater Biosolids-derived Biochar

Organic micropollutants are ubiquitous in the environment and stem from municipal wastewater treatment plant discharges. Adsorption can be used as a tertiary treatment to complement the conventional activated sludge process to remove micropollutants prior to discharge. This research evaluated the performance of wastewater biosolids-derived biochar as an adsorbent to remove triclosan from water. Pre-conditioning of the biochar using hydrochloric acid (HCl) was an essential step for triclosan adsorption. Using acid-conditioned biochar, maximum adsorption of 872 μg triclosan per g biochar was achieved with biochar produced at 800 °C. Biochar produced at higher pyrolysis temperatures tended to have higher triclosan sorption capacity using initial triclosan concentrations of 200 μg L−1 levels. However, pyrolysis temperature had less impact on triclosan sorption at lower, environmentally relevant concentrations. Low solution pH (3) enhanced adsorption and high pH (11) inhibited adsorption. Effective triclosan sorption was observed between pH 5 and 9, with little variation, which is positive for practical applications operated at near-neutral solution pH. In wastewater, acid-treated biochar also effectively sorbed triclosan, albeit at a decreased adsorption capacity and removal rate due to competition from other organic constituents. This study indicated that adsorption may occur mainly due to high surface area, hydrophobicity, and potential interaction between biochar and triclosan functional groups including hydrogen bonding and π-stacking. This work demonstrated that acid-conditioned biosolids-derived biochar could be a suitable sorbent to remove triclosan from wastewater as a final polishing treatment step

Hellinger Distance Trees for Imbalanced Streams

Classifiers trained on data sets possessing an imbalanced class distribution are known to exhibit poor generalisation performance. This is known as the imbalanced learning problem. The problem becomes particularly acute when we consider incremental classifiers operating on imbalanced data streams, especially when the learning objective is rare class identification. As accuracy may provide a misleading impression of performance on imbalanced data, existing stream classifiers based on accuracy can suffer poor minority class performance on imbalanced streams, with the result being low minority class recall rates. In this paper we address this deficiency by proposing the use of the Hellinger distance measure, as a very fast decision tree split criterion. We demonstrate that by using Hellinger a statistically significant improvement in recall rates on imbalanced data streams can be achieved, with an acceptable increase in the false positive rate.Comment: 6 Pages, 2 figures, to be published in Proceedings 22nd International Conference on Pattern Recognition (ICPR) 201

Fate and Impacts of Triclosan, Sulfamethoxazole, and 17β-estradiol during Nutrient Recovery via ion Exchange and Struvite Precipitation

Increasing emphasis on resource recovery from wastewater highlights the importance of capturing valuable products, e.g., nutrients such as nitrogen and phosphorus, while removing contaminants, e.g., organic micropollutants. The objective of this research was to evaluate the fate of the micropollutants triclosan (present as a mixture of neutral and anionic species at neutral pH), 17β-estradiol (neutral at neutral pH), and sulfamethoxazole (anionic at neutral pH) during nutrient recovery using ion exchange-precipitation. Adsorption of the three micropollutants to the phosphate-selective ion exchange resins LayneRT and DOW-HFO-Cu ranged from 54% to 88% in Milli-Q water tests and 50% to 71% in wastewater tests using anaerobic effluent. The micropollutants did not sorb to the ammonium-selective exchanger, clinoptilolite. The presence of the micropollutants reduced the kinetic rates of nutrient exchange onto ion exchangers. However, the micropollutants did not interfere with nutrient capacity on the ion exchangers, likely due to the low concentration of micropollutants and potentially different mechanisms of adsorption (i.e., Coulombic and non-Coulombic attractions for micropollutants) compared to the target ions. Micropollutants that sorbed to the phosphate exchangers were released with phosphate ions during regeneration. Concentrations of NaOH and NaCl in regeneration solutions did not correlate with micropollutant desorption. Among the micropollutants studied, the more hydrophobic triclosan and 17β-estradiol adsorbed to the resins to greater extents. These compounds also demonstrated lower desorption rates than sulfamethoxazole during regeneration in Milli-Q water tests. Batch struvite precipitation tests revealed that the micropollutants were not enmeshed in precipitated struvite crystals nor sorbed during crystallization, indicating that the struvite product was free of triclosan, 17β-estradiol, and sulfamethoxazole

Comparing Wearer DNA Sample Collection Methods for the Recovery of Single Source Profiles

Wearer DNA is the deposit of epithelial cells on clothing worn by an individual. Detection of the last individual to handle or wear an item is often an important and desirable determination in forensic science. The most commonly used collection methods for wearer DNA include swabbing and scraping. These often result in mixture profiles. Recently, adhesives have been introduced as a possible reliable method for the collection of biological evidence. The goal of the research was to compare the current collection methods of swabbing and scraping with a gel film called Gel-Pak ‘0’ which shares similar properties with adhesives. Gel-Pak ‘0’ has been previously studied in comparison to other adhesives for the collection of epithelial cells, and was shown to recover the top layer of loose particulate. This particulate had a tendency to be deposited by the individual who last came in contact with an item. Therefore, in comparison to the other two collection methods, Gel-Pak ‘0’ was hypothesized to recover single source profiles on clothing items from the most recent wearer. DNA analysis was performed on samples collected by the three methods from various clothing items including baseball hats, t-shirts, sweatpants, socks, and other items commonly submitted to crime labs for DNA analysis. The habitual wearer and the second/last wearer wore each item for a predetermined amount of time. The results of the research showed that Gel-Pak ‘0’ recovered a similar number of CODIS (local and national) eligible profiles as swabbing. However, coupled with the fact that it is time consuming, costly, and cannot be used on all surfaces, Gel-Pak ‘0’ was determined to not make for an effective collection method of the most recent wearer’s DNA. Therefore, Gel-Pak ‘0’ will not be considered for casework. Although Gel-Pak ‘0’ will not be further used, the results did reveal some trends that may shed light on how DNA analysts may approach wearer DNA cases. Swabbing had a tendency to yield smaller amounts of DNA in comparison to scraping, but obtain DNA from the last wearer of the piece of clothing more effectively than the other two methods. Scraping had a tendency to yield greater quantities of DNA, recovering more DNA from the habitual wearer due to its invasive nature. Revealing individuals who last wore an item can be of great importance in forensic science, and therefore, further research with various adhesives and gel films could be vital for solving forensic investigations