X-ray Scattered Halo around IGR J17544-2619

X-ray photons coming from an X-ray point source not only arrive at the detector directly, but also can be strongly forward-scattered by the interstellar dust along the line of sight (LOS), leading to a detectable diffuse halo around the X-ray point source. The geometry of small angle X-ray scattering is straightforward, namely, the scattered photons travel longer paths and thus arrive later than the unscattered ones; thus the delay time of X-ray scattered halo photons can reveal information of the distances of the interstellar dust and the point source. Here we present a study of the X-ray scattered around IGR J17544-2619, which is one of the so-called supergiant fast X-ray transients. IGR J17544-2619 underwent a striking outburst when observed with Chandra on 2004 July 3, providing a near delta-function lightcurve. We find that the X-ray scattered halo around IGR J17544-2619 is produced by two interstellar dust clouds along the LOS. The one which is closer to the observer gives the X-ray scattered at larger observational angles; whereas the farther one, which is in the vicinity of the point source, explains the halo with a smaller angular size. By comparing the observational angle of the scattered halo photons with that predicted by different dust grain models, we are able to determine the normalized dust distance. With the delay times of the scattered halo photons, we can determine the point source distance, given a dust grain model. Alternatively we can discriminate between the dust grain models, given the point source distance.Comment: Accepted for publication in ApJ. 25 pages, 9 figures, 6 table

Convolution quadratures based on block generalized Adams methods

This paper studies a class of convolution quadratures, well-known numerical methods for calculation of convolution integrals. In contrast to the existing counterpart, which uses the linear multistep formula or Runge-Kutta method, we employ the block generalized Adams method to discretize the underlying initial value problem. Similar to the convolution quadrature method based on the linear multistep formula, the proposed method can also be implemented on an equispaced grid. In addition, the proposed approach is as stable as the convolution quadrature based on the Runge-Kutta method, which indicates that it can accurately solve a wide range of problems without becoming unstable. We provide a detailed convergence analysis for the proposed convolution quadrature method and numerically illustrate our theoretical findings for convolution integrals with smooth and weakly singular kernels.Comment: 21 page

An identification based network link backup method

in order to solve the problem of network link failure or link congestion, this paper proposes an identifi cation based link backup method, which uses the identification network to carry out collaborative backup of links, formulates the link level through the network identifi cation mechanism, divides the routing characteristics through the link level, and calculates the link level through the link backup protocol between routers. When the high priority link fails or the link congestion occurs, the low priority link can be used for routing; When the transmission rate of a single link decreases, the low priority link can also be enabled. So as to achieve network load balancing and maximize link utilization. Through mini net simulation, the experimental topology is built and verifi ed. The results show that this method can quickly repair the link failure, quickly switch the link, reduce the network interruption delay, when the high priority link failure or congestion, it can quickly establish the route update, and quickly recover, so as to achieve the purpose of network load balancing

Ceiling-fan-integrated air conditioning: Airflow and temperature characteristics of a sidewall-supply jet interacting with a ceiling fan

Ceiling-Fan-Integrated Air Conditioning (CFIAC) is a proposed system that can greatly increase buildings’ cooling efficiency. In it, terminal supply ducts and diffusers are replaced by vents/nozzles, jetting supply air toward ceiling fans that serve to mix and distribute it within the room. Because of the fans’ air movement, the system provides comfort at higher room temperatures than in conventional commercial/ institutional/retail HVAC. We have experimentally evaluated CFIAC in a test room. This paper covers the distributions of air-speed, temperature, and calculated comfort level throughout the room. Two subsequent papers report tests of human subject comfort and ventilation effectiveness in the same experimental conditions. The room’s supply air emerged from a high-sidewall vent directed toward a ceiling fan on the jet centerline; we also tested this same jet on a fan located off to the side of the jet. Primary variables are: ceiling fan flow volumes in downward and upward directions, supply air volume, and room-vs-supply temperature difference. Velocity, turbulence, and temperature distributions are presented for vertical and horizontal transects of the room. The occupied zone is then evaluated for velocity and temperature non-uniformity, and for comfort as predicted by the ASHRAE Standard 55 elevated air speed method. We show that temperatures are well-mixed and uniform across the room for all of the fan-on configurations, for fans both within or out of the supply jet centerline. The ceiling fan flow dominates the CFIAC airflow, and even though non-uniform is capable of providing comfortable conditions throughout the occupied area of the room

Aerobinen bakteeriviljelynäyte haavasta

Pinnallisen haavan bakteeriviljelyn näytteenotto on tärkeä tutkimuksen osa-alue luotettavan viljelytuloksen saamisen kannalta. Näytteenottoon liittyy monia vaiheita, jotka on tärkeä suorittaa oikein, jotta mahdollinen infektion aiheuttaja löytyisi ja potilas saisi tarvittaessa nopeasti mikrobilääkehoidon, eikä hänen paraneminen viivästyisi. Näytteenoton oikeel-lisuutta on mahdotonta arvioida laboratoriossa, joten oikea tulos on täysin hyvän bakteeri-viljelynäytteenoton varassa. Opinnäytetyössäni kartoitettiin yhdentoista Suomen laboratorion sekä Oslon, Tukholman ja Kööpenhaminan laboratorioiden pinnallisten haavanäytteiden näytteenotto-ohjeiden eroja induktiivisen sisällönanalyysin teoriaa soveltaen. Työssä pyrittiin tarkastelemaan ohjeita mahdollisimman tarkasti, jotta saatiin laaja kuva laboratorio kohtaisista eroista ja yhtäläi-syyksistä. Aiempien tutkimusten ja hyvän ohjeen kriteerien perusteella arvioitiin mitkä koh-dat ohjeissa ovat tärkeitä ja missä laboratorioilla olisi parantamisen varaa pinnallisen haavan bakteeriviljelynäytteenotonohjetta päivitettäessä. Työn tutkimustulosten perusteella laboratorioiden pinnallisen haavan bakteeriviljelynäyt-teenoton ohjeiden rakenne oli pääpiirtein samankaltainen laboratoriosta riippumatta. Suuria eroja löytyi kappaleiden sisältä, sillä monet laboratoriot olivat painottaneet ohjeessaan eri näytteenoton vaiheita. Tiettyjen laboratorioiden ohjeista löytyi suuria puutteita esimerkiksi haavan puhdistusvaiheen ja näytteenoton kuvaamisen suhteen. Yleisin puute oli ky-rettinäytteen ottamisen ja säilytyksen suhteen. Kansalliset näytteenoton suositukset voisivat täten olla hyödyllisiä, jotta ainakin Suomen sisällä pinnallisen haavan bakteeriviljely-näytteiden laatu olisi yhtenevä.Superficial wound sampling is one of the most important parts of getting reliable cultivation results. There are many steps in taking the specimen correctly, these steps needs to be followed thoroughly to ensure the quick determination of the infectious agent. Leading to the correct antibiotic treatment being administered with minimum delay to overall patient recovery. It is impossible to asses in a laboratory whether the sample was taken properly. A correct result is dependent on good bacteria sampling. The purpose of this final project was to study the differences of the superficial wound sam-pling instructions at eleven Finnish laboratories, one laboratory in Oslo, Stockholm and Copenhagen by applying the methods of inductive content analysis. It was necessary to look at the instructions as precisely as possible in order to get a comprehensive picture of laboratory-specific differences and similarities. Previous studies and good guide criteria were used to evaluate which parts were important in the instructions and which parts the laboratories could improve their superficial wound sampling instructions by updating it. Based on the project results the structures of the laboratory instructions of the superficial wound sampling were roughly similar apart of laboratory. The biggest differences were found inside the chapters for many laboratories had stressed different parts of sampling. Certain instructions contained major shortcomings in the area of wound cleansing and sampling. The most common deficiency was taking and transportation of curette specimen. National sampling recommendations may be useful. This way superficial wound sampling instructions would be congruent at least in Finland

Vector Auto-Regression-Based False Data Injection Attack Detection Method in Edge Computing Environment

With the wide application of advanced communication and information technology, false data injection attack (FDIA) has become one of the significant potential threats to the security of smart grid. Malicious attack detection is the primary task of defense. Therefore, this paper proposes a method of FDIA detection based on vector auto-regression (VAR), aiming to improve safe operation and reliable power supply in smart grid applications. The proposed method is characterized by incorporating with VAR model and measurement residual analysis based on infinite norm and 2-norm to achieve the FDIA detection under the edge computing architecture, where the VAR model is used to make a short-term prediction of FDIA, and the infinite norm and 2-norm are utilized to generate the classification detector. To assess the performance of the proposed method, we conducted experiments by the IEEE 14-bus system power grid model. The experimental results demonstrate that the method based on VAR model has a better detection of FDIA compared to the method based on auto-regressive (AR) model

Finite element analysis and experimental validation of the thermomechanical behavior in laser solid forming of Ti-6Al-4V

A three-dimensional (3D) thermomechanical coupled model for Laser Solid Forming (LSF) of Ti-6Al-4V alloy has been calibrated through experiments of 40-layers metal deposition using different scanning strategies. The sensitivity analysis of the mechanical parameters shows that the thermal expansion coefficient as well as the elastic limit of Ti-6Al-4V have a great impact on the mechanical behavior. Using the validated model and optimal mechanical parameters, the evolution of thermo-mechanical fields in LSF has been analyzed. It has been found that the stresses and distortions develop in two stages, after the deposition of the first layer and during the cooling phase after the manufacturing of the component. The cooling phase is the responsible of 70% of the residual stresses and 60% of the total distortions. The analyses indicate that by controlling the initial substrate temperature (pre-heating phase) and the final cooling phase it is possible to mitigate both distortion and residual stresses. Hence, the influence of different pre-heating procedures on the mechanical fields has been analyzed. The results show that increasing the pre-heating temperature of the substrate is the most effective way to reduce the distortions and residual stresses in Additive Manufacturing

Species specific exome probes reveal new insights in positively selected genes in nonhuman primates

Nonhuman primates (NHP) are important biomedical animal models for the study of human disease. Of these, the most widely used models in biomedical research currently are from the genus Macaca. However, evolutionary genetic divergence between human and NHP species makes human-based probes inefficient for the capture of genomic regions of NHP for sequencing and study. Here we introduce a new method to resequence the exome of NHP species by a designed capture approach specifically targeted to the NHP, and demonstrate its superior performance on four NHP species or subspecies. Detailed investigation on biomedically relevant genes demonstrated superior capture by the new approach. We identified 28 genes that appeared to be pseudogenized and inactivated in macaque. Finally, we identified 187 genes showing strong evidence for positive selection across all branches of the primate phylogeny including many novel findings

Innovation Dynamics of Cultural Production: Evidence in Rap Lyrics

Culture is a driving force in organizing the structure of societies, and is conjoined with economic development. However, quantifying the impact of culture is difficult. Culture manifests itself in cultural production, through art, performance, music, etc. Innovation and influence in cultural production industries partially determines product quality. Using techniques from the “digitized humanities”, we agnostically identify informational distance to describe the spatiotemporal dynamics of innovation and influence in Rap music lyrics. Rap emphasizes lyricism and hometown pride more than other genres of popular music, and is interesting as a globally impactful manifestation of the racially segregated labor market in the U.S. Resources and production are not spread evenly within an economy. Geographic clustering of economic activity is well discussed across the social sciences. Although first discussed in relation to manufacturing, urban agglomeration has been observed empirically for both cultural production and innovation in general. We find that number of Rappers and maximum novelty scale with overall and Black/African-American population at the MSA-level, suggesting an increasing return to maximum novelty through greater chance of recombination. Rapper population is predicted by Black/African-American population, while measures of song quality are predicted by total population. This paper contributes a novel dataset and application of the methodology to economic questions of cultural production