TimeTrader: Exploiting Latency Tail to Save Datacenter Energy for On-line Data-Intensive Applications

Datacenters running on-line, data-intensive applications (OLDIs) consume significant amounts of energy. However, reducing their energy is challenging due to their tight response time requirements. A key aspect of OLDIs is that each user query goes to all or many of the nodes in the cluster, so that the overall time budget is dictated by the tail of the replies' latency distribution; replies see latency variations both in the network and compute. Previous work proposes to achieve load-proportional energy by slowing down the computation at lower datacenter loads based directly on response times (i.e., at lower loads, the proposal exploits the average slack in the time budget provisioned for the peak load). In contrast, we propose TimeTrader to reduce energy by exploiting the latency slack in the sub- critical replies which arrive before the deadline (e.g., 80% of replies are 3-4x faster than the tail). This slack is present at all loads and subsumes the previous work's load-related slack. While the previous work shifts the leaves' response time distribution to consume the slack at lower loads, TimeTrader reshapes the distribution at all loads by slowing down individual sub-critical nodes without increasing missed deadlines. TimeTrader exploits slack in both the network and compute budgets. Further, TimeTrader leverages Earliest Deadline First scheduling to largely decouple critical requests from the queuing delays of sub- critical requests which can then be slowed down without hurting critical requests. A combination of real-system measurements and at-scale simulations shows that without adding to missed deadlines, TimeTrader saves 15-19% and 41-49% energy at 90% and 30% loading, respectively, in a datacenter with 512 nodes, whereas previous work saves 0% and 31-37%.Comment: 13 page

Advanced Bank locker system using RFID and GSM technology

The main objective of this paper is to design andimplement a secure advanced bank locker system based on RFID and GSM technology which can be organized in banks, offices or even in homes. In this designed project the authenticated personcan only recover the thing present inside the locker. Thetraditional locker systems using mechanical and key mechanismare replaced by new advanced techniques of locking system. These techniques are an integration of mechanical and electronic devicesand are highly intelligent, simple and high efficiency. Here, we have implemented bank security system consisting of door locksystem based on RFID and GSM which can activate, authenticate,and validate the user and give the access for the door in real time. This system consists of a microcontroller, RFID and its reader, lcd display, keyboard, GSM module and a relay. The main advantage of using passive RFID and GSM is for two step authentication and to make system more secure than the others. On other hand it also has advantage of generating real time password. In this system, the RFID reader reads the id number from passive tag and later itwill be checked by the microcontroller, if id number matches it sends a message to the registered phone number to generate a password in the real time. Then it will provide you an option to enter thegenerated password on the keyboard present at the locker. If bothpassword matches the door will get unlocked otherwise it denies theaccess and the user cannot make furtheruse of locker

Community-partnered contracts in developing countries

There is a growing recognition in developing countries of community-based infrastructure procurement and its potential to achieve sustainable development. The advantages of such an approach are that it encourages participative negotiation of activities and speedier implementation, the use of local resources, skills and appropriate technology, and entrepreneurship within communities. These wider socio-economic impacts arising from community-partnered micro-projects can lead to more sustainable infrastructure through meeting local stakeholders’ needs, community empowerment and capacity building. This paper describes the development and use of performance indicators for community-contracted urban infrastructure provision in low-income communities in India, Pakistan and Sri Lanka. In particular, these indicators refer to the dimensions of time and cost; some key performance yardsticks are also proposed. The urban infrastructure and services referred to in these cases are the facilities needed for water and sanitation provision, access roads, street lighting and solid waste management. In general, it was found that costs for community-contracted micro-projects were normally very close to being on target. The quality of infrastructure and service provision also tended to be superior to that envisioned by local government engineers. However, project duration generally exceeded the target but was still comparable to conventional contracts. The overall performance of the community-partnered micro-projects was found to be comparable or better than the conventional micro-contracts; in addition, the performance of these projects in terms of socio-economic elements was likely to far exceed that of the conventional micro-projects

Combined Spatially Resolved Optical Emission Imaging and Modeling Studies of Microwave-Activated H₂/Ar and H₂/Kr Plasmas Operating at Powers and Pressures Relevant for Diamond Chemical Vapor Deposition

Microwave (MW) activated H2/Ar (and H2/Kr) plasmas operating under powers and pressures relevant to diamond chemical vapor deposition have been investigated experimentally and by 2-D modeling. The experiments return spatially and wavelength resolved optical emission spectra of electronically excited H2 molecules and H and Ar­(/Kr) atoms for a range of H2/noble gas mixing ratios. The self-consistent 2-D­(r, z) modeling of different H2/Ar gas mixtures includes calculations of the MW electromagnetic fields, the plasma chemistry and electron kinetics, heat and species transfer and gas–surface interactions. Comparison with the trends revealed by the spatially resolved optical emission measurements and their variations with changes in process conditions help guide identification and refinement of the dominant plasma (and plasma emission) generation mechanisms and the more important Ar–H, Ar–H2, and H–H2 coupling reactions. Noble gas addition is shown to encourage radial expansion of the plasma, and thus to improve the uniformity of the H atom concentration and the gas temperature just above the substrate. Noble gas addition in the current experiments is also found to enhance (unwanted) sputtering of the copper base plate of the reactor; the experimentally observed increase in gas phase Cu* emission is shown to correlate with the near substrate ArH+ (and KrH+) ion concentrations returned by the modeling, rather than with the relatively more abundant H3+ (and H3O+) ions

Cochlear implant in a patient with Mondini\u27s deformity of the cochlea: pilot patient in Pakistan

Abstract Autosomal-recessive genes account for about 80% of the patients of non-syndromic deafness, and a major portion of those lead to cochlear pathology. Given the strong cultural practice of consanguineous marriages and the lack of awareness regarding screening modalities, a high prevalence of hereditary pre-lingual deafness is seen in Pakistan. Considering the situation, cochlear implant surgery was introduced by Aga Khan University Hospital (AKUH), Karachi, Pakistan, in 2003. Recently we decided to expand the profile and services available and conducted the first ever cochlear implant on an anatomically-challenged cochlea. The case report relates to the experience of our pilot patient who was suffering from Mondini\u27s deformity

Prevalence of non-aureus Staphylococcus species causing intramammary infections in Canadian dairy herds

Non-aureus staphylococci (NAS), the microorganisms most frequently isolated from bovine milk worldwide, are a heterogeneous group of numerous species. To establish their importance as a group, the distribution of individual species needs to be determined. In the present study, NAS intramammary infection (IMI) was defined as a milk sample containing ≥1,000 cfu/mL in pure or mixed culture that was obtained from a cohort of cows assembled by the Canadian Bovine Mastitis Research Network. Overall, 6,213 (6.3%) of 98,233 quarter-milk samples from 5,149 cows and 20,305 udder quarters were associated with an NAS IMI. Of the 6,213 phenotypically identified NAS isolates, 5,509 (89%) were stored by the Canadian Bovine Mastitis Research Network Mastitis Pathogen Collection and characterized using partial sequencing of the rpoB housekeeping gene, confirming 5,434 isolates as NAS. Prevalence of each NAS species IMI was estimated using Bayesian models, with presence of a specific NAS species as the outcome. Overall quarter-level NAS IMI prevalence was 26%. The most prevalent species causing IMI were Staphylococcus chromogenes (13%), Staphylococcus simulans (4%), Staphylococcus haemolyticus (3%), Staphylococcus xylosus (2%), and Staphylococcus epidermidis (1%). The prevalence of NAS IMI as a group was highest in first-parity heifers and was evenly distributed throughout cows in parities ≥2. The IMI prevalence of some species such as S. chromogenes, S. simulans, and S. epidermidis differed among parities. Overall prevalence of NAS IMI was 35% at calving, decreased over the next 10 d, and then gradually increased until the end of lactation. The prevalence of S. chromogenes, Staphylococcus gallinarum, Staphylococcus cohnii, and Staphylococcus capitis was highest at calving, whereas the prevalence of S. chromogenes, S. haemolyticus, S. xylosus, and S. cohnii increased during lactation. Although the overall prevalence of NAS IMI was similar across barn types, the prevalence of S. simulans, S. xylosus, S. cohnii, Staphylococcus saprophyticus, S. capitis, and Staphylococcus arlettae IMI was higher in tie-stall barns; the prevalence of S. epidermidis IMI was lowest; and the prevalence of S. chromogenes and Staphylococcus sciuri IMI was highest in bedded-pack barns. Staphylococcus simulans, S. epidermidis, S. xylosus, and S. cohnii IMI were more prevalent in herds with intermediate to high bulk milk somatic cell count (BMSCC) and S. haemolyticus IMI was more prevalent in herds with high BMSCC, whereas other common NAS species IMI were equally prevalent in all 3 BMSCC categories. Distribution of NAS species IMI differed among the 4 regions of Canada. In conclusion, distribution differed considerably among NAS species IMI; therefore, accurate identification (species level) is essential for studying NAS epidemiology

Clinical spectrum of systemic lupus erythematosus at the Aga Khan University Hospital.

BACKGROUND: Systemic lupus erythematosus is a disease of unknown etiology, which at onest may involve only one organ system or be multisystemic. The aim of our study is to determine the clinical presentation of SLE patients presenting to AKUH to establish whether guidelines laid down about this disease are in agreement with our experience. METHODS: A retrospective log review was carried out at AKUH, based on data obtained from 165 files of individuals admitted to the hospital over a period of 12 years with a confirmed diagnosis of SLE. RESULTS: From the sample size of 165, 143 (86.7%) were females and 22 (13.3%) males. The mean age of diagnosis was 30.9 years. Frequency of symptomatology was observed to be in the following order: systemic 78.8%, musculoskeletal 63% and hematological 60.6%. Oninvestigation ANA levels were positive in 112 patients. CONCLUSION: Our result lead us to conclude that the classification set forth by the American Rheumatological Association is applicable to patients presenting with SLE in our setting

Effects of a Commercial Insurance Policy Restriction on Lumbar Fusion in North Carolina and the Implications for National Adoption

Analysis of the State Inpatient Database of North Carolina, 2005–2012, and the Nationwide Inpatient Sample, including all inpatient lumbar fusion admissions from non-federal hospitals

Computational modelling of heat transfer in an annular porous medium solar energy absorber with the p1-radiative differential approximation

We study the steady, laminar thermal convection flow in a participating, absorbing-emitting fluid-saturated porous medium occupying a cylindrical annulus with significant thermal radiation effects as a simulation of a solar energy absorber system. The dimensionless incompressible, viscous conservation equations for mass, axial momentum, radial momentum, heat conservation and radiative transfer equation are presented with appropriate boundary conditions in an axisymmetric (X, R) coordinate system. The Traugott P1-Differential radiative transfer model is used which reduces the general integro-differential equation for radiation heat transfer to a partial differential equation. The Darcy-Forcheimmer isotropic porous medium drag force model is employed to simulate resistance effects of the solar porous medium with constant permeability in both the radial (R) and axial (X) direction. A numerical finite difference (FTCS) scheme is used to compute the velocity (U,V), temperature () and dimensionless zero moment of intensity (I0) distributions for the effects of conduction-radiation parameter (N), Darcy parameter (Da), Forchheimer parameter (Fs), Rayleigh buoyancy number (Ra), aspect ratio (A) and Prandtl number (Pr). The computations have shown that increasing aspect ratio increases both axial and radial velocities and elevates the radiative moment of intensity. Increasing Darcy number accelerates both axial and radial flow whereas increasing Forchheimer number decelerates the axial and radial flow. Higher values of optical thickness induce a weak deceleration in the radial flow whereas they increase both axial flow velocity and temperature. Increasing optical thickness also reduces radial radiative moment of intensity at intermediate axial coordinate values but enhances them at low and high axial coordinate values. Extensive validation is conducted with the network thermo-electric simulation program RAD-SPICE. The model finds important applications in solar energy porous wafer absorber systems, crystal growth technologies and also chemical engineering thermal technologies