Unique Server Research Articles

HighAltitudeOmicsDB, an integrated resource for high-altitude associated genes and proteins, networks and semantic-similarities

Millions of people worldwide visit, live or work in the hypoxic environment encountered at high altitudes and it is important to understand the biomolecular responses to this stress. This would help design mitigation strategies for high altitude illnesses. In spite of a number of studies spanning over 100 years, still the complex mechanisms controlling acclimatization to hypoxia remain largely unknown. To identify potential diagnostic, therapeutic and predictive markers for HA stress, it is important to comprehensively compare and analyse these studies. Towards this goal, HighAltitudeOmicsDB is a unique resource that provides a comprehensive, curated, user-friendly and detailed compilation of various genes/proteins which have been experimentally validated to be associated with various HA conditions, their protein–protein interactions (PPIs) and gene ontology (GO) semantic similarities. For each database entry, HighAltitudeOmicsDB additionally stores the level of regulation (up/down-regulation), fold change, study control group, duration and altitude of exposure, tissue of expression, source organism, level of hypoxia, method of experimental validation, place/country of study, ethnicity, geographical location etc. The database also collates information on disease and drug association, tissue-specific expression level, GO and KEGG pathway associations. The web resource is a unique server platform that offers interactive PPI networks and GO semantic similarity matrices among the interactors.These unique features help to offer mechanistic insights into the disease pathology. Hence, HighAltitudeOmicsDBis a unique platform for researchers working in this area to explore, fetch, compare and analyse HA-associated genes/proteins, their PPI networks, and GO semantic similarities. The database is available at http://www.altitudeomicsdb.in.

MyomirDB: A unified database and server platform for muscle atrophy myomiRs, coregulatory networks and regulons

Muscular atrophy or muscle loss is a multifactorial clinical condition during many critical illnesses like cancer, cardiovascular diseases, diabetes, pulmonary diseases etc. leading to fatigue and weakness and contributes towards a decreased quality of life. The proportion of older adults (>65 y) in the overall population is also growing and aging is another important factor causing muscle loss. Some muscle miRNAs (myomiRs) and their target genes have even been proposed as potential diagnostic, therapeutic and predictive markers for muscular atrophy. MyomirDB (http://www.myomirdb.in/) is a unique resource that provides a comprehensive, curated, user- friendly and detailed compilation of various miRNA bio-molecular interactions; miRNA-Transcription Factor-Target Gene co-regulatory networks and ~8000 tripartite regulons associated with 247 myomiRs which have been experimentally validated to be associated with various muscular atrophy conditions. For each database entry, MyomirDB compiles source organism, muscle atrophic condition, experiment duration, its level of expression, fold change, tissue of expression, experimental validation, disease and drug association, tissue-specific expression level, Gene Ontology and KEGG pathway associations. The web resource is a unique server platform which uses in-house scripts to construct miRNA-Transcription Factor-Target Gene co-regulatory networks and extract tri-partite regulons also called Feed Forward Loops. These unique features helps to offer mechanistic insights in disease pathology. Hence, MyomirDB is a unique platform for researchers working in this area to explore, fetch, compare and analyse atrophy associated miRNAs, their co-regulatory networks and FFL regulons.

Performance evaluation of holonic control of a switch arrival system

The application of holonic paradigm to the hybrid control system class is a promising way to give flexibility to the control of such systems, leading to new industrial intelligent processes. However, there is a need for performance evaluation of such solutions in order to give them credit among the multiple formalisms used in the literature. This article aims at evaluating the optimality and stability of the holonic control of a switch arrival system, a classical system from the literature where a unique server has to switch between leaking tanks full of fluids before they get empty. Optimality is evaluated compared to a scheduling algorithm aimed at minimizing the number of switches of the server while respecting the constraints. Stability is evaluated through a stochastic simulation run aiming at finding cyclic behavior of the control in a whole set of random initial configurations. The results tend to show a good overall performance of the control, especially considering the algorithms used are quite simple, thus could be made better and enhance the performance.

Benefits of an automatic patient dose registry system for interventional radiology and cardiology at five hospitals of the Madrid area.

The purpose of this article is to present the results of connecting the interventional radiology and cardiology laboratories of five university hospitals to a unique server using an automatic patient dose registry system (Dose On Line for Interventional Radiology, DOLIR) developed in-house, and to evaluate its feasibility more than a year after its introduction. The system receives and stores demographic and dosimetric parameters included in the MPPS DICOM objects sent by the modalities to a database. A web service provides a graphical interface to analyse the information received. During 2013, the system processed 10 788 procedures (6874 cardiac, 2906 vascular and 1008 neuro interventional). The percentages of patients requiring clinical follow-up due to potential tissue reactions before and after the use of DOLIR are presented. The system allowed users to verify in real-time, if diagnostic (or interventional) reference levels are fulfilled.

Stationary analysis of the shortest queue first service policy

We analyze the so-called shortest queue first (SQF) queueing discipline whereby a unique server addresses queues in parallel by serving at any time, the queue with the smallest workload. Considering a stationary system composed of two parallel queues and assuming Poisson arrivals and general service time distributions, we first establish the functional equations satisfied by the Laplace transforms of the workloads in each queue. We further specialize these equations to the so-called “symmetric case,” with same arrival rates and identical exponential service time distributions at each queue; we then obtain a functional equation $$\begin{aligned} M(z) = q(z) \cdot M \circ h(z) + L(z) \end{aligned}$$ for unknown function M, where given functions $$q, L$$ , and $$h$$ are related to one branch of a cubic polynomial equation. We study the analyticity domain of function M and express it by a series expansion involving all iterates of function $$h$$ . This allows us to determine empty queue probabilities along with the tail of the workload distribution in each queue. This tail appears to be identical to that of the head-of-line preemptive priority system, which is the key feature desired for the SQF discipline.

Threshold signature for distributed time stamping scheme

The aim of a time-stamping system is to prove the existence of a digital document at a particular time in the past. Implemented time-stamping systems are generally based on a centralized server model. However, the unique server may represent a weakness for the system. In this paper, we propose a distributed time-stamping scheme which is more robust against a denial of service attack. Our protocol is based on a multisignature scheme. In order to be valid, time-stamps need to be accepted by at least X servers. The interesting point is that the size of the time-stamp token does not depend on X and that there is no publication process.

MASHA: A multi-agent system handling user and device adaptivity of Web sites

A user that navigates on the Web using different devices should be characterized by a global profile, which represents his behaviour when using all these devices. Then, the user's profile could be usefully exploited when interacting with a site agent that is able to provide useful recommendations on the basis of the user's interests, on one hand, and to adapt the site presentation to the device currently exploited by the user, on the other hand. However, it is not suitable to construct such a global profile by a software running on the exploited device since this device (e.g., a mobile phone or a palmtop) may have limited resources. Therefore, in this paper, we propose a multi-agent architecture, called MASHA, handling user and device adaptivity of Web sites, in which each device is provided with a client agent that autonomously collects information about the user's behaviour associated to just that device. However, the user profile contained in this client is continuously updated with information coming from a unique server agent, associated with the user. Such information is collected by the server agent from the different devices exploited by the user, and represents a global user profile. The third component of this architecture, called adapter agent, is capable to generate a personalized representation of the Web site, containing some useful recommendations derived by both an analysis of the user profile and the suggestions coming from other users exploiting the same device.

Computing performance bounds of fork-join parallel programs under a multiprocessing environment

We study a multiprocessing computer system which accepts parallel programs that have a fork-join computational paradigm. The multiprocessing computer system under study is modeled as K homogeneous servers, each with an infinite capacity queue. Parallel programs arrive at the multiprocessing system according to a series-parallel phase type interarrival process with mean arrival rate of h. Upon the program arrival, it forks into K-independent tasks and each task is assigned to an unique server. Each task's service time has a k-stage Erlang distribution with mean service time of /spl lambda/. A parallel program is completed upon the completion of its last task. This kind of queuing model has no known closed form solution in the general (K/spl ges/2) case. In this paper, we show that by carefully modifying the arrival and service distributions at some imbedded points in time, we can obtain tight performance bounds. We also provide a computational efficient algorithm for obtaining upper and lower bounds on the expected response time. The methodology is flexible and allows one to trade-off the tightness of the bounds and computational cost.

RACE “MARS” project for the experimentation of multimedia interactive services: Architecture solutions and results

AbstractThis paper describes the architecture implemented in five different countries to validate, by means of tests carried out with expert users, a service architecture for the interactive retrieval of multimedia information. The service architecture definition (which corresponds to the DA VIC 1.0 Specifications) and all activities for the set‐up and running of the experiments, have been carried out within the RACE R2120 “Multimedia Audiovisual Retrieval Services” (MARS) project. A unique server and terminal architecture has been developed and put in operation at each site, while a combination of different public network solutions were used for the terminal access side. All national experiments made use of an ATM‐based transport network. The interconnections between the five countries were provided by the European ATM Pilot (EAP). The minimal testbed configuration implemented in each country consisted of one server and two terminals. After the integration and test phases, this configuration was extensively tested within the national environment to obtain the users' perception of the service.