46 research outputs found

    The Strahler number of a parity game

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    The Strahler number of a rooted tree is the largest height of a perfect binary tree that is its minor. The Strahler number of a parity game is proposed to be defined as the smallest Strahler number of the tree of any of its attractor decompositions. It is proved that parity games can be solved in quasi-linear space and in time that is polynomial in the number of vertices~n and linear in (d/2k)k, where d is the number of priorities and k is the Strahler number. This complexity is quasi-polynomial because the Strahler number is at most logarithmic in the number of vertices. The proof is based on a new construction of small Strahler-universal trees. It is shown that the Strahler number of a parity game is a robust parameter: it coincides with its alternative version based on trees of progress measures and with the register number defined by Lehtinen~(2018). It follows that parity games can be solved in quasi-linear space and in time that is polynomial in the number of vertices and linear in (d/2k)k, where k is the register number. This significantly improves the running times and space achieved for parity games of bounded register number by Lehtinen (2018) and by Parys (2020). The running time of the algorithm based on small Strahler-universal trees yields a novel trade-off k⋅lg(d/k)=O(logn) between the two natural parameters that measure the structural complexity of a parity game, which allows solving parity games in polynomial time. This includes as special cases the asymptotic settings of those parameters covered by the results of Calude, Jain Khoussainov, Li, and Stephan (2017), of Jurdziński and Lazić (2017), and of Lehtinen (2018), and it significantly extends the range of such settings, for example to d=2O(lgn√) and k=O(lgn−√)

    Novel Sampling Algorithm for Human Mobility-Based Mobile Phone Sensing

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    Smart phones or mobile phones enabled with global positioning system (GPS), different types of sensors, and communication technologies have become ubiquitous application development platform for Internet of Things (IoT) and new sensing technologies. Improving sensing area coverage, reducing overlap of sensing area, and energy consumption are important issues under mobile phone sensing. This paper presents human mobility-based mobile phone sensors sampling algorithm. Human mobility patterns and geographical constraints have an impact on performance of mobile phone sensing applications. The real-outdoor location traces of volunteers, collected using GPS-enabled mobile phones are used for performance analysis of proposed work. The proposed mobile phone sensor sampling algorithm considers velocity of human mobility as an important parameter for improving sensing area coverage and reduction of energy consumption. To an extent overlap between sensing area coverage is allowed to overcome, the reduction of sensor data samples caused by spatial regularities of human mobility. The performance is analyzed and evaluated by considering general regular sampling and proposed sampling method for mobile phone sensing activity. The results show that for normal human walking velocity (<;1.5 m/s) proposed mobile phone sensor sampling algorithm performs better in terms of sensing area coverage and reduction of battery energy consumption for mobile phone sensing activity

    Levy walk based multi-hop data forwarding protocol for opportunistic mobile phone sensor networks

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    Unstable link connectivity due to dynamic mobility nature of mobile phone users and error prone wireless link quality increases end-to-end delay for mobile phone based opportunistic network applications. This problem becomes more worse in the presence of large amount of data transmission, like multimedia data. This paper refers to Levy walk based multi-hop data forwarding protocol called Data Transmission Time and Human Walk Velocity (DTT-HWV) for Opportunistic Mobile Phone Sensor Networks (OMPSN). This paper, in particular evaluates the performance of proposed protocol in terms of end-to-end waiting time to receive data, which is an important QoS requirement for data transmission in opportunistic networks. The proposed protocol DTT-HWV reduces end-to-end waiting time to receive data compared to Random Progress (RP) data forwarding method in presence of low battery power and high path loss. Obtained results are helpful in designing and building of large scale data retrieval services for opportunistic networks involving humans in the communication network loop

    Experimental and Numerical Studies on Setback Buildings Considering the SSI Effect under Seismic Response

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    From the previous studies it is observed that due to the effect of the earthquake, several irregular buildings failed vulnerably. Further the effect of sub soil conditions where these buildings have been founded also play an important role on the seismic response of these buildings. In the past, experimental studies on the seismic response of different setback building configurations have not been carried out. Therefore, in the present study the seismic behaviour of setback buildings considering Soil Structure Interaction (SSI) has been evaluated by conducting experimental and numerical investigations. Buildings with various setback configurations were considered and are designed as pile foundation supported structures. The irregularity index of these building configurations have been determined as per the existing codal provisions. These piles supported buildings representing the prototype structure have been scaled down according to geometric, kinematic and dynamic scaling laws. The scaled building models are subjected to vibrations beyond resonant frequencies using shake table facility. A comparison of the results has been made between experimental and numerical investigations. Based on the study it has been observed that storey displacements of building with regular configurations are higher in comparison with the setback buildings. It is also found that asymmetrical and symmetrical setback buildings having different irregularity indices as per IS:1893-2016 indicate nearly the same displacements at resonant frequencies. Doi: 10.28991/cej-2021-03091664 Full Text: PD

    Study of prevalence of thyroid peroxidase antibodies in preterm deliveries and recurrent pregnancy loss

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    Background: Evaluation of thyroid disorder in pregnancy is essential for maternal health, obstetrical outcome and neurodevelopment of the child. Euthyroid pregnant women having positive thyroid peroxidase antibodies have an elevated risk of miscarriage, premature birth, gestational hypertension, and intrauterine fetal demise. Thyroid autoimmunity (TAI) and subclinical hypothyroidism (SCH) have been connected with adverse outcomes in pregnancy and foetus. The present aim of the study was to estimate the prevalence of TPO antibodies in recurrent pregnancy losses, first trimester abortions and preterm deliveries.Methods: This was a hospital-based cross-sectional prevalence study conducted for 18 months. The study consists of 100 women who had preterm deliveries and miscarriages attending to department of obstetrics and gynaecology, Narayana medical college and hospital, Nellore, Andhra Pradesh.Results: In our study out of 100 cases, 11 had high thyroid peroxidase antibody (TPOAb) levels, of which 9 had preterm deliveries and 2 had miscarriages. Out of 100 cases 5 cases had elevated T3 levels, 6 cases had elevated T4 levels and 24 cases had elevated TSH levels.Conclusions: There was a statistically significant association of thyroid peroxidase antibodies (TPOAb) with T3, T4, and, TSH (P<0.05) and it leads to developing hypothyroidism during pregnancy. The presence of TPOAb in pregnant women significantly increases the risk of preterm delivery. The screening of TSH and thyroid peroxidase antibodies is essential during pregnancy to avoid complications. So, screening T3, T4, TSH and thyroid peroxidase antibodies are essential during pregnancy to avoid complications.

    Hardware Trojan Detection and Mitigation in NoC using Key authentication and Obfuscation Techniques

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    Today's Multiprocessor System-on-Chip (MPSoC) contains many cores and integrated circuits. Due to the current requirements of communication, we make use of Network-on-Chip (NoC) to obtain high throughput and low latency. NoC is a communication architecture used in the processor cores to transfer&nbsp; data from source to destination through several nodes. Since NoC deals with on-chip interconnection for data transmission, it will be a good prey for data leakage and other security attacks. One such way of attacking is done by a third-party vendor introducing Hardware Trojans (HTs) into routers of NoC architecture. This can cause packets to traverse in wrong paths, leak/extract information and cause Denial-of-Service (DoS) degrading the system performance. In this paper, a novel HT detection and mitigation approach using obfuscation and key-based authentication technique is proposed. The proposed technique prevents any illegal transitions between routers thereby protecting data from malicious activities, such as packet misrouting and information leakage. The proposed technique is evaluated on a 4x4 NoC architecture under synthetic traffic pattern and benchmarks, the hardware model is synthesized in Cadence Tool with 90nm technology. The introduced Hardware Trojan affects 8% of packets passing through infected router. Experimental results demonstrate that the proposed technique prevents those 10-15% of packets infected from the HT effect. Our proposed work has negligible power and area overhead of 8.6% and&nbsp; 2% respectively

    Selective Sensing Framework for Opportunistic Mobile Phone Sensing Networks

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    The rise of opportunistic mobile phone sensing paradigm is due to ubiquitous mobile phones usage. Optimisation of battery energy consumption and achieving required spatial coverage of sensing area are important issues under opportunistic mobile phone sensing networks. Human mobility enable collection of mobile phones sensor data and sensing area coverage by forming communication network with surrounding neighbors devices (mobile phones). This paper proposes a human mobility based selective sensing framework called as HWSS (Human Walk based Selective Sensing) for sensor data collection in opportunistic mobile phone sensing networks. In proposed HWSS method, mobile phones are selected for sensing task based on users current and predicted future locations and sensing overlap area. The proposed HWSS method is compared with non-selective sensing method (NSS), where all mobile nodes are allowed for sensing during sensor data collection process, in an given application area. The simulation results show that compared to NSS method proposed HWSS method achieves reduction in energy consumption and required spatial coverage

    Energy efficient in-network data processing in sensor networks

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    The Sensor Network consists of densely deployed sensor nodes. Energy optimization is one of the most important aspects of sensor application design. Data acquisition and aggregation techniques for processing data in-network should be energy efficient. Due to the cross-layer design, resource-limited and noisy nature of Wireless Sensor Networks (WSNs), it is challenging to study the performance of these systems in a realistic setting. In this paper, we propose optimizing queries by aggregation of data and data redundancy to reduce energy consumption without requiring all sensed data and directed diffusion communication paradigm to achieve power savings, robust communication and processing data in-network. To estimate the per-node power consumption POWER-Tossim mica2 energy model is used, which provides scalable and accurate results. The performance analysis shows that the proposed methods overcomes the existing methods in the aspects of energy consumption in wireless sensor networks

    Secure data aggregation using clusters in sensor networks: World academy of science

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    Wireless sensor network can be applied to both abom�inable and military environments. A primary goal in the design of wireless sensor networks is lifetime maximization, constrained by the energy capacity of batteries. One well-known method to reduce energy consumption in such networks is data aggregation. Providing efcient data aggregation while preserving data privacy is a chal�lenging problem in wireless sensor networks research. In this paper, we present privacy-preserving data aggregation scheme for additive aggregation functions. The Cluster-based Private Data Aggregation (CPDA)leverages clustering protocol and algebraic properties of polynomials. It has the advantage of incurring less communication overhead. The goal of our work is to bridge the gap between collaborative data collection by wireless sensor networks and data privacy. We present simulation results of our schemes and compare their performance to a typical data aggregation scheme TAG, where no data privacy protection is provided. Results show the efficacy and efficiency of our schemes

    Ten years survival results of randomized study comparing weekly vs. triweekly cisplatin with concurrent radiation in locally advanced carcinoma cervix

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    Background: The current standard of treatment for locally advanced cervical cancer is concurrent chemo-radiation with improved overall survival (OS) by 6% with manageable toxicities. The cisplatin 40 mg/m2 given weekly is the widely practiced regimen for 4–6 cycles concurrently with irradiation. Materials and methods: Two hundred and twelve patients with histologically proven squamous cell carcinoma of cervix with stages IIB to IIIB were enrolled between 2007–2011. External beam radiation dose of 45 Gy in 25 fractions was delivered over 5 weeks. Brachytherapy was delivered by manual afterloading cesium-137 (Cs137) low dose brachytherapy (LDR) using modified Fletcher suit intracavitary applicators to a total dose of 30 Gy to Point A or interstitial template to dose of 21 Gy/3 fractions with remote afterloading iridium-192 (Ir192) high dose brachytherapy (HDR). Patients were randomized to arm A receiving 40 mg/m2 of concurrent cisplatin weekly and arm B receiving 100 mg/m2 of concurrent cisplatin triweekly. Results: One hundred and nine patients were randomized to weekly cisplatin and one hundred and three patients to triweekly cisplatin at the end of recruitment. At ten years, the OS was higher in the weekly arm (79.8%) compared to triweekly arm (70.9%). Disease free survival (DFS) was almost equal (76.1% and 73.8%) in the weekly and three-weekly arms. There is definite significance in overall DFS with patients receiving the cumulative cisplatin doses of more than 250 mg (p = 0.028). The patients with more than 45 years of age had better overall survival (OS) (79%) with statistical significance 31 (p = 0.020). Conclusion: Both cisplatin based triweekly and weekly concurrent chemotherapy are equally effective in terms of OS and DFS
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