595 research outputs found

    On a whale shark at landed Pamban

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    A male whale shark Rhincodon typus Smith measuring a total length of 9.2 m was landed at Pamban on 17-4-'9

    Throughput Optimization in High Speed Downlink Packet Access (HSDPA)

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    In this paper, we investigate throughput optimization in High Speed Downlink Packet Access (HSDPA). Specifically, we propose offline and online algorithms for adjusting the Channel Quality Indicator (CQI) used by the network to schedule data transmission. In the offline algorithm, a given target BLER is achieved by adjusting CQI based on ACK/NAK history. By sweeping through different target BLERs, we can find the throughput optimal BLER offline. This algorithm could be used not only to optimize throughput but also to enable fair resource allocation among mobile users in HSDPA. In the online algorithm, the CQI offset is adapted using an estimated short term throughput gradient without specifying a target BLER. An adaptive stepsize mechanism is proposed to track temporal variation of the environment. We investigate convergence behavior of both algorithms. Simulation results show that the proposed offline algorithm can achieve the given target BLER with good accuracy. Both algorithms yield up to 30% HSDPA throughput improvement over that with 10% target BLER

    Real-time Measurement of Stress and Damage Evolution During Initial Lithiation of Crystalline Silicon

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    Crystalline to amorphous phase transformation during initial lithiation in (100) silicon-wafers is studied in an electrochemical cell with lithium metal as the counter and reference electrode. It is demonstrated that severe stress jumps across the phase boundary lead to fracture and damage, which is an essential consideration in designing silicon based anodes for lithium ion batteries. During initial lithiation, a moving phase boundary advances into the wafer starting from the surface facing the lithium electrode, transforming crystalline silicon into amorphous LixSi. The resulting biaxial compressive stress in the amorphous layer is measured in situ and it was observed to be ca. 0.5 GPa. HRTEM images reveal that the crystalline-amorphous phase boundary is very sharp, with a thickness of ~ 1 nm. Upon delithiation, the stress rapidly reverses, becomes tensile and the amorphous layer begins to deform plastically at around 0.5 GPa. With continued delithiation, the yield stress increases in magnitude, culminating in sudden fracture of the amorphous layer into micro-fragments and the cracks extend into the underlying crystalline silicon.Comment: 12 pages, 5 figure

    Major and minor fisheries harbours of India. 4. Jetty for fishing boats at Mandapam along Gulf of Mannar coast

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    The Mandapam fish landing centre on the Gulf of Mannar side is a medium one. The jetty was constructed by the erstwhile Indo-Norwegean Project for the berthing of its boats. Only departmental boats are berthed at present at the Jetty

    Effect of Diphenyl Siloxane on the Catalytic Activity of Pt on Carbon

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    The effect of silicone on the catalytic activity of Pt for oxygen reduction and hydrogen adsorption was studied using diphenyl siloxane as a source compound at a rotating disk electrode (RDE). Diphenyl siloxane did not affect the catalytic activity of Pt when it was injected into the electrolyte. However, it blocked the oxygen reduction reaction when it was premixed with the catalyst. Proton transport was not blocked in either case. We postulate that diphenyl siloxane induces hydrophobicity and causes local water starvation, thereby blocking oxygen transport. Hence, the slow leaching of silicone seals in a fuel cell could cause silicon accumulation in the electrode, which irreversibly degrades fuel cell performance by blocking oxygen transport to the catalyst sites

    Water Sustainability: Current and Future Challenges at SRM Institute of Science and Technology, Chennai, India

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    SRMIST has healthy approach to sustainability, incorporating social economic and environmental principles that have been in place for nearly a decade implementing short and long-term sustainable objectives. SRMIST developed, maintained the estate, and the surrounding landscape, with due environmental impact and social values and implemented effective, efficient utility management measures, policies and procedures. The 2018/2019 UI Green Metric ranked SRMIST as 9 th in India and 392nd in Global Ranking overall and 264th rank globally and 9th rank in India for water parameter and 3rd in the Nation and 243rd globally and 2nd rank nationally and 42nd rank globally for water. SRM IST improved implementation of the water conservation and recycling program from 75% in 2018 to 95 % in 2019. Water efficient appliances increased > 70% and has a long-term commitment for conservation of water by regularly monitoring the use of water with regular meters. SRMIST has 20 RO plants running 24x7 collecting 31,000L per day for all and installing Ultra Filtration unit. SRMIST’s goal is to reduce per capita water consumption varies from 3.7m3 to 3.3m. Among the 4600 M3 waste water generated an average 4140 M3 wastewater is treated and recycled. Rainwater harvesting pits have been constructed in 65% college buildings and hostels is used for the water recharge in the campus and the rainwater stored in the roof tanks are used for toilet flushing

    WebWISE: Web Interface Control and Sequential Exploration with Large Language Models

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    The paper investigates using a Large Language Model (LLM) to automatically perform web software tasks using click, scroll, and text input operations. Previous approaches, such as reinforcement learning (RL) or imitation learning, are inefficient to train and task-specific. Our method uses filtered Document Object Model (DOM) elements as observations and performs tasks step-by-step, sequentially generating small programs based on the current observations. We use in-context learning, either benefiting from a single manually provided example, or an automatically generated example based on a successful zero-shot trial. We evaluate the proposed method on the MiniWob++ benchmark. With only one in-context example, our WebWISE method achieves similar or better performance than other methods that require many demonstrations or trials

    Lift-and-Round to Improve Weighted Completion Time on Unrelated Machines

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    We consider the problem of scheduling jobs on unrelated machines so as to minimize the sum of weighted completion times. Our main result is a (3/2c)(3/2-c)-approximation algorithm for some fixed c>0c>0, improving upon the long-standing bound of 3/2 (independently due to Skutella, Journal of the ACM, 2001, and Sethuraman & Squillante, SODA, 1999). To do this, we first introduce a new lift-and-project based SDP relaxation for the problem. This is necessary as the previous convex programming relaxations have an integrality gap of 3/23/2. Second, we give a new general bipartite-rounding procedure that produces an assignment with certain strong negative correlation properties.Comment: 21 pages, 4 figure
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