1,642 research outputs found

    J Regularization Improves Imbalanced Multiclass Segmentation

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    We propose a new loss formulation to further advance the multiclass segmentation of cluttered cells under weakly supervised conditions. When adding a Youden's J statistic regularization term to the cross entropy loss we improve the separation of touching and immediate cells, obtaining sharp segmentation boundaries with high adequacy. This regularization intrinsically supports class imbalance thus eliminating the necessity of explicitly using weights to balance training. Simulations demonstrate this capability and show how the regularization leads to correct results by helping advancing the optimization when cross entropy stagnates. We build upon our previous work on multiclass segmentation by adding yet another training class representing gaps between adjacent cells. This addition helps the classifier identify narrow gaps as background and no longer as touching regions. We present results of our methods for 2D and 3D images, from bright field images to confocal stacks containing different types of cells, and we show that they accurately segment individual cells after training with a limited number of images, some of which are poorly annotated

    Delivering Live Multimedia Streams to Mobile Hosts in a Wireless Internet with Multiple Content Aggregators

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    We consider the distribution of channels of live multimedia content (e.g., radio or TV broadcasts) via multiple content aggregators. In our work, an aggregator receives channels from content sources and redistributes them to a potentially large number of mobile hosts. Each aggregator can offer a channel in various configurations to cater for different wireless links, mobile hosts, and user preferences. As a result, a mobile host can generally choose from different configurations of the same channel offered by multiple alternative aggregators, which may be available through different interfaces (e.g., in a hotspot). A mobile host may need to handoff to another aggregator once it receives a channel. To prevent service disruption, a mobile host may for instance need to handoff to another aggregator when it leaves the subnets that make up its current aggregator�s service area (e.g., a hotspot or a cellular network).\ud In this paper, we present the design of a system that enables (multi-homed) mobile hosts to seamlessly handoff from one aggregator to another so that they can continue to receive a channel wherever they go. We concentrate on handoffs between aggregators as a result of a mobile host crossing a subnet boundary. As part of the system, we discuss a lightweight application-level protocol that enables mobile hosts to select the aggregator that provides the �best� configuration of a channel. The protocol comes into play when a mobile host begins to receive a channel and when it crosses a subnet boundary while receiving the channel. We show how our protocol can be implemented using the standard IETF session control and description protocols SIP and SDP. The implementation combines SIP and SDP�s offer-answer model in a novel way

    Karakteristik Pembakaran CH4 Dengan Penambahan Co2 Pada Model Helle- Shaw Cell Pada Penyalaan Bawah

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    Along with the development of industrial technologies is rapidly increasing the demand for renewable energy sources becomes a very important consideration. One of the alternative energy is now being developed is the energy derived from organic materials, this is because the organic compounds are classified as renewable energy. One energy technology in accordance with the requirements of the biogas technology. If biogas is purified or cleaned of impurities in this case CO2 is good, he would have the same characteristics as natural gas. How big is the influence of CO2 on heating value (heat) in the combustion process it is necessary to an investigation. one by looking at the characteristics of combustion, both the pattern and pace of rambatnya. Combustor used in this study is a model of Helle-shaw cell measuring 50 x 20 x 1 cm. Variation of the mixture used is the ratio 7,5:1 to 10: 1 with the addition of 10% 20%, 30% CO2. Performed on the ignition of ignition. Observation of the shape and rate of flame propagation is done using a high speed camera. The results showed that the ratio of 7,5:1 to 10: 1 blue color of the flame and the flame propagation speed greater penembahan but with 10% CO2 20%, 30% color changing flame reddish yellow which indicates incomplete combustion occurs, and the smaller the rate of flame propagation. This is influenced by the presence of buoyancy forces generated by the combustion
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