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Yayın Cost-effective fault diagnosis of a multi-component dynamic system under corrective maintenance(Elsevier Ltd, 2021-04) Özgür Ünlüakın, Demet; Türkali, Busenur; Aksezer, Sezgin ÇağlarMaintenance planning and execution are challenging tasks for every system with complex structure. Interdependent nature of the components that builds up the system may have significant effect on system integrity. While preventive maintenance actions can be carried out in a more planned fashion, corrective actions are more time sensitive as they directly affect the availability of the system. This study proposes a cost-effective dynamic Bayesian network modeling scheme to be used in the planning of corrective maintenance actions on systems having hidden components which have stochastic and structural dependencies. In such context, the regenerative air heater system which is a key element of a power plant is taken into consideration. The proposed maintenance framework offers several methods, each aiming to balance the cost with the probability effect using a normalization procedure. The methodologies are extensively simulated for sensitivity analysis under various downtime cost values. Fault effect methods with worst state probability efficiency measures give the least total cost for all downtime cost values and their distinction becomes significant as this value increases. Further statistical analysis concludes that considerable gains on maintenance costs can be achieved by the proposed approach.Yayın Optimization of wastewater treatment systems for growing industrial parks(Elsevier B.V., 2023-12-20) Savun Hekimoğlu, Başak; İşler, Zülal; Hekimoğlu, Mustafa; Burak, Selmin; Karlı, Deniz; Yücekaya, Ahmet; Akpınar, Ersin; Ediger, Volkan Ş.Wastewater treatment is one of the crucial functions of industrial parks as wastewater from industrial facilities usually contains toxic compounds that can cause damage to the environment. To control their environmental loads, industrial parks make investment decisions for wastewater treatment plants. For this, they need to consider technical and economic factors as well as future growth projections as substantial construction and operational costs of wastewater treatment plants have to be shared by all companies in an industrial park. In this paper, we consider the long-term capacity planning problem for wastewater treatment facilities of a stochastically growing industrial park. By explicitly modeling randomness in the arrival of new tenants and their random wastewater discharges, our model calculates the future mean and variance of wastewater flow in the industrial park. Mean and variance are used in a Mixed Integer Programming Model to optimize wastewater treatment plant selection over a long planning horizon (30 years). By fitting our first model to empirical data from an industrial park in Turkey, we find that considering the variance of wastewater load is critical for long-term planning. Also, we quantify the economic significance of lowering wastewater discharges which can be achieved by water recycling or interplant water exchange.Yayın Analysis and design of low-cost bit-serial architectures for motion estimation in H.264/AVC(Springer, 2013-05) Fatemi, Mohammad Reza Hosseiny; Ateş, Hasan Fehmi; Salleh, Rosli BinVariable block-size motion estimation (VBSME) process occupies a major part of computation of an H.264 encoder, which is usually accelerated by bit-parallel hardware architectures with large I/O bit width to meet real-time constrains. However, such kind of architectures increase the area overhead and pin count, and therefore will not be suitable for area-constrained electronic consumer designs such as small portable multimedia devices. This paper addresses this problem by proposing two area efficient least significant bit (LSB) bit-serial architectures with small pin numbers. Both designs take advantage of data reusing technique in different ways for sum of absolute differences (SAD) computation and reading reference pixels, leading to a considerable reduction of memory bandwidth. The first architecture propagates the partial SAD and sum results and broadcasts the reference pixel rows whereas the second design reuse the SAD of small blocks and has a reconfigurable reference buffer leading to a better memory bandwidth when using hardware parallelism. The proposed designs benefit from several optimization techniques including an efficient serial absolute difference architecture, word length reduction by parallelism, bit truncation, mode filtering, and macroblock (MB) level subsampling, which significantly enhance their performances in terms of silicon area, throughput, latency, and power consumption. The first and second designs can support full search VBSME of 720 x 480 video with 30 frames per second (fps), two reference frames, and [-16, 15] search range at a clock frequency of 414 MHz with 29.28 k and 31.5 k gates, respectively.
