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151.
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The paper presents a new method introducing an anchored discrete convolution for calculating the length of a digital curve. The method is based on discrete convolution by using convolution masks and point anchoring in the pixel. The use of ordinary convolution distorts the curve shape and gives large errors in length calculation. The advantage of anchoring is that it limits the point shifting into the pixel during the calculation of the curve length. The method is applied to an analytical arc and various calculations are performed. In addition different methods from the literature were compared and a real sample was tested. 相似文献
153.
Aye Akbalk Sekoun Kebe Bernard Penz Najiba Sbihi 《International Transactions in Operational Research》2008,15(2):195-214
In this paper we study the coordination of different activities in a supply chain issued from a real case. Multiple suppliers send raw materials (RMs) to a distribution center (DC) that delivers them to a unique plant where the storage of the RMs and the finished goods is not possible. Then, the finished goods are directly shipped to multiple customers having just‐in‐time (JIT) demands. Under these hypotheses, we show that the problem can be reduced to multiple suppliers and one DC. Afterwards, we analyze two cases; in the first, we consider an uncapacitated storage at DC, and in the second, we analyze the capacitated storage case. For the first case, we show that the problem is NP‐hard in the ordinary sense using the Knapsack decision problem. We then propose two exact methods: a mixed integer linear program (MILP) and a pseudopolynomial dynamic program. A classical dynamic program and an improved one using the idea of Shaw and Wagelmans are given. With numerical tests we show that the dynamic program gives the optimal solution in reasonable time for quite large instances compared with the MILP. For the second case, the capacity limitation in DC is assumed, which makes the problem solving more challenging. We propose an MILP and a dynamic programming‐based heuristic that provides solutions close to the optimal solution in very short times. 相似文献
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由于CCD(Charge Coupled Devices)芯片价格昂贵而且极易损坏,本文提出了一种利用CPLD和D/A转换器构成的信号发生器的原理方案和实现方法.通过对CPLD器件isp1032e和D/A转换器件DAC2900的配置,频率为11MHz的模拟CCD信号,同时通过改进PCB设计和滤波电路,提高了输出信号的精度,降低了噪声.本设计具有可编程、宽频、高精度和低硬件复杂度等特点. 相似文献
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针对传统机械式抄表计费系统的缺陷,本文介绍一种基于实时操作系统μC/OS-II新一代抄表计费系统.通过把实时操作系统μC/OS-II移植到AT89C52单片机来实现多任务实时抄表计费.两者结合,既能充分发挥实时操作系统μC/OS-II的高实时性以及多任务调度的特点,又可以体现单片机的经济实惠的优势,具有实际市场推广意义. 相似文献
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A new image segmentation system is presented to automatically segment and label brain magnetic resonance (MR) images to show normal and abnormal brain tissues using self-organizing maps (SOM) and knowledge-based expert systems. Elements of a feature vector are formed by image intensities, first-order features, texture features extracted from gray-level co-occurrence matrix and multiscale features. This feature vector is used as an input to the SOM. SOM is used to over segment images and a knowledge-based expert system is used to join and label the segments. Spatial distributions of segments extracted from the SOM are also considered as well as gray level properties. Segments are labeled as background, skull, white matter, gray matter, cerebrospinal fluid (CSF) and suspicious regions. 相似文献