On Packet Scheduling with Adversarial Jamming and Speedup

In Packet Scheduling with Adversarial Jamming packets of arbitrary sizes arrive over time to be transmitted over a channel in which instantaneous jamming errors occur at times chosen by the adversary and not known to the algorithm. The transmission taking place at the time of jamming is corrupt, and the algorithm learns this fact immediately. An online algorithm maximizes the total size of packets it successfully transmits and the goal is to develop an algorithm with the lowest possible asymptotic competitive ratio, where the additive constant may depend on packet sizes. Our main contribution is a universal algorithm that works for any speedup and packet sizes and, unlike previous algorithms for the problem, it does not need to know these properties in advance. We show that this algorithm guarantees 1-competitiveness with speedup 4, making it the first known algorithm to maintain 1-competitiveness with a moderate speedup in the general setting of arbitrary packet sizes. We also prove a lower bound of $\phi+1\approx 2.618$ on the speedup of any 1-competitive deterministic algorithm, showing that our algorithm is close to the optimum. Additionally, we formulate a general framework for analyzing our algorithm locally and use it to show upper bounds on its competitive ratio for speedups in $[1,4)$ and for several special cases, recovering some previously known results, each of which had a dedicated proof. In particular, our algorithm is 3-competitive without speedup, matching both the (worst-case) performance of the algorithm by Jurdzinski et al. and the lower bound by Anta et al.Comment: Appeared in Proc. of the 15th Workshop on Approximation and Online Algorithms (WAOA 2017

Studi Tentang Perilaku Kesehatan Pengguna Sumur Gali di Desa Luhu Kecamatan Telaga Kabupaten Gorontalo Tahun 2012

Perilaku mempunyai peranan besar dalam meningkatkan derajat kesehatan masyarakat antara lain dalam penyediaan air bersih. Sarana air bersih yang paling masyarakat antara lain dalam penyediaan air bersih. Sarana air bersih yang paling banyak digunakan oleh masyarakat Indonesia khususnya daerah pedesaan adalah banyak digunakan oleh masyarakat Indonesia khususnya daerah pedesaan adalah sarana sumur gali. Sekitar 45% masyarakat di Indonesia menggunakan sumur sebagai sarana sumur gali. Sekitar 45% masyarakat di Indonesia menggunakan sumur sebagai sarana air bersih, dan diperkirakan sekitar 75% menggunakan jenis sumur gali. sarana air bersih, dan diperkirakan sekitar 75% menggunakan jenis sumur gali. Tujuan dalam penelitian ini yakni untuk mengetahui gambaran perilaku Tujuan dalam penelitian ini yakni untuk mengetahui gambaran perilaku pengguna sumur gali di Desa Luhu Kecamatan Telaga Kabupaten Gorontalo. Jenis pengguna sumur gali di Desa Luhu Kecamatan Telaga Kabupaten Gorontalo. Jenis penelitian ini adalah deskriptif dengan rancangan survei. Teknik pengambilan sampel penelitian ini adalah deskriptif dengan rancangan survei. Teknik pengambilan sampel yang digunakan yakni purposive sampling. Jumlah populasi sebanyak 432 responden yang digunakan yakni purposive sampling. Jumlah populasi sebanyak 432 responden dengan jumlah sampel sebanyak 208 responden dan dianalisis secara deskriptif. dengan jumlah sampel sebanyak 208 responden dan dianalisis secara deskriptif. Hasil penelitian menunjukkan bahwa 63% masyarakat yang ada di Desa Hasil penelitian menunjukkan bahwa 63% masyarakat yang ada di Desa Luhu memiliki pengetahuan yang cukup dan 37% lainnya memiliki pengetahuan Luhu memiliki pengetahuan yang cukup dan 37% lainnya memiliki pengetahuan yang baik, yang diperoleh dari pengetahuan mengenai kualitas air dan sumur gali yang baik, yang diperoleh dari pengetahuan mengenai kualitas air dan sumur gali layak yang baik sedangkan perlakuan air pada sumur gali kurang baik. berdasarkan layak yang baik sedangkan perlakuan air pada sumur gali kurang baik. berdasarkan sikap, diperoleh 100% masyarakat memiliki sikap yang baik tentang penggunaan sikap, diperoleh 100% masyarakat memiliki sikap yang baik tentang penggunaan sumur gali khususnya dalam penggunaan air sumur gali dan sumber pencemar sumur sumur gali khususnya dalam penggunaan air sumur gali dan sumber pencemar sumur gali. dalam hal tindakan diperoleh sebanyak 66,3% masyarakat memiliki tindakan gali. dalam hal tindakan diperoleh sebanyak 66,3% masyarakat memiliki tindakan yang baik dan 33,7% memiliki tindakan yang cukup, yang diketahui dari tindakan yang baik dan 33,7% memiliki tindakan yang cukup, yang diketahui dari tindakan pengguna sumur gali dan yang dilakukan jika air sumur gali tidak layak yang rata-rata pengguna sumur gali dan yang dilakukan jika air sumur gali tidak layak yang rata-rata memiliki tindakan baik. memiliki tindakan baik. Berdasarkan hasil penelitian dapat disimpulkan bahwa pengetahuan Berdasarkan hasil penelitian dapat disimpulkan bahwa pengetahuan responden pada kategori cukup, sikap pada kategori baik dan tindakan pada kategori responden pada kategori cukup, sikap pada kategori baik dan tindakan pada kategori baik. Disarankan agar ada pemberian informasi dari instansi terkait dalam hal baik. Disarankan agar ada pemberian informasi dari instansi terkait dalam hal peningkatan perilaku masyarakat mengenai penggunaan sumur gali dan dampak yang peningkatan perilaku masyarakat mengenai penggunaan sumur gali dan dampak yang ditimbulkan. ditimbulkan. Kata Kunci : Perilaku Kesehatan, Pengguna, Sumur Gali. Kata Kunci : Perilaku Kesehatan, Pengguna, Sumur Gali

Multi-round Master-Worker Computing: a Repeated Game Approach

We consider a computing system where a master processor assigns tasks for execution to worker processors through the Internet. We model the workers decision of whether to comply (compute the task) or not (return a bogus result to save the computation cost) as a mixed extension of a strategic game among workers. That is, we assume that workers are rational in a game-theoretic sense, and that they randomize their strategic choice. Workers are assigned multiple tasks in subsequent rounds. We model the system as an infinitely repeated game of the mixed extension of the strategic game. In each round, the master decides stochastically whether to accept the answer of the majority or verify the answers received, at some cost. Incentives and/or penalties are applied to workers accordingly. Under the above framework, we study the conditions in which the master can reliably obtain tasks results, exploiting that the repeated games model captures the effect of long-term interaction. That is, workers take into account that their behavior in one computation will have an effect on the behavior of other workers in the future. Indeed, should a worker be found to deviate from some agreed strategic choice, the remaining workers would change their own strategy to penalize the deviator. Hence, being rational, workers do not deviate. We identify analytically the parameter conditions to induce a desired worker behavior, and we evaluate experi- mentally the mechanisms derived from such conditions. We also compare the performance of our mechanisms with a previously known multi-round mechanism based on reinforcement learning.Comment: 21 pages, 3 figure

Set-Based Concurrent Engineering Model for Automotive Electronic/Software Systems Development

Organised by: Cranfield UniversityThis paper is presenting a proposal of a novel approach to automotive electronic/software systems development. It is based on the combination of Set-Based Concurrent Engineering, a Toyota approach to product development, with the standard V-Model of software development. Automotive industry currently faces the problem of growing complexity of electronic/software systems. This issue is especially visible at the level of integration of these systems which is difficult and error-prone. The presented conceptual proposal is to establish better processes that could handle the electronic/software systems design and development in a more integrated and consistent manner.Mori Seiki – The Machine Tool Compan

Probabilistic Bounds on the Length of a Longest Edge in Delaunay Graphs of Random Points in d-Dimensions

Motivated by low energy consumption in geographic routing in wireless networks, there has been recent interest in determining bounds on the length of edges in the Delaunay graph of randomly distributed points. Asymptotic results are known for random networks in planar domains. In this paper, we obtain upper and lower bounds that hold with parametric probability in any dimension, for points distributed uniformly at random in domains with and without boundary. The results obtained are asymptotically tight for all relevant values of such probability and constant number of dimensions, and show that the overhead produced by boundary nodes in the plane holds also for higher dimensions. To our knowledge, this is the first comprehensive study on the lengths of long edges in Delaunay graphsComment: 10 pages. 2 figures. In Proceedings of the 23rd Canadian Conference on Computational Geometry (CCCG 2011). Replacement of version 1106.4927, reference [5] adde

An experimental characterization of workers'' behavior and accuracy in crowdsourced tasks

Crowdsourcing systems are evolving into a powerful tool of choice to deal with repetitive or lengthy human-based tasks. Prominent among those is Amazon Mechanical Turk, in which Human Intelligence Tasks, are posted by requesters, and afterwards selected and executed by subscribed (human) workers in the platform. Many times these HITs serve for research purposes. In this context, a very important question is how reliable the results obtained through these platforms are, in view of the limited control a requester has on the workers'' actions. Various control techniques are currently proposed but they are not free from shortcomings, and their use must be accompanied by a deeper understanding of the workers'' behavior. In this work, we attempt to interpret the workers'' behavior and reliability level in the absence of control techniques. To do so, we perform a series of experiments with 600 distinct MTurk workers, specifically designed to elicit the worker''s level of dedication to a task, according to the task''s nature and difficulty. We show that the time required by a worker to carry out a task correlates with its difficulty, and also with the quality of the outcome. We find that there are different types of workers. While some of them are willing to invest a significant amount of time to arrive at the correct answer, at the same time we observe a significant fraction of workers that reply with a wrong answer. For the latter, the difficulty of the task and the very short time they took to reply suggest that they, intentionally, did not even attempt to solve the task. © 2021 Christoforou et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited