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Srijuntongsiri G.,Sirindhorn International Institute of Technology | Vavasis S.A.,University of Waterloo
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2010

In [1], Srijuntongsiri and Vavasis propose the Kantorovich-Test Subdivision algorithm, or KTS, which is an algorithm for finding all zeros of a polynomial system in a bounded region of the plane. This algorithm can be used to find the intersections between a line and a surface. The main features of KTS are that it can operate on polynomials represented in any basis that satisfies certain conditions and that its efficiency has an upper bound that depends only on the conditioning of the problem and the choice of the basis representing the polynomial system. This article explores in detail the dependence of the efficiency of the KTS algorithm on the choice of basis. Three bases are considered: the power, the Bernstein, and the Chebyshev bases. These three bases satisfy the basis properties required by KTS. Theoretically, Chebyshev case has the smallest upper bound on its running time. The computational results, however, do not show that Chebyshev case performs better than the other two. © 2010 Springer-Verlag Berlin Heidelberg. Source

Kerdsri J.,Defense Technology Institute | Wipusitwarkun K.,Sirindhorn International Institute of Technology
International Conference on Advanced Communication Technology, ICACT | Year: 2012

Networking Technology, undoubtedly, plays a vital role in modern warfare especially in Network Centric Operations (NCOs) and Global Information Grid (GIG) concept. However, the current popular network infrastructure, mainly TCP/IP architecture, is in fact unsuitable with advanced military communication especially in tactical operation networks. The key characteristics of military communications are classified as delay/disruption/disconnection tolerant networks (DTNs) which are long and variable delays, high error rates and greatly heterogeneous. As a result a call for new type of network architecture emerges to support such peculiar characteristics of military communication network. This paper reviews the current approaches in network technology of military communication and proposes the conceptual design of Virtualization Network (VN) for military communication to address the limitation of current network infrastructure. The implementation of Military Network Virtualization Environment (MVNE) introduces the crucial two new key features of military tactical network: information classification and movable nodes. These features along with essential research challenges must be analyzed to realize a viable virtualization network for military communications. © 2012 GIRI. Source

Ekkachai K.,Sirindhorn International Institute of Technology | Tungpimolrut K.,National Electronics and Computer Technology Center | Nilkhamhang I.,Sirindhorn International Institute of Technology
Smart Materials and Structures | Year: 2013

An inverse controller is proposed for a magnetorheological (MR) damper that consists of a hysteresis model and a voltage controller. The force characteristics of the MR damper caused by excitation signals are represented by a feedforward neural network (FNN) with an elementary hysteresis model (EHM). The voltage controller is constructed using another FNN to calculate a suitable input signal that will allow the MR damper to produce the desired damping force. The performance of the proposed EHM-based FNN controller is experimentally compared to existing control methodologies, such as clipped-optimal control, signum function control, conventional FNN, and recurrent neural network with displacement or velocity inputs. The results show that the proposed controller, which does not require force feedback to implement, provides excellent accuracy, fast response time, and lower energy consumption. © 2013 IOP Publishing Ltd. Source

Siriruang C.,Institute of Chemical Technology | Toochinda P.,Institute of Chemical Technology | Julnipitawong P.,Sirindhorn International Institute of Technology | Tangtermsirikul S.,Sirindhorn International Institute of Technology
Journal of Environmental Management | Year: 2016

The utilization of fly ash as a solid sorbent material for CO2 capture via surface adsorption and carbonation reaction was evaluated as an economically feasible CO2 reduction technique. The results show that fly ash from a coal fired power plant can capture CO2 up to 304.7 μmol/g fly ash, consisting of 2.9 and 301.8 μmol/g fly ash via adsorption and carbonation, respectively. The CO2 adsorption conditions (temperature, pressure, and moisture) can affect CO2 capture performance of fly ash. The carbonation of CO2 with free CaO in fly ashes was evaluated and the results indicated that the reaction consumed most of free CaO in fly ash. The fly ashes after CO2 capture were further used for application as a mineral admixture for concrete. Properties such as water requirement, compressive strength, autoclave expansion, and carbonation depth of mortar and paste specimens using fly ash before and after CO2 capture were tested and compared with material standards. The results show that the expansion of mortar specimens using fly ash after CO2 capture was greatly reduced due to the reduction of free CaO content in the fly ash compared to the expansion of specimens using fresh fly ash. There were no significant differences in the water requirement and compressive strength of specimens using fly ash, before and after CO2 capture process. The results from this study can lead to an alternative CO2 capture technique with doubtless utilization of fly ash after CO2 capture as a mineral admixture for concrete. © 2016 Elsevier Ltd. Source

Kerdsri J.,Sirindhorn International Institute of Technology | Wipusitwarakun K.,Sirindhorn International Institute of Technology
International Journal of Distributed Sensor Networks | Year: 2015

An opportunistic network is a network where the nodes need to communicate with each other even if existing routes between them may not permanently exist due to the nodes' random movement. Most routing algorithms employ a paradigm by which a node can keep the receiving messages, carrying the messages with them when moving and then forwarding the messages to the opportunistic meeting nodes when possible. This routing model works well in the networks with high-to-moderate node density in which the opportunity that the moving nodes can meet with each other is rather high. On the other hand, the delivery ratio becomes remarkably low in the sparse network environment especially when there is a strict constraint on message delivery deadline. In this paper, we introduce the novel concept of rendezvous place where the passing nodes can announce, deposit, or pick up their own messages without having to meet the other nodes carrying the desired message. The rendezvous place can be detected automatically and its area's shape is dynamically changed according to the interaction among nodes. The results from extensive simulations show that our routing algorithm can achieve higher delivery ratio and utilize lower energy consumption than traditional opportunistic routing algorithms especially in sparse network environment. © 2015 Jiradett Kerdsri and Komwut Wipusitwarakun. Source

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