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.
Kaewmanee K.,Sirindhorn International Institute of Technology |
Krammart P.,Rajamangala University of Technology at Thanyaburi |
Sumranwanich T.,Burapha University |
Choktaweekarn P.,Sirindhorn International Institute of Technology |
Tangtermsirikul S.,Sirindhorn International Institute of Technology
Construction and Building Materials | Year: 2013
This research aims to clarify the limitation of free lime content in fly ash according to EN-450. The form and existence of free lime in fly ash by SEM, EDX, and free lime content by a titration method, were observed. Some basic properties of fly ashes with various free lime contents and durability properties of mortar incorporating the fly ashes were also preliminary studied. It was found that free lime particles were mostly distributed outside the fly ash particles and that a minor amount of free lime was encapsulated inside the fly ash particles in the fly ash formation process, meaning that the originally high free lime and added free lime similarly affects properties of fly ash mixtures. A free lime addition method was selected by adding free lime to the originally collected fly ash in order to vary free lime content of the fly ash. The studied basic properties consisted of normal consistency, autoclave expansion, initial and final setting time, water requirement, and compressive strength. In terms of durability, alkali-aggregate reaction, carbonation, shrinkage, and chloride and sulfate resistances, were investigated. Test results revealed that physical properties such as normal consistency and water requirement were unaffected by free lime, and that a free lime content up to 4.51% had only slight chemical effects on fly ash-cement mixtures, i.e., faster setting, higher compressive strength, especially at early age, and higher autoclave expansion. However, the values of autoclave expansion were still within the standard limit. Regarding durability, mixtures with the high free lime fly ash led to higher expansion due to alkali-aggregate reaction. The expansion was smaller than that of a cement-only mixture. Carbonation depth, shrinkage, and chloride and sulfate resistances were only slightly affected by the added free lime. © 2012 Elsevier Ltd. All rights reserved.
Pawgasame W.,Defence Technology Institute |
Wipusitwarakun K.,Sirindhorn International Institute of Technology
ACM International Conference Proceeding Series | Year: 2016
A belt region can be used to describe a border area, which has the characteristic as a long strip area. Intruders may want to trespass this region without authorization. To prevent this illegal border crossing, a mobile sensor network can be deployed in the region. Mobile sensors can move throughout a region looking for an intruder, while the number of mobile sensor nodes can be kept at the minimum. However, there are some design factors that impact the intruder detection probability of a mobile sensor network. These factors are environment model, intruder arrivals, intruder mobility, sensing capability of a sensor node, and sensor selection mechanism. By understanding the impacts of these factors to the intruder detection probability, a mobile sensor network can be designed for better performance. This paper presents a decent method to derive the intruder detection probability and analyzes the effects of the design factors to the intruder detection probability. The result will guide the way to design a mobile sensor network in a belt region with improved intruder detection probability. © 2016 ACM.
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.
Hussain Q.,Sirindhorn International Institute of Technology |
Rattanapitikon W.,Sirindhorn International Institute of Technology |
Pimanmas A.,Sirindhorn International Institute of Technology
Polymer Composites | Year: 2015
Many experimental and theoretical investigations have been carried out to study the compressive strength of concrete confined externally with unidirectional fiber-reinforced polymer (FRP) composites. These unidirectional FRP(s) include carbon, glass, aramid, polyethylene terephthalate, and polyethylene naphthalates. In this article, the performance of randomly distributed sprayed fiber-reinforced polymer (SFRP) composites on the enhancement of strength and deformability of concrete column through external confinement is investigated. The salient features of SFRP are quick and easy application as well as the uniform tensile properties in all directions. In the present study, 24 small concrete specimens were loaded to failure under the uniaxial compression loading. The study parameters covered SFRP thickness, fiber length, and column sectional shape (circular and square). Test results showed that the external confinement by SFRP is significantly effective to increase the strength and deformability of confined concrete. Based on the experimental results, the performance of existing strength models developed for the unidirectional FRP is assessed to examine its applicability to the SFRP confinement. It is found that none of the existing models is capable of accurately predicting the strength of concrete confined with SFRP. Finally, new strength models based on a linear relationship between confined concrete compressive strength and lateral confining pressure are proposed to predict the compressive strength of circular and square sections. The strengths predicted by the proposed models are found to have a good agreement with experimental results. © 2015 Society of Plastics Engineers.
Phiboonbanakit T.,Sirindhorn International Institute of Technology |
Horanont T.,Sirindhorn International Institute of Technology
7th International Conference on Information Communication Technology for Embedded Systems 2016, IC-ICTES 2016 | Year: 2016
With an innovation in mobile technology, trend of use mobile device as function to record individual activity is increasing in various fields. In order to determine the taxi meter quality of service in the urban area, we used mobile data to determine cause and fact. Normally, Taxi Route for Fare-Rate Calculation and Customer survey. In the first part, we developed an algorithm to calculate taxi fare-rate and compared the benefit between old and new fare-rate. We calculated the Taxi GPS data to determine each trajectory distance then use GIS spatial technique to clean undesired data. Next, a survey to collect data from customer who have experience on using taxi service and get use to their opinion was performed. The result indicate that using taxi new fare rate would increase benefit to taxi driver about 13.16% in average and could earn benefit the most when use new rate in long distance mode. Which 55.35% of customers satisfy in an increased fare rate, they also concerned in standard and quality of taxi service. In conclusion, we could contrast the fact and consequences from both side of people and suggest solutions to solve this issue. © 2016 IEEE.
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.
Hung N.D.,Sirindhorn International Institute of Technology
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2016
We develop inference procedures for a recently proposed model of probabilistic argumentation called PABA, taking advantages of well-established dialectical proof procedures for Assumption-based Argumentation and Bayesian Network algorithms.We establish the soundness and termination of our inference procedures for a general class of PABA frameworks. We also discuss how to translate other models of probabilistic argumentation into this class of PABA frameworks so that our inference procedures can be used for these models as well. © Springer International Publishing Switzerland 2016.
Pawgasame W.,Sirindhorn International Institute of Technology |
Wipusitwarakun K.,Sirindhorn International Institute of Technology
ACDT 2015 - Proceedings: The 1st Asian Conference on Defence Technology | Year: 2015
As network centric warfare becoming the key concept in the modern military doctrine, tactical wireless networks have been used extensively throughout military operations for sharing crucial information among deployed units. Most tactical wireless networks are operating in a hostile environment, in which normal network operation cannot be easily achieved. In military operations, tactical wireless networks have high demands for robustness, responsiveness, reliability, availability and security. These requires continuous development of new technologies in order to cope with random behaviours of hostile environment. However, the random behaviour of tactical wireless networks under hostile environment has not been fully understood. This paper provides a survey on current issues, and research challenges in tactical wireless networks due to hostile environment. Several research gaps in performance, security, routing, and management of tactical wireless networks that are needed to be improved, are pointed out to pave the way for future research in this area. This paper provides insight understanding about the issues and trends for future development of tactical wireless networks. © 2015 IEEE.
PubMed | Sirindhorn International Institute of Technology and Institute of Chemical Technology
Type: | Journal: 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 mol/g fly ash, consisting of 2.9 and 301.8 mol/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.