In order to understand the present status of heavy metal contamination and the risk associated wi... more In order to understand the present status of heavy metal contamination and the risk associated with human consumption, commercial freshwater eels in Vietnam were examined. The concentration of eight elements (Cr, Mn, Co, Cu, Zn, Sr, Cd, and Pb) was determined in muscle tissue of tropical eel Anguilla marmorata collected in four provinces, Quang Tri, Quang Ngai, Binh Dinh, and Phu Yen, from the central part of Vietnam. Concentrations of Cu, Zn, Cd, and Sr were found to be highest, whereas Co concentration showed the lowest at Quang Tri. Cr was recorded to be lowest in Quang Ngai, while the amounts of Mn and Pb did not vary among locations. Although the metal concentrations in the muscle of A. marmorata did not represent a risk for human consumption, elevated Cd concentrations in Quang Tri related to agriculture activities suggest that further investigations should be undertaken to clarify the potential risk to the eel population.
Wireless sensor-actuator network (WSAN) comprises of a group of distributed sensors and actuators... more Wireless sensor-actuator network (WSAN) comprises of a group of distributed sensors and actuators that communicate through wireless links. Sensors are small and static devices with limited power, computation, and communication capabilities responsible for observing the physical world. On the other hand, actuators are equipped with richer resources, able to move and perform appropriate actions. Sensors and actuators cooperate with each other: While sensors perform sensing, actuators make decisions and react to the environment with the right actions. WSAN can be applied in a wide range of applications, like environmental monitoring, battlefield surveillance, chemical attack detection, intrusion detection, space missions, etc. Since actuators perform actions in response to the sensed events, real-time communications and quick reaction are necessary. To provide effective applications by WSAN, two major problems remain: how to minimize the transmission delay from sensors to actuators, and how to improve the coordination among the actuators for fast reaction. To tackle these problems, we designed a real-time communication framework to support event detection, reporting, and actuator coordination. This paper explores the timely communication and coordination problems among the sensors and actuators. Moreover, we proposed two self-organized and distributed algorithms for event reporting and actuator coordination. Some preliminary results are presented to demonstrate the advantages of our approach
Our aim is to study fractional order differential inclusions with infinite delays in Banach space... more Our aim is to study fractional order differential inclusions with infinite delays in Banach spaces. We impose the regularity condition on multivalued nonlinearity in terms of measures of noncompactness to get the existence result. Some properties of the solution map are proved.
The binary classification problem consists in finding a separating surface minimizing an appropri... more The binary classification problem consists in finding a separating surface minimizing an appropriate measure of the classification error. Several mathematical programming-based approaches for this problem have been proposed. The aim of spherical seperation is to find, in the input space or in the feature space, a minimal volume sphere separating set A from set B (i.e. a sphere enclosing all points of A and no points of B). The problem can be cast into the DC programming framework. Afterwards, we propose a simple DCA scheme for solving the resulting DC program in which all computations are explicit. Computational results show the efficiency of the proposed algorithms over the two other spherical seperation methods: FC[6] and UCM[7].
Phase array radars are designed to tight tolerances in order to meet exact design constraints pla... more Phase array radars are designed to tight tolerances in order to meet exact design constraints placed upon the characteristics of their main beam. A numerical and statistical approach will be utilized to investigate the variation of the following key parameters; gain degradation, side-lobe perturbation, beam width variation and beam pointing error (BPE). Their subsequent effect on normal operation of the radar will be looked at in detail in this paper.
This paper presents a new approach to learn a rule based system for the task of part of speech ta... more This paper presents a new approach to learn a rule based system for the task of part of speech tagging. Our approach is based on an incremental knowledge acquisition methodology where rules are stored in an exception-structure and new rules are only added to correct errors of existing rules; thus allowing systematic control of interaction between rules. Experimental results of our approach on English show that we achieve in the best accuracy published to date: 97.095% on the Penn Treebank corpus. We also obtain the best performance for Vietnamese VietTreeBank corpus.
To better understand and serve Asian-Americans, it is imperative for the family science related f... more To better understand and serve Asian-Americans, it is imperative for the family science related fields to take a leadership role in providing in-depth insight into Asian-American families. In this article we report a descriptive analysis of articles published in prominent family-based journals over a 14-year period (1992–2006) relative to their attention to Asian-American families. This study examines the types of research conducted and the knowledge that has been generated about Asian-American families. It also provides a framework for considering future culturally centered research with this population.
In order to understand the present status of heavy metal contamination and the risk associated wi... more In order to understand the present status of heavy metal contamination and the risk associated with human consumption, commercial freshwater eels in Vietnam were examined. The concentration of eight elements (Cr, Mn, Co, Cu, Zn, Sr, Cd, and Pb) was determined in muscle tissue of tropical eel Anguilla marmorata collected in four provinces, Quang Tri, Quang Ngai, Binh Dinh, and Phu Yen, from the central part of Vietnam. Concentrations of Cu, Zn, Cd, and Sr were found to be highest, whereas Co concentration showed the lowest at Quang Tri. Cr was recorded to be lowest in Quang Ngai, while the amounts of Mn and Pb did not vary among locations. Although the metal concentrations in the muscle of A. marmorata did not represent a risk for human consumption, elevated Cd concentrations in Quang Tri related to agriculture activities suggest that further investigations should be undertaken to clarify the potential risk to the eel population.
Wireless sensor-actuator network (WSAN) comprises of a group of distributed sensors and actuators... more Wireless sensor-actuator network (WSAN) comprises of a group of distributed sensors and actuators that communicate through wireless links. Sensors are small and static devices with limited power, computation, and communication capabilities responsible for observing the physical world. On the other hand, actuators are equipped with richer resources, able to move and perform appropriate actions. Sensors and actuators cooperate with each other: While sensors perform sensing, actuators make decisions and react to the environment with the right actions. WSAN can be applied in a wide range of applications, like environmental monitoring, battlefield surveillance, chemical attack detection, intrusion detection, space missions, etc. Since actuators perform actions in response to the sensed events, real-time communications and quick reaction are necessary. To provide effective applications by WSAN, two major problems remain: how to minimize the transmission delay from sensors to actuators, and how to improve the coordination among the actuators for fast reaction. To tackle these problems, we designed a real-time communication framework to support event detection, reporting, and actuator coordination. This paper explores the timely communication and coordination problems among the sensors and actuators. Moreover, we proposed two self-organized and distributed algorithms for event reporting and actuator coordination. Some preliminary results are presented to demonstrate the advantages of our approach
Our aim is to study fractional order differential inclusions with infinite delays in Banach space... more Our aim is to study fractional order differential inclusions with infinite delays in Banach spaces. We impose the regularity condition on multivalued nonlinearity in terms of measures of noncompactness to get the existence result. Some properties of the solution map are proved.
The binary classification problem consists in finding a separating surface minimizing an appropri... more The binary classification problem consists in finding a separating surface minimizing an appropriate measure of the classification error. Several mathematical programming-based approaches for this problem have been proposed. The aim of spherical seperation is to find, in the input space or in the feature space, a minimal volume sphere separating set A from set B (i.e. a sphere enclosing all points of A and no points of B). The problem can be cast into the DC programming framework. Afterwards, we propose a simple DCA scheme for solving the resulting DC program in which all computations are explicit. Computational results show the efficiency of the proposed algorithms over the two other spherical seperation methods: FC[6] and UCM[7].
Phase array radars are designed to tight tolerances in order to meet exact design constraints pla... more Phase array radars are designed to tight tolerances in order to meet exact design constraints placed upon the characteristics of their main beam. A numerical and statistical approach will be utilized to investigate the variation of the following key parameters; gain degradation, side-lobe perturbation, beam width variation and beam pointing error (BPE). Their subsequent effect on normal operation of the radar will be looked at in detail in this paper.
This paper presents a new approach to learn a rule based system for the task of part of speech ta... more This paper presents a new approach to learn a rule based system for the task of part of speech tagging. Our approach is based on an incremental knowledge acquisition methodology where rules are stored in an exception-structure and new rules are only added to correct errors of existing rules; thus allowing systematic control of interaction between rules. Experimental results of our approach on English show that we achieve in the best accuracy published to date: 97.095% on the Penn Treebank corpus. We also obtain the best performance for Vietnamese VietTreeBank corpus.
To better understand and serve Asian-Americans, it is imperative for the family science related f... more To better understand and serve Asian-Americans, it is imperative for the family science related fields to take a leadership role in providing in-depth insight into Asian-American families. In this article we report a descriptive analysis of articles published in prominent family-based journals over a 14-year period (1992–2006) relative to their attention to Asian-American families. This study examines the types of research conducted and the knowledge that has been generated about Asian-American families. It also provides a framework for considering future culturally centered research with this population.
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Papers by Ngai Dinh