A unified framework for cluster manager election and clustering mechanism in mobile ad hoc networks

In Mobile Ad-hoc NETwork (MANET), every node could become active dynamically. Therefore, those nodes will affect the stability of network topology because of clustering and de-clustering, and continuously make reconfiguration for the groups of network, all that will influence the overall function of network. How to choose a cluster manager to keep the stability of network topology is an important issue. In this paper, a mechanism for the designation of clustering and cluster manager is given by MANET. The mechanism is named as Unified Framework Clustering Mechanism (UFCM for short), which is a kind of processing mechanism under consideration in multi-network service, such as processing mode of initial state in the network system, processing mode of access of nodes in the group, and the processing mode concerned on failing to manage the group because the cluster manager is erroneous. Beyond that, we also propose a backup manager to take the work of the cluster manager when the cluster manager fails.     

Incrementally fast updated frequent pattern trees

The frequent-pattern-tree (FP-tree) is an efficient data structure for association-rule mining without generation of candidate itemsets. It was used to compress a database into a tree structure which stored only large items. It, however, needed to process all transactions in a batch way. In real-world applications, new transactions are usually inserted into databases. In this paper, we thus attempt to modify the FP-tree construction algorithm for efficiently handling new transactions. A fast updated FP-tree (FUFP-tree) structure is proposed, which makes the tree update process become easier. An incremental FUFP-tree maintenance algorithm is also proposed for reducing the execution time in reconstructing the tree when new transactions are inserted. Experimental results also show that the proposed FUFP-tree maintenance algorithm runs faster than the batch FP-tree construction algorithm for handling new transactions and generates nearly the same tree structure as the FP-tree algorithm. The proposed approach can thus achieve a good trade-off between execution time and tree complexity.     

A multi-level ant-colony mining algorithm for membership functions

Fuzzy data mining is used to extract fuzzy knowledge from linguistic or quantitative data. It is an extension of traditional data mining and the derived knowledge is relatively meaningful to human beings. In the past, we proposed a mining algorithm to find suitable membership functions for fuzzy association rules based on ant colony systems. In that approach, precision was limited by the use of binary bits to encode the membership functions. This paper elaborates on the original approach to increase the accuracy of results by adding multi-level processing. A multi-level ant colony framework is thus designed and an algorithm based on the structure is proposed to achieve the purpose. The proposed approach first transforms the fuzzy mining problem into a multi-stage graph, with each route representing a possible set of membership functions. The new approach then extends the previous one, using multi-level processing to solve the problem in which the maximum quantities of item values in the transactions may be large. The membership functions derived in a given level will be refined in the subsequent level. The final membership functions in the last level are then outputted to the rule-mining phase to find fuzzy association rules. Experiments are also performed to show the performance of the proposed approach. The experimental results show that the proposed multi-level ant colony systems mining approach can obtain improved results.     

On Trellis Coded Noncoherent Space-Time Modulation

Unitary space-time modulation (USTM) is well-tailored for noncoherent space-time modulation. Trellis coded USTM (TC-USTM) can obtain significant coding gains over uncoded USTM for the noncoherent block fading channel. Conventional TC-USTM schemes expand the signal set of uncoded USTM by a factor of two. In this letter, we propose a new TC-USTM scheme in which the size of USTM set is not limited to be just double for uncoded USTM. However, in TC-USTM schemes, because signals of the same trellis branch are transmitted over the same fading coefficients, one trellis branch can only obtain one temporal diversity. In this letter, we also propose a new trellis coded noncoherent space-time modulation scheme by interleaving space-time signals. The proposed scheme can enlarge temporal diversity at the price of increased complexity and delay. Simulation results demonstrate the excellent error performances of codes found by computer searches for both schemes.     

Crabp1 Modulates HPA Axis Homeostasis and Anxiety-like Behaviors by Altering FKBP5 Expression

Retinoic acid (RA), the principal active metabolite of vitamin A, is known to be involved in stress-related disorders. However, its mechanism of action in this regard remains unclear. This study reports that, in mice, endogenous cellular RA binding protein 1 (Crabp1) is highly expressed in the hypothalamus and pituitary glands. Crabp1 knockout (CKO) mice exhibit reduced anxiety-like behaviors accompanied by a lowered stress induced-corticosterone level. Furthermore, CRH/DEX tests show an increased sensitivity (hypersensitivity) of their feedback inhibition in the hypothalamic–pituitary–adrenal (HPA) axis. Gene expression studies show reduced FKBP5 expression in CKO mice; this would decrease the suppression of glucocorticoid receptor (GR) signaling thereby enhancing their feedback inhibition, consistent with their dampened corticosterone level and anxiety-like behaviors upon stress induction. In AtT20, a pituitary gland adenoma cell line elevating or reducing Crabp1 level correspondingly increases or decreases FKBP5 expression, and its endogenous Crabp1 level is elevated by GR agonist dexamethasone or RA treatment. This study shows, for the first time, that Crabp1 regulates feedback inhibition of the the HPA axis by modulating FKBP5 expression. Furthermore, RA and stress can increase Crabp1 level, which would up-regulate FKBP5 thereby de-sensitizing feedback inhibition of HPA axis (by decreasing GR signaling) and increasing the risk of stress-related disorders.     

Load Profile Synthesis and Wind-Power-Generation Prediction for an Isolated Power System

This paper investigates the power load composition of an isolated power system using a load survey study and estimates wind power generation with a probabilistic network. The typical load pattern of various customer classes is derived, which are then used to derive the total power consumption of all customers within each class. A probabilistic neural network is used to solve the wind power generation based on the wind speed for an offshore island in Taiwan. With the hourly wind speed and load composition, the power generation of diesel generators was obtained. Results of this paper demonstrate that wind power generation can economically and effectively replace the power generation of the island's diesel power plant and provide partial power-supply capability for the net peak load requirement.     

Reconstruction of chirped fiber Bragg grating parameters and phase spectrum using two thermally modulated intensity spectra and a genetic algorithm

This study presents a synthesis method for reconstructing the multiple parameters such as grating position, length, period profile, refractive index modulation, and phase response of a chirped fiber Bragg grating (FBG) and its phase spectrum using two thermally modulated reflection intensity spectra and a genetic algorithm. In the proposed approach, the FBG parameters are determined using the genetic algorithm and are then used to reconstruct the phase response. The advantages of the proposed method include its simplicity, low cost, and nondestructive nature. Furthermore, the proposed method does not require a prior knowledge of the sign of the chirp of the grating period distribution of FBGs.     

Optical coherence tomography system with no high-precision scanning stage and stage controller

Optical coherence tomography (OCT) is a novel technique for noninvasive imaging based on the use of a low-coherence interferometer. Conventionally, obtaining high-resolution images requires the use of high-precision sample and scanning stages and a stage controller for simultaneous measurement of the refractive index and the thickness of an optical sample. However, in this study a novel optical-fiber-type OCT system is developed that does not need both a high-precision scanning stage and a stage controller. Additionally, two signal demodulation processes are described. Compared with that of conventional OCT systems, the current configuration eliminates the high-precision scanning stage and stage controller and is therefore cheaper and less complex. Also, this new technique could be applied to conventional OCTs in biotissue scanning.     

Simultaneous strain and temperature distribution sensing using two fiber Bragg grating pairs and a genetic algorithm

This study uses two pairs of FBGs to perform simultaneous strain and temperature field measurements. The first pair of FBGs, comprising one uniform FBG and one chirped FBG, measures the strain and temperature fields, while the second pair of FBGs, also comprising one uniform FBG and one chirped FBG, measures the temperature field only. A genetic algorithm is applied to reconstruct the arbitrary strain and temperature distribution profiles simultaneously from the measured reflection intensity spectra of the four FBGs. Various examples of nonmonotonic variations in the strain and temperature fields are considered for illustration purposes. It is found that the proposed scheme successfully reconstructs the applied strain and temperature fields.     

Protective relay setting of the tie line tripping and load sheddingfor the industrial power system

This paper presents the proper underfrequency relay settings to enhance the operation of industrial power systems with cogeneration facilities. A cogeneration unit was installed in the plant in 1996 to supply the power demand of the plant. The cogeneration unit always faces the shutdown problem when a severe fault occurs on the nearby Taipower network. It is, therefore, necessary to investigate plant protective relay settings to prevent a whole plant blackout when the contingency occurs. A transient stability analysis has been performed by considering both the detailed models of the cogenerators with the governor and exciter control systems and the external utility power system. The underfrequency relay settings for tie line tripping and load shedding are designed to prevent the tripping of the cogeneration units so that the electricity service to the critical loads of the industrial customer can be maintained in case serious external disturbances such as short circuit faults occur. In this study, the scheme of underfrequency relay settings has been developed for the power system of a large synthetic rubber manufacturer with a large cogeneration unit. Three study cases have been selected for the transient stability analysis to verify the effectiveness of the proposed protective relay setting