An Outline of Security in Wireless Sensor Networks: Threats, Countermeasures and Implementations

With the expansion of wireless sensor networks (WSNs), the need for securing the data flow through these networks is increasing. These sensor networks allow for easy-to-apply and flexible installations which have enabled them to be used for numerous applications. Due to these properties, they face distinct information security threats. Security of the data flowing through across networks provides the researchers with an interesting and intriguing potential for research. Design of these networks to ensure the protection of data faces the constraints of limited power and processing resources. We provide the basics of wireless sensor network security to help the researchers and engineers in better understanding of this applications field. In this chapter, we will provide the basics of information security with special emphasis on WSNs. The chapter will also give an overview of the information security requirements in these networks. Threats to the security of data in WSNs and some of their counter measures are also presented

Factors determining physical and mental quality of life of living kidney donors in Taiwan

[[abstract]]Background Living-donor kidney transplantation has a positive influence on recipients' life expectancy and improves quality of life for patients with end-stage renal disease compared with dialysis patients. Evaluation of the physical and mental quality of life for donors can promote positive perceptions about donation and help potential donors in their decision-making process. The aim of this study was to explore the predictive factors of quality of life for living kidney donors. Methods A cross-sectional and descriptive design was used, and the study was conducted from January to July 2013. The donors were a convenience sample of 34 participants who had undergone kidney transplant surgery >1 year earlier. Results The results showed that kidney donors had a low to moderate physical and mental quality of life. Multiple regression analysis revealed that financial concerns and anxiety explained 27.8% of the total variance of quality of life in the physical component. Anxiety and paid work explained 61.4% of the total variance of quality of life in the mental component. Conclusions After renal transplantation, living kidney donors experienced low to moderate quality of life. Because donors are family members (siblings, sons or daughters, spouses, or parents), monthly family income is a significant issue that influences both the decision to donate and quality of life after transplantation. Our findings suggest that pre-transplantation assessment must include social workers as part of the health care team to evaluate the impact of a donor's financial status on post-transplantation quality of life

Factors determining social function of patients after renal transplantation in Taiwan.

[[abstract]]Background Patients who are no longer in need of dialysis as a consequence save time and reduce stress every day. Social function was an important issue in patients with successful renal transplantation. According Bandura's social cognitive theory, ones' behavior is affected by social context and affective factors continuously. The quality of social function needs further investigation. Purpose The aims of this study were to describe the degree of social function after renal transplantation and to explore its predictive factors. Method A cross-sectional and descriptive study design was conducted in the outpatient department of a medical center in northern Taiwan from July to October 2010. The recipients were a convenience sample of 101 participants who had undergone renal transplantation. Hierarchical multivariate regression analysis was used to explore the predictive factors related to social function. Results The results showed that renal transplant recipients have moderate to high social function. Regression analyses showed that psychological factors (perceived stress, stress after renal transplantation, and depressive symptoms) and social participation (paid-work and leisure activity) explained 37.1% of the total variance for social function. Depressive symptoms explained most of the total variance. Conclusion After renal transplantation, patients experienced higher levels of social function. Perceived stress, stress after renal transplantation, depressive symptoms, paid-work, and leisure activity were the predictive factors of social function. Managing levels of depressive symptoms is highly recommended to elevate the patient's social function

Miniaturized Design of Microstrip-Fed Slot Antennas for MIMO System Applications

本論文提出一種以微帶線饋入之微型開槽偶極天線設計，主要是利用其槽孔內所增加的C形金屬環，可同時達到天線尺寸縮小以及雙頻的特性。C型金屬環主要是用作電感性負載以增強慢波效應，便能有效縮短等效傳播波長以及天線所需的共振長度。本論文對於C形金屬環在槽孔天線內的物理機制及其大小、相對位置皆有進一步的探討，並歸納出有效利用此C型金屬環達到最佳縮小化的方法。除了可使天線尺寸縮小之外，此C型金屬環亦提供了在原本開槽偶極天線以外的匹配低點，使得整體天線的頻寬可適用於無線區域網路所規範的雙頻頻段。利用C型金屬環可將槽孔天線縮小化的優點，本論文亦提出一應用在多重輸入多重輸出系統中的四埠開槽分集天線。從結果顯示此天線同時具有極化及場型分集的良好特性。對於此分集天線的系統表現亦有進一步的數據探討，包括相關係數、平均有效增益、以及有效分集增益。In this thesis, a miniaturized design of microstrip-fed slot antennas is presented. By adding C-shaped rings inside the slot, the antenna size is reduced and dual-band characteristic may also be obtained. The C-shaped rings are used as inductive loadings to enhance the slow-wave effects leading to the effective propagation wavelength and the required antenna resonant lengths can be shorten. The mechanism, location in the slot, and dimensions of C-shaped rings are extensively studied and the optimization is made to effectively reduce the antenna size. Besides antenna size reduction, the C-shaped rings can produce an additional impedance-matched deep so that the impedance bandwidth can cover the dual-band specification of IEEE 802.11a/b/g/n. Taking advantage of size reduction by using C-shaped rings in slot antennas, a four-element open-slot diversity antenna for MIMO system application is also proposed. It shows good pattern and polarization diversity characteristics. The system performances are studied by calculating the correlation coefficients, mean effective gains, and effective diversity gains