Symmetrical Multilevel Diversity Coding (SMDC) is a network compression problem for which a simple separate coding strategy known as superposition coding is optimal in terms of achieving the entire admissible rate region. Carefully constructed induction argument along with the classical subset entropy inequality of Han played a key role in proving the optimality. This thesis considers a generalization of SMDC for which, in addition to the randomly accessible encoders, there is also an all-access encoder. It is shown that superposition coding remains optimal in terms of achieving the entire admissible rate region of the problem. Key to our proof is to identify the supporting hyperplanes that define the boundary of the admissible rate region and then build on a generalization of Han's subset inequality. As a special case, the (R0,Rs) admissible rate region, which captures all possible tradeoffs between the encoding rate, R0, of the all-access encoder and the sum encoding rate, Rs, of the randomly accessible encoders, is explicitly characterized. To provide explicit proof of the optimality of superposition coding in this case, a new sliding-window subset entropy inequality is introduced and is shown to directly imply the classical subset entropy inequality of Han.

Orthogonal frequency division multiplexing (OFDM) technique has been extensively used in digital wireless communications, such as Digital Broadcasting and wireless local area network (WLAN). It is considered to be one of the most promising techniques for transmission on the downlinks of broadband wireless access systems to combat multipath and multiple access interference (MAI). Spatial processing that exploits the diversity provided by smart antenna (SA) or intelligent antenna (IA) arrays, in which the adaptive beamformer is employed, is another alternatives to increase the efficiency of wireless system capacity and performance without allocating additional frequency spectrum. It allows the system to make full use of spatial diversity due to multiple antennas [5][6]. To further improve the performance for suppressing various interference sources; including narrowband and wideband interference, flat and frequency selective fading, for different channel environmentin. In this thesis, a smart antenna with wideband beamspace approach array beamformer associated with the slideing window (SW) linearly constrained RLS (SW-LC-RLS) algorithm, and the OFDM systems with smart antenna array are emhasized. Computer simulation results confirmed that our proposed scheme could achieve desired performance compared with the conventional approach, in terms of MAI and other interference suppression.

The emerging widespread use of real-time multimedia applications over wireless networks makes the support of Quality of Service (QoS) a key problem. In this paper, we focus on QoS support mechanisms for IEEE 802.11 Wireless ad-hoc networks. First, we review the IEEE 802.11 standard and other enhanced MAC schemes that have been proposed to support QoS for 802.11 ad hoc networks. Then we propose a new priority MAC scheme which uses the different initial contention window instead of CWmin in IEEE 802.11 MAC to reduce the collision rate, then reduces the average delay and increases the throughput.

Spatial processing that exploits the diversity provided by smart antenna arrays, in which the adaptive beamformer is employed, is another alternative to increase the efficiency of wireless system capacity and performance without allocating additional frequency spectrum. An array beamformer is a processor used in conjunction with an array of sensors to provide a versatile form of spatial filtering; it can be designed to form main lobe in direction corresponding to the desired source and nulling the interferences from others direction. They are two types of adaptive array beamformer structures, viz., broadband and narrowband array structures. To deal with the wideband desired signal or interferences the broadband array beamformer is preferred. For broadband interferences suppression, many adaptive array beamforming algorithms, based on the linearly constrained have been extensively used. In this thesis, the beamspace approach for designing the broadband antenna array beamformer, with frequency invariant character, is devised and implemented with the sliding window linearly constrained RLS (SW-LC-RLS) algorithm, to deal with the broadband moving jammers (or interferences) suppression. Also, to combat the pointing error effect of desired user¡¦s look direction, the derivative constraint is adopted for devising the derivative SW-LC-RLS beamforming algorithm for broadband moving jammers suppression. Computer simulation results confirmed that the proposed scheme is more robust against the moving jammers over the conventional algorithms. It can be applied to the existing wideband wireless communications systems to achieve desired performance for supporting high data rate communication services.

In this dissertation, we present performance prediction models for rate-based and window¡Vbased flow control mechanisms. For rate-based flow control, such as in ATM network, we derive two analytical models to predict the ACR rates for congestion-free and congestion networks, respectively. To coordinate the cooperative problems of TCP over ATM networks, we propose a new algorithm to monitor the states of ATM switches and adjust TCP congestion window size based on RM cells. For window-based flow control mechanisms, such as in TCP-Reno and TCP-SACK, we respectively present analytical models to systematically capture the characteristics of multiple consecutive packet losses in TCP windows. Through fast retransmission, the lost packets may or may not be recovered. Thus, we present upper bound analyses for slow start and congestion avoidance phases to study the effects of multiple packet losses on TCP performance. Above the proposed upper bounds, the lost packets may not be successfully recovered through fast retransmission. Finally, we develop a model to study the TCP performance in terms of throughput degradation resulted from multiple consecutive packet losses. The analytical results from the throughput degradation model are validated through OPNET simulation.

¡@¡@An embedded system has improved quickly in recent years and now functions like a small computer. Equipped with operating systems (OS), graphic user interfaces (GUI), and software developed for various platforms, an embedded system provides users with services more powerful and friendlier than ever. Qt/Embedded and OpenGL ES are an OS and a GUI developed for embedded systems. In this thesis, We integrated Qt/Embedded with OpenGL ES on a Versatile PB 92EJ-S and conducted various tests. ¡@¡@The Versatile PB 92EJ-S was equipped with ARM926EJ-S, an onboard chip capable of performing VFP9 vector floating operation. However, not all embedded systems are powered by a floating coprocessor. To make the test results applicable to all systems, We performed only fixed-point operations, a practice also improving the overall performance. In addition, to provide communications between OpenGL ES and Windows and interfaces for OpenGL ES to draw, We implemented EGL, a platform interface layer defined in OpenGL ES. Furthermore, We developed GLUT ES, a modification of GLUT, to make the embedded system compatible with Windows of different versions. Finally, We benchmarked the platform with programs developed by GLUT ES interfaces and OpenGL ES.

In this essay, we use two stage data envelopment analysis (Two-stage DEA) with an application to evaluate the efficiency of six teams from Chinese Professional Baseball League (CPBL) during 2004 to 2005. In the essay, we use three methods to develop the research. First, we use the Window Analysis based on fewer DMUs situation. Second, the modification across different period has been made by Malmquist Index Analysis. Last one is Cross Efficiency; we use it for ranking efficiency performance for those teams during 2004 to 2005. According to above methods, it shows that: 1. the efficiency performance of Brother Elephants, Sinon Bulls, Chinatrust Whales, Uni Lions in the management stage is better than it in the production stage, vice versa Macoto Cobras and La new Bears in the production stage is better than management stage. 2. Each team is over optimal scale in the production stage during 2004 to 2005. 3. The result of overall performance during is shown as following place: Bulls, Elephants, Lions, Cobras, Whales, Bears; the orders in production stage are Cobras, Whales, Bulls, Bears, Elephants, Lions; the orders in management stage are Elephants, Bulls, Lions, Cobras, Bears, Whales. 4. The Malmquist Productivity Index across different period each year indicates that only La new Bears reach 4.7% according average growth rate.

Many applications in modern science need to transmit extremely massive amount of data over wide area networks. These data usually do not need stringent real-time requirements but require large bandwidth to finish transmission with unreasonable time. High-energy physics experiments and climate modeling and analysis are typical examples of such applications. As TCP is known to perform inefficiently over networks of large delay-bandwidth product, efficient transmission of this kind of massive, non-real-time data has been heavily studied in the past. The previous results work well in dedicated networks but will compete for fair share of bandwidth with normal TCP connections if they operate in the public networks. The objective of this thesis is to design a new transmission protocol for the above applications that can operate in the public networks without affecting normal TCP connections. The new protocol is called Rate Control Transmission Protocol (RCTP). The idea is to apply the packet-pair measurement technique to measure the bandwidth share in the network for the transmission. The sending rate is based on that measurement and is precisely compensated by the RTT variance measurement. Due to the RTT compensation, RCTP can efficiently utilize the unused bandwidth in the network while not affecting the normal TCP transmissions, making it perfect for transmitting massive, non-real-time data in the public networks.

The direct sequence (DS) code division multiple access (CDMA) is one of the most promising multiplexing technologies for wireless communications. It is also a core technology used in the wideband CDMA (WCDMA) system for the third generation (3G) wireless communication systems. In practice, in the CDMA systems the incomplete orthogonal of the spreading codes between users may introduce the so-called multiple access interference (MAI). Usually, the near-far problem exists when the interfering users are assigned powers much higher than the desired user. Such that the system performance might degrade, dramatically, and thus limits the system capacity. To circumvent the above-mentioned problems many effective adaptive multiuser detectors, based on the minimum mean square error (MMSE) and the minimum output energy (MOE) criteria subject to certain constraints have been proposed. In addition, to mitigate multipath fading effect, RAKE receiver was adopted due to the advantages of path diversity, thus, enhances the system performance. To implement the blind adaptive multiuser detector the linearly constrained minimum variance (LCMV), which is the constrained version of MOE, has been suggested. Further, the LCMV-based receivers exhibit high sensitivity to the channel mismatch caused by the unreliable estimation. To deal with this problem the constant modulus (CM) criterion was considered. In this dissertation, to deal with diverse phenomena encountered in practical channels, we first propose new blind adaptive multi-user detectors, based on the Min/Max criterion associated with the LCCM approach. For implementation the LC exponential window (EW) recursive least-square (RLS) algorithm is derived, and is referred to as the EW LCCM-RLS receiver. It can be used to effectively suppress the MAI and ISI, simultaneously, over multipath fading channels and are robust to mismatch problem caused by inaccuracies in the acquisition of timing and spreading code of the desired user. To reduce the complexity of the above-mentioned blind adaptive multi-user receiver with the LCCM-RLS algorithm, the so-called generalized sidelobe-canceller (GSC) structure is adopted, results in obtaining new CM-GSC-RLS algorithm. Moreover, to further improve the system performance for multipath fading and time-varying channel, the sliding window (SW) LCCM-RLS and SW CM-GSC-RLS algorithms are developed. It can be employed for multipath fading channel with the rapidly changing strong narrowband interference (NBI), which is joined suddenly to the CDMA systems. To look more inside the effect of selecting the initial value of the input signals autocorrelation matrix, some theoretical analyses for the SW LC-RLS as well as EW LC-RLS are provided. Since, unfortunately, the LCCM criterion is known to highly depend on the exact knowledge of the desired user amplitude that is not known exactly at receiver. In the final of this dissertation, a novel linearly constrained adaptive constant modulus RLS (LC-ACM-RLS) algorithm for blind DS-CDMA receiver is proposed. With this new proposed LC-ACM-RLS algorithm, the amplitude variation of the desired user, due to changing characteristics of the channel, can be tracked adaptively. Thus, better performance achievement, in terms of output signal-to-interference-plus-noise ratio (SINR) and bit error rate (BER), over the conventional LCCM-LMS and LCCM-RLS algorithms can be expected.

The archaeological questions of historical glass have lead to remarkable research activities such as identification and sourcing the raw materials used in the glass production, investigations of the ways in which the colors of glass can be modified due to dissolved and/or colloidal coloring agents, the furnace conditions, and the time of fritting and melting. Considering publications, it can be suggested that compositional studies of well-dated glass samples have supplied useful information concerning raw materials&rsquo / characteristics and technology of glassmaking. Within this context, the aim of this study was to determine elemental compositions and production techniques of some 13th century Seljukian Period window glasses from Alanya excavation region. During the excavations at Alanya archaeological site involving Inner Castle and out of Inner Castle many glass pieces of varying colors have been found. In this study 25 samples from the area have been examined. Elemental analyses have been carried out using X-Ray Fluorescence Spectroscopy (XRF) to determine major, minor, and trace elements. The data v obtained by XRF has revealed that all samples have typical soda-lime-silica composition with the average values of, 68.22 % (SiO2) / 11.3 % (Na2O) / and 6.7 % (CaO). Hierarchical Cluster analysis has been employed and the samples have been grouped depending on their potassium oxide (K2O) and magnesium oxide (MgO) contents which indicate the probable alkali flux source. The colors of the samples are honey-yellow, brown-yellow, navy blue, blue, turquoise, purple, and green. The coloring agents have been determined as Fe, Cu, Co, and Mn. The data from Optical Microscopy has shown that most of the window glasses might have been produced by cylinder technique. Some other samples have revealed the signs of crown technique, and some might have been produced by casting.