Analytic models for the performance of the forward link of 3G CDMA systems using different maximum ratio combining (MRC) RAKE finger weight assignments are presented. The spreading modulations under investigation are the balanced QPSK and the complex-spreading QPSK. The models are computationally efficient, accurate, and applicable to Root Raised Cosine (RRC) pulse shaping with any roll-off factor, variable processing gain, chip rate, and data rate for orthogonal codes, random codes, quasi-orthogonal codes, Gaussian noise, and realistic channel models. The expressions derived are then used to obtain the so-called orthogonality factor, which is commonly used in system-level simulations. Next, closed-form mathematical expressions for the variance due to infinite chips interfering in systems using arbitrary Nyquist pulses are derived. These expressions are applicable to both the forward link and the reverse link. For the latter, the existing knowledge on the accurate and efficient estimation of the performance of CDMA systems is extended by presenting closed mathematical expressions for bandlimited systems using arbitrary Nyquist pulses for both BPSK and Offset-QPSK (OQPSK) modulation. The impact of adjacent channel interference in bandlimited systems is subsequently considered. Finally, mathematical expressions for the accurate and efficient estimation of a CDMA system using RRC pulse-shaping and a RAKE receiver in the presence of multipath interference are presented.

In recent years, the service industries such as restaurants, hotels & finance have treated consumers and satisfying their needs as their first priority. This kind of service concept is also greatly valued and practiced by the medical industry. While the national health insurance system reduces the financial strain and increases more medicare choices for people, the environment of operating a hospital has become more challenged and competitive. The increase of income and the high service quality provided by Starbucks and Wang Steak both have significantly impact on people's expectation for receiving higher service quality. By recognizing the demand of public, hospital management can then provide service quality that's within or even beyond expectation. This research will exam the importance and satisfaction of hospital service quality to people, as well as compare people's loyalty level toward hospitals and doctors. This research takes Kaohsiung residents as example and the total number of effective example is 351. The questionnaire is created based on SERVQUAL and the patient's satisfaction questionnaire of THIS. The result is analyzed by statistic software SPSS 17.0 and Importance Performance Analysis. The research result: 1. The importance level of hospital service quality measures from high to low is professional abilities of doctors and nurses, medical equipments in hospitals, communication and interaction with doctors and nurses, facilities and convenient access to hospitals, attitude of medical staffs, waiting time. 2. Professional abilities of doctors and nurses, medical equipments in hospitals belong in the keep up the good work category. Attitude of medical staffs and waiting time belong in the lower priority category. Communication and interaction with doctors and nurses, facilities and convenient access to hospitals belong in the possible overkill category. No item for concentrate here category. 3. Interviewees show more loyalty toward doctors rather than hospitals and their attitude is consistent with their behavior.

Adaptive modulation and diversity combining represent very important adaptive solutions for future generations of wireless communication systems. Indeed, to improve the performance and the efficiency of these systems, these two techniques recently have been used jointly in new schemes named joint adaptive modulation and diversity combining (JAMDC) schemes. Considering the problem of finding lowcomplexity, bandwidth-efficient, and processing-power efficient transmission schemes for a downlink scenario and capitalizing on some of these recently proposed JAMDC schemes, we propose and analyze three fully joint adaptive modulation, diversity combining, and power control (FJAMDC) schemes. More specifically, the modulation constellation size, the number of combined diversity paths, and the needed power level are determined jointly to achieve the highest spectral efficiency with the lowest possible combining complexity, given the fading channel conditions and the required bit error rate (BER) performance. The performance of these three FJAMDC schemes is analyzed in terms of their spectral efficiency, processing power consumption, and error-rate performance. Selected numerical examples show that these schemes considerably increase the spectral efficiency of the existing JAMDC schemes with a slight increase in the average number of combined paths for the low signal to noise ratio range while maintaining compliance with the BER performance and a low radiated power resulting in a substantial decrease in interference to co-existing systems/users.

This thesis considers the analysis of system performance and resource allocation for a coded OFDM system over frequency selective fading channels. Due to the inseparable role taken by channel coding in a coded OFDM system, an information theoretical analysis is carried out and taken as the basis for the system performance and throughput. Based on the results of the information theoretical analysis, the optimal system BER performance of a coded OFDM system is first shown to converge to the outage probability for large OFDM block lengths. Instead of evaluating the outage probability numerically, we provide in this thesis a simple analytical closed form approximation of the outage probability for a coded OFDM system over frequency selective quasi-static fading channels. Simulation results of the turbo-coded OFDM systems further confirm the approximation of the outage probability. By taking the instantaneous channel capacity as the analytical building block, system throughput of a coded OFDM system is then provided. With the aim to compare the performance difference between adaptive and uniform resource allocation strategies, the system throughput of different allocation schemes under various channel conditions is analyzed. First, it is demonstrated that adaptive power allocation over OFDM sub-carriers at the transmitter achieves very little gain in terms of throughput over a uniform power distribution scheme. Theoretical analysis is then provided of the throughput increase of adaptive-rate schemes compared with fixed-rate schemes under various situations. Two practical OFDM systems implementing rate-compatible-punctured-turbo-code-based (RCPT-based) hybrid automatic-repeat-request (Hybrid-ARQ) and redundancy incremental Hybrid-ARQ protocols are also provided to verify the analytical results.

"Enhanced index fund" is an investment strategy, combining active and passive management elements, for index tracking and return enhancing through disciplined market timing, stock selection and leverage activities. Though enhanced index funds have been well developed globally, there is only one enhanced index fund in Taiwan - "Polaris/P-Shares Taiwan Dividend+ ETF". Taiwan's stock market falls between weak form and semi-strong form efficiency. With the growth of Taiwan's mutual fund industry size, the enhanced index funds have very good chance to become the main investment instruments of institutional investors, index investors, and pensions. This study attempts to build enhanced index funds, then analyzes the performance and checks the feasibility of launching such products in Taiwan. In this study, we select "TSEC Taiwan 50 index (TW50)" as the benchmark index. The innovative "Multi-section Adjustment Model" divides the original weights of constituent stocks into two sections. Each section is adjusted through parameters. The "multi-factor model section" is responsible for the delivery of enhanced return, while the "cash dividend yield section" is used to provide excess cash dividend yield. The investment target is set for less than 1.5 percent tracking error, at least 1 percent tracking difference, and higher cash dividend yield than the benchmark. Building methodology can be divided into "fixed parameter model" and "floating parameters model" according to its update frequency. Empirical studies show that: (1) The enhanced index fund built from the "fixed parameter model" not only exhibits risk slightly lower than the benchmark, but also enjoys higher return. (2) In the short-term, the performance of the enhanced index fund built from "floating parameters model" is difficult to predict; in the long-term, however, the risk is lower and the return is higher than TW50. The cumulative return from the "fixed parameter model" is higher than the "floating parameters model" by about 2 percent. (3) The effectiveness of the parameters used to control the optimal weight distribution is decreasing over time, so it is necessary to update parameters regularly. (4) Raising "enhancement multiplier" will cause higher tracking error, but also bring higher tracking difference. This result proves that "multi-factor model section" works nicely and has its contribution. (5) As the "section allotment" and/or "fixed rate" getting lower, there will be more and more weights distributed to the cash dividend yield level, resulting in higher cash dividend yield. It means the "cash dividend yield section" has its merit as well. (6) Regular parameter updates to the "floating parameters model" helps to reduce the tracking error and, at the same time, maintain positive tracking difference. Considering the perpetual life of real world funds, "floating parameters model" should be a better building methodology. "Multi-Section Adjustment Model" has following advantages: (1) Its concept is intuitive and easy to use. (2) Sections can be customized based on investment objectives. (3) It is easy to analyze the impacts and trade-off among the parameters.

In this dissertation, we propose using and analytically evaluate the predictive multicast polling scheme and the tree splitting algorithm for medium access control in interference dominating wireless access networks with random traffic and finite nodes. In an interference dominating wireless network, a receiver could simultaneously receive multiple packets from a variety of transmitters, as long as the signal-to-interference-plus-noise ratio exceeds a predetermined threshold. We concentrate on the case of in which the maximum queue size in a node is finite. We use discrete-time Markov chains, reward processes and regenerative processes to derive the throughput, the packet blocking probability, the average packet delay, and the average system size. We show that the system performance of the predictive multicast polling scheme can be significantly improved with a few additional buffers in the queues. Our study also shows that exact performance of the splitting algorithm depends on the total number of nodes in the networks. We verify our numerical results by rigorous mathematical proof and computer simulations.

<p>Lifetime Engineering (or Life Cycle Engineering) is a technical approach for meeting the current objective of sustainable development. The approach is aimed to turn today’s reactive and short-term design, management and maintenance planning towards an optimised and long-term technical approach. The life cycle based management and maintenance planning approach includes condition assessment, predictive modelling of performance changes, maintenance, repair and refurbishment planning and decisions. The Life Cycle Management System (LMS) is a predictive and generic life cycle based management system aimed to support all types of decision making and planning of optimal maintenance, repair and refurbishment activities of any constructed works. The system takes into account a number of aspects in sustainable and conscious development such as human requirements, life cycle economy, life cycle ecology and cultural requirements. The LMS is a system by which the complete system or parts thereof, works in co-operation or as a complement to existing business support systems. The system is module based where each module represents a subprocess within the maintenance management process. The scope of this thesis is focused on development and adaptation of the predictive characteristic of LMS towards a presumptive user. The objective is to develop and adapt a Service Life Performance Analysis module applicable for condition based Facility Management System in general and for condition based Bridge Management System in particular. Emphasis is placed on development and adaptation of a conditional probability based Service Life Performance Analysis model in which degradation models and Markov chains play a decisive role. The thesis deals also with development and adaptation of environmental exposure data recording and processing, with special emphasis on quantitative environmental classification in order to provide a simplified method of Service Life Performance Analysis.</p>

Der Anteil der Schießleistung in Bezug auf die Komplexleistung gewinnt durch die Einführung neuer und kürzerer Wettkampfdisziplinen sowie durch die zunehmende Verdichtung der Weltspitzenleistung immer mehr an Bedeutung. Neben den allgemeinen Schießtechnikelementen Atmung, Abzug, Zielen und Anschlag sowie deren optimaler Koordination können Körperschwankungen und Anschlagsstabilität als wesentliche Einflussgrößen der Schießtechnik im Biathlon benannt werden. Zielstellung dieser Untersuchung war die Aufhellung des komplexen Beziehungsgeflechts der Schießtechnik in den Anschlagsarten Liegend und Stehend im Biathlon. Auf der Grundlage der sportartspezifischen Anforderungen des Biathlonschießens, wurden in beiden Anschlägen, in Abhängigkeit anthropometrischer Merkmale (z. B. Alter und Körpergröße) sowie in Abhängigkeit der Art der Vorbelastung, die Zusammenhänge zwischen der Anschlagsstabilität und der Anschlagsgestaltung, im Hinblick auf möglichst geringe Bewegungen der Laufmündung im Moment der Schussabgabe, als Voraussetzung für sichere Trefferergebnisse, analysiert. Zur Beantwortung der Forschungsfragen wurde ein komplexer Schießmessplatz eingesetzt, welcher die synchrone Erfassung und Analyse von Kraft-Zeit-Verläufen an den Kontaktstellen Sportler-Gewehr, Bewegungen an der Laufmündung, Schwankungen des Systems Sportler-Waffe, die Belastungsverteilung der Auflagepunkte auf der Unterstützungsfläche sowie Winkel und Winkelveränderungen der Anschlagsposition in der Schussvor- und Nachbereitung sowie im Verlauf einer kompletten Schussserie ermöglicht. Im Rahmen einer Evaluationsstudie konnten über einen Zeitraum von zwei Jahren eine Vielzahl von leistungsrelevanten Parametern identifiziert werden. Neben der Präzisierung des sporttechnischen Leitbildes konnten Norm- und Richtwerte als Orientierungsgrößen für den Techniktrainingsprozess abgeleitet werden. Auf der Basis der Erkenntnisse aus der Evaluationsstudie, ist es im Rahmen einer spezifischen Interventionsstudie gelungen, Möglichkeiten aufzuzeigen, eine Steigerung der Schießleistung durch Abbau entsprechender Leistungsdiskrepanzen zu erreichen.

In wireless communication systems, receivers have generally been designed under the assumption that the additive noise in system is Gaussian. Wireless receivers, however, are affected by radio frequency interference (RFI) generated from various sources such as other wireless users, switching electronics, and computational platforms. RFI is well modeled using non-Gaussian impulsive statistics and can severely degrade the communication performance of wireless receivers designed under the assumption of additive Gaussian noise. Methods to avoid, cancel, or reduce RFI have been an active area of research over the past three decades. In practice, RFI cannot be completely avoided or canceled at the receiver. This dissertation derives the statistics of the residual RFI and utilizes them to analyze and improve the communication performance of wireless receivers. The primary contributions of this dissertation are to (i) derive instantaneous statistics of co-channel interference in a field of Poisson and Poisson-Poisson clustered interferers, (ii) characterize throughput, delay, and reliability of decentralized wireless networks with temporal correlation, and (iii) design pre-filters to mitigate RFI in wireless receivers. / text

Η μερική αντικατάσταση των παραδοσιακών ενσύρματων επικοινωνιών από ασύρματες οδήγησε στην ανάγκη για κατάλληλη σχεδίαση των ασύρματων δικτύων, ώστε να υποστηρίζουν τα απαιτούμενα επίπεδα ποιότητας. Η προσφερόμενη ποιότητα περιορίζεται σίγουρα από φυσικά εμπόδια όπως τα όρια που έθεσε ο Shannon, αλλά και από την περιορισμένη γνώση μας στην εκπομπή και διάδοση κυμάτων. Η διαρκής βελτίωση της ικανότητας των ασύρματων δικτύων να προσφέρουν υψηλής ποιότητας υπηρεσίες είναι όμως γεγονός και οφείλεται σε δύο βασικούς ερευνητικούς άξονες, αυτόν που εφευρίσκει νέες μεθόδους επικοινωνίας (διαμόρφωση, κωδικοποίηση, πολυπλεξία, κεραίες κ.α.) και αυτόν που προσπαθεί να βελτιώσει τη διαχείριση των ήδη υπαρχόντων πόρων. Η παρούσα διατριβή προσφέρει επιστημονικές ιδέες και μοντέλα, που έχουν σαν σκοπό την καλύτερη διαχείριση των πόρων. Τα παραδοσιακά αλλά και τα μοντέρνα δίκτυα κινητής τηλεφωνίας έχουν κατακλύσει την αγορά. Η λειτουργία τους όμως, παραμένει να κινείται στα πλαίσια συμβιβασμών, προσφέροντας χαμηλή ποιότητα υπηρεσίας. Η είσοδος των ασύρματων δικτύων υπολογιστών στην αγορά, ως ανταγωνιστές παροχής κλασικών υπηρεσιών (υπηρεσία φωνής και υπηρεσία δεδομένων), δίνει μια ώθηση αναπροσαρμογής των στόχων των δικτύων κινητής τηλεφωνίας. Οι προτεινόμενοι αλγόριθμοι διαχείρισης των δικτύων αυτών προσφέρουν καλύτερη ποιότητα υπηρεσιών με αλλαγή μεμονωμένων μόνο τμημάτων του δικτύου, χωρίς την ασύμφορη ολική επανασχεδίασή του. Αποτελούν δηλαδή πρακτικές λύσεις για την αποδοτικότερη λειτουργία των ήδη εγκατεστημένων δικτύων. Από την άλλη πλευρά, η ανερχόμενη τεχνολογία των ασύρματων δικτύων υπολογιστών βρίσκεται περισσότερο σε ανταγωνισμό με τα κλασικά ενσύρματα δίκτυα υπολογιστών. Το πλεονέκτημα της ελεύθερης κίνησης μετατρέπεται σε δυσβάσταχτο περιορισμό όταν η σύγκριση ποιότητας των δύο δικτύων είναι αναπόφευκτη. Για το λόγο αυτό, υπάρχει η μεγάλη ανάγκη τα ασύρματα δίκτυα να γίνουν ανταγωνιστικά των ενσύρματων και κυρίως να παρέχουν ποιότητα ικανού επιπέδου, ώστε οι διάφορες υπηρεσίες να μπορούν να λειτουργήσουν ανεπηρέαστες από την χρήση του ασύρματου καναλιού. Οι προτεινόμενοι αλγόριθμοι σε αυτόν τον τομέα αποσκοπούν στην βελτίωση της λειτουργίας των ασύρματων δικτύων με τελικό σκοπό την εξασφάλιση επιπέδων ποιότητας. Για την μελέτη των ασύρματων δικτύων κινητής τηλεφωνίας και υπολογιστών και την εξαγωγή συμπερασμάτων απαιτούνται αναλυτικές μέθοδοι περιγραφής και εξομοιώσεις των δικτύων αυτών ώστε να γίνουν και οι κατάλληλες συγκρίσεις της προσφερόμενης ποιότητας. Ο τομέας αυτός της επιστήμης είναι διαρκώς ενεργός καθώς νέες τεχνικές και αναλύσεις προτείνονται συνεχώς. Με στόχο την ανάλυση και την εξομοίωση των προηγούμενα αναφερθέντων αλγορίθμων αναπτύχθηκε ένας αριθμός τεχνικών, που αποτελούν αναπόσπαστο τμήμα της διατριβής αυτής. Στα πλαίσια της διατριβής αυτής και συγκεκριμένα στο τμήμα μελέτης της επίδοσης των δικτύων, προτείνεται η μετατροπή μη γραμμικών αλυσίδων Markov σε γραμμικές, για χρήση σε προβλήματα κίνησης ταυτόχρονων πολλαπλών υπηρεσιών. Η προτεινόμενη μεθοδολογία οδηγεί σε ταχύτατο υπολογισμό της αλυσίδας με τη χρήση μιας προσέγγισης. Παράλληλα, αναλύεται ο χρόνος διαμονής και ο εναπομένων χρόνος διαμονής σε μια κυψέλη. Η ανάλυση γίνεται εκ του μηδενός και με χρήση βασικών στοχαστικών μοντέλων, ενώ το αποτέλεσμα καταλήγει σε κατανομή gamma, κάτι που είχε ήδη παρατηρηθεί από πειράματα στην βιβλιογραφία. Στη συνέχεια κατασκευάζεται ένα ντετερμινιστικό μοντέλο εξομοίωσης που μπορεί να εφαρμοστεί εύκολα μέσω ενός χάρτη σε κάθε πόλη με ορθογώνια δόμηση. Στο τμήμα των δικτύων κινητής τηλεφωνίας προτείνεται ένας αλγόριθμος διαχείρισης και αποδοχής κλήσεων που προκαλεί μεταπομπές συστήματος (system initiated handover). Η χρήση των μεταπομπών αυτών επιφέρει μεταβλητή χωρητικότητα (soft capacity) σε μια ομάδα κυψελών με αποτέλεσμα την αποδοτικότερη διαχείριση πόρων σε περιπτώσεις άνισης κατανομής κίνησης. Ένας άλλος αλγόριθμος προτείνεται για διαρκή διαπραγμάτευση (real-time negotiation) ποιότητας μεταξύ του δικτύου και του χρήστη με αποτέλεσμα την καλύτερη οργάνωση και διαχείριση των πόρων. Αποδεικνύονται η δυνατότητα χρήσης του αλγορίθμου σε πραγματικό χρόνο και τα οφέλη που αποκομίζονται από αυτήν. Στο τμήμα ασύρματων δικτύων υπολογιστών προτείνεται ένα νέο πρωτόκολλο πρόσβασης μέσου, για χρήση στα ασύρματα τοπικά δίκτυα. Το πρωτόκολλο αυτό είναι πλήρως κατανεμημένο (μπορεί να χρησιμοποιηθεί και σε αυτοοργανονούμενα δίκτυα - ad hoc), ενώ προσφέρει τη δυνατότητα παροχής διαφορετικών επιπέδων ποιότητας, από άριστη ποιότητα για κλήσεις πραγματικού χρόνου μέχρι ποιότητα καλύτερης δυνατής προσπάθειας (best effort). Επίσης προτείνονται αλγόριθμοι βελτίωσης των ασύρματων δικτύων αισθητήρων. Αναλύεται συγκεκριμένα ο αυτόματος εντοπισμός κόμβων με χρήση τριγωνισμού και μεταβλητής ισχύος σημάτων-φάρων και η εξοικονόμηση ενέργειας με χρήση συστημάτων πολλαπλών κεραιών (MIMO). / The trend of replacing the traditional wired communications with their wireless counterparts led to the need for better design and organization of wireless networks so as to provide the necessary Quality of Service (QoS) levels. The offered QoS is bounded by Shannon’s limit and from the limitation of human knowledge on the wireless channel matters. However, the constant improvement of network performance is a fact based on two parallel scientific axes, the one that provides new communication techniques (modulation, coding, multiple access, antennas, etc) and the one that handles the already invented methods in an optimized manner. This thesis offers new scientific ideas and models for better resource management of wireless networks. Traditional and modern mobile telephone networks have occupied the market. Nevertheless, their functionality is still based on compromising of offered quality with the needs of a two-way voice application. Wireless computer networks appear in the market as contenders of voice service, acting like a threat to telephone networks. The proposed models for the mobile telephone networks provide solutions for improving overall QoS by altering only minor parts of these already-installed networks. On the other hand, the advancement of the wireless technology gives rise to visions of the so called Broadband Wireless Access. Computer Networks are expected to offer global roaming and provide traditional services over the IP protocol. In this context, QoS is necessary for guaranteeing service levels of quality. The proposed models in this part are focused in offering acceptable quality levels over the wireless channel for these services. The performance analysis of wireless networks requires the use of analytical approaches and simulation of these networks in order to assess the final offered quality. This section of science is constantly developing since new methods and techniques are applied to different parts of research. Through the procedure of analyzing the wireless networks in this thesis, a number of new techniques have been invented which constitute an important part of it. In terms of network traffic description, a new transformation of nonlinear markov chain to linear is proposed. By means of this transformation, the calculation of unbalanced nonuniform traffic can be accelerated. In the section of performance analysis, the sojourn time and the remaining sojourn time are analytically calculated. These cell parameters are found to follow a gamma distribution, a result that is backed from simulations in bibliography. Moreover, a deterministic simulation model is derived to enable easy calculation of these parameters from a map. As regards the mobile telephone networks, a new call admission control scheme is proposed in order to simulate soft capacity functionality in 2G networks. This feature, organizes better the resources in a cluster in cases of inhomogeneous network traffic. Moreover, a QoS negotiation algorithm is proposed for use in 3G networks (e.g. UMTS). Real-time negotiation is proposed for better resource organization and management. The gain from these schemes is calculated and presented. A new Medium Access Control (MAC) protocol is proposed for use in 802.11 Wireless Local Area Networks. This protocol is backward compatible with the protocol 802.11e and offers better quality infrastructure for VoIP services. The proposed protocol is analyzed and simulated and the results are compared to the previously used protocols to showcase the improvements. A new analytical approach with better accuracy is proposed for this reason. Finally, two techniques are proposed for improving the quality of wireless sensor networks. Firstly, a technique for low cost real-time localization with a small number of GPS or other beacons is proposed and tested. Secondly, a means of energy conservatiοn by use of Multiple Input Multiple Output (MIMO) systems is proposed, and then the gain from a QoS scheme is derived.