Study of the Compressive Strength of Aluminum Curved Elements

Currently, the Specification for Aluminum Structures (Aluminum Association, 2010) shows thin-walled aluminum plate sections with radii greater than eight inches have a lower compressive strength capacity than a flat plate with the same width and thickness. This inconsistency with intuition, which suggests any degree of folding a plate should increase its elastic buckling strength, inspired this study. A wide range of curvatures are studied—from a nearly flat plate to semi-circular. To quantify the curvature, a single non-dimensional parameter is used to represent all combinations of width, thickness and radius. Using the finite strip method (CU-FSM), elastic local buckling stresses are investigated. Using the ratio of stress values of curved plates compared to flat plates of the same size, equivalent plate-buckling coefficients are calculated. Using this data, nonlinear regression analyses are performed to develop closed form equations for five different edge support conditions. These equations can be used to calculate the elastic critical buckling stress for any curved aluminum section when the geometric properties (width, thickness, and radius) and the material properties (elastic modulus and Poisson’s ratio) are known. This procedure is illustrated in examples, each showing the applicability of the derived equations to geometries other than those investigated in this study and also providing comparisons with theoretically exact numerical analysis results.

Non-State United States Support For The Contras During The Reagan Era

Under President Ronald Reagan, the White House pursued a complex foreign policy towards the Contras, rebels in trying to overthrow the Sandinista regime in Nicaragua, in Nicaragua. In 1979, the leftist Sandinista government seized power in Nicaragua. The loss of the previous pro-United States Somoza military dictatorship deeply troubled the conservatives, for whom eradication of communism internationally was a top foreign policy goal. Consequently, the Reagan Administration sought to redress the policy of his predecessor, Jimmy Carter, and assume a hard line stance against leftist regimes in Central America. Reagan and the conservatives within his administration, therefore, supported the Contra through military arms, humanitarian aid, and financial contributions. This intervention in Nicaragua, however, failed to garner popular support from American citizens and Democrats. Consequently, between 1982 and 1984 Congress prohibited further funding to the Contras in a series of legislation called the Boland Amendments. These Amendments barred any military aid from reaching the Contras, including through intelligence agencies. Shortly after their passage, Central Intelligence Agency Director William Casey and influential members of Reagan¿s National Security Council (NSC) including National Security Advisor Robert McFarlane, NSC Aide Oliver North, and Deputy National Security Advisor John Poindexter cooperated to identify and exploit loopholes in the legislation. By recognizing the NSC as a non-intelligence body, these masterminds orchestrated a scheme in which third parties, including foreign countries and private donors, contributed both financially and through arms donations to sustain the Contras independently of Congressional oversight. This thesis explores the mechanism and process of soliciting donations from private individuals, recognizing the forces and actors that created a situation for covert action to continue without detection. Oliver North, the main actor of the state, worked within his role as an NSC bureaucrat to network with influential politicians and private individuals to execute the orders of his superiors and shape foreign policy. Although Reagan articulated his desire for the Contras to remain a military presence in Nicaragua, he delegated the details of policy to his subordinates, which allowed this scheme to flourish. Second, this thesis explores the individual donors, analyzing their role as private citizens in sustaining and encouraging the policy of the Reagan Administration. The Contra movement found non-state support from followers of the New Right, demonstrated through financial and organizational assistance, that allowed the Reagan Administration¿s statistically unpopular policy in Nicaragua to continue. I interpret these donors as politically involved, but politically philanthropic, individuals, donating to their charity of choice to further the principles of American freedom internationally in a Cold War environment. The thesis then proceeds to assess the balance of power between the executive and other political actors in shaping policy, concluding that the executive cannot act alone in the formulation and implementation of foreign policy.

Effects Of The Flash Welding Process On Mechanical And Microstructural Properties Of Structural Steel Joints Assessed Using Dest

ASTM A529 carbon¿manganese steel angle specimens were joined by flash butt welding and the effects of varying process parameter settings on the resulting welds were investigated. The weld metal and heat affected zones were examined and tested using tensile testing, ultrasonic scanning, Rockwell hardness testing, optical microscopy, and scanning electron microscopy with energy dispersive spectroscopy in order to quantify the effect of process variables on weld quality. Statistical analysis of experimental tensile and ultrasonic scanning data highlighted the sensitivity of weld strength and the presence of weld zone inclusions and interfacial defects to the process factors of upset current, flashing time duration, and upset dimension. Subsequent microstructural analysis revealed various phases within the weld and heat affected zone, including acicular ferrite, Widmanstätten or side-plate ferrite, and grain boundary ferrite. Inspection of the fracture surfaces of multiple tensile specimens, with scanning electron microscopy, displayed evidence of brittle cleavage fracture within the weld zone for certain factor combinations. Test results also indicated that hardness was increased in the weld zone for all specimens, which can be attributed to the extensive deformation of the upset operation. The significance of weld process factor levels on microstructure, fracture characteristics, and weld zone strength was analyzed. The relationships between significant flash welding process variables and weld quality metrics as applied to ASTM A529-Grade 50 steel angle were formalized in empirical process models.

A New Symbiosis: Municipalities, Private Contractors and Non-Governmental Organisations for the Provision of Local Public Services"

This project considered the second stage of transforming local administration and public service management to reflect democratic forms of government. In Hungary in the second half of the 1990s more and more public functions delegated to local governments have been handed over to the private or civil sectors. This has led to a relative decrease of municipal functions but not of local governments' responsibilities, requiring them to change their orientation and approach to their work so as to be effective in their new roles of managing these processes rather than traditional bureaucratic administration. Horvath analysed the Anglo-Saxon, French and German models of self-government, identifying the differing aspects emphasised in increasing the private sector's role in the provision of public services, and the influence that this process has on the system of public administration. He then highlighted linkages between actors and local governments in Hungary, concluding that the next necessary step is to develop institutional mechanisms, financial incentives and managerial practices to utilise the full potential of this process. Equally important is the need for conscious avoidance of restrictive barriers and unintended consequences, and for local governments to confront the social conflicts that have emerged in parallel with privatisation. A further aspect considered was a widening of the role of functional governance at local level in the field of human services. A number of different special purpose bodies have been set up in Hungary, but the results of their work are unclear and Horvath feels that this institutionalisation of symbiosis is not the right path in Hungary today. He believes that the change from local government to local governance will require the formulation of specific public policy, the relevance of which can be proven by processes supported with actions.

An Elaboration of the Psycho-Physiological Method and its Application on the Process of Socialization of Mentally Handicapped People

The socialisation of mentally handicapped people is a long-term process during which the disabled person learns new habits and abilities step by step through education and training. Anxiety and neuroses due to an inadequate social environment can place obstacles in the path of the disabled person's integration into society. A method of regulating the psycho-physiological condition of mentally handicapped people (MRPC) was developed in order to reduce anxiety and neuropsychological tension and to establish positive social attitudes. Both verbal and non-verbal means of manipulating the psycho-physiological condition were used and experimental and control groups were formed from among the clients of Israelian's institute. The experimental groups applied the new method for six months, leading to a significant shift in the response of the clients involved. Expressed anxiety and defensive responses to mental tasks were transformed into orienting responses after 30 psycho-regulative exercises. Cognitive functions such as attention and memory also improved significantly. EEG examinations of the actual process of psycho-regulation revealed a tendency towards a change of brain activity by increasing the fast pulse frequency values in the alpha zones. Israelian concludes that the application of the MRPC creates better functional conditions for the socialisation of mentally handicapped people.

A Comparative Study of Two Semantic Systems: Body Russian and Russian Phraseology

Grigorij Kreidlin (Russia). A Comparative Study of Two Semantic Systems: Body Russian and Russian Phraseology. Mr. Kreidlin teaches in the Department of Theoretical and Applied Linguistics of the State University of Humanities in Moscow and worked on this project from August 1996 to July 1998. The classical approach to non-verbal and verbal oral communication is based on a traditional separation of body and mind. Linguists studied words and phrasemes, the products of mind activities, while gestures, facial expressions, postures and other forms of body language were left to anthropologists, psychologists, physiologists, and indeed to anyone but linguists. Only recently have linguists begun to turn their attention to gestures and semiotic and cognitive paradigms are now appearing that raise the question of designing an integral model for the unified description of non-verbal and verbal communicative behaviour. This project attempted to elaborate lexical and semantic fragments of such a model, producing a co-ordinated semantic description of the main Russian gestures (including gestures proper, postures and facial expressions) and their natural language analogues. The concept of emblematic gestures and gestural phrasemes and of their semantic links permitted an appropriate description of the transformation of a body as a purely physical substance into a body as a carrier of essential attributes of Russian culture - the semiotic process called the culturalisation of the human body. Here the human body embodies a system of cultural values and displays them in a text within the area of phraseology and some other important language domains. The goal of this research was to develop a theory that would account for the fundamental peculiarities of the process. The model proposed is based on the unified lexicographic representation of verbal and non-verbal units in the Dictionary of Russian Gestures, which the Mr. Kreidlin had earlier complied in collaboration with a group of his students. The Dictionary was originally oriented only towards reflecting how the lexical competence of Russian body language is represented in the Russian mind. Now a special type of phraseological zone has been designed to reflect explicitly semantic relationships between the gestures in the entries and phrasemes and to provide the necessary information for a detailed description of these. All the definitions, rules of usage and the established correlations are written in a semantic meta-language. Several classes of Russian gestural phrasemes were identified, including those phrasemes and idioms with semantic definitions close to those of the corresponding gestures, those phraseological units that have lost touch with the related gestures (although etymologically they are derived from gestures that have gone out of use), and phrasemes and idioms which have semantic traces or reflexes inherited from the meaning of the related gestures. The basic assumptions and practical considerations underlying the work were as follows. (1) To compare meanings one has to be able to state them. To state the meaning of a gesture or a phraseological expression, one needs a formal semantic meta-language of propositional character that represents the cognitive and mental aspects of the codes. (2) The semantic contrastive analysis of any semiotic codes used in person-to-person communication also requires a single semantic meta-language, i.e. a formal semantic language of description,. This language must be as linguistically and culturally independent as possible and yet must be open to interpretation through any culture and code. Another possible method of conducting comparative verbal-non-verbal semantic research is to work with different semantic meta-languages and semantic nets and to learn how to combine them, translate from one to another, etc. in order to reach a common basis for the subsequent comparison of units. (3) The practical work in defining phraseological units and organising the phraseological zone in the Dictionary of Russian Gestures unexpectedly showed that semantic links between gestures and gestural phrasemes are reflected not only in common semantic elements and syntactic structure of semantic propositions, but also in general and partial cognitive operations that are made over semantic definitions. (4) In comparative semantic analysis one should take into account different values and roles of inner form and image components in the semantic representation of non-verbal and verbal units. (5) For the most part, gestural phrasemes are direct semantic derivatives of gestures. The cognitive and formal techniques can be regarded as typological features for the future functional-semantic classification of gestural phrasemes: two phrasemes whose meaning can be obtained by the same cognitive or purely syntactic operations (or types of operations) over the meanings of the corresponding gestures, belong by definition to one and the same class. The nature of many cognitive operations has not been studied well so far, but the first steps towards its comprehension and description have been taken. The research identified 25 logically possible classes of relationships between a gesture and a gestural phraseme. The calculation is based on theoretically possible formal (set-theory) correlations between signifiers and signified of the non-verbal and verbal units. However, in order to examine which of them are realised in practice a complete semantic and lexicographic description of all (not only central) everyday emblems and gestural phrasemes is required and this unfortunately does not yet exist. Mr. Kreidlin suggests that the results of the comparative analysis of verbal and non-verbal units could also be used in other research areas such as the lexicography of emotions.

Poverty in Slovenia: A Conseqence of Economic Transition

Slovenia is considered to be one of the most successful Central and Eastern European countries undergoing the process of transition. It has a high GDP per capita (the highest in the Visegrad group) amounting to about 7200 US dollars (at the exchange rates pertaining during Ms. Stropnik's research). In 1994, a low rate of inflation, a low level of public debt and almost balanced public finances, were all positive elements. However, there is a darker side, for instance the dramatic increase in unemployment and (somewhat less dramatic) fall in production during the transition period. This analysis aimed to provide insights into what is actually happening at the household level, since households are the ultimate bearers of macroeconomic and social change. The final output totalled 166 pages in English and Slovenian, available also on disc. The income concept used by Ms. Stropnik is that of the disposable (monetary) household income, i.e. the cash income of all household members - including social security transfers and family benefits, and the net sum of taxes and social security contributions - plus the equivalent of domestic production, used in the household. Non-monetary income sources, such as household own production, benefits in kind, subsidies for goods and services, and fringe benefits, were not taken into account. The concept of relative and objective poverty was followed. Poverty means having less than others in society, it is a state of relative deprivation. Objective aspects of the situation, e.g. command over resources (i.e. the household income) and the relative position of the household in the income distribution, determine who is poor and who is not. Changes in household composition - an increase in the number of pensioners, unemployed and self-employed, concomitant with a large decrease in the number of employees - obviously played a part in the changing structure of household income sources during this period. The overall decrease in the share of wages and salaries from primary employment in 1993 is to be observed in all income deciles. On the other hand, the importance of salaries gained from secondary employment has increased in all deciles. The lower seven deciles experienced a sharp rise in the share of social benefits in the period 1988-1993, mostly because of the increase in the number of persons entitled to claim unemployment benefits. In Slovenia, income inequality has increased considerably during the 1988-1993 period. To make matters worse, the large increase in income inequality occurred in a period of falling real incomes. In 1983 the bottom decile disposed of 3.8 percent and the top decile disposed of 23.4 percent of total monetary income in Slovenia, whereas by 1993 the same statistics revealed 3.1 percent and 18.9 percent respectively. Unemployment greatly increases the risk of living in poverty. In 1993, 35 per cent of all unemployed persons in Slovenia were living in the lowest income quintile. Ms. Stropnik found certain features that were specific to Slovenia and not shared by most countries in transition. For example, the relative income position of pensioners has improved. Retirement did not increase the risk of poverty in 1993 as much as it did in 1983 and 1988. Also, it appears that children have not been particularly hard-hit by the transition upheavals. The incidence of poverty amongst children has not increased in the period 1983-1993. Children were also fairly evenly distributed across income quintiles. In 1983, 11.8 percent of households with children aged 18 or less were poor. In 1993, this figure was 8.4 per cent. On the other hand, poor households with children were, in comparison with other households of the same type, poorer in 1993 than in 1983. Ms. Stropnik also analysed the impact of social transfers. Her conclusion was that the level of social transfers prevented them from being successful in alleviating poverty. Family policy transfers (child allowances, child tax allowances, subsidised child care) did, however, contribute to the lowering of income inequality between families with and without children, and amongst families with different numbers of children. Ms. Stropnik is determined that the results of her research be used in the creation of social policy aimed at helping the poor. She quotes Piachaud approvingly: "If the term 'poverty' carries with it the implication and moral imperative that something should be done about it, then the study of poverty is only ultimately justifiable if it influences individual and social attitudes and actions."

[In Process Citation]

Elevated transaminases in asymptomatic patients can be detected in more than 5 % of the investigations. If there are no obvious reasons, the finding should be confirmed within the next 3 months. Frequent causes are non-alcoholic fatty liver disease (NAFLD), non-alcoholic steatohepatitis (NASH), alcohol, hepatitis B or C, hemochromatosis and drugs or toxins. Rarer causes are autoimmune hepatitis, M. Wilson and α1-antitrypsine deficiency. There are also non-hepatic causes such as celiac disease or hemolysis and myopathies in the case of an exclusive increase of ASAT. I recommend a two-step investigational procedure; the more frequent causes are examined first before the rare causes are studied. The value of the proposed investigations is discussed.

Ethnosciences - A step towards the integration of scientific and non-scientific forms of knowledge in the management of natural resources for the future

Integration of indigenous knowledge and ethnoscientific approaches into contemporary frameworks for conservation and sustainable management of natural resources will become increasingly important in policies on an international and national level. We set the scene on how this can be done by exploring the key conditions and dimensions of a dialogue between ‘ontologies’ and the roles, which ethnosciences could play in this process. First, the roles which ethnosciences in the context of sustainable development were analysed, placing emphasis on the implications arising when western sciences aspire to relate to indigenous forms of knowledge. Secondly, the contributions of ethnosciences to such an ‘inter-ontological dialogue’ were explored, based on an ethnoecological study of the encounter of sciences and indigenous knowledge in the Andes of Bolivia, and reviewed experiences from mangrove systems in Kenya, India and Sri Lanka, and from case-studies in other ecosystems world-wide.

Cyclin D1 in non-small cell lung cancer: a key driver of malignant transformation

PURPOSE: To review the evidence implicating the deregulation of cyclin D1 in the pathogenesis of non-small cell lung cancer (NSCLC), and to discuss the opportunities for targeted clinical intervention. METHODS: Data published until June 2006 are summarized, and previously unpublished results from our own research are included. RESULTS: In normal cells, cyclin D1 complexes with and activates cyclin-dependent kinases (CDK) and acts as a transcriptional regulator. The protein is frequently overexpressed in a wide range of cancers, sometimes coincident with CCND1 (cyclin D1) gene amplification (5-20% of tumours). A low level of somatic mutations have been seen in certain tumours. CCND1 is amplified in NSCLC and cyclin D1 is frequently overexpressed in tumours and pre-invasive bronchial lesions, generally from one parental allele. Mutation analyses revealed a frequent CCND1 gene polymorphism (A870G) that modulates alternative splicing and allows expression of an alternative cyclin D1 transcript (transcript cyclin D1b). The encoded cyclin D1b protein lacks a specific phosphorylation site required for nuclear export. Genotype has been correlated with the risk and/or severity of disease or drug response across a range of malignancies, including lung cancer. Together, these findings suggest a strong pathological role for cyclin D1 deregulation in bronchial neoplasia. CONCLUSION: Current data indicate that cyclin D1 overexpression is not a consequence of, but rather a pivotal element in the process of malignant transformation in the lung and other tissues. This understanding may open new avenues for lung cancer diagnosis, treatment and prevention.

Isolated Islands? Memory of the Holocaust in Formal and Non-Formal Education. The Case Study of Post-Communist Poland

Existing studies revealed several conflicts around the memory of the Holocaust in Poland: between understanding the need to teach about the Holocaust and indifference toward anti-Jewish graffiti; a conflict around the perception of Polish help to Jews; and the competing images of Polish and Jewish suffering during World War II. Those conflicts will be addressed in the paper as reflecting educational gaps in the Polish education system (lack of bad memory). This paper will look at the consciousness of young Poles, in terms of attitudes toward Jews, the Holocaust and memory of the Holocaust. The data presented are the preliminary results of the author’s longitudinal study „Attitudes of Young Poles toward the Jews and the Holocaust”. Quantitative and qualitative studies include field studies and participant observation of educational projects in Tykocin, Treblinka, Warsaw, Lublin, Bodzentyn and Kielce. The paper will present some components of the development of education about the Holocaust in Poland. There is a need to evaluate the attempt to bring back the memory of Jewish neighbours in some of the states of Central and Eastern Europe, a process with an ongoing effort to renovate monuments, destroyed cemeteries and synagogues. The number and scope of such initiatives in Poland indicate that civic institutions and individuals are intensifying their efforts to teach their fellow citizens about the Holocaust, however their impact should be assessed in detail.

Point Process Methodology for On-line Spatio-temporal Disease Surveillance

The AEGISS (Ascertainment and Enhancement of Gastrointestinal Infection Surveillance and Statistics) project aims to use spatio-temporal statistical methods to identify anomalies in the space-time distribution of non-specific, gastrointestinal infections in the UK, using the Southampton area in southern England as a test-case. In this paper, we use the AEGISS project to illustrate how spatio-temporal point process methodology can be used in the development of a rapid-response, spatial surveillance system. Current surveillance of gastroenteric disease in the UK relies on general practitioners reporting cases of suspected food-poisoning through a statutory notification scheme, voluntary laboratory reports of the isolation of gastrointestinal pathogens and standard reports of general outbreaks of infectious intestinal disease by public health and environmental health authorities. However, most statutory notifications are made only after a laboratory reports the isolation of a gastrointestinal pathogen. As a result, detection is delayed and the ability to react to an emerging outbreak is reduced. For more detailed discussion, see Diggle et al. (2003). A new and potentially valuable source of data on the incidence of non-specific gastro-enteric infections in the UK is NHS Direct, a 24-hour phone-in clinical advice service. NHS Direct data are less likely than reports by general practitioners to suffer from spatially and temporally localized inconsistencies in reporting rates. Also, reporting delays by patients are likely to be reduced, as no appointments are needed. Against this, NHS Direct data sacrifice specificity. Each call to NHS Direct is classified only according to the general pattern of reported symptoms (Cooper et al, 2003). The current paper focuses on the use of spatio-temporal statistical analysis for early detection of unexplained variation in the spatio-temporal incidence of non-specific gastroenteric symptoms, as reported to NHS Direct. Section 2 describes our statistical formulation of this problem, the nature of the available data and our approach to predictive inference. Section 3 describes the stochastic model. Section 4 gives the results of fitting the model to NHS Direct data. Section 5 shows how the model is used for spatio-temporal prediction. The paper concludes with a short discussion.

Multi-node TOA-DOA cooperative LOS-NLOS localization : enabling high accuracy and reliability

This dissertation investigates high performance cooperative localization in wireless environments based on multi-node time-of-arrival (TOA) and direction-of-arrival (DOA) estimations in line-of-sight (LOS) and non-LOS (NLOS) scenarios. Here, two categories of nodes are assumed: base nodes (BNs) and target nodes (TNs). BNs are equipped with antenna arrays and capable of estimating TOA (range) and DOA (angle). TNs are equipped with Omni-directional antennas and communicate with BNs to allow BNs to localize TNs; thus, the proposed localization is maintained by BNs and TNs cooperation. First, a LOS localization method is proposed, which is based on semi-distributed multi-node TOA-DOA fusion. The proposed technique is applicable to mobile ad-hoc networks (MANETs). We assume LOS is available between BNs and TNs. One BN is selected as the reference BN, and other nodes are localized in the coordinates of the reference BN. Each BN can localize TNs located in its coverage area independently. In addition, a TN might be localized by multiple BNs. High performance localization is attainable via multi-node TOA-DOA fusion. The complexity of the semi-distributed multi-node TOA-DOA fusion is low because the total computational load is distributed across all BNs. To evaluate the localization accuracy of the proposed method, we compare the proposed method with global positioning system (GPS) aided TOA (DOA) fusion, which are applicable to MANETs. The comparison criterion is the localization circular error probability (CEP). The results confirm that the proposed method is suitable for moderate scale MANETs, while GPS-aided TOA fusion is suitable for large scale MANETs. Usually, TOA and DOA of TNs are periodically estimated by BNs. Thus, Kalman filter (KF) is integrated with multi-node TOA-DOA fusion to further improve its performance. The integration of KF and multi-node TOA-DOA fusion is compared with extended-KF (EKF) when it is applied to multiple TOA-DOA estimations made by multiple BNs. The comparison depicts that it is stable (no divergence takes place) and its accuracy is slightly lower than that of the EKF, if the EKF converges. However, the EKF may diverge while the integration of KF and multi-node TOA-DOA fusion does not; thus, the reliability of the proposed method is higher. In addition, the computational complexity of the integration of KF and multi-node TOA-DOA fusion is much lower than that of EKF. In wireless environments, LOS might be obstructed. This degrades the localization reliability. Antenna arrays installed at each BN is incorporated to allow each BN to identify NLOS scenarios independently. Here, a single BN measures the phase difference across two antenna elements using a synchronized bi-receiver system, and maps it into wireless channel’s K-factor. The larger K is, the more likely the channel would be a LOS one. Next, the K-factor is incorporated to identify NLOS scenarios. The performance of this system is characterized in terms of probability of LOS and NLOS identification. The latency of the method is small. Finally, a multi-node NLOS identification and localization method is proposed to improve localization reliability. In this case, multiple BNs engage in the process of NLOS identification, shared reflectors determination and localization, and NLOS TN localization. In NLOS scenarios, when there are three or more shared reflectors, those reflectors are localized via DOA fusion, and then a TN is localized via TOA fusion based on the localization of shared reflectors.

Multi-antenna non-line-of-sight identification techniques for target localization in mobile ad-hoc networks

Target localization has a wide range of military and civilian applications in wireless mobile networks. Examples include battle-field surveillance, emergency 911 (E911), traffc alert, habitat monitoring, resource allocation, routing, and disaster mitigation. Basic localization techniques include time-of-arrival (TOA), direction-of-arrival (DOA) and received-signal strength (RSS) estimation. Techniques that are proposed based on TOA and DOA are very sensitive to the availability of Line-of-sight (LOS) which is the direct path between the transmitter and the receiver. If LOS is not available, TOA and DOA estimation errors create a large localization error. In order to reduce NLOS localization error, NLOS identifcation, mitigation, and localization techniques have been proposed. This research investigates NLOS identifcation for multiple antennas radio systems. The techniques proposed in the literature mainly use one antenna element to enable NLOS identifcation. When a single antenna is utilized, limited features of the wireless channel can be exploited to identify NLOS situations. However, in DOA-based wireless localization systems, multiple antenna elements are available. In addition, multiple antenna technology has been adopted in many widely used wireless systems such as wireless LAN 802.11n and WiMAX 802.16e which are good candidates for localization based services. In this work, the potential of spatial channel information for high performance NLOS identifcation is investigated. Considering narrowband multiple antenna wireless systems, two xvNLOS identifcation techniques are proposed. Here, the implementation of spatial correlation of channel coeffcients across antenna elements as a metric for NLOS identifcation is proposed. In order to obtain the spatial correlation, a new multi-input multi-output (MIMO) channel model based on rough surface theory is proposed. This model can be used to compute the spatial correlation between the antenna pair separated by any distance. In addition, a new NLOS identifcation technique that exploits the statistics of phase difference across two antenna elements is proposed. This technique assumes the phases received across two antenna elements are uncorrelated. This assumption is validated based on the well-known circular and elliptic scattering models. Next, it is proved that the channel Rician K-factor is a function of the phase difference variance. Exploiting Rician K-factor, techniques to identify NLOS scenarios are proposed. Considering wideband multiple antenna wireless systems which use MIMO-orthogonal frequency division multiplexing (OFDM) signaling, space-time-frequency channel correlation is exploited to attain NLOS identifcation in time-varying, frequency-selective and spaceselective radio channels. Novel NLOS identi?cation measures based on space, time and frequency channel correlation are proposed and their performances are evaluated. These measures represent a better NLOS identifcation performance compared to those that only use space, time or frequency.

Dynamic modeling of active regeneration in catalyzed and non-catalyzed diesel particulate filters

Particulate matter (PM) emissions standards set by the US Environmental Protection Agency (EPA) have become increasingly stringent over the years. The EPA regulation for PM in heavy duty diesel engines has been reduced to 0.01 g/bhp-hr for the year 2010. Heavy duty diesel engines make use of an aftertreatment filtration device, the Diesel Particulate Filter (DPF). DPFs are highly efficient in filtering PM (known as soot) and are an integral part of 2010 heavy duty diesel aftertreatment system. PM is accumulated in the DPF as the exhaust gas flows through it. This PM needs to be removed by oxidation periodically for the efficient functioning of the filter. This oxidation process is also known as regeneration. There are 2 types of regeneration processes, namely active regeneration (oxidation of PM by external means) and passive oxidation (oxidation of PM by internal means). Active regeneration occurs typically in high temperature regions, about 500 - 600 °C, which is much higher than normal diesel exhaust temperatures. Thus, the exhaust temperature has to be raised with the help of external devices like a Diesel Oxidation Catalyst (DOC) or a fuel burner. The O2 oxidizes PM producing CO2 as oxidation product. In passive oxidation, one way of regeneration is by the use of NO2. NO2 oxidizes the PM producing NO and CO2 as oxidation products. The passive oxidation process occurs at lower temperatures (200 - 400 °C) in comparison to the active regeneration temperatures. Generally, DPF substrate walls are washcoated with catalyst material to speed up the rate of PM oxidation. The catalyst washcoat is observed to increase the rate of PM oxidation. The goal of this research is to develop a simple mathematical model to simulate the PM depletion during the active regeneration process in a DPF (catalyzed and non-catalyzed). A simple, zero-dimensional kinetic model was developed in MATLAB. Experimental data required for calibration was obtained by active regeneration experiments performed on PM loaded mini DPFs in an automated flow reactor. The DPFs were loaded with PM from the exhaust of a commercial heavy duty diesel engine. The model was calibrated to the data obtained from active regeneration experiments. Numerical gradient based optimization techniques were used to estimate the kinetic parameters of the model.