Occurrence Of Specific Events Research Articles

Time-frequency analysis of single-point engine-block vibration measurements for multiple excitation-event identification

The short-term-Fourier-transform (STFT) is used to identify different sources of IC engine-block vibration from single-point acceleration measurements taken with a commercial knock sensor. Interest is focused on using the STFT to distinguish normal combustion from other sources of excitation including valve impact, injector pulses, and abnormal combustion, such as knocking. Positive identification of these other events using a single method can be useful for pre-processing of measured knock-sensor data for neural-network-based reconstruction of cylinder pressure. It can also be useful separately as part of a fast knock detection system. A series of experiments is discussed to create the data to isolate these different events on a 3-cylinder gasoline engine. In each case, the measured data is processed using the STFT to attempt to isolate the occurrence of particular events in the time domain. Four classes of experiments are undertaken: (i) an un-fired (motored) engine, driven by a dynamometer, with spark plugs fitted, and then removed, to isolate valve impact; (ii) a fired engine running under idle conditions, to contrast no-load combustion with no combustion; (iii) a part-loaded engine running normally, and then running with one injector switched-off, and (iv) a fully-loaded engine running normally, and then running with knock-control switched-off. The paper shows that a single Time-frequency analysis method, applied to knock sensor data in the form of an appropriately-tuned STFT, can effectively identify the occurrence of these events in the time domain if responses are adequately separated and strong enough.

XMLNET: An Architecture for Cost Effective Network Management Based on XML Technologies

XML technologies have been recently introduced in network management towards alleviating limitations of SNMP. The XML W3C standard, along with XML technologies has the potential to boost open, interoperable, cost-effective and standards-based management solutions. This paper highlights recent efforts towards XML network management and introduces an architecture supporting XML-based network management applications. This architecture specifies a runtime environment that parses XML documents containing composite operations for individual devices, as well as for heterogeneous mutli-vendor networks. Management operations in the scope of XML documents are defined in a programmable fashion based on an XML-based composition language supporting aggregations of elementary operations, looping commands, conditional statements, as well as simple rules signifying the occurrence of specific events. The introduced environment allows network managers to define management operations featuring high-level semantics and accordingly produce sophisticated applications through XML authoring. Following the illustration of the architecture, its composition language and issues relating to security and error handling, the paper ends up presenting a prototype implementation, along with associated performance evaluation results.

MRC/BHF Heart Protection Study of cholesterol lowering with simvastatin in 20 536 high-risk individuals: a randomised placebocontrolled trial

Throughout the usual LDL cholesterol range in Western populations, lower blood concentrations are associated with lower cardiovascular disease risk. In such populations, therefore, reducing LDL cholesterol may reduce the development of vascular disease, largely irrespective of initial cholesterol concentrations. 20,536 UK adults (aged 40-80 years) with coronary disease, other occlusive arterial disease, or diabetes were randomly allocated to receive 40 mg simvastatin daily (average compliance: 85%) or matching placebo (average non-study statin use: 17%). Analyses are of the first occurrence of particular events, and compare all simvastatin-allocated versus all placebo-allocated participants. These "intention-to-treat" comparisons assess the effects of about two-thirds (85% minus 17%) taking a statin during the scheduled 5-year treatment period, which yielded an average difference in LDL cholesterol of 1.0 mmol/L (about two-thirds of the effect of actual use of 40 mg simvastatin daily). Primary outcomes were mortality (for overall analyses) and fatal or non-fatal vascular events (for subcategory analyses), with subsidiary assessments of cancer and of other major morbidity. All-cause mortality was significantly reduced (1328 [12.9%] deaths among 10,269 allocated simvastatin versus 1507 [14.7%] among 10,267 allocated placebo; p=0.0003), due to a highly significant 18% (SE 5) proportional reduction in the coronary death rate (587 [5.7%] vs 707 [6.9%]; p=0.0005), a marginally significant reduction in other vascular deaths (194 [1.9%] vs 230 [2.2%]; p=0.07), and a non-significant reduction in non-vascular deaths (547 [5.3%] vs 570 [5.6%]; p=0.4). There were highly significant reductions of about one-quarter in the first event rate for non-fatal myocardial infarction or coronary death (898 [8.7%] vs 1212 [11.8%]; p<0.0001), for non-fatal or fatal stroke (444 [4.3%] vs 585 [5.7%]; p<0.0001), and for coronary or non-coronary revascularisation (939 [9.1%] vs 1205 [11.7%]; p<0.0001). For the first occurrence of any of these major vascular events, there was a definite 24% (SE 3; 95% CI 19-28) reduction in the event rate (2033 [19.8%] vs 2585 [25.2%] affected individuals; p<0.0001). During the first year the reduction in major vascular events was not significant, but subsequently it was highly significant during each separate year. The proportional reduction in the event rate was similar (and significant) in each subcategory of participant studied, including: those without diagnosed coronary disease who had cerebrovascular disease, or had peripheral artery disease, or had diabetes; men and, separately, women; those aged either under or over 70 years at entry; and--most notably--even those who presented with LDL cholesterol below 3.0 mmol/L (116 mg/dL), or total cholesterol below 5.0 mmol/L (193 mg/dL). The benefits of simvastatin were additional to those of other cardioprotective treatments. The annual excess risk of myopathy with this regimen was about 0.01%. There were no significant adverse effects on cancer incidence or on hospitalisation for any other non-vascular cause. Adding simvastatin to existing treatments safely produces substantial additional benefits for a wide range of high-risk patients, irrespective of their initial cholesterol concentrations. Allocation to 40 mg simvastatin daily reduced the rates of myocardial infarction, of stroke, and of revascularisation by about one-quarter. After making allowance for non-compliance, actual use of this regimen would probably reduce these rates by about one-third. Hence, among the many types of high-risk individual studied, 5 years of simvastatin would prevent about 70-100 people per 1000 from suffering at least one of these major vascular events (and longer treatment should produce further benefit). The size of the 5-year benefit depends chiefly on such individuals' overall risk of major vascular events, rather than on their blood lipid concentrations alone.

Management of High Performance Scientific Applications using Mobile Agents based Services

High performance scientific applications are currently implemented using native languages for optimizing performance and utilization of resources. It often deals with thousands of code lines in FORTRAN or in C built of legacy applications. On the other hand new technologies can be exploited to improve flexibility and portability of services on heterogeneous and distributed platforms. We propose here an approach that allows programmers to extend their applications to exploit this kind of services for management purposes. It can be done simply by adding some methods to the original code, which specialize application management on occurrence of particular events. We mean that applications do not need to be rewritten into different languages or adopting specific programming models. We implemented a native console that is used by Mobile Agents to control the application life-cycle. Agents implement a mobile service that supports check-pointing, suspension, resume, cloning and migration of managed applications. A WSRF interface has been provided to Grid users who do not need to be aware about agents technology. We used a FORTRAN code for simulation of plasma turbolence as a real case study.

Problemy związane ze statystycznym opisem przestępczości w oparciu o dane statystyk policyjnych

Problemy związane ze statystycznym opisem przestępczości w oparciu o dane statystyk policyjnych

Managing Conflicts between Rules

Rules are used as a programming paradigm in several application domains, including active databases, planning, expert systems, and billing. For example, active databases have rules that execute upon the occurrence of particular events if specified condition predicates are satisfied. It is often the case that multiple rules are fireable when a particular event occurs. We propose a declarative mechanism to control the interaction and execution of multiple rules. The mechanism is based upon logical meta-rules that can express various types of relationships between rules. The meta-rules allow us to reason statically about the rule behavior. We can determine, in polynomial time, whether a rule will never execute, whether two rules can ever be executed together, and whether a rule system is guaranteed to have a unique execution set for all possible rules that become fireable. In this paper, we illustrate our techniques using rules in an active database. A system based upon the meta-rules and the static analysis presented here has been found to be of value in a billing application at AT & T to control interactions between discount plans.

Using Event History Analysis in Historical Research: With Illustrations from a Study of the Passage of Women's Protective Legislation

Historians and social scientists often investigate the conditions that influence the occurrence of particular events. For instance, a researcher might be concerned with the causes of revolutionary action in some countries or the forces that unleash racial rioting in major cities. Or perhaps the researcher wishes to examine why industrial workers decide to strike or what prompts policy-makers to pass new legislation. In each of these examples, a qualitative shift occurs, from a circumstance without racial rioting in a particular city, for instance, to one with racial rioting. Event history analysis can aid researchers in uncovering the conditions that lead to such a shift.

Doomed to Failure: Narratives of Inevitability and Conspiracy in a Failed IS Project

Episodes of failure provide an interesting arena for the observation of alternative interpretations of organizational events. The social psychology literature suggests that individuals tend to attribute failure to external forces and that this may be due to selective perception, which may be motivated by the preservation of self-esteem and/or image enhancement. This paper discusses the differing narratives describing the failure of an information system in a UK hospital. It is suggested that these narratives may be seen as attributing failure to either the occurrence of particular events, or to the deliberate actions of specific groups or individuals. These are characterized as narratives of inevitability and conspiracy. Some possible reasons for the promotion of these alternative narratives are discussed.

Semantic fields and meaning: A bridge between mind and matter

The model hypothesizes that the semantic structure of the local universe will tend to allow for the occurrence of specific events while diminishing the likelihood of others. This could be seen as the dynamic underlying synchronicities or “chance” series. Several parameters relevant to this informing and “blending” of reality can be identified, including the psychological and cognitive traits correlated to psi performance in laboratory research, as well as the depth‐psychological dynamics observed in psychoanalytical studies. Whether seen as a product of symbolic operations or as a neural‐network emergent, meaning is largely conceived as an internally generated epiphenomenal process. Little attention is given to the active role of meaning. The basic hypothesis presented here is that the generation of meaning is, in itself, an organizing process shaping reality, while the mind is, in its turn, shaped by a reality endowed with meaning. Extending a basic connectionist premise, we might view the mind as a network organized in semantic constellations, generated by the interplay of experience, genetic constraints and cultural context. This network, which we will call the noo‐semantic field, reflects an ongoing conceptualization and valuing process; it constitutes the totality of a person's cognitive/affective dynamics, and serves as the basic interpretational framework. It is postulated, however, that the noo‐semantic field is also the source of a projective process imprinting information and order upon the outer world. The effects of this process range from the everyday creation of “world‐three” objects, to an ongoing, but far subtler “impregnation” of the environment with meaning. This dynamic generates a semantic dimension in objects themselves—an eco‐semantic field of an allopoietic nature. The two facets of global semantic interaction are engaged in a circular dynamic. Perception of a novel object activates and reorganizes internal constellations, while, simultaneously, the emergent meaning‐clusters are injected into the eco‐semantic field of the external object, thus changing its organization and status in consensual reality. The modified eco‐semantic field, in turn, will be “retrojected” into the psyche, starting a new loop, until eventually, this mind/object interaction stabilizes. It is proposed that this semantic synergy primarily implicates events or objects relevant to the noo‐semantic field—especially those of our immediate environment. This leads to the concept of “local universe” as being, for an individual, that part of phenomenal reality imprinted and shaped by his/her noo‐semantic field; thus, the way in which the local universe is organized tends to reflect the person's own worldview and set of values. Analogous semantic dynamics come into play at a collective level. Groups sharing common beliefs, aims, activities, etc. can be viewed as a collective noo‐semantic field creating its own local universe. Thus the group consciousness also shapes events and objects within its local universe—the more coherent the group, the stronger the shaping of reality.

High susceptibility of U937-derived subclones to human immunodeficiency virus type 1 infection correlates with accumulation of unintegrated circular viral DNA.

Our previous report showed that U937-derived subclones were differentiated into at least three types (high, middle, and low types), even in the subclones expressing similar levels of surface CD4, in terms of the kinetics of the appearance of viral antigens and virus production after infection with human immunodeficiency virus type 1 (HIV-1). Here we showed the evidence that high susceptibility to HIV-1 infection, which was confirmed by the profound expression of viral messages and antigens, was exclusively associated with a high number of the unintegrated extrachromosomal form of viral DNA, but not with the amounts of adsorbed virus RNA nor those of integrated DNA form. The difference in the amounts of extrachromosomal form of viral DNA was also observed in the culture with 3'-azido-3'-deoxythymidine (AZT), indicating that the susceptibility is essentially unrelated to multiple infection events. Thus, the susceptibility of U937-derived subclones to HIV-1 infection seems to be affected by the occurrence of specific events involved in the accumulation of unintegrated viral DNA after viral adsorption.

Instantaneous frequency of a transient mechanical signature and its estimation by a moving window; applicability and physical interpretation

Instantaneous frequency often indicates the occurrence of specific events which could indicate a change in the action of machinery. It is therefore useful to find a way to utilise instantaneous frequency on the characterisation of transient actions of mechanical components. This can also be based on conventional signal processing techniques such as amplitude--time domain data and Fourier analysis. In this paper, we look at the possibility of applying instantaneous frequency to analyse transient mechanical signatures. We found that instantaneous frequency is quite sensitive to signal to noise ratio and therefore to utilise this measure an improved estimator which can minimise the effect of noise on the estimation is needed. The suggested method is a moving window in the time domain, which essentially averages out the noise effect for the prescribed window length. The proposed method reduces the noise effect on the instantaneous frequency estimation but is not satisfactory for signals which have quite low signal to noise ratios. To deal with this, we proposed an 'instantaneous frequency histogram' which shows the number of occurrences of instantaneous frequency and can thus be used to grade the meaningful instantaneous frequency components. The non-linear characteristics of the instantaneous frequency which produce the additional component of the signal which in general has frequencies which differ from the original signals is discussed in terms of its applicability and limitations for mechanical signature analysis.

The first two moment matrices of the counts for the markovian arrival process

Analytic, asymptotic and algorithmic properties of the first two moment matrices of the counts during an interval (0,t ] in the Markovian arrival process (MAP) are discussed. These properties are useful in the computation of Palm densities and dispersion functions with arbitrary initial conditions. These descriptors, in turn, are helpful in visualizing the behavior of the point process following the occurrence of special events, such as bursts of arrivals, or in studying the superposition of two independent MAPs.

Integration of Quality Assurance Activities into a Computerized Patient Data Management System in an Intensive Care Unit

A prototype computer-based patient data management system (PDMS) was developed for a surgery-anesthesiology intensive care unit (ICU) to reduce the time and staff needed to implement quality assurance (QA) functions. Goals of the system were to make QA functions routine and minimally intrusive to the daily operation of the ICU. PDMS collects general data (eg, admissions and discharges, lengths of stay, and bed utilization rates) and specialized data (eg, specific indicators) unique to the ICU and performs prospective monitoring for the occurrence of specific events (occurrence screening) and retrospective examinations of patient records (targeted reviews). Preliminary results suggest that PDMS facilitates the acquisition and analysis of QA data and reduces the time needed to acquire these data. Research to validate these claims and efforts to improve and expand the prototype system with a permanent production system are in progress.

Event-based estimation of interacting Markov chains with applications to electrocardiogram analysis

The problem of estimating the state of a distributed finite-state Markov process consisting of several interacting finite-state systems each of whose transition probabilities are influenced by the states of the other processes is examined. The observations on which the estimation procedure is based are continuous signals containing signatures indicative of the occurrence of particular events in the various finite-state systems. The problem of electrocardiogram analysis serves both as the primary motivation for this investigation and as the source of a case study we describe. The principal focus of the paper is on the development of an approach that overcomes the combinatorial explosion of truly optimal estimation algorithms. We accomplish this by constructing a systematic design methodology in which the resulting estimator consists of several interacting estimators, each focusing on a particular sub-process, Important questions that we address concern the way in which these estimators interact and the met...

Characteristics of Microtubules at the Different Stages of Neuronal Differentiation and Maturation

The developing nervous system has proved to be a very powerful tool to analyze how MT are involved in basic biological processes such as cell proliferation, cell migration, cell shaping, and transport. A better knowledge of the basic events occurring during neurogenesis also affords us the possibility of establishing the basis of experiments and trying to solve unanswered and important questions. Despite the considerable value of cell culture, we need to use more discrete regions of the developing brain in situ in order to analyze the MT and their modifications into cells developing their "natural" environment. One major problem remains the question of the mode of assembly and disassembly, that is, the behavior of MT in living cells. Dynamic instability and/or treadmilling are accurate interpretations of the dynamics of MT at least in vitro or in cell culture, but we do need more information on what happens in situ and in vitro. One of the main tasks of cell biologists is to devise satisfactory tests to approach this fundamental question. In this view, pharmacological manipulation of embryos treated in whole-embryo culture systems might be a possible way. Microtubules are ubiquitous cell components. However, the extensive heterogeneity of MAP and tubulin in the CNS confers on the neurons a wide range of capabilities of assembly of these proteins and suggests that the neuron has a unique potential of a relation between MT composition and cell function. We have seen that each major event during neurogenesis is related to a specific series of modifications of the MT components. It remains to be determined if there is a causal or just a correlative relationship between the appearance of specific isotypes and the occurrence of specific events and/or functions. We have also to determine the exact spatial and temporal relations among the different isotypes of MT proteins, tubulin, and MAP. Is there a close correspondence between a tubulin and a MAP isotype? Can the appearance of one isotype of tubulin influence the appearance and the assembly of a specific MAP, or vice versa? Recent results obtained with the Tyr- and Glu-MT shed light on these questions and suggest a whole series of possibilities for cells to modulate the structure, behavior, and function of MT in specific domains of the neuron or in specific regions of the brain, by only a minute modification of the molecule of tubulin. Microtubule protein heterogeneity raises also a number of questions.(ABSTRACT TRUNCATED AT 400 WORDS)

Automatic load incrementation for rubber-like bodies in contact

Incremental Newton methods are generally used for solving static problems with strong geometric and material nonlinearities. In this context we propose and study an algorithm for automatic load incrementation, suitable for general path-dependent problems with nonproportional loading and frictional contact phenomena. The load steps are chosen adaptively on the basis of the iteration history and the occurrence of special events, such as contact (material overlap). Automatic restart is made at the indication of the beginning of divergence or overlap. At overlap we restart from the latest converged solution with a step chosen to reach a configuration immediately before contact, from which we then proceed with a strongly reduced step. The applicability of the algorithm is demonstrated on typical problems involving highly nonlinear rubber structures.

A note on independent fireability in Petri nets: P.B. Sheridan: IBM Thomas J. Watson Research Center, Yorktown Heights, (Sept. 1982)

Rules are used as a programming paradigm in several application domains, including active databases, planning, expert systems, and billing. For example, active databases have rules that execute upon the occurrence of particular events if specified condition predicates are satisfied. It is often the case that multiple rules are fireable when a particular event occurs. We propose a declarative mechanism to control the interaction and execution of multiple rules. The mechanism is based upon logical meta-rules that can express various types of relationships between rules. The meta-rules allow us to reason statically about the rule behavior. We can determine, in polynomial time, whether a rule will never execute, whether two rules can ever be executed together, and whether a rule system is guaranteed to have a unique execution set for all possible rules that become fireable. In this paper, we illustrate our techniques using rules in an active database. A system based upon the meta-rules and the static analysis presented here has been found to be of value in a billing application at AT & T to control interactions between discount plans.

Institutionalizing Administrative Controls

An institution is an action pattern, a social complex of interrelated habits. Members of an institution occupy habitual positions in relation to other members. The conduct of each individual moves in repetitious patterns governed, by that individual's positional relationships in the institution and by the total action pattern of the institution. These positions are defined in the organizational structure of the institution; they evolve, grow, reach an established routine as the institution becomes a stabilized pattern of social action.An institution may have a formally integrated structure and may be in continuous activity—like a given church; or it may be a contingent pattern of action invoked only on the occurrence of specific events—as marriage or portions of the law. Administration involves both types of institution, but the most frequently observed and commonly studied is the formal structural organization.The administration as a whole (of the Federal Government, for example), or of any well defined unit of it (as a department or independent agency), may be looked upon as an institution. In general, the form is hierarchical, necessitated by the division of labor involved, the requirements of supervision and coördination, the necessity for authority and direction. As a going concern, the administrative unit has daily, monthly, yearly patterns of action. The effectiveness with which the unit achieves its objectives depends upon the appropriateness of its organization to the functions required of it, the perfection with which its various elements are integrated into a smooth-running going concern.