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This paper presents a technique for simulation of the stock preparation and Fourdrinier dynamics which is flexible, convenient, and detailed enough to allow the user to study physical process modifications and transient response dur ing upsets and "furnish" (fibers with different character istics, fillers, dyes, etc.) changes and to evaluate simplified mathematical models and control schemes. The technique uses digital simulation in a block diagram form, each block of which corresponds to one type of physical unit in the process (e.g., cleaner or tanks). Simu lation of a particular process then involves specification of the particular parameters of each physical unit together with the way in which they are interconnected. Individual components of the furnish may be traced through the whole process. A complete wet-end configuration, including the white water recovery system, is simulated using the technique described in the paper, and typical results obtained during grade changes and disturbances are presented.

This paper presents a tutorial analysis of a hybrid computer model of a missile reentering the atmosphere. An important aspect of the paper is that an example of how to go about analyzing the suitability of a hybrid computer configuration for a particular large- scale simulation is presented from an overall systems point of view. Equations describing a missile (six- degrees of freedom) reentering the atmosphere are given, as is a hybrid computer configuration for solving them. This configuration is then analyzed to establish its suitability for simulation.

The author wishes to note that the models discussed in this paper are all now under construction. Al though they are all being designed by the Environ mental Studies Division (ESD), there are large num bers of inputs from various other members of the research and policy community. Further, not all of the members of the ESD design team look at the models exactly as the author does. Each member of ESD's teams was chosen because of his unique point of view and the resulting models all represent a meld. Specifically, the SEAS project staff is composed of Martin Brossman, John Gerba, Sam Ratick, and Gene Tyndall; the carrying-capacity team, of Dr. Martin Redding and Robert Livingston; and so forth. Dr. Philip Patterson and I are members of each of these teams. Because the staff is small in number, there is considerable cross-fertilization in each model area. As a result, the points of view in this paper are mine to the extent that team members disagree, and are all of ours when all do agree. The reader is asked to forgive the nonrigorous and informal presentation of the models in this paper. More detailed documentation presented in a more for mal style can be obtained by writing to the author.

The serious consequences of blade-path deterioration that may result from boiler carry-over has led to active research into the performance aspects by the Air Flow Laboratory of the English Electric Company at Rugby. This paper reviews some of this work and illustrates the conclusions. Data are required to determine nozzle and blade efficiencies with various types of surface finish, from polished specimens which can be regarded as hydraulically smooth, to the type of deposit build-up and/or surface pitting which can be experienced after periods of operation at site. There is a great variety and randomness embraced by the term ‘surface roughness’. In a practical machine the difficulty is not only to obtain an accurate record of the roughened surface, but to assess its effect on the frictional loss. However, very many data have been obtained on the resistance to flow in pipes and along flat plates with varying degress of sand-grain roughness, and the simple theoretical treatment for turbine nozzles and blades explained in the paper makes use of these data. In this way, it has been possible to derive curves showing efficiency correction factors for both Reynolds number and roughness. The enormous variation in Reynolds number through a modern steam turbine makes this a highly important factor. Experimental work using cascades of typical turbine profiles has also been carried out in the laboratory to try to substantiate the theoretical analysis, various grades of emery paper being used as a yardstick. A fair measure of agreement was obtained, and other workers' results are also available for comparison. The cascade tests of efficiency were also extended to reveal the particular areas on the nozzle convex and concave faces which were more susceptible to performance loss owing to localized roughening. Finally both a 200-MW and a 500-MW steam turbine have been worked through to arrive at the worsening in heat rate that might be expected for specific sand-grain roughness values applied to all nozzle and blade surfaces. This sort of information assists the turbine manufacturer in deciding the extent of refinement necessary in his manufacturing processes to obtain satisfactory finishes. On the other hand, these ex-works finishes may well deteriorate after only short periods of site running according to evidence from many sources. Evidently increasing collaboration on these matters between manufacturers, the electricity boards, and station operators is necessary.

Digital simulation studies have been carried out on many traffic phenomena because, being stochastic, they are frequently too complex to be represented by a reasonable mathematical model. Furthermore, empirical laws are difficult to obtain because con ditions on the road rarely remain stable for a sufficient time to obtain reliable data. Most simulations have been carried out to determine maximum flows, queue length, delays, etc. in terms of conflicting traffic flow, driver behaviour para meters, etc. A number of examples of this type of simulation are mentioned in the paper. The author's simulation program, however, was written to give information on vehicle behaviour within the platoon dispersion process. Having modelled starting condi tions at the stopline and arrival patterns at points along the road sufficiently well, it was assumed that vehicle behaviour within the process was also being accurately modelled. The queues of vehicles at stopline are of random length with randomly selected vehicle type and random performance para meters. Leading vehicles in each lane accelerate according to an exponential law, and other vehicles are given accelerations according to one or other of the car- following laws. A novel technique allows driver reaction time to be taken into account. Vehicles may turn from the main road and overtake, the simulation program giving data on every vehicle's position, speed, and acceleration at each scan. The paper describes in detail the more important of the steps which make up the whole complex dispersion process and the various measures taken to verify the simulation.

This paper is primarily concerned with investment by life offices and pension funds in British Government stocks with lives of more than 5 years, although there are important implications for all classes of investors. Investing in British Government stocks over the post-war period has become a highly technical process. The advent of the electronic computer has opened up an entirely new field of statistical data thus making some of the old methods obsolete. The paper illustrates some of the new techniques developed by the author and his colleagues. Other actuaries have also been developing new approaches and it is hoped that they will contribute to a lively and constructive discussion.

SummarySome of the published information that will help an engineer to select a painted metal-sprayed coating for a structure is reviewed, and results of recently-completed field trials on shop-coat paints for sprayed metals are reported. When designing a new steel structure, the engineer must decide on a suitable protective scheme bearing in mind how long the structure will be in use, the costs of protection and maintenance, the risks inherent in coating failure, the need for decoration and the practicability of the scheme chosen. The paper sets out to review his sources of information, to outline the relevant planning and design considerations, and to describe the principles on which the selection of the protective scheme should be based. B I S R A research on the subject is described. Further progress is expected from the exchange of practical experiences linked to field trials and laboratory studies, and the paper ends by quoting several practical examples of steel structures successfully protected by...

Handwriting Recognition Technology has been improving much under the purview of pattern recognition and image processing since a few decades. This paper focuses on the comprehensive survey on on-line handwriting recognition system along with the real application by taking Nepali natural handwriting (a real example of one of the cursive handwritings). The survey mainly includes pre-processing, feature vector and similarity measures in between the non-linear 2D sequences of coordinates, and their effective applications. A very highlighting topic "Dynamic Time Warping Algorithm'' (DTW) is introduced, which has been popular in determining the distance between two non-linear sequences ranging from handwriting to speech recognition. Besides these contemporary research issues/areas, stroke number and order free Nepalese natural handwritten recognition system is presented in the second step. Writing one's own style brings unevenness in writing units, which is the most difficult part to classify. Writing units reveal number, shape, size, order of stroke, and speed in writing. Variation in the number of strokes, their order, shapes and sizes, tilting angles and similarities among characters from one another are the important factors, which are to be considered in classification for Nepali. This paper utilizes structural properties of those alphanumeric characters, which have variable writing units. It uses a string of pen tip's positions and tangent angles of every consecutive point as a feature vector sequence of a stroke. We constructed a prototype recognizer that uses the DTW algorithm to align handwritten strokes with stored strokes' templates and determine their similarity. Separate system is trained for original and preprocessed writing samples and achieved recognition rates of 85.87% and 88.59% respectively. This introduces novel real time handwriting recognition on Nepalese alphanumeric characters, which are independent of number of strokes, as well as their order. Key Words: Handwriting Recognition System; Pre-processing; Feature Vector; Dynamic Time Warping; Agglomerating Hierarchical Clustering; Nepali. DOI: 10.3126/kuset.v5i1.2845 Kathmandu University Journal of Science, Engineering and Technology Vol.5, No.1, January 2009, pp 31-55

This paper addresses several social concerns: population trends; quality of urban life; policies for urban growth; and the unexpected, ineffective, or detrimental results often generated by government programs. Society becomes frustrated as repeated attacks on deficiencies in social systems lead only to worse symptoms. Legislation is debated and passed with great hope, but many programs prove to be ineffective. Results are often far short of expectations. Because dynamic behavior of social systems is not understood, government programs often cause exactly the reverse of desired results. The field of system dynamics now can explain how such contrary results happen. Fundamental reasons cause people to misjudge behavior of social systems. Orderly processes in creating human judgment and intuition lead people to wrong decisions when faced with complex and highly interacting systems. Until we reach a much better public understanding of social systems, attempts to develop corrective programs for social troubles will continue to be disappointing. This paper cautions against continuing to depend on the same past approaches that have led to present feelings of frustration. New methods developed over the last 30 years will lead to a better understanding of social systems and thereby to more effective policies for guiding the future.

This paper stems from a suggestion that it would be worth while to bring to the notice of the profession the progress which has been made and the statistical problems that have arisen in the study of epidemiology in its wider sense, viz. the study, not merely of the spread of communicable disease as was formerly implied by this term, but of the natural history of disease; its prevalence, causation, symptomology and prognosis. It would, however, require a series of papers to cover so wide a field and would demand medical as well as statistical competence. It therefore seemed advisable to use the more restrictive title chosen in order to emphasize the fact that, in the main, consideration is devoted to statistical rather than to clinical aspects.

A draft of this paper was prepared for the Workshop on Simu lation Languages, Graduate School of Business, Stanford Univer sity, March 6 and 7, 1964. The paper has benefited from sugges tions from participants at the Workshop, particularly Michael Montalbano, and from projects carried out by students in the Graduate School of Business: H. Barnett, H. Guichelaar, Lloyd Krause, John P. Seagel, Charles Turk, Victor Preisser. The paper has also benefited from discussions held in connection with the Workshop on Simulation Languages, University of Pennsylvania, March 17 and 18, 1966. Characteristics of computer languages and software packages change rapidly. Some statements in the paper were originally intended for the situation current in March, 1964. Where signifi cant changes have occurred the text has been modified.

Almost every kind of material and fabrication process now has to be used to meet the demands of ocean engineering, ranging as it does from hydrofoils to research submersibles, and from giant tankers to offshore drilling rigs. Some of the difficulties are obvious, for example when aircraft-like design procedures must be adopted for hovercraft to operate at sea; others, such as the vagaries of corrosion and the risks of brittle fracture, are more subtle. This paper briefly reviews the history of the use of materials in ocean engineering and touches upon their impact on contemporary affairs; some present material capabilities and weaknesses are discussed, and the new philosophy of structural validation and some of the supporting techniques being introduced into the Navy are outlined. Some case histories of the use and abuse of materials in ocean engineering are also described and the paper closes with a glance to the future and some suggested golden rules which may help designers to minimize the abuse of materials.

This paper describes the results of an investigation into the feasibility of an automatic patching system for an analog or hybrid computer. The objective of the study is to reduce the number of switches required to a "rea sonable" number. Actual design of hardware is not con sidered. The final result is a "paper" design, which is evaluated by attempting to program several problems to see if enough paths exist. The proposed design uses about 8,000 switches for an EAI-680-sized computer, which is far fewer switches than are required by any previously proposed system. The evaluation shows that this system is more than adequate and that, in fact, about 2,000 switches could be saved by modifying the design slightly.

Shot processes may be used as models for a wide class of naturally occurring random processes ranging from non-Gaussian impulse processes to nearly Gaussian processes. This paper shows how shot processes with desired spectral properties may be simulated easily. Sev eral models are proposed for using shot processes as locally generated noise sources with statistical charac teristics which conform to many naturally occurring noise processes. More general models could be considered and the range of applicability can be extended beyond that men tioned in this paper. However, even the basic models treated can provide a much wider range of noise envi ronment than that usually considered in simulation tech niques.

This paper is mainly concerned with the division of a trust fund between the beneficiaries, when an actuary is asked for a solution which, in his opinion, is fair to all parties concerned. It may be that the beneficiaries are all sui juris and form a closed class, in which case they approach the actuary as umpire, and adopt a passive role, at least until they have considered the implications of his recommendations. Alternatively, the actuary's report may be required to assist the Court to approve a scheme involving beneficiaries, e.g. infants, whom it is the Court's object to protect. In that case the actuary's role—as discussed later in the paper—is rather different, but it may still be necessary for him to state what in his judgment would be an impartial solution.

This paper describes the application of digital and hybrid simulation to the problem of deliberate unba lancing of production lines to obtain shorter produc tion times. The paper demonstrates that hybrid simulation tech niques adequately match the accuracy of digital simulation of the same system. The hybrid provided more flexibility with a reduction in cost.

The 60-square-mile region of extreme northwest Indiana, which includes the cities of Gary and East Chicago, is a highly urbanized and industrialized area. Pollution data over the region show high levels of cadmium, a toxic metal. There are several hundred sources of cadmium in the area, and the impact of each type of source is unclear. An accurate representation of the flow of cadmium would make it possible to structure a reasonable and efficient policy for controlling cadmium pollution. This paper describes a GASP IV computer model for that flow. The basic model is an aggregate continuous model which displays the time behavior of cadmium levels in each of nineteen compartments over a two-year period. This aggregate model raises several ques tions regarding the effects of discrete events such as rainfall. Since the GASP IV language is capable of combined continuous-discrete simulation, these new factors are easily incorporated into the model. Results of the simulation show the relative impact of the various types of sources and provide some insight into control policies. A continuous model was first constructed. Then modifications based on real-world data were implemented as discrete events. The successive forms of the model proved useful for studying at least two of the characteristics of cadmium flow in an urban ecosystem.

There have been many sales of insurance companies in recent years, but there is nothing in the literature of the Institute which deals with valuation for this purpose. It is hoped that this paper and the discussion on it will fill this gap.

The concepts and application of graph theory to practical problems involving networks are discussed. Examples are given from digital system design. The paper was presented at a one-day symposium on Networks, organized by the Computer-Aided Design specialist group of the British Computer Society and held on the 18th March 1974.

Every system has specific kinds and levels of re sponses to conditions as they exist and change in the environment in which the system is immersed. Each response can be expressed quantitatively by a structure in N- dimensional space, where N refers to the number of different environmental factors which operate together to determine the level of that response, and each dimension represents one of the determinative environmental factors. Examination via this response structure of the relationship between environmental factor levels and the system's response permits analysis and modeling of the system's dynamics and allows accurate evaluation of its relationships to other systems. This paper in cludes examples of use of this approach in the modeling of the ecological processes of population growth, competition, predation, and evolution, and it presents a model of a simple hierarchical eco system. Suggestions are made concerning the utiliza tion of this analytical and heueristic approach to examine other, very different systems; brief examples from economics, public health, and social psychology are given.

The ROBOT INVESTOR is an integrated system of computer heuristics based in part on human experience and port folio management theory. It is designed to receive information about the state of the current stock mar ket and the investor's existing portfolio and to translate this information into actions that will provide a reasonable and stable rate of return. This paper is the next logical step in the process. The robot forecasts the future price behavior of, and estimates risks of, individual stocks. This informa tion is passed to a decision model, which is designed to meet the dynamic real-world problem of continuous portfolio management. The Robot Investor includes a forecaster, a decision model, an accounting section, and an adaptive control section. The robot has been tested on a randomly selected list chosen from 740 major corporations traded on the New York and American Stock Exchanges and over the counter, using the monthly prices from January 1960 to December 1967. The results are competitive with those of mutual funds over the same period. An advanced model based on this study has significantly improved the performance of an investment club.

SummaryThe paper describes the historical development of electrolytic colouring processes from the early observations in Italy and Germany, to the first industrial use in Japan and the now very widespread use of electrolytic colouring techniques throughout the world. Details of colouring processes are provided and the patent literature on this subject is reviewed. Finally properties of the finishes, such as light-fastness, heat resistance, corrosion resistance and chemical resistance are described.

This paper outlines the software for an open-water version of CLEAN, an ecosystem model for lakes. The modular program structure is described, examples of driving variables are given, and the output (including values of several parameters) is shown. The program, with extensive annotations to facilitate adaptation by potential users, is available from author Richard A. Park or from SCS.

Computer simulation of cognitive processes requires con structing an explicit model of human thinking behavior in the form of a computer program. Such a program cannot avoid being explicit and unambiguous. Thus it serves as a hypothesis to be tested against the corresponding human behavior. Models that don't "work" suggest questions to ask. Recent work in simulating cognition suggests that the basic elements in cognitive processes are attention, conscious ness, and memory. In this paper, a hypothesis is presented describing probable interactions among these elements for a simple cognitive process. To facilitate simulation a paradigm is presented which characterizes experimenter subject interactions in such a way as to allow an investiga tor to more easily attempt a simulation. A sample simu lation of concept identification behavior is included to illustrate the use. of this paradigm.

Ecosystem modeling for simulation and systems analy sis is complicated by (i) size and complexity of ecosystems, (ii) lack of data and methods for obtain ing needed measurements, and (iii) inadequacies of modeling theory for macrosystem applications. This paper presents an S/360 CSMP simulation of a gener alized shortgrass prairie scaled large enough to preserve meaningful biological detail, but still small enough for computer implementation. Both nomi nal and small perturbation behaviors are described, together with a modeling rationale tied to the closed-loop recycling structure of ecosystems. The model, which is piecewise linear and piecewise stationary, demonstrates in the context of system complexity and insufficient data the potential of linear methods for successfully characterizing ecosystem dynamics.

SummaryThis paper investigates the recalculation from its base date of theFinancial TimesIndex of Industrial Ordinary Shares (hereafter called theFTIndex) using the ordinary arithmetic mean of the values of its constituents, rather than the geometric mean that is actually used in its calculation. The value of this arithmetic version of theFTIndex represents that of a portfolio invested equally in each of the original constituents at the base date. The behaviour of the recalculated index may therefore be described in portfolio terms.The arithmeticized index has been calculated at each end-year since the base date of theFTIndex (1 July 1935). By the end of 1970 its value was 38% higher than that of the (geometric)FTIndex. The percentage by which the new index exceeded the original was found to have increased approximately linearly with time; a least-squares linear fit over the whole period indicated that the percentage excess of the arithmetic version over the original index had increased on average by 0·8% a year. A separate fit for the period from end-1960 onwards shows that this rate had increased to 2·7% per year, and even over the period since 1950, it has been 1·1% per year. Use of these relationships gives a rough adjustment of theFTIndex for portfolio comparison purposes.We also calculated a series of arithmetic indices with base dates at the end of each year since the original base date of theFTIndex. In the majority of calendar years since its foundation, theFTIndex has not fallen far behind the corresponding arithmetic version over the twelve month period. However, over periods of more than a year, the geometric and arithmetic indices can show dramatically different results, particularly if the percentage change in the index value is considered. It is clear that longer-term changes in the value of theFTIndex cannot be interpreted as the changes that would have occurred in the value of a portfolio equally invested in the thirty constituent shares at the beginning of the period.None of these findings affects the usefulness of theFTIndex for its original purpose, as a sensitive daily indicator of changes in the industrial ordinary share market. It is purely its long-run use as a portfolio standard that is misleading. For this purpose the more recently instituted arithmetic indices are likely to be useful in the future. Meanwhile, our arithmeticizedFTIndex values may be useful to correct the downward drift imposed on theFTIndex by its geometric construction.

The most obvious effect produced when microwaves are directed into an absorbing substance is the conversion of electromagnetic energy into heat. Awareness of microwave exposure is developed by several mechanisms among which are cutaneous thermal sensation or pain. Although the subjective awareness of warmth is only a rough indicator of microwave exposure, nevertheless, several investigators have established the thresholds for microwave induced thermal sensation and pain in man. The threshold for warmth perception is reached at a warming of the skin at a rate of about .001 °C per second. Threshold and intensity of temperature sensation depend to a large extent on the size of the skin area changing temperature. This paper is a review of the available information on cutaneous sensation of microwave energy which indicates that when a 40 cm2 area of the face is exposed to microwaves, thermal sensation can be elicited within 1 second at power densities of 21 mW/cm2for 10,000 MHz and 58.6 mW /cm2 for 3,0...

While attention in the iron and steel industry has been focused on the study and analysis of the flow of materials through the main productive units (blast furnaces, steel works, and rolling mills), the analysis of this flow through the nonproductive units (the mixer and soaking pits) is generally over looked. These two units would create serious bottle necks in production if their capacities were not properly determined before being installed. This paper considers the soaking-pit/rolling-mill complex as a queueing system in which the soaking pits are viewed as units circulating a cyclic queue, and the rolling mill as the service station. A simulation model representing the pit-mill system is developed: (1) To predict the improvement in the capacity of the system through adding more pits (2) To predict the effect of breakdowns and mainte nance or the shutdown of a pit. Several criteria, including their economic aspects, are used to measure the performance of the system. The optimal capacity of the system is determined such that an economic balance between the cost of service and the cost of waiting for that service is achieved.

This paper is concerned with a hybrid computer simulation of the space-time xenon oscillation problem. Such prob lems are important in large thermal nuclear power reactors. The basic nuclear reaction is modeled by three slightly nonlinear partial differential equations-a diffusion equa tion describing the neutron flux concentration, and two first-order partial differential equations which contain only partials with respect to time and which describe the gen eration and decay of iodine and xenon. The continuous-space discrete-time approximation is used to implement the equations on the hybrid computer. By discretizing the time variable the xenon and iodine equations are reduced to algebraic expressions and the flux equation is reduced to a boundary value problem. The algebraic equations are decoupled from the boundary value problem and, therefore, solvable on the digital computer, by invoking the assumption that the nonlinear flux terms change slowly with respect to the time step. This assump tion also simplifies the boundary value problem which is solved on the analog computer in conjunction with digital function storage. The simulation effectively displays the space-time xenon oscillatory behavior resulting from an initial spatial per turbation of the flux shape. This information is used to study the stability of the local changes in the xenon con centration and, hence, the spatial variations of reactivity in the core.

SummaryThe paper considers the action of accelerators in zinc phosphate systems and other chemical additives which, in conjunction with accelerators, influence the nature of the phosphate coating and the processing conditions. It also considers nitrate and nitrite accelerated systems, chlorate containing systems, peroxy accelerated systems, and other possible accelerators. The effect of the accelerator on coating structure is illustrated by the scanning electron microscope, and factors influencing the choice of accelerator system, and hence the type of processes, and equipment requirements are reviewed.

Due to rise in the price of fossil fuels and technical advances in the area of renewable energy, integrated systems became more popular now a day. However uncertain nature of wind, solar irradiation due to weather and climate change, integration of renewable power generation system complicates the ELD formulation. The paper presents optimum scheduling of integrated solarwind- thermal system using backtracking search algorithm (BSA). BSA is a novel population based stochastic search optimization technique, having simple structure and only one control parameter as population size. BSA has two new types of operator’s as crossover and mutation for exploration and exploitation of search space of problem desired to be optimized and also satisfies all associated constraints of the objective function.Keywords: BSA, Photovoltaic cell, Valve point loading effect, Probability density function.

Tuberculosis at the present time still causes over 20,000 deaths a year in England and Wales and is one of the major medical problems of the day. The mortality of the disease has been considered several. times recently in papers or discussions of the Institute (Pedoe, 1947; Elderton, 1947; Conybeare, 1948), and always it is the mortality by calendar years that has been mentioned or implied. It is the purpose of this note to draw attention to the somewhat different picture obtained when generation mortality rates for tuberculosis are examined.

The limited reserves of mineral resources will soon become a problem facing all the countries of this globe. In an attempt to plan for the needed supply, the static reserve life index of a resource has been used as a measure of future availability. This static index is an inadequate measure of resource availability, one which could cause severe misjudg ments concerning resource supplies. Long-term re source planning requires a better understanding than that afforded by the static reserve life index. This paper illustrates that knowledge already available about the relationships governing the supply of and demand for resources is sufficient to develop a frame work, a simulation model, which can form the basis for more meaningful analysis of long-term resource utili zation.

Previous work relating to the control of legged locomo tion systems has suggested that it might be possible to achieve stable locomotion in a machine using only on-off actuators at each joint. It has further been hypothesized that the coordination of joint motions could be accom plished by a simple finite algorithm implemented as an extremely small special-purpose digital computer. The re search reported in this paper establishes the validity of these conjectures by means of a successful experiment. A quadruped with four identical legs, each with a powered hip joint and knee joint, has been constructed and tested. The results obtained have significance both with respect to prosthetics and orthotics and with respect to the design of vehicles for off-the-road transportation.

This paper reviews the software and hardware requirements for on-line computing. It shows these facilities can be used to conduct on-line simulation experiments of models of agricultural systems. The general problems associated with modelling are indicated and the advantages of the on-line approach are discussed. Key words and phrases: on-line computing, modelling agricultural systems, systems analysis in agricul ture.

The right way to negotiate with Europe is the way in which, at its best, the Common Market has handled its own problems. One should start from the view that there is a collective European interest to be served, as there always is. One should then make sure that the separate national interests are reconciled with the interests of Europe. Only a man who thinks in European terms can make this adjustment of national and European interests successfully.The Times—29 July 1970.This paper must be forward-looking. To dwell on the past, and even the present, would fill many pages to little purpose. The author is convinced after reviewing many files of documents that the European Common Market would not have gone forward if its founders had allowed themselves to be sidetracked by narrow interests. This perhaps sounds ominous to experts in particular fields, such as actuaries, for it is not always a happy position when political motives may overrule, or cut short, technical considerations. But the concept of the Common Market is a political one and this is becoming more apparent as the years roll on. The collective European interest will prevail but that does not mean that British philosophy and practice cannot make a distinguished contribution to European thought in the field of insurance, particularly life assurance. In practical terms, it is clearly not possible to argue for the adoption of British practice in its entirety. But I do believe that unless the profession takes every opportunity to argue the merits of our own ways of providing life assurance in the private sector, we may well live to regret the omission.

Continuous parameter tracking systems utilizing the out put-error method have been analyzed by intuitive argu ments1 and by linearized equations2. This paper presents a method for analyzing the convergence properties of this type of system; it is applicable when the input signal is either a single sinusoid or a sum of sinusoids. The method is based on the technique advanced by Kryloff and Bogo liuboff3.

This paper describes a method for obtaining an engineering solution for integrodifferential equations of physical systems using an electronic system. The components consist of standard plug-in feed-back amplifier units. As the interconnections are wires, resistors, and capacitors, no complicated mechanical layout problem is involved and a generally flexible analyzer need not be set up, for it is a simple matter to assemble the particular circuit for any system of equations for which solutions are desired. The system should, therefore, be of interest to those involved in a study of the dynamics of physical systems.

In October, 1968 the U.S. Congress passed, and former President Johnson signed, Public Law 90–602, The Electronic Products Control Law. To carry out the provisions of this law the Bureau of Radiological Health (BRH) of the United States Public Health Service was given the responsibility of setting standards and maintaining surveillance over all electronic products that may emit hazardous levels of electromagnetic radiation. In addition to the problem of ionizing radiation, a very large area of concern involves exposure to microwaves. The exact nature of the biologic effects of microwaves is not completely understood. Although most of the experimental data support the concept that the effects of microwave exposure are primarily a response to local or general hyperthermia, there are large areas of confusion, uncertainty and actual misinformation. This paper reviews the present state of knowledge on biologic effects of microwaves and attempts to (1) differentiate between the known and substantiated f...

In the recent literature, a paper1 and a contract report2 indicate that automatic analog computer patching sys tems have become economically and technologically feasible. In anticipation of the development of a variety of proposed patching systems, a specific decision pro cedure is developed for the rational evaluation of com peting automatic analog patching systems. The design procedure described in this paper facilitates selection of the patching system best suited for a partic ular computer and a particular problem class. Sufficient information is abstracted from a typical problem set to determine the number of relays required for (and thus to assign a cost figure to) each possible patching system without requiring the actual design of each system. Nom inally, the best system is that with the lowest cost figure. It is recognized, however, that there are many subjective decisions (e.g., captive vs. free pots) involved in the de sign process that are not quantified in this overall cost figure. This problem is met in part by providing inter mediate information relating to the optimal module size, combinations of proposed systems, etc. to help estab lish some of the sensitivity properties of the optimal system. The procedure is illustrated by applying it to a particu lar case and evaluating a number of alternative switching systems.

This paper describes a new solid-state, monolithic inte grated analog multiplier, based on the controlled-trans conductance principle that is designed for high speed, high accuracy, and excellent linearity. A novel differ ential amplifier circuit permits cancellation of undesired nonlinearities, and carefully matched device geometries account for the good accuracy of the new multiplier. With an inherent voltage gain of A v = 1/10, the multi plier will provide a ± 10 V output at ± 10 mA with linearity approaching 0.1 % at 100 Hz. The multiplier package may be used in conjunction with an external operational amplifier and external resistors, and offers the advantages of monolithic construction (low cost, ex cellent temperature tracking) with the precision of ad justable-parameter, discrete construction.

This paper emphasises the fact that mathematical modelling techniques have important applications in routine medical practice and medical education. It is argued that the development of mathematical models should be more closely linked to experimentation and that techniques based on computer simulation can extend the range of applicable models to models based on nonlinesr differential equations which are the largest class of models in biological work. Model have an important role in hypothesis testing and in the development of indirect methods for measuring physiological quantities. The important of model validation is stressed.

An automatic patching system for analog computers is proposed. The system patches any set of component ter minals together, yet size and cost are practical. The design is accomplished in three steps: First, a "model" analog computer is defined and its components divided into modules. Components within a module connect to one another through an "intraface" which allows any terminal to connect to any other ter minal. Problem sections are patched within the modules and then joined together by an "intermodular" trunking system. Secondly, the principle of module chaining permits in dividual modules to access a limited number of other modules, rather than all other modules. This reduces the number of patching switches required by the intermodular trunking system and reduces the overall number of switches required. The third step, called concentration, brings the required number of patching switches down to a practical value by assuming that all analog computer terminals will not be in use at once. Switching devices called "concentrators" exploit this fact to reduce switch requirements. The automatic patching system is driven by a digital computer under control of specialized software, and to gether with the automatic patching control system it can patch large problems in times of the order of fifteen sec onds. The information in this paper is a result of work done for a Master of Science thesis.1

In the investigation of many physical systems, it becomes necessary to simulate the time-delay phenomenon on the computer. This phenomenon arises in such investigations as shock waves in mechanical systems, sound waves in acoustical systems, and more generally in connection with the flow of materials in chemical processes and heat exchangers. Since information about such systems is not available until a finite time after certain actions have been performed, it is essential to represent this time-delay phenomenon adequately. Various methods have been used to do this, depend ing on the value of the time delay involved and the frequencies contained in the variable quantity passing through the delay. This paper discusses the application of operational amplifiers to form time-delay approximations for those applications where the delay is more or less constant. A number of such approaches are discussed and the resulting approximations are brought into a common form and scale, so that comparisons between the different approximations may be easily accomplished.

CHEMCSMP is a convenient problem-oriented language based on CSMP/360 and is designed specifically to solve problems in kinetic chemical equations. Users' statements, which resemble conventional chemical nota tion, describe slow and fast reactions in multicompartment systems and flows between compartments. CSMP statements may be inter mixed with chemical equations to provide for a variety of computations and convenient output. CHEMCSMP is implemented via a pre compiler which translates the user's pro gram into pure CSMP. The paper describes the use and implementation of CHEMCSMP and provides an illustrative example.

This paper deals with a design of optimal parameters of PI regulator in voltage control loop. The design aims to minimize voltampere (VA) loading of synchronous reference frame (SRF) based multi converter-DVR in parallel feeder distribution systems. To improve the power quality by using power conditioner with multi converters in each feeder distribution system under different load considerations, a dynamic model of synchronous-reference- frame (SRF) has been adopted. It is desirable to have optimization of PI components and generate the reference compensate voltages for series active filters (SAF) of MC-DVR. Therefore, series active filters help to inject optimal voltages at optimal angle in such a way that a minimum VA loading of MCDVR is possible. The optimal value PI components and optimal series injected angle of series active power filters are computed using particle swarm optimization (PSO) technique and the results are verified with genetic algorithm (GA). The simulation results show that the proposed PSO technique causes minimum error and minimum VA loading angle by optimally choosing parameters of PI and minimum VA angle as compared to GA technique.Keywords: Active power filter (APF), synchronous reference frame (SRF), Genetic algorithm (GA), Particle Swarm Optimization (PSO) and multi converter dynamic voltage restorer (MC-DVR).

This paper describes a visual simulation technique by which fully computer-generated perspective views of three-dimensional objects may be produced. The method is based on a relatively simple geometric modeling technique for the mathematical representa tion of the three elements essential to the picture- taking process, namely, a camera, a light source, and the object or objects to be photographed. Once these three basic components have been defined, geometric ray tracing is employed to compute a "picture" of the object as it appears in the simu- Zated camera. In essence, individual light rays are traced from their source to the surface of the object. The reflected component of each ray is computed and traced to its point of intersection with the film plane. Thus, each reflected ray pro vides the intensity at a single point on the pic ture, and, when a sufficient number of points have been computed, the entire area of intensity data may be displayed on a cathode ray tube. Several examples of the pictorial output of this process are shown, and the application to the computer- generated films is discussed.

Previous investigationA previous investigation into the mortality of diabetics was made by A. J. Steeds following the analysis of data based upon a large London clinic. The present paper is based on data derived more recently from the experience of the patients attending a large Birmingham clinic.Diabetes mellitus2. Diabetes mellitus is a very ancient disease which may be described as a disturbance of the normal insulin mechanism of the body. The pancreas is a gland which secretes insulin for the purpose of converting sugar and starches into the energy forms required by the body (the metabolism of carbohydrates) and disturbance in this metabolism is accompanied by an abnormality in the breakdown of fats. Apart from physical damage to the pancreas the causes of diabetes are various and obscure (although they are thought to include heredity, overweight and, in females, a high level of childbearing). It is generally accepted that diabetes in young lives is a more severe form associated with insulin deficiency, whereas in older lives the disease is of a milder type, but there are many exceptions to this broad division.

The simulation of high-speed reciprocating refrigeration compressors was motivated by the needs of design engi neers. In this paper a mathematical model describing the dynamic behavior of a reciprocating compressor is pre sented. The model is semianalytic in that two types of empirical factors are required to relate phenomena not yet analytically predictable. One type is obtained from steady- state tests and the other by trial and error based on com parison with experimental results. Both analog and digital computers were considered as means of simulating the model. Due to nonlinearities in the model, the digital com puter, using Fortran IV, was selected. To evaluate the sim ulation, a one-quarter horsepower 3600-rpm stock com pressor was modified and used as a laboratory vehicle. A typical correlation between the computer simulation and experimental results is given. In general, good correlation was achieved.

This paper presents the results of a survey of hybrid computer laboratories in the United States and abroad. The survey included personal visits to 15 hybrid computer laboratories and a mailing of 195 questionnaires. The survey questionnaire was design ed to determine the current status of hybrid computer facility configurations, management policies, and facility utilization levels.