bluuebunny/crossref_metadata_2025 huggingface dataset:
Imaging Characteristics of Growing and Ruptured Vertebrobasilar Non-Saccular and Dolichoectatic Aneurysms
Authors: Nasr Deena M. , Brinjikji Waleed , Rouchaud Aymeric , Kadirvel Ramanathan , Flemming Kelly D. , Kallmes David F.
Published: November 2015

Background and Purpose—

Vertebrobasilar, nonsaccular, and dolichoectatic aneurysms generally have a poor natural history. We performed a study examining the natural history of vertebrobasilar, nonsaccular, and dolichoectatic aneurysms receiving serial imaging and studied imaging characteristics associated with growth and rupture.

Methods—

We included all vertebrobasilar dolichoectatic, fusiform, and transitional aneurysms with serial imaging follow-up seen at our institution over a 15-year period. Two radiologists and a neurologist evaluated aneurysms for size, type, mural T1 signal, mural thrombus, daughter sac, mass effect, and tortuosity. Primary outcomes were aneurysm growth or rupture. Univariate analysis was performed with chi-squared tests for categorical variables and Student’s
t
test or analysis of variance for continuous variables. Multivariate logistic regression analysis was performed to identify variables independently associated with aneurysm growth or rupture.

Results—

One hundred and fifty-two patients with 542 patient-years (mean 3.6±3.5 years) of imaging follow-up were included. Aneurysms were fusiform in 45 cases (29.6%), dolichoectatic in 75 cases (49.3%), and transitional in 32 cases (21.1%). Thirty-five aneurysms (23.0%) grew (growth rate=6.5%/year). Eight aneurysms (5.3%) ruptured (rupture rate=1.5%/year). Variables associated with growth and rupture on univariate analysis were size >10 mm (57.6% versus 16.0%,
P
<0.0001), mural T1 signal (39.7% versus 16.3%,
P
=0.001), daughter sac (56.3% versus 21.3%), and mural thrombus (45.5% versus 13.4%,
P
<0.0001). 26.7% of fusiform aneurysms, 9.3% of dolichoectatic aneurysms, and 59.4% of transitional aneurysms grew or ruptured (
P
<0.0001). The only variable independently associated with rupture was transitional morphology (
P
=0.003).

Conclusions—

Vertebrobasilar, nonsaccular, and dolichoectatic aneurysms are associated with a poor natural history with high growth and rupture rates. Further research is needed to determine the best treatments for this disease.
South Asian Regionalism and un Peacekeeping Missions
Authors: Zaman Rashed Uz , Biswas Niloy Ranjan
Published: November 2015

United Nations (un) peacekeeping missions have become an important feature of world politics since the end of the Cold War. In recent times, the intensity of peacekeeping missions has increased and new challenges have also emerged. Under such circumstances, the un has often highlighted the importance of regional organizations getting more involved in undertaking and sustaining such missions. South Asian countries provide a large number of troops to un missions and yet, a regional collaboration has not been accorded much importance by countries of the region. This paper argues, given the emerging challenges, South Asian countries may have to resort to a regional approach with regard to peacekeeping missions.
Differences in the formalization of the semantic category of definiteness / indefiniteness
Authors: Roszko Danuta , Roszko Roman
Published: November 2015

Differences in the formalization of the semantic category of definiteness / indefinitenessBasing on theoretical contrastive studies guidelines, the article defines the semantic category of definiteness/indefiniteness where two basic opposition meanings are being ascribed to. It also distinguishes crucial sub-meanings for this category. The category established like this constitutes a characteristic interlanguage typical of theoretical contrastive studies, which is here used as tertium comparationis for demonstrating the formal differences between Polish, Lithuanian and dialectal exponents to express particular sub/meanings. The differences demonstrated in the article are to confirm a different degree of the formalization of the category in each of the natural codes compared here. The idea of taking the local dialect of Puńsk into consideration results from a clearly visible influence of Polish and Lithuanian on the traditional dialectal system. In consequence, the dialectal system of exponents to express the meanings within the semantic category of definiteness/indefiniteness keeps a high degree of the traditional exponents specialization on one hand, but on the other hand, a low degree of specialization is being ascribed to some forms borrowed from Lithuanian (as a consequence of the Polish language influence), which results from the bilingualism of the Lithuanians living in Poland.
Semantic contrastive linguistics theory and dialectological studies
Authors: Roszko Danuta
Published: November 2015

Semantic contrastive linguistics theory and dialectological studiesTheoretical contrastive studies (hereinafter referred to as TCS) emerged with a view to compare and contrast natural languages on the basis of a logical interlanguage. The idea of making the TCS guidelines available to science resulted in discontinuing the division into the original language and the target language when comparing and contrasting two (or more languages), and at the same time, terminating the dependence of the resulting material (i.e. form indexes in the target language) on the formal structures in the original language. The TCS essence is included in the interlanguage, which is used as tertium comparationis in the studies. To get more on this topic see Koseska, Korytkowska, R. Roszko (2007). Till now, TCS have not been applied in dialectal studies. There are a lot of reasons for this conjuncture. First of all, dialectal studies usually concentrate on one code (i.e. only a single local dialect is being specified), whilst in TCS, a comparison and contrast between (at least two) languages is provided. Moreover, research on the dialectal differentiation of a specific language (i.e. at least two dialects (/ local dialects) are being specified together) is based on demonstrating the features shared and differentiated on the level of (a) lexis, (b) morphology (most often narrowed to demonstrate differential morphological features) and (c) syntactic (relatively most rarely). Thus, dialectal studies are essentially a description of the formal conjuncture, whereas semantic aspects are out of the area of researchers interest. With this article, I am going to break the current patterns and prove that dialectal studies can be conducted in accordance with the TCS guidelines. The advantage of such dialectal studies is not only a different/new look at a specific local dialect, but also a possibility of an instant comparison and contrast between the local dialect and the standardized language or other local dialects (of one language or another) on the semantic level providing the highest standard of the relevances demonstrated (i.e. similarities and differences).
Bulgarian sense-annotated corpus – between the tradition and novelty
Authors: Koeva Svetla
Published: November 2015

Bulgarian sense-annotated corpus – between the tradition and noveltyThe Bulgarian Sense-annotated Corpus (BulSemCor) is compiled according to the general methodology established by the SemCor project. It is a subset of the Brown Corpus of Bulgarian semantically annotated with a corresponding synonym set (synset) in the Bulgarian wordnet. Unlike the bulk of sense-annotated corpora where only (sets of) content words are annotated, in BulSemCor each lexical unit has been assigned a sense. The main contributions achieved in the work on BulSemCor are briefly decides in the presented paper: definition of an annotation schema, compilation of an input corpus, development of a sense-annotated corpus, Bulgarian wordnet enlargement.
Bulgarian-Polish parallel digital corpus and quantification of time
Authors: Dimitrova Ludmila , Koseska-Toszewa Violetta
Published: November 2015

Bulgarian-Polish parallel digital corpus and quantification of timeThe paper presents the current state of the first Bulgarian-Polish parallel and aligned corpus, prepared in the frame of the joint research project “Semantics and Contrastive linguistics with a focus on a bilingual electronic dictionary” between the Institute of Mathematics and Informatics, Bulgarian Academy of Sciences and the Institute of Slavic Studies, Polish Academy of Sciences, coordinated by L. Dimitrova and V. Koseska-Toszewa. In particular, problems related to tense quantification are also discussed
Cognitive approach to the construction of three-language terminological thesaurus
Authors: Chetverikov Grigorij , Vechirska Iryna
Published: November 2015

Cognitive approach to the construction of three-language terminological thesaurusThe paper is devoted to developing a lexicographic database of a three-language terminological dictionary. The detailed analysis of a relations scheme between tables and structures of tables with the help of three-layer decomposition predicate method is carried out, which has allowed to define ways of solving direct and reversible three-language electronic dictionaries creation problem.
Machine componential analysis of Bulgarian kinship terminology and more on the problem of multiple solutions
Authors: Pericliev Vladimir
Published: November 2015

Machine componential analysis of Bulgarian kinship terminology and more on the problem of multiple solutionsThe Bulgarian kin terms of reference and address are subjected to componential analysis, using the sophisticated computer program KINSHIP. It is shown that an unconstrained and separate analysis of the two sets of terms yields an astronomical number of alternative componential models for each, threatening to compromise the componential method as a whole. However, after combining the set of reference and the set of address terms into a unitary kin term domain and applying the program to this new enlarged data set, further employing appropriate simplicity criteria on overall features (=dimensions) and components of kin term definitions, yields a unique componential model. This result is evaluated in the context of a famous debate on the problems of multiple solutions of kinship systems. It is concluded that componential analysis properly used is an indispensable tool for revealing the structuring of semantic domains.
Brain Stem Auditory Evoked Response
Authors: Kavanagh Kevin T. , Beardsley James V.
Published: November 2015

Brain stem auditory evoked responses (BAER) elicited by bone-conducted click stimuli were studied in 37 subjects. This technique was plagued with problems such as: low amplitude, poor wave configuration, and calibration difficulties. The authors found the technique of limited value in differentiating conductive from neurosensory hearing disorders in all but severely affected subjects. It can, however, evaluate cochlear function in the presence of a known severe conductive hearing loss, ie, external ear atresia. If an abnormal bone-conducted BAER is obtained the etiology of this abnormality (cochlear vs. retrocochlear) cannot be ascertained because a wave I is rarely elicited in individuals with neurosensory hearing disorders. In subjects with a severe conductive hearing loss, air-conduction elicited markedly prolonged wave V latencies. Such a marked prolongation was not observed in individuals with peripheral neurosensory loss and when present signified that a subject had a major conductive component to his hearing disorder. The authors also believe that all control subjects should be established as normal with an audiogram and not by an otologic history or auditory (subjective) click thresholds.
Design Factors in the Assessment of Intelligence
Authors: Horowitz Frances Degen
Published: November 2015

The use of intelligence tests to assess the effects of otitis media on the development of children is discussed in this article. An overview of the development of intelligence tests is provided and some of the limitations and central issues of controversy concerning intelligence testing and the IQ are reviewed. Basic intelligence tests are described in terms of their characteristics and uses; the questions which an investigator must ask about any given intelligence test measure are posed and answered. Finally, cautions concerning the applicability of intelligence tests for evaluating the effects of otitis media are offered.
A Study on the Pathogenesis of Recurrent Parotitis in Childhood
Authors: Konno Akiyoshi , Ito Eiko
Published: November 2015

Roentgenologic, histopathologic, electron microscopic, virologic and immunologic studies were performed to investigate the etiologic features of recurrent parotitis in children. When examined sialographically and histopathologically, it was considered that pathologic changes in the parotid gland had developed as latent chronic inflammation with mild glandular destruction long before the disease became manifest clinically with acute exacerbation. Proliferation of the duct epithelium in the regenerative process and increase of intraductal pressure due to obstruction of the salivary outflow were assumed to be the causative factors of dilative changes of the peripheral ductal system. Investigation of complement fixation antibody, hemoagglutination inhibition antibody and neutralization antibody responses to mumps virus showed that onset of the disease was unrelated to mumps infection in the majority of cases. Increase of complement fixation antibody titer to various viruses was observed in many cases during acute exacerbation, and were considered to have brought about secondary ascending bacterial infection of the parotid gland by lowering of the systemic resistance. Comparison of serums IgA, IgG, IgM and salivary IgA in these patients with those of control children did not reveal participation of immunodeficiency in the development of this disease. But judging from the results of the long-term clinical follow-up study it was difficult to disregard the possibility that physiological immaturity of the immune response in young children may play some role in onset and recurrent exacerbation of the disease.
A Scanning Electron Microscopic Study of the Normal Human Stapes
Authors: Graham Malcolm D. , Perkins Rodney
Published: November 2015

The structure of the normal human stapes was studied with the scanning electron microscope. Specimens were obtained 48 hours after death from adult human temporal bones free from obvious inflammatory disease. The specimens were fixed, dissected, critical-point dried and coated with gold. In this scanning electron microscopic study an attempt has been made to systematically demonstrate the average scanning electron microscopic features of various areas of the normal human stapes. An emphasis has been placed upon demonstrating as clearly as possible the details previously unclear or unrecognized and duplication of many excellent earlier light and electron microscopic studies has not been attempted. The typical appearance of the stapes head, neck, arch, crura and footplate has been presented. It is apparent that there exists a high degree of structural specialization particularly in the stapes arch and footplate area.
Experimental Evaluation of a Visual Detection Model
Authors: Greening Charles P. , Wyman Melvin J.
Published: November 2015

A fixed-base simulation experiment was performed to gather visual air-to-ground target recognition performance data for comparison with predictions from the Autonetics Detection Model. Color motion picture imagery obtained during a low-altitude flight was used to simulate the observer's forward view. Observer performance was measured in terms of probability and range of correct target recognition. The Autonetics Detection Model incorporates parameters related to the target, the environment, and the observer. In generating theoretical predictions from the model, values of all parameters were specified independently of the data obtained in the experiment. No curve fitting techniques were used to improve the fit between the empirical and theoretical curves. Results indicated a close relationship between the obtained performance data and the model predictions. A product-moment correlation of +0.53, significant at the 0.001 level, was obtained between the empirical and theoretical 50% recognition ranges.
Accuracy of Interpolation between Scale Graduations
Authors: Cohen Edwin , Follert Richard L.
Published: November 2015

This study is concerned with the accuracy with which subjects can interpolate the position of a pointer or index between two scale graduations. Each of 20 subjects estimated the position of a mark on each of 99 5-in, linear, ungraduated scales. Estimates were given in units over the range 0–100 units. The median error was only 1.5% of the distance between the two marked graduations. Accuracy was greatest at the ends and middle of the scale. The data indicate that interpolation of fifths and even tenths will provide accuracy satisfactory for most situations.
Performance Prediction in a Single-Operator Simulated Surveillance System
Authors: Mills Robert G. , Williges Robert C.
Published: November 2015

A semiautomatic radar surveillance system was simulated using a time-compressed, real-time cathode-ray tube display. Subjects were required to detect targets entering the surveillance area, initiate automatic tracking of these targets, and reinitiate lost tracks when automatic tracking failed. A within-subject response surface methodology (RSM) central-composite design was employed which permitted simultaneous investigation of the effects of five system parameters on surveillance operator performance. Response surface fits (second-order polynomials) were obtained and analyses of variance were conducted to describe these effects on two dependent measures of performance. Results support the contention that operator performance may be dependent upon complex relationships among the five system parameters tested. Furthermore, an RSM central-composite design provided an efficient method for obtaining data and quantifying these relationships.
Field Testing Medical Decision-Aiding Systems
Authors: Gustafson David H. , Huber George P. , Delbecq Andre L.
Published: November 2015

Two studies concerned with the valuation of computer-supplemented medical decision-aiding systems were used to derive and illustrate guidelines for designing, conducting, and analyzing field tests of medical systems. The guidelines are not exhaustive and are intended to supplement those commonly found in books dealing with research and evaluation.
Vision through Various Scuba Facemasks
Authors: Luria S. M. , Ferris Steven H. , McKay Christine L. , Kinney Jo Ann S. , Paulson Helen M.
Published: November 2015

The visual performance using five commercially avaible facemasks was compared. Measurements were made of visual fields, visual acuity, stereoacuity, hand-eye coordination, accuracy of distance estimates, and accuracy of size estimates at both near and far distances. In addition, the optical properties of the masks were measured and the susceptibility of each mask to fogging was tested. There were significant differences among the masks for every visual process tested. Some masks were superior for one purpose and inferior for another purpose. For example, the mask which had lenses designed to compensate for the optical distortions found under water improved size and distance estimates and hand-eye coordination, but degraded acuity and stereoacuity. The results were not expplained on the basis of differential susceptibility to fogging.
The Effect of Spurious Angular Accelerations on Tracking in Dynamic Simulation
Authors: Beck Lawrence J.
Published: November 2015

A laboratory study was conducted to investigate the effect of spurious simulator yaw motions on a pilot's control performance. A second objective was to compare the efficiency of static and dynamic simulator tracking in previously unexamined vehicle dynamics. Twelve airline pilots served as subjects in a moving-base flight simulator under congruent-motion, spurious-motion, and no-motion conditions. The results indicated a significant increase in the amount of error with increasing levels of spurious motion during the initially administered series of trials. The influence of spurious motion, however, was absent in a second series of trials. The data suggest that the pilots learned to compensate in their performance for the spurious inputs. It was also found that congruent visual and rotational cueing produced superior performance to that of tracking with visual information alone.
Practice and Augmentation in Learning
Authors: Williams Ian D.
Published: November 2015

A linear-positioning task was learned over 1, 3, or 10 practice trials under high feedback (HFB-augmented position cues) or low feedback (LFB—no positional cue augmentation). Subjects' abilities to sustain accurate performance without IF and to appraise the magnitude and direction of errors were examined during 10 further test trials. Absolute errors were least after 10 practices with HFB, as predicted by closed-loop theory. However, HFB apparently caused performance inferior to LFB when only one practice trial was permitted.
Toward a More Musical Foghorn
Authors: Molino John A. , Zerdy Gerald A. , Frome Francine S.
Published: November 2015

Ten college students gave preference judgments for 4 pure tones (120, 300, 500, and 835 IIz) and 11 tone composites constructed from combinations of the pure tones. Equal aversion (tolerance) levels were also measured for the four pure tones and for five of the composites. Sensation-level measures were employed to express aversion thresholds in order to take account of the differential sensitivity of the human ear at different frequencies. Certain operational conclusions were suggested for the design of acoustic navigation aids. The higher frequency pure tones and composites were generally more preferred, and were also tolerated at higher sensation levels. The 120-IIz pure tone was a highly non-preferred signal. The presence of a 120-Hz component in any composite lowered both the preference value and the maintained sensation level. In the case of the moderately preferred 500-Hz pure tone, adding other more-preferred, pure-tone components increased the preference for the signal.
Posture and Subjective Evaluation at Flat and Slanted Desks
Authors: Eastman M. C. , Kamon E.
Published: November 2015

Back posture was photographed and back, neck, and upper arm electromyograms(EMGs) were recorded for six subjects during reading and writing at flat and slanted (12°, 24°) desk surfaces. In addition, the subjects rated fatigue and back discomfort. Sitting with a backpack, while leaning 45° forward, was used as a preliminary procedure to standardize the back discomfort ratings. Results indicated more erect posture and less back movement (reduced EMG) at the slanted surfaces, while slanting the desks also reduced fatigue and discomfort. The pattern in which the slanted surfaces were significantly better than the flat surface varied with each measurement technique.
Braking Movement Time and Accelerator-Brake Separation
Authors: Snyder Harry L.
Published: November 2015

Movement times were obtained for nine adult drivers for three accelerator-brake pedal separations. The typical separation (6.35 cm laterally and 5.08 cm vertically) produced significantly longer movement times than did either a 10.16-cm or 15.24-cm lateral separation with no vertical separation.
Note on Driver Adaptation to Modified Vehicle Starting Acceleration
Authors: Evans Leonard , Herman Robert
Published: November 2015

Driver behavior in crossing a highway was experimentally investigated for acar with normal starting acceleration characteristics and for this same car with reduced starting acceleration capabilities. It was found that subjects driving the car with its starting acceleration capabilities reduced required a larger time headway gap in front of an on-coming car before they would cross in front of its path. However, the increase in gap required was not as great as the additional time required to clear the path of the on-coming car.
An Evaluation of the Texas Driver Improvement Training Program
Authors: Edwards Mark L. , Ellis Newton C.
Published: November 2015

A major problem currently confronting law enforcement agencies is the assessment of the effectiveness of various driver improvement activities. The objectives of this research were to evalute the effect of the Texas Department of Public Safety driver improvement training program on driving record and to develop a technique for predicting reduction in accident and violation frequencies for the 12-month period following training. The results of this study indicated that the training program has a significant effect on accident and violation frequencies for selected groups. It was also found that it is possible to construct an equation that will predict with some accuracy, reduction in the number of accidents and violations for a 12-month period following training.
Reaction Time as an Index of Traffic Sign Perception
Authors: Dewar Robert E. , Ells Jerry G. , Mundy Glen
Published: November 2015

Verbal reaction times to identify and to classify 20 traffic sign messages were measured under three conditions-sign alone, sign plus visual loading task, and sign plus visual loading task plus visual distraction. Similar trends were found in the three experiments: reaction times were smaller for the classification task than for the identification task, smaller for warning than for regulatory signs, and smaller for verbal than for symbolic messages. Comparison of these reaction time data with on-the-road measures of legibility distance revealed significant correlations. The correlational data add credibility to laboratory measures of reaction times as valid indices of traffic sign perception.
Driving “Immunization” in Alienated Young Men
Authors: Pelz Donald C.
Published: November 2015

When driving workshops were conducted in classes of seniors in five high schools in southeastern Michigan, using non-directive discussion of trigger films and members' own highway experiences, young men appeared to drive somewhat more dangerously for the first nine months and then more safely, relative to control groups. A medical analogy is suggested: the workshops appeared to produce a mild “infection” of unsafe driving followed by an increase in “immunity.” These effects were more visible for workshop men who were relatively alienated from the school system in terms of having poorer grades and being older than average; during the second year their driving record was as good as that of their non-alienated peers.
Peripheral Acuity and Photointerpretation Performance
Authors: Leachtenauer Jon C.
Published: November 2015

Previous laboratory studies have shown a relationship between measures of peripheral acuity and performance in searching for artificial targets. In the present study, these findings were extended to the case of real targets in aerial photography using trained image interpreters. Correlations between field size and search performance ranged from 0.619 to 0.920. Significant increases in field size resulted from repeated testing but not, on an overall basis, from training. A measure of peripheral field size appears to provide a useful selection tool; the benefits of field expansion training remain somewhat in question.
The On-Line Measurement of Water in Polymers
Authors: Collier G. L. , Green R. E.
Published: November 2015

Water is a common contaminant of many products. Most natural products such as grain and flour, tobacco, wood and paper contain a high proportion of water in their normal states and can be too wet or too dry. Many synthetic materials such as polymers manufactured from petroleum are hydrophobic in nature, and give the most satisfactory performance during processes such as extrusion, moulding and spinning when they are completely dry. Polypropylene and polyvinyl chloride come into this category. Both these polymers, however, exist in a finely divided state during manufacture and tend to retain significant quantities of water upon the large surfaces they present. This water may then cause trouble during fabrication such as surface imperfections on injection mouldings, filament breakages during spinning and voids in extruded sections. Routine analysis for moisture content is therefore an important control on the manufacturing process, and there are many advantages in a semi-continuous on-line analyser for this purpose. On-line analysis avoids the necessity for product storage pending laboratory analysis for moisture by giving early warning of a change in the drier performance and enables the drier to be run at the lowest possible temperature. Material packed for despatch must have a water content not exceeding 0.03% w/w so that equipment capable of detecting 0.003% water is required. This paper describes a fully automatic analyser for this duty.
On-Line Analysis of a Non-Linear Control System Using Correlation Methods
Authors: Selway R. E. , Bell D.
Published: November 2015

In non-linear control processes the application of optimal control generally leads to a solution which is difficult to implement.

The problem is approached here by the use of a correlation method of continual tracking of the working point on the static and dynamic characteristics of the control system.

A hybrid computer is utilised to compute the correlation functions and continually to identify and reoptimise about the working point using quasi-linearisation techniques.

The non-linear system considered is a hyrdaulic servomotor of a type used in aircraft flight control systems.

The three-level m-sequences used as test signals are injected into the system during normal operation and, since they are uncorrelated with any other signal, may have an extremely small amplitude compared with the normal working input signal.

Optimal control in this instance is applied by the use of a phase compensation network with a variable bandwidth. The change of bandwidth required to satisfy the performance criterion is calculated on-line and used to optimise the system.

A brief summary of correlation methods is presented together with the equation's governing identification and optimisation. The hybrid computer arrangement is described and a selection of typical results is shown and discussed.

A note on the stability of the overall system as a system with time delays is included.

In conclusion, the problems of time-variant dynamics on non-linear systems are considered. A proposed hybrid computer scheme is presented for this purpose in which the characteristics of the m-sequences are up-dated to match the identified time constants of the system.
Accommodation and Convergence in the Human Eye
Authors: Toates F. M.
Published: November 2015

The control systems of accommodation and convergence in the human eye are theoretically examined, together with their interactions which represent accommodative convergence and convergence induced accommodation. A control model is proposed in order to help to understand the system, and it is used to make predictions concerning accommodation and convergence placed in conflict, monocular vision, fusional after-effects and the effect of age and drugs on accommodation and accommodative convergence. In each case the theoretical predictions are compared with established experimental results.
A Solid/Liquid Stale Holding Transducer for Metallic Charges
Authors: Roots William K. , Kadhim Mazin A. H.
Published: November 2015

In electroheat processes used in the metallurgical industries it is often desired to hold metallic charges at a temperature corresponding to their solid/liquid stat? interface. Similar requirements exist in the manufacture of chocolate, wax and similar products. A solid/liquid state sensing transducer has been developed in which a probe is plunged into and withdrawn from the charge. The armature current of the servomotor driving the probe gives information as to the state of the charge. A form of this transducer was developed which gave excellent results in holding metallic charges. The final transducer was well within the accuracy requirements of industrial processes, yet was unsophisticated and could easily be inexpensively constructed.
The Design of Digital Controller Algorithms
Authors: Williams B. J.
Published: November 2015

This paper describes some work done in implementing computer control algorithms on the six plate pilot-scale distillation column at the NPL. The method of algorithm design due to Ziegler and Nichols was used on the column for regulation and set-point change control, and these results were compared with those obtained from using an algorithm designed using a method based on the z transform. This latter method requires knowledge of the plant z transfer function and the method is a logical application of various constraints and rules that have been in the literature for some time.
Conrad Software in the Paper and Cement Industries
Authors: Higham J. D. , Jones R. E.
Published: November 2015

This paper gives some examples of the control systems currently operating in the paper and cement industries where CONRAD software is in use. While the primary concern is to show how the various strategies that are required on applications are implemented with CONRAD software, control strategies themselves may be of some interest.

The main advantages of digital computer regulation on the majority of processes lie not in the direct replacement of functions, which can be performed by three term analogue controllers, but rather in implementing the type of control that cannot be tackled satisfactorily by analogue control equipment. This includes feedforward, feedback, and multivariable non-interactive control on processes with long time scales and complex transfer functions, particularly where dead times or transport delays are involved.
A Process for On-Line Spectral Analysis
Authors: Moseley E.
Published: November 2015

As a modest contribution to the development of more problem-oriented control solutions, a simple on-line spectral-analysis process is presented and some of its possible applications discussed.
A Few Remarks about Humidity Measurement and Control with Capacitance Type Gauges
Authors: Ramaz A.
Published: November 2015

As part of a study into the computerised automation of paper machines we have begun to investigate the problem of paper humidity and control. The first results and reflections thereon are given below.

The pilot unit is equipped with two gauges: one at the dry end, of the conventional capacitive type, with co-planar electrodes in contact with the sheet, the other at the wet end, which is also based on the variation of the dielectric constant but with two opposed heads and no contact.
The Practising Manager's Control Requirements
Authors: Bostock Christopher
Published: November 2015

This paper endeavours to follow the logic of examining firstly what the manager is trying to do in his job and, in particular, what he means by the control function; secondly considering what information he needs in order to be able to control; and thirdly in what areas he has to try and make control effective.
Stability Criterion of Linear Control Systems with Time Delay
Authors: N-Nagy F. L. , Al-Tikriti M. N.
Published: November 2015

The paper outlines the Nyquist stability criterion linear control systems with time delay, using frequency response results. The variation of the loop-gain and time delay are investigated when the time delay occurs in the forward-loop or the feedback-loop or both. The stability condition of a simple control system is used to illustrate the method.
Control Theory and Decision Making in Organisations A Reconnaissance
Authors: Mallen G. L.
Published: November 2015

Differences between the domains of application of classical control theory and applied cybernetics are examined. It is suggested that a unifying concept for the understanding of both simple mechanical control systems and complex social systems is that of the decision process. Simple decision systems are equated to those for which transfer functions can be specified. Complex systems demand a simulation approach. No prescriptive organisational control theory based on simulation methods yet exists but one is required and is seen to be emerging from such diverse fields as artificial intelligence and Industrial Dynamics.
Past President Elected FRS
Authors: Coales J. F.
Published: November 2015

The President, Officers and Council of the Institute of Measurement and Control heartily congratulate Professor J. F. Coales, OBE, on his being elected Fellow of the Royal Society.
Measurement of Oxygen Content in Gases
Authors: Tipping F.
Published: November 2015

Of all gases oxygen plays a unique part in human existence. Without it, life as we know today, could not exist. The nature and the measurement of oxygen has, therefore, always been a challenge to scientists throughout the ages.

Modern technological advances, both in industry and medicine, over the past quarter of a century, have resulted in demands for increased accuracy in oxygen measurement.

The application of oxygen analysers ranges from the measurement of the atmosphere inside an incubator containing a premature baby, to the monitoring of oxygen content in the process streams on giant chemical plants to ensure safe operation.
Dynamic Modelling of a Steam Reformer and the Implementation of Feedforward/Feedback Control
Authors: Godfrey K. R. , Shackcloth B.
Published: November 2015

A simplified theoretical model for the dynamics of a side-fired steam reformer is derived. Experimental work, designed to confirm the theoretical model, is described, and the use of the results in the design of a feed-forward/feedback control scheme for throughput changes is discussed. This scheme, implemented on an on-line computer, enables large throughput changes to be made with a minimum of disturbance to the plant and a minimum of effort by the plant operators. Results from a typical throughput change are presented.
Commissioning and Operation of a Direct Digital Control Computer on a Cement Plant
Authors: Barton A. D. , Jenkins D. G. , Lees F. P. , Murtagh R. W.
Published: November 2015

The installation and commissioning of an on-line computer on a new cement plant is described. The computer carries out direct digital control, although conventional controllers are also provided. Part I of the paper gives an account of the background to the project, the process characteristics and the computer functions and an assessment of the value of the computer. The main functions performed are control of raw materials blending and of the kiln. A mathematical model has been used for the development of the kiln control scheme. The computer has assisted in learning about the process, in overcoming commissioning difficulties and in developing control schemes both with and without the use of models. Direct digital control has made possible finer adjustments to valves and set points, has allowed automatic calibration of an important feed flow meter and has made the implementation of alternative control loop configurations easier. Part II gives a detailed description of the computer system and an assessment of its reliability. The availability achieved over a three-year period is 99.1 per cent. Many of the faults which have occurred have been identified and could in future be eliminated in design. It is expected that the availability attainable after such improvements would be about 99.9 per cent.
Modelling and Control of Processes by Computer
Authors: Robbins T. , Francis N. W.
Published: November 2015

Two applications of digital computers to control of crude oil distillation units are outlined. Results from both applications are quoted and comparisons made with normal operator control of the units. Difficulties encountered with the applications are mentioned and comments are made on steady-state control. The purpose of this paper is to describe two aspects of the application of digital computers to the control of crude oil distillation units.
An In-Line Consistency Meter for Dough-like Materials
Authors: Babb A. T. S. , Casson C. B.
Published: November 2015

A recording in-line consistency meter has been developed primarily for testing bread dough flowing in pulses from a continuous dough mixer. Its use is based on the measurement of the torque required to rotate a sensor paddle at a constant speed in the flowing product. An electrical signal related to consistency has been obtained from a dynamometer used to constrain one output of a differential gear, while the other output is driving the sensor paddle. Interference due to pulsating flow has been removed by a combination of electrical and mechnical damping. Products of widely different consistencies (e.g. bread dough and pumpable oatflour slurry) can be tested by using paddles of different sizes and shapes, by varying their speed of rotation, and by choosing a dynamometer of appropriate sensitivity. In-line factory tests on bread and pastry doughs, and on compound fat, have shown the instrument to be accurate to ±2 % and to give consistent results which are relatively insensitive to changes in product flow rate. The instrument can be made compact, so that it can be installed in a confined space on the processing plant. The novel features of this meter are embodied in a patent (British Patent application No. 34805-67).
Assessment of Water Quality—Field Instrumentation
Authors: Briggs R.
Published: November 2015

Instruments and systems developed at the Water Pollution Research Laboratory and elsewhere, for the continuous measurement of those parameters which are of most significance in water pollution research are discussed. Particular attention is given to instruments and systems which are also of value in sewage-works operation or in the water-quality monitoring stations now being set up by River Authorities and the Water Resources Board. Recent developments such as equipment for monitoring organic matter and ammonia are described and the commercial availability of equipment based on developments at the Laboratory indicated. The possible value in this context of the recently available specific-ion electrodes is also considered.
Process Control Panel Design and Construction in the Seventies
Authors: Barrow S. A. E.
Published: November 2015

The accent on centralised control has led to a considerable reduction in panel length by the use of high density instrumentation. Condensing the panel length introduces the problem of mounting back of panel equipment in a much reduced area. Several designs of control panels have been developed within the process industry and the paper reviews the various answers to this problem. One particularly successful integrated design is described and includes development, layout, fabrication, shop testing, transport, installation, maintenance and control house layout. The paper concludes with various improvements and innovations for the future and the impact of integrated panel design on manufacturers and users.
Recent Advances in Cryogenic Thermometry
Authors: Foddy J. , Hanley P. E.
Published: November 2015

The recent availability of a linear resistance thermometer makes possible a simple direct-reading cryogenic thermometer, which does not require calibration charts or linearization networks. Another instrument for cryogenic thermometry is also described. This is a semiautomatic mutual inductance bridge developed specifically for paramagnetic thermometry. This bridge enables greater accuracy and speed of operation than earlier techniques.
Power Supplies for Process Transmitters
Authors: Cook Brian
Published: November 2015

This paper deals with power supplies for electronic transmitting instruments as employed in the process control industries. Single and multiple transmitter schemes are considered, and from an analysis of the applicational problems often encountered, design recommendations are offered for both individual supplies and for overall systems. Consideration is made of the problems imposed by intrinsic safety applications and by requirements for enhanced system reliability.
Electrostatic Measurement of Moving Flat Belt Drive
Authors: Bear J H F , Palmer R S J
Published: November 2015

The development and calibration of a probe for the measurement of the electrostatic charge produced on a flat belt drive whilst running is described. The need for such an investigation, in preference to tests of a simulative nature, is stressed. Typical oscilloscope traces obtained with the probe are included.
On-Line Software Error-Correcting System for Converted Signals
Authors: Pirouzan A
Published: November 2015

A software package has been developed for the correction of errors in analog to digital and quasi-digital transducers. The system relies on periodic calibration of the input transducers.
The Effect of Leading Edge Geometry on the Performance of Wedge Type Pitot-Static Yawmeters
Authors: Ferguson T. B. , Lakhwani C. K. , Horsley D. M. , Hollis E. J.
Published: November 2015

Results are presented showing how the performance of wedge-probes at low Mach number may be affected by the geometry of the front pressure tapping recess in the leading edge and also by the shape of the leading edge.
A Ratemeter with Large Dynamic Range
Authors: Schofield J. W.
Published: November 2015

A ratemeter is described which uses integrated circuits and light-emitting diodes to combine the wide dynamic range of a digital counter with the readability of an analogue instrument by displaying the most significant bit from a binary counter. On average, the instrument is accurate within a factor of √2.
The Principle of Ultrasonic Cross-Correlation Flowmetering
Authors: Coulthard J.
Published: November 2015

This paper describes the principles and general operating characteristics of ultrasonic cross-correlation flowmeters for liquids and gases. A great deal of research is currently proceeding to determine the performance of these instruments when measuring different types of fluids, but the general form of results are given for various flow systems. Since there is no restriction to flow and the measurement is largely independent of the fluid properties there is a great deal of interest in applying the technique in industry when suitable ‘peak-seeking’ correlators become available.
Development and Marketing of an Alternative to Filled Thermal Systems
Authors: Sullivan K. , Sargeant R. A. E.
Published: November 2015

This article describes the market requirement development and successful acceptance by industry of a newly developed addition to an instrument manufacturer's range — the Temperature to Motion Element (TME).
System Identification in Parallel Systems
Authors: Brook D.
Published: November 2015

In Systems Identification work using correlation methods, it could arise that the excitation signal must be transmitted through another system other than that under identification in order to perform the correlation function. This note discusses some aspects of this problem.
Determination of Pollutant Emissions in Car Exhaust Gases
Authors: Grimm E. , Emling A. , Richardson D.
Published: November 2015

The ever increasing density of industrial areas and the corresponding increase of petrol driven engines emitting harmful elements such as carbon monoxide, hydrocarbons and nitric oxide in the exhaust make it necessary to substantially reduce these toxic levels to create better living conditions.

Measures applied in various countries to limit these pollutions are discussed and the operating principles and design of analysers are detailed.
Simple Tuning of Discrete PI and PID Controllers
Authors: Roberts P. D.
Published: November 2015

The paper investigates the effectiveness of a simple procedure for tuning discrete PI and PID controllers applied to processes subject to set point changes and load disturbances. Previous work is extended to obtain closed-loop stability properties and a complete set of graphical tuning relationships to minimise the ITAE performance index when the process under control can be represented adequately by a single time constant and time delay. In addition, the simple tuning procedure is shown to exhibit satisfactory performance when applied to the control of a process represented by an eighth order transfer function.