bluuebunny/crossref_metadata_2025 huggingface dataset:
An approximation to the description of growth of coherent precipitates
Authors: Simmich O. , Löffler H.
Published: July 2007

The tree‐dimensional growth of a spherical coherent particle in an isotropic infinite matrix is considered in the frame of the stationary solution of the classical diffusion equation applying WAGNERS approximation in a varied manner and taking into account both the concentration dependence of the diffusion constant D and the influence of elastic energy.

From the obtained results qualitative conclusions are drawn on the stability of the precipitates during the OSTWALD‐ripening process in dependence on their size. The evaluations doubtlessly confirm the higher stability and the favoured growth of the larger precipitates.
The Crystal and Molecular Structure of the Smectogenic Compound 5‐Hexyl‐2‐(4‐bromophenyl)‐1,3‐dioxane
Authors: Hertung H. , Rapthel I. , v. Kurnatowski Ch.
Published: July 2007

The title compound with the formula C6H13C4O2H6C6H 4Br (HBPD) crystallizes in the monoclinic space group C 2/c with lattice parameters a = 28.48 Å, b = 5.71 Å, c = 20.19 Å, β = 97.4° and molecules per unit cell. The structure has been solved by the heavy atom method and refined to a final R value of 0.094. – The HBPD molecules adopt a fully stretched form, both the alkyl and phenyl substituent are in equatorial position with respect to the chair‐shaped dioxane ring. The orientation of the phenyl group is an intermediate between the perpendicular and parallel conformation. The molecules show a nearly perfect parallel arrangement in the crystal lattice.
On the dependence of interfacial tension on the size of two‐dimensional nucleation
Authors: Dhanasekaran R. , Ramasamy P.
Published: July 2007

Among the assumptions in the derivation of the classical nucleation equations has been important that of the independence of the interfacial tension on the critical size of the two‐dimensional nucleus. The one layer adsorption model based on Bragg‐Williams approximation with empty sites has been used to investigate the dependence of interfacial tension on the number of molecules in the square shaped critical nucleus. Using the Gibbs adsorption at constant temperature for a two‐component system, the number of molecules in the critical nucleus is exactly calculated in terms of the supersaturation, the interfacial tension and the interaction energies between the adsorbed molecules. The correction for the free energy of formation of critical two‐dimensional nucleus due to the new term associated with the dependence of the interfacial tension on cluster size is derived. Assuming the correction term for the free energy is negligibly small, the expression for the variation of interfacial tension of an embryo from that of a plane surface is established. It is found that the deviation is significant for small clusters and decreases with increase in the size of thejnucleus.
On the theory of growth of an ideally stoichiometric A—B crystal
Authors: Dhanasekaran R. , Ramasamy P.
Published: July 2007

Using the simple model of evenly spaced kink distribution on a single straight step in the case of an ideally stoichiometric A—B crystal, the differential equations for the stationary distributions of A and B adatoms are estabilshed and they are solved in terms of the retardation factors. For the chosen model, the potential function of the components are periodic. The total flux of A and B adatoms going to the kink are separately calculated and the rate of advance of the straight step is determined as a function of their respective supersaturations.
Political forecasting as a management tool
Authors: Austin James E. , Yoffie David B.
Published: July 2007

Political forces in developing countries permeate and significantly shape the business environment. Yet the political information used by managers is usually general, subjective and superficial. Managers lack an appropriate analytical framework for systematically examining political factors and forecasting their impact on the firm. This paper attempts to present such a framework. The framework focuses on the impact of political forces on development strategies, public policies and policy instruments. It then discusses how the analysis of these factors can be made managerially relevant by integrating them with firm specific characteristics and corporate strategy. This approach departs from many of the traditional political forecasting techniques which only concentrate on macro‐level factors and indicators.
Variance intervention
Authors: Young Peter , Ng Cho
Published: July 2007

Variance intervention is a simple state‐space approach to handling sharp discontinuities of level or slope in the states or parameters of models for non‐stationary time‐series. It derives from earlier procedures used in the 1960s for the design of self‐adaptive, state variable feedback control systems. In the alternative state‐space forecasting context considered in the present paper, it is particularly useful when applied to structural time series models. The paper compares the variance intervention procedure with the related ‘subjective intervention’ approach proposed by West and Harrison in a recent issue of theJournal of Forecasting, and demonstrates it efficacy by application to various time‐series data, including those used by West and Harrison.
Variance estimation for multivariate dynamic linear models
Authors: Barbosa Emanuel , Harrison Jeff
Published: July 2007

The problem of estimating unknown observational variances in multivariate dynamic linear models is considered. Conjugate procedures are possible for univariate models and also for special very restrictive common components models but they are not generally applicable. However, for clarity of operation and in order to avoid numerical integration, it is desirable to have conjugacy or approximate conjugacy. Such an approximate procedure is proposed based upon a simple analytic approximation. It is exact for the sub‐class of conjugate models and improves on a previous procedure based upon the Robust filter.
Increasing the feature size in handwritten numeral recognition to improve accuracy
Authors: Wakabayashi Tetsushi , Tsuruoka Shinji , Kimura Fumitaka , Miyake Yasuji
Published: July 2007

The relationship between the recognition rate of handwritten numerals and the normality of the distribution of their features has been investigated experimentally with a large amount of data in various combinations of quantized orientations and regions. The recognition method is based on the histogram of local orientation of contours of each numeral. To obtain a more accurate orientation quantization, the effectiveness of the orientation quantization using the gray‐scale gradient has also been investigated. The results show that: (1) to increase the dimensionality of features, it is better to increase the number of quantized orientations, keeping the number of regions small (e.g., 4 × 4 or 5 × 5); (2) in the same dimensionality, the better the normality of a feature distribution, the higher the recognition rate; (3) a quantization of orientations using gray scales is effective for normalizing a feature distribution; and (4) the filter processing in reduction of the number of quantization scales improves the normality and recognition rate. The recognition of handwritten numerals collected from actual posts were carried out by using the gray‐scale local‐orientation histogram (400 dimensions). A correct recognition rate of 99.18 percent (mean value) has been obtained.
Recognition of Coronary Arterial Stenosis Using Neural Network on DSA System
Authors: Suzuki Kenji , Horiba Isao , Ikegaya Kazuo , Nanki Michio
Published: July 2007

This paper proposes a new recognition method of coronary arterial stenosis in DSA image, because conventional evaluation algorithms have not been satisfactory to medical doctors. To solve this problem, the neural network which takes into account the experience of the medical doctor is employed. This method consists of the extraction of characteristic parameters which are highly correlated with stenosis and the recognition of stenosis by the neural network. By means of phantom experiments and clinical evaluation, the efficiency of the proposed method has been shown.
An analysis of the hot spot contention and message combining on the simple serial synchronized‐multistage interconnection network
Authors: Gaye Kalidou , Hanawa Toshihiro , Amano Hideharu
Published: July 2007

Simple serial synchronized (SSS) multistage interconnection network (MIN) is a processor‐memory connection network that has a high performance/cost ratio, where the packet is inputted and switch synchronously in the MIN, which has a high pass‐through ratio and is composed of simple elements. This paper evaluates the effect of the hot spot contention and the effect of the synchronous bit‐serial (SBS) message combining in SSS‐MIN, by the theoretical analysis based on probability and simulation. In contrast to conventional MIN, there does not arise a complete tree saturation in SSS‐MIN, but an area, to which the access is difficult, is produced according to the relative position to the hot spot contention. From such a viewpoint, an analysis method for the pass‐through ratio is presented, which considers the position of the switching element to the hot spot. It is verified as a result of evaluation that the proposed method of analysis gives a result close to that of simulation, so long as the access to the hot spot and the connection network architecture stay within a practical range. It is also seen that the pass‐through ratio is deteriorated less in SSS‐MIN by the hot spot contention than in the conventional MIN, and the effect can be almost completely eliminated by the SBS message combining. When a multiprocessor system is actually constructed, performance deterioration due to hot spot contention is greater than in the case where only the pass‐through ratio is considered. This can also be eliminated almost completely by the SBS message combining.
A simplification algorithm of and‐exor expressions guaranteeing minimality for some class of logic functions
Authors: Hirayama Takashi , Nishitani Yasuaki
Published: July 2007

Among all AND‐EXOR expressions that represent a logic functionf, those with a minimum number of products are called minimum AND‐EXOR expressions off. The number of products in the minimum AND‐EXOR expressions offis denoted by τ(f). The minimization algorithms of AND‐EXOR expressions take a great deal of time for computing (time complexityO(22n)), wherenis the number of variables. Thus it is necessary to develop a simplification algorithm that does not always find the exact minimum AND‐EXOR expressions but runs fast. This paper presents a simplification algorithm of AND‐EXOR expressions, which partially guarantees minimality and has the following properties: (1) it computes a minimum AND‐EXOR expression for a logic functionfwith τ(f) < 3(k+ 1), wherekis a nonnegative integer; (2) if an AND‐EXOR expression obtained by this algorithm takes less than or equal to 3(k+ 1) of products, then it is minimum; and (3) its time complexity isO(τkn2+(k+C)n). From the experimental results fork= 0, 1, 2, we can conclude that its computational time is practical forn= 20, 7, 6, respectively. Modifying this algorithm, we present an exact minimization algorithm for 5‐variable functions, which is faster than previously known ones.
Image screening based on projection pursuit for statistical image recognition
Authors: Arimura Koichi , Hagita Norihiro
Published: July 2007

A preprocessing method, called image screening, is presented to improve the recognition rate and efficiency in statistical image recognition. The problem of detecting a specified object in input images is treated as a two‐class classification problem in which the image falls into both a set of subimages in the target object (figure) class and the other set of subimages in the ground class. An image screening algorithm based on projection pursuit selects a candidate set of subimages that is similar to the object class, it rejects the remaining set using screening filters whose design is based on projection pursuit. The feature space for recognition is obtained from the selected subimages. Two kinds of measures to evaluate the performance of image screening are defined. The error rate in image screening is related to the total recognition rate of the system and the rejection rate of the noise image is related to the recognition efficiency. Two kinds of experiments were conducted, one to detect the eye and mouth areas in a face image and the other to detect the text area in a document image. Experimental results for these two tasks demonstrate that our method improves the recognition accuracy and efficiency.
Automatic generation of efficient hidden markov network by a state‐splitting and merging algorithm
Authors: Takami Jun‐Ichi
Published: July 2007

Until now, the successive state‐splitting algorithm (SSS) has been proposed as an automatic generation algorithm for the hidden Markov network (HMnet), which can be used as a high‐performance efficient context‐dependent model. SSS is a splitting‐type algorithm in which the HMnet is detailed only by splitting states.

On the other hand, the “merge‐type” algorithm also is proposed, where the model is constructed while merging the parameters based on the partial similarity of the model parameters. The two methods have the common goal, but take completely different approaches. Consequently, they should complement each other.

From such a viewpoint, this paper introduces the mechanism of the “merge‐type” technique into SSS as the “splitting‐type” algorithm. In other words, the “state‐splitting and merging” algorithm is proposed, where a higher‐performance automatic generation of HMnet is realized by complementing the defects of the two methods. An HMnet actually is constructed using 25 Japanese phoneme samples. By various evaluation experiments, the performance of the proposed algorithm is demonstrated.
Design of logic circuits with wired‐logic utilizing transduction method
Authors: Yamashita Shigeru , Kambayashi Yahiko , Muroga Saburo
Published: July 2007

Wired‐logic is especially useful when designing fan‐in restricted logic circuits which are implemented with bipolar and MOS transistors. There is, however, little published on the subject outside of the work done by the present authors. In this paper, a method of reducing the levels of circuits by utilizing Wired‐Logic is presented. The method restricts the number of fanins for a gate utilizing Wired‐Logic and transforms circuits using the transduction method optimization. To attain the proper combination of NOR gates and Wired‐OR gates, an algorithm using Wired‐OR gates for the fan‐in restriction is also presented. By performing experiments on third level NOR circuits, the proposed method is comparable toGeneralized Serial Duplicationwhich is an efficientserial duplication.The levels of most circuits are reduced by Wired‐OR gates, thereby demonstrating the efficiency of Wired‐Logic. Although connection length is important to LSI, the cost function simplifies circuit levels. Hence, for the purposes of this paper, analysis is expanded to include the cost function.
Optimization methods for look‐up table‐type FPGAs based on permissible functions
Authors: Yamashita Shigeru , Kambayashi Yahiko , Muroga Sabura
Published: July 2007

Recently, due to remarkable technological developments and because their logic can be modified flexibly and easily, Field Programmable Gate Arrays (FPGAs) have increasingly been applied to hardware prototyping and the design of restructurable computer architectures. For this reason, it is highly necessary to establish logic design techniques for FPGAs.

This paper describes methods for optimizing the circuits mapped in look‐up table‐type FPGAs. These methods apply the concept of permissible functions from the transduction method, which is a logic circuit optimization technique based on design improvement, and attempt to reduce the degree of redundancy. The following two methods were investigated: 1) reducing the number of blocks by using a logic block to replace another; and 2) together with replacing logic blocks, modifying the internal logic that implements a logic block as long as the outputs are not affected. Although the latter generally is more flexible, the former requires less processing time and sometimes produces better results. The effectiveness of these methods is demonstrated by showing that the degree of redundancy was reduced by about 9 percent when the methods were applied to circuits mapped in look‐up table‐type FPGAs. The methods proposed in this paper can also be applied to designs using standard cells and gate arrays.
Snoring, witnessed sleep apnoeas and pregnancy‐induced hypertension
Authors: PÉREZ‐CHADA DANIEL , VIDELA ALEJANDRO J. , O'FLAHERTY MARTIN E. , MAJUL CLAUDIO , CATALINI ANA M. , CABALLER CARLOS A. , FRANKLIN KARL A.
Published: July 2007

Background. Snoring is common in pregnancy, but there are only a few studies that have investigated the relationship of snoring and pregnancy complications. We aimed to investigate the relationship of snoring and witnessed sleep apnoeas with pregnancy‐induced hypertension. Methods. A questionnaire was administered on the day of delivery to 456 women at the Department of Obstetrics, Hospital Donación F. Santojanni, Buenos Aires, Argentina. Pregnancy complications and blood pressure measurements were recorded from each woman's medical chart. Results. Some 156 (35%) of 447 women with singleton pregnancies who answered the questionnaire, snored at some time during their pregnancy. Snoring was related to pregnancy‐induced hypertension and pre‐eclampsia combined, with an adjusted odds ratio of 1.82 (95% CI: 1.16–2.84; p <0.01), independent of body mass index before pregnancy, weight gain during pregnancy, neck circumference, smoking, alcohol and age. Witnessed sleep apnoeas were also related to pregnancy‐induced hypertensive disease, with an adjusted odds ratio of 8.00 (95% CI: 2.71–23.55; p <0.001). Daytime sleepiness was more prevalent in snoring women. Conclusions. Snoring and witnessed sleep apnoeas are independently related to pregnancy‐induced hypertensive disease.
Effect of Practice on the Perception of Temporal Patterns
Authors: Handel Stephen , Lewis William E.
Published: July 2007

The effect of practice on the organization and the rate of identification of temporal patterns was investigated. The patterns involved a set of eight dichotomous left-right elements, repeated without interruption until the subject was able to identify the patterns. The patterns were presented in the auditory, tactual, or visual modalities, or in pairs of these modalities. In some conditions, all the pattern elements were presented in one modality; in other conditions, four elements were presented in one modality and the remaining four elements were presented in the second modality.

The results demonstrated that when all pattern elements were presented in one modality, naive subjects organized the sequence into a well-structured pattern; practiced subjects organized the sequence into a pattern beginning at the starting element. These patterns may be poorly-structured. When four pattern elements were presented in each of two modalities, naive subjects organized the elements in each modality separately; practiced subjects disregarded the modality structure and organized the sequence into a well-structured pattern.

These changes in organization suggest a hierarchy of perceptual modes; perception by modality (i.e. by sensations) is least complex, perception by pattern structure is intermediate, and perception by start point is most complex. Changes in the rate of pattern identification confirm this hierarchy. Furthermore, the changes in organization and identification found for highly practiced patterns were also found for novel patterns.
Proactive Interference in Short-Term Memory as a Function of Prior-Item Retention Interval
Authors: Turvey M. T. , Brick P. , Osborn J.
Published: July 2007

The experiment was conducted to examine the effect of prior-item retention interval on the retention of a given item in a short-term memory test series. There were five conditions. The retention interval for the fifth test of five successive tests was 15 sec. for all five conditions. The retention intervals for tests 1–4 were constant for a condition but varied across conditions. These retention intervals were 5, 10, 15, 20 and 25 sec. Five consonant trigrams constructed from the set of letters sharing the vowel sound “e” were used for all conditions. Recall on test 5 was a direct function of prior-item retention interval. The data indicate, therefore, that the availability of prior items for proactive interference is an inverse function of prior-item retention interval.
Verbal Learning: Incremental vs. All-Or-None Theory
Authors: Richardson John T. E.
Published: July 2007

The incremental and all-or-none theories of verbal learning are compared by means of a little-used but methodologically superior variation of the “drop-out” paradigm with paired associates. Earlier experiments purporting to be relevant to the controversy are rejected as failing to offer a conclusive distinction between the two theories. The results presented here are taken to support the incremental theory. It is suggested that irregularities in the results of this and other experiments are caused by several intrusive factors, and a “dual-factor” hypothesis which was put forward to account for these irregularities is questioned on logical and methodological grounds.
Free Recall of Verbal and Non-Verbal Stimuli
Authors: Sampson Jeffrey R.
Published: July 2007

In two experiments, 40 and 72 male subjects viewed 24 items, half as words and half as drawings. In Experiment I, all subjects were given a learning set; free recall was tested immediately after stimulus presentation and 30 min. later. In Experiment II, half the subjects were set; recall was tested immediately and/or 1 day later. Picture recall was superior to word recall in all conditions (P < 0.005), in agreement with the findings of other investigators. Major extensions to previous procedures involved incidental learning, mixed stimulus lists, non-verbal reporting of pictures and delayed recall. A double-encoding explanation for the superior non-verbal performance is discussed.
Independent Functioning of Verbal Memory Stores: A Neuropsychological Study
Authors: Shallice T. , Warrington Elizabeth K.
Published: July 2007

Five experiments are described concerning verbal short-term memory performance of a patient who has a very markedly reduced verbal span. The results of the first three, free recall, the Peterson procedure and an investigation of proactive interference, indicate that he has a greatly reduced short-term memory capacity, while the last two, probe recognition and missing scan, show that this cannot be attributed to a retrieval failure. Since his performance on long-term memory tasks is normal, it is difficult to explain these results with theories of normal functioning in which verbal STM and LTM use the same structures in different ways. They also make the serial model of the relation between STM and LTM less plausible and support a model in which verbal STM and LTM have parallel inputs.
Capacity of Severely Subnormal Children with Relation to the Non-Additivity of Cues Effect and to Discrimination Difficulty
Authors: Glenn Sheila M. , Pickersgill Mary J.
Published: July 2007

The phenomenon of non-additivity of cues has been shown to exist in the learning of various types of discriminations by rats (Sutherland and Mackintosh, 1964; Sutherland and Holgate, 1966). In the present study severely subnormal children were trained to discriminate stimuli differing along two dimensions, both dimensions being relevant to the discrimination. Having learned to criterion they were then transfer-tested on each of the dimensions presented separately. Results showed both that subjects tended to respond in terms of dimensions and also that slow learners tended to learn the discrimination in terms of only one dimension whereas faster learners tended to learn about both dimensions. In a further study it was found that the more difficult the discrimination to be made the more the subjects tended to learn it in terms of only one of the two possible relevant dimensions. Some varying interpretations of the concepts of attention and capacity and their value and precision in explaining these results are considered.
Encoding and the rea for speech signals
Authors: Haggard Mark P.
Published: July 2007

A number of different possible explanations are distinguished for the findings on the right ear advantage (REA) for speech signals varied in their acoustic and phonetic properties. Two experiments are reported, using synthesized semivowels and vowels in monosyllable word frames. Both show REA. The detailed results of both experiments support the idea that a complicated “encoded” relationship between the acoustical stimulus and the response phoneme is a necessary condition for the REA, but that the encoding need only be signalled by an acoustical “trigger feature” in the stimulus; a task requiring a perceptual decoding is not necessary for REA to occur.
Ear Differences in the Recall of Fricatives and Vowels
Authors: Darwin C. J.
Published: July 2007

Two experiments on the free recall of dichotically presented synthetic speech sounds are reported. The first shows that the right ear advantage for initial fricative consonants is not simply a function of the recognition response class, but that it is also a function of the particular acoustic cues used to achieve that response. This is true both for the whole response, and for the constituent phonetic features. The second experiment shows that when both the response class and the particular stimuli presented on certain trials are held constant, the right ear advantage for the constant stimuli can be influenced by the range of other stimuli occurring in the experiment. Vowels show a right ear advantage when, within the experiment, there is uncertainty as to vocal tract size, but they show no ear advantage when all the vowels in the experiment are from the same vocal tract. These results are interpreted as demonstrating that there are differences between the ears, and probably between the hemispheres, at some stage between the acoustic analysis of the signal and its identification as a phonetic category.
Food Preferences Acquired by Association with Variations in Amino Acid Nutrition
Authors: Booth D. A. , Simson P. C.
Published: July 2007

Protein-deprived rats were given, on one day, a balanced mixture of amino acids followed by access to protein-free food having a distinctive odour. On another day, an imbalanced (histidine-free) amino acid mixture was given just before food having another odour. The rats afterwards preferred the balance-paired odour to the imbalance-paired odour. The preference was acquired whether the duration of odour presentation, or the amount of odourised food taken, was kept constant on the two conditioning days. Retention of the preference seemed unattenuated after 4 weeks. An attraction to the balance-paired odour (relative to odours paired with a water load) contributed to the acquired preference. There was also a relative aversion to unfamiliar odours when they had been paired with imbalance. Such acquired chemosensory control of preferences, together with an anorexigenic effect of imbalanced amino acid mixtures, can account for characteristics of feeding behaviour under conditions in which the diet is deficient in an essential amino acid.
Some Types of Error in a Choice Response Task
Authors: Green T. R. G. , Sime M. E. , Guest D. J.
Published: July 2007

Errors from a serial response task involving single-finger responses to alphabetic stimuli are analysed and discussed in relation to findings which have been reported from tasks with more compatible stimulus-response relationships. Errors are divided into three distinguishable subsets and in each case found to have longer latencies than correct responses. Those which result from mirroring the required response about the centre of the hand are found to resist elimination during practice and their frequency seems to depend on the type of code used. In all cases error correction times are faster than the times to make a correct response but mirror errors and errors involving a finger adjacent to the correct response are corrected faster than other errors. The findings are discussed in relation to the theory of choice reaction time and error correction.
Inhibition of ad Libitum Feeding in Rats by Salt Injections and Water Deprivation
Authors: Toates F. M. , Oatley Keith
Published: July 2007

Inhibition of ad libitum feeding in rats was induced by hypertonic NaCl injections. Though osmotic loads of sufficient size were capable of abolishing feeding completely for a time, the effect was not as large as had been predicted from a hypothesis of strictly linear subtractive inhibition. Feeding at a low level of hunger seems to be somewhat less affected by osmotic inhibition than feeding on a deprivation schedule. Inhibition of feeding was also produced by deprivation of water, and both the inhibition of food intake during deprivation, and the disinhibition by subsequent drinking indicated that the amount of inhibition of food intake is a non-linear (accelerating) function of water deficit. A model of the process indicating that the thirst signal undergoes a non-linear transformation before being subtracted from the signal corresponding to food demand is proposed.
The Immediate Processing of Sentences
Authors: Green D. W.
Published: July 2007

Two independent groups of subjects, under instruction orienting them towards understanding or towards memorizing sentences were timed to respond to a brief auditory signal which occurred at some point during the course of a sentence. Latency appeared to be primarily a function of the task, such that the deeper the semantic processing of the sentence the longer the reaction time. Together with other aspects of the data, it is argued that such tasks affect the extent to which a subject retrieves the meanings of the words in a sentence and integrates them at the end of it. Concrete and abstract sentences were processed in fundamentally the same way. The conclusion drawn is that speech comprehension is an integrative process, under voluntary control, which collates together different aspects of the speech signal.
Response Selection in Spatial Choice Reaction: Further Evidence against Associative Models
Authors: Duncan John
Published: July 2007

In a “consistent” spatial choice reaction task the same spatial relationship obtains between each stimulus and its correct response. In an “inconsistent” task this is not so. While Duncan (1977a) found both easy (spatially corresponding) and difficult (spatially opposite) responses to be slowed in inconsistent tasks, Smith (1977) found this only for the corresponding responses, the reverse holding for opposites. Reasons for this discrepancy are examined. The result of Smith (1977) depends on the use of different numbers of alternative responses in consistent and inconsistent tasks, a situation allowing no useful comparison between the two. Effects of consistency are related to others in the literature. The general conclusion is that, in these tasks, response selection is based not on a list of associations between individual stimuli and responses, but on operations or rules each of which will generate a set of stimulus–response pairs.
The Effect of Visual and Acoustic Similarity on Short-Term Memory for Chinese Words
Authors: Yik Wai Fong
Published: July 2007

Four lists of Chinese words in a 2 × 2 factorial design of visual and acoustic similarity were used in a short-term memory experiment. In addition to a strong acoustic similarity effect, a highly significant visual similarity effect was also obtained. This was particularly pronounced in the absence of acoustic similarity in the words used. The results not only confirm acoustic encoding to be a basic process in short-term recall of verbal stimuli in a language other than English but also lend support to the growing evidence of visual encoding in short-term memory as the situation demands.
Hearing by Eye
Authors: Campbell Ruth , Dodd Barbara
Published: July 2007

Recent work on integration of auditory and visual information during speech perception has indicated that adults are surprisingly good at, and rely extensively on, lip reading. The conceptual status of lip read information is of interest: such information is at the same time both visual and phonological. Three experiments investigated the nature of short term coding of lip read information in hearing subjects. The first experiment used asynchronous visual and auditory information and showed that a subject's ability to repeat words, when heard speech lagged lip movements, was unaffected by the lag duration, both quantitatively and qualitatively. This suggests that lip read information is immediately recoded into a durable code. An experiment on serial recall of lip read items showed a serial position curve containing a recency effect (characteristic of auditory but not visual input). It was then shown that an auditory suffix diminishes the recency effect obtained with lip read stimuli. These results are consistent with the hypothesis that seen speech, that is not heard, is encoded into a durable code which has some shared properties with heard speech. The results of the serial recall experiments are inconsistent with interpretations of the recency and suffix effects in terms of precategorical acoustic storage, for they demonstrate that recency and suffix effects can be supra-modal.
Influence of Control — Display Compatibility on Tracking Behaviour
Authors: Neilson Peter D. , Neilson Megan D.
Published: July 2007

In continuous tracking tasks it is generally accepted that the level of compatibility between control and display influences the accuracy of tracking performance. However, the nature of the changes in tracking behaviour have not been specified. In this study two experiments are reported in which the effect of control-display compatibility on pursuit visual tracking performance is assessed by means of a cross correlational and spectral analysis. A reduction in control-display compatibility results in a decrease in gain, an increase in phase lag, and an increase in average amplitude of the remnant component of the operator's response. The utility of these measures as descriptors of tracking behaviour is discussed with reference to the results obtained if overall measures of error are used.
Effects of Post-Operative Environment on Recovery from Dorsal Hippocampal Lesions in Young Rats: Tests of Spatial Memory and Motor Transfer
Authors: Einon D. F. , Morgan M. J. , Will B. E.
Published: July 2007

Young rats (30 days old) were given dorsal hippocampal lesions and then housed in different conditions to assess the contribution of the environment to recovery from the effects of the lesion. They were subsequently tested on a spatial memory task and on a task requiring complex motor movements and transfer ability. Animals with lesions were inferior to sham-operates on both these tasks. Social housing and environmental enrichment improved performance on both tests, but there was no evidence for an interaction between lesion and environmental effects. The validity of using the term “recovery” in these circumstances is discussed, and called into question.
Polycentric Urban Regions and the Quest for Synergy: Is a Network of Cities More than the Sum of the Parts?
Authors: Meijers Evert
Published: July 2007

Polycentric urban regions, or urban networks, are often associated with the notion of synergy, the assumption being that the individual cities in these collections of distinct but proximally located cities relate to each other in a synergetic way, making the whole network of cities more than the sum of its parts. Drawing on economic network theories, an analysis of the presence of synergy is carried out for the Randstad region in the Netherlands, which is often considered a classic example of a polycentric urban region. The analysis focuses on the synergy mechanisms of co-operation and in particular complementarity. The results are mixed. In terms of co-operation, the Randstad has become more synergetic. However, the less complementary economic roles of the cities caused a reverse effect.
High-voltage Overhead Power Lines and Property Values: A Residential Study in the UK
Authors: Sims Sally , Dent Peter
Published: July 2007

The effect of electricity distribution equipment, in particular high-voltage overhead transmission lines (HVOTLs), on the value of residential property in England remains relatively unexplored due, in part, to the lack of available transaction data for analysis. This paper compares the results of two UK studies undertaken by the authors. The first is a national survey of property valuers' perceptions (Chartered Surveyors and members of the National Association of Estate Agents) of the presence of distribution equipment in close proximity to residential property. The results from this study are then compared with an analysis of transaction data from a case study in Scotland. This paper presents the initial findings from these studies.
Arts Festivals and the City
Authors: Quinn Bernadette
Published: July 2007

There has been a remarkable rise in the number of urban arts festivals in recent decades. The outcomes of cities' engagement with arts festivals, however, remain little understood, particularly in social and cultural terms. This article reviews existing literature on urban festivals and argues that city authorities tend to disregard the social value of festivals and to construe them simply as vehicles of economic generation or as 'quick fix' solutions to city image problems. While such an approach renders certain benefits, it is ultimately quite limiting. If arts festivals are to achieve their undoubted potential in animating communities, celebrating diversity and improving quality of life, then they must be conceived of in a more holistic way by urban managers. Currently, the tasks of conceptualising the problems at issue and devising appropriate policies are hampered by the scarcity of empirical research conducted in the area.
Urban Designscapes and the Production of Aesthetic Consent
Authors: Julier Guy
Published: July 2007

Studies on the identity formation of urban centres and the use of aesthetic markers within that regeneration process largely fall into two camps that reflect their respective academic provenance. On the one hand, this effect is assessed by reference to urban planning and architectural processes. Here, the interest is firmly in the design hardware of buildings, streets and public spaces and how they are used to differentiate and communicate. On the other, this is reviewed by reference to the marketing strategies of place branding. Here the emotional software of brand identity programmes, as carried through literature, websites, the copywriting of slogans and other largely two-dimensional platforms comes into view. Within the remit of 'culture-led regeneration', the article considers a more extended version of the role of design in this process. Designers are implicated among networks of urban elites that decide strategies. But their involvement takes the process of design-led regeneration beyond buildings or leaflets to a loosely coherent, hegemonic network of signifiers to produce what I call 'designscapes'. The article takes a critical approach to three designscapes: Barcelona, Manchester and Hull. In doing so, it evaluates contrasting approaches while keeping in view the interactions of design elites and their public, the flows between individual and collective consumption and their roles in forming an urban habitus.
‘A symbol that cannot be substituted’: The role of Mwalimu J K Nyerere in the liberation of Southern Africa, 1955–1990
Authors: Ishemo Shubi L.
Published: July 2007

Mwalimu Nyerere, the first President of Tanzania, passed away on 14 October 1999. He fought for the liberation of Tanzania from British colonialism and fought tirelessly against colonialism, racism, injustice and to preserve human dignity not only in Africa, but also throughout the Third World. He was well known for his uncompromising support for the liberation movement and his untiring work to ensure their victory. He was not only Father of the Tanzanian nation but also a mentor of the birth of other nations in the region. This essay is a brief appreciation of his work, a memory to his warmth and his love for humanity.
Maintaining corporate dominance after decolonization: the ‘first mover advantage’ of Shell‐BP in Nigeria
Authors: Frynas Jêdrzej
                      George , Beck Matthias P , Mellahi Kamel
Published: July 2007

Nigeria's oil industry came into being during colonial rule. Preferential treatment by British colonial authorities had given a British oil company — Shell — a virtual monopoly over oil exploration in the country and Shell has remained the dominant oil company in Nigeria.

While there is substantial evidence to suggest that Shell‐BP established its dominant position in Nigeria with the support of British colonial officials, it was by no means clear that Shell would be able to maintain this advantageous position. Indeed, the historical record shows that both the Nigerian government and a number of competitors posed a potential threat to Shell's dominant position.

The purpose of this article is to answer the question why Shell was able to maintain a position of dominance in Nigeria. It examines Nigeria's diversification and nationalisation policies from the late 1950s to‐date with the view of identifying the factors which allowed Shell to maintain its position vis‐à‐vis potential competitors. This investigation is based on the analysis of secondary sources as well as documents from the Public Record Office (PRO) in London and the BP Archive.

In order to explain Shell's dominance in Nigeria, the article proposes to utilise the concept of a ‘first mover advantage’. On the most basic level, this concept suggests that pioneering firms are able to obtain positive economic profits as the consequence of early market entry, that means, profits in excess of the cost of capital. The article concludes that a micro‐theoretical analysis based on the idea of a ‘first mover advantage’, which explores the position of individual corporate entities within a political economy framework, provides a superior explanation of Shell's dominance in Nigeria as compared to conventional macro‐theoretical structuralist approaches.
Clientelism, corruption & catastrophe
Authors: Szeftel Morris
Published: July 2007

In the previous issue of this journal (ROAPE 84), the author argued that international anti‐corruption efforts created conflicts between aid donors and African debtor governments because they attacked the ability of local interests to control and appropriate state resources. The control of corruption is an essential element in the legitimation of liberal democracy and in the promotion of global markets. However, it also threatens the local accumulation of wealth and property (dependent as it is on access to the state) in post‐colonial Africa. This article explores another dimension of this problem, namely the way in which clientelist forms of political mobilisation have promoted corruption and intensified crisis. Clientelism has been a key mechanism through which political interests have built the electoral support necessary to ensure access to the state's resources. In turn, it has shaped a politics of factional competition over power and resources, a politics obsessed with the division of the political spoils. The article argues that this process is not unique to Africa. What is different, however, is that factional conflict and its attendant corruption have had such devastating consequences. This reflects the particular forms which clientelism has taken on the continent. There is a need, it concludes, to find ways to shift African politics towards issues of social justice and government performance and away from a concern with a division of the state's resources.
Ethnic ‘nationalities’, God & the state: Whither the federal republic of Nigeria?
Authors: Ifeka Caroline
Published: July 2007

There is a continuing contradiction between the state as the corporate representation of Nigerian society and sectional (ethno‐religious) interests struggling to counter perceived margin‐alisation by revenue ‘sharing’ among patrons and clients (Joseph, 1987). Power elites in command of the centre identify with the state and proclaim its indivisible ‘unitary’ character; poly‐ethnic labour activists believe in the Federal Republic but criticise their exclusion from state power by a mege‐rich elite (Ojewale, 2000). Other (southern) leaders are so dissatisfied with the unitary Nigerian state that they are campaigning for a confederation of ethnic ‘nationalities’ or secession into independent republics. As well, certain northern leaders are emphasising the Islamic identity of the Hausa‐Fulani ‘nationality’ by substituting Shari'a law for the criminal code so some people believe core northern states are engaging in covert religio‐legal secession (Soyinka, 2000).

The state and ethno‐religious sectionalism thus continue to interact, power elite networking and patronage ensuring that each party to the contradiction reproduces politically unitary and divisive forces in changing constellations, rendering uncertain indeed the outcome of present empowerment struggles.

In this Briefing Caroline Ifeka explores current conflicts. She identifies historical constants in political relations between the state and ethno‐religious ‘nationalities’ and highlights those that are crumbling. As conflicts intensify the (unitary) viewpoints of certain power elites, reported daily in the print and visual media, become more strident. Ifeka compares these with the sectional perspectives of the struggling masses she encounters in tropical high forest villages, in vigilante meetings, and in guest houses in downtown city quarters. She asks: do current crises and discourses of ‘marginalisation’ constitute a penultimate phase in the history of a state born and governed through violence, and nurtured in mystifying discourses of ‘faith and unity'?
Knowledge, culture & the internet in Africa: a challenge for political economists
Authors: Powell Mike
Published: July 2007

The development and use of Information and Communications Technologies (ICT) are undoubtedly important in today's world. Not surprisingly this raises issues of ‘ICT and development’, ‘ICT and health’, ‘ICT and agriculture’ and above all of a ‘digital divide’ between those with permanent access to new technologies and those with none. Such topics are not unimportant but they should not obscure the need for a more profound, critical analysis of what these changes mean. ICT are only one element in a process of changing organisational forms and changing understanding of how information and knowledge can be applied for economic ends. It is argued that these changes are creating a new mode of production, one which may offer Africa more opportunities relative to the world economy than have been experienced in the past. Such opportunities are more likely to be generated, the more ordinary Africans get access to basic communication tools and use them for their own ends. Such a process, which can be either aided or obstructed by the policies of the state and international institutions, would inevitably lead to significant changes in economic and political relationships.