Showing papers by "Lancaster University published in 1968"
TL;DR: An approach to the design of discrete feedforward and feedback control schemes, which are of great importance for example, in the chemical industry, is given and has a close link with the forecasting problems discussed there.
Abstract: A brief discussion of Statistical Quality Control Charting procedures is first presented with special reference to the relevance of the objectives and assumptions. An approach to the design of discrete feedforward and feedback control schemes, which are of great importance for example, in the chemical industry, is then given. This approach to control employs discrete stochastic and dynamic models discussed in Part I of this paper (Box and Jenkins, 1968) and has a close link with the forecasting problems discussed there. The control algorithms obtained are ideally suited to discrete digital computer control. However, for common simple situations the algorithms may be represented by suitable charts or nomograms which may be employed to obtain improved manual control. The paper ends with a discussion of a problem typical of that arising in the parts manufacturing industry. Here, attention must be given to the cost of making an adjustment to the machine as well as to the cost of being off target and to the stochastic nature of the disturbance. An example is given where the appropriate form of action is like that required by Roberts's modification of a Shewhart chart. However, the justification required to make such action appropriate is very different from that previously given.
292 citations
01 Apr 1968
TL;DR: A paranorm is a topological linear space in which the topology is given by a real subadditive function on X such that g(θ) = 0, g(x) = g(−x) and such that multiplication is continuous as discussed by the authors.
Abstract: A paranormed space X = (X, g) is a topological linear space in which the topology is given by paranorm g—a real subadditive function on X such that g(θ) = 0, g(x) = g(−x) and such that multiplication is continuous. In the above, θ is the zero in the complex linear space X and continuity of multiplication means that λn → λ, xn → x(i.e. g(xn − x) → 0) imply λnxn → λx, for scalars λ and vectors x. We shall use the term semimetric function to describe a real subadditive function g on X such that g(θ) = 0, g(x) = g(−x). Two familiar paranormed sequence spaces, which have been extensively studied (3), are l(p) and m(p). For a given sequence p = (gk) of strictly positive numbers, l;(p) is the set of all complex sequences x = (xk) such that and m(p) is the set of x such that sup Throughout, sums and suprema without limits are taken from 1 to ∞. Simons (3) considered only the case in which 0 < pk ≤ 1 so that natural paranorms would seem to be in m(p). In fact Simons showed that g1 was a paranorm for l(p), but that g2 did not satisfy the continuity of multiplication axiom.
146 citations
TL;DR: In this paper, it was shown that in an insulator containing a high density of traps and donors, such as one might expect in evaporated insulating films, the conduction process can change from being electrode-limited to being bulk-limited.
Abstract: If a blocking contact exists at a metal-semiconductor interface, the conduction process is electrode-limited and will normally remain so, that is, it will not become bulk-limited with increasing applied voltage unless the semiconductor is inordinately thick. It is shown, however, that in an insulator containing a high density of traps and donors, such as one might expect in evaporated insulating films, the conduction process can change from being electrode-limited to being bulk-limited. This process results at low voltages in a very steep $I\ensuremath{-}V$ characteristic which is essentially thickness-independent (electrode-limited), and at high voltages in a law $I\ensuremath{\propto}\mathrm{exp} \ensuremath{\beta}{V}^{\frac{1}{2}}$ which is thickness-dependent (bulk-limited). The results are shown to be in agreement with existing experimental data.
115 citations
[...]
55 citations
TL;DR: A simple technique for the measurement of drinking rates of fish is described and rates found compare favourably with rates found using more complex procedures.
47 citations
TL;DR: In this article, the authors emphasize the urgent need to apply the systems approach to senior management, both in government and industry, and emphasize the need for a detailed systems study to decide on the best objectives and then subsidiary systems must be set up to realize these objectives as efficiently as possible.
Abstract: By a systems approach to management is meant the study of a firm in its totality so that the men and material resources of the firm can be organized to realize the firm's overall objectives as efficiently as possible. This approach is now becoming essential because of the growth of complexity of firms and the increasing potential of automatic computers. The systems approach to management implies that every manager should be much more precise about decision-making and information flow. For this to be effective, a company should have an overall system of corporate objectives. First a detailed systems study will be necessary to decide on the best objectives and then subsidiary systems must be set up to realize these objectives as efficiently as possible. This paper is directed at senior management and is a simple attempt to emphasize the urgent need to apply the systems approach, both in government and industry.
36 citations
TL;DR: In this paper, a band-structure calculation for silver has been made using Mueller's interpolation scheme and the first-principles calculation by Segall has been adjusted to give better agreement with experiment, and a set of parameters derived to fit these adjusted bands.
Abstract: A band-structure calculation for silver has been made using Mueller's interpolation scheme. The first-principles calculation by Segall has been adjusted to give better agreement with experiment, and a set of parameters derived to fit these adjusted bands. A density-of-states calculation using these parameters confirms deductions from experimental work using the photoelectric effect which suggest two main peaks in the $d$-band region. However, we find an additional low-energy peak which has not been observed experimentally and no evidence of structure near the Fermi level. The Fermi surface is computed after a recalculation of the Fermi energy which agrees with Segall's results. Reasonable correlation with the experimental dimensions of the Fermi surface is obtained. Finally, various effective masses are calculated. The value obtained for the electronic specific heat suggests that electron-phonon enhancement is somewhat smaller in silver than in copper.
23 citations
TL;DR: In this article, the iterative extended Huckel method for σ-electrons was used to calculate wave functions for BH4−, NH4+, CH4, C2H6, B2H4, CH4 and C6H6.
Abstract: The iterative extended Huckel method for σ-electrons, analogous to the ω-technique for π-electrons, is used to calculate wave functions for BH4−, NH4+, CH4, C2H6, B2H6, C2H4 and C6H6. Results are compared with the simple extended Huckel method and with published selfconsistent field molecular orbital wave functions. It is found that iterating the extended Huckel method does not always lead to improvements in the wave function but that some improvements are found particular for ionic molecules. It is suggested that the reason for the failure of the iterated method is the neglect of terms due to charges on adjacent atoms.
22 citations
TL;DR: A vacuum-deposited thin film metal-insulator-metal (AlSiO-Au) device, after an electro-forming process, emits hot electrons, and constitutes a cold cathode as discussed by the authors.
Abstract: A vacuum-deposited thin film metal-insulator-metal (Al-SiO-Au) device, after an electro-forming process, emits hot electrons,and constitutes a cold cathode. An array of 25 of these Al-SiO-Au cold cathodes, each of approximately 0.1 cm2 area, is used with a phosphor screen in an alpha-numeric display panel, which is clearly visible under normal laboratory lighting conditions. The normal cathode bias is about 12 V. The normal screen potential is about 3 kV. Screen brightness varies directly with the screen potential and exponentially with cathode bias. Pulse operation shows th t the rise and decay times of the light output are limited only by the phosphor used. The thickness and composition of the cathode insulator film determine the operating characteristics, notably life. Cathodes of high emission current density, for example, 250 µA cm−2, may operate for about 1 hour. Some with initial high ratio of emission current to current circulating through the cathode, for example, up to one per cent, may operate for 1000 hours. Cathodes of emission current density that is approximately uniform over the cathode area, and therefore suitable for a display, operate for several hundred hours. Failure mechanisms are due to continued forming during operation,and dielectric breakdown.
20 citations
01 Feb 1968
TL;DR: In presenting some account of the work being done at Lancaster on the systems analysis of a university library, the author makes it quite clear at the beginning what he does not mean by “scientific management”.
Abstract: In presenting some account of the work being done at Lancaster on the systems analysis of a university library, I wish to make it quite clear at the beginning what I do not mean. We are not concerned with “scientific management” as defined in the recent book by Dougherty and Heinritz — time and motion study, work measurement or work simplification, the re‐design of forms and stationery, and all the other paraphernalia of low‐level industrial or commercial management. These admittedly have their place, but only a minor one: it profits a library little if its procedures are all perfect, but all directed to the wrong ends.
19 citations
TL;DR: In this paper, tritium-labeled NADPH (either 4R or 4S-diastereoisomers) was taken up by seedlings of Phaseolus vulgaris and Avena sativa by transpiration, and sterospecific transfer of hydrogen from the nicotinamide ring of NADPH to the isoprene residues of phytol and α-tocopherol during biogenesis was detected.
TL;DR: It is concluded that the results are likely to indicate the distribution in the intact cell of sodium, potassium, calcium and magnesium in rat tissues.
TL;DR: In this article, the preparation and characterisation of sulphinate complexes of palladium and platinum has been reported and the structure of the complexes has been investigated using both infrared spectroscopy and chemical reactivity, concluding that the sulphinate ligand in all these complexes behaves as a terminal, sulphur bonded ligand.
TL;DR: In this paper, a semi-infinite chain of identical atoms is discussed using molecular orbital theory including next-nearest-neighbour interactions, and it is shown that localized electronic surface states can exist in this model, the maximum number possible being two.
TL;DR: A Member of the Manchester Athenaeum as discussed by the authors wrote that a few humble mechanics in Lanarkshire, distinguished by scarcely anything more than mechanical ingenuity and perseverance of character, succeeded in forming a few, but important mechanical combinations, the effect of which has been to revolutionize the whole of British society, and to influence, in a marked degree, the progress of civilization in every quarter of the globe.
Abstract: ‘It is not more than seventy or eighty years since,’ wrote ‘A Member of the Manchester Athenaeum’ in 1844, ‘that a few humble mechanics in Lanarkshire, distinguished by scarcely anything more than mechanical ingenuity and perseverance of character, succeeded in forming a few, but important mechanical combinations, the effect of which has been to revolutionize the whole of British society, and to influence, in a marked degree, the progress of civilization in every quarter of the globe.’
TL;DR: It is concluded that uranyl acetate ions exert their potentiating effects via the muscle calcium release mechanism by inhibiting or delaying the reactivation of the calcium pump of the sarcoplasmic reticulum.
TL;DR: In this paper, measurements of the anisotropy of the electronic attenuation, the electron mean free path and the superconducting energy gap in cadmium are presented for the propagation of longitudinal ultrasound along the three principle crystallographic directions.
TL;DR: The membership of the Operational Research Society at the end of 1967 has been analysed to provide information on the numbers of organizations in different industrial classifications which use operational research.
Abstract: The membership of the Operational Research Society at the end of 1967 has been analysed to provide information on the numbers of organizations in different industrial classifications which use operational research. Statistics relating to the size of the activity are also given.
TL;DR: It is concluded that it is a difference in the efficiency of absorption of CO2 which leads to the marked difference between maize and Pelargonium, rather than the absence of photorespiration in maize or anatomicad differences between the leaves of the two species.
Abstract: The carbon dioxide compensation paint established by maize leaves in 10,000 lux at 25°C was less Than 2 μl/l. whereas that achieved by Pelargonium under the same conditions was greater than 60 μl/l. Maize and Pelargonium leaves together in the same leaf chamber established a compensation point between 9 and 19 μl/l. It is concluded that it is a difference in the efficiency of absorption of CO2 which leads to the marked difference between maize and Pelargonium, rather than the absence of photorespiration in maize or anatomicad differences between the leaves of the two species.
TL;DR: In this paper, a no-cut-off formulation of the ρ bootstrap is deduced which is seen to correspond to a certain procedure suggested by Atkinson and Contogouris.
Abstract: Starting fromN/D equations proved for theexact I=J=1 ππ-scattering amplitude, a no-cut-off formulation of the ρ bootstrap is deduced which is seen to correspond to a certain procedure suggested by Atkinson and Contogouris. The introduction of a cut-off parameter is also studied; it is found that for very small values of the ρππ coupling constant the large-cut-off limit exists and corresponds to the present formulation, but that for physical values of the coupling constant no limit exists. Results are for the most part stated and proved rigorously, using the techniques of functional analysis in Hilbert space. Much weaker conditions are given than have hitherto been published for i) existence of anN/D decomposition, ii) uniqueness of the solution of the integral equation forN, iii) the boundedness and continuity behaviour of principal-value integrals extending to infinity.
[...]
TL;DR: In this article, the authors discuss the recent measurements of excitation of higher nucleon isobars in both pp and π p collisions, together with speculations that their excitation is due to a diffraction dissociation process, and show how this mechanism can be related to recent models ascribing such high energy direct reactions to sums of quark-quark interactions.
TL;DR: In this article, the electrical conductivity of the following six compounds has been determined in the molten state; C 5 H 5 N, AlCl 3, 2C 5 H5 N, AII 3, 3C 5H 5 N and AlI 3, which lie in the range 1 −10 × 10 −3 ohm −1 cm −1.
TL;DR: In this paper, the effects of interference on the apparent angular distribution for decay of the N∗ were examined, and it was shown that there is indication of strong interference, of a form which supports the assumption that the peripheral production is a one-pion exchange process.