bluuebunny/crossref_metadata_2025_split huggingface dataset:
Contribution of early intensive prolonged pelvic floor exercises on urinary continence recovery after bladder neck‐sparing radical prostatectomy: Results of a prospective controlled randomized trial
Authors: Manassero Francesca , Traversi Cinzia , Ales Valeria , Pistolesi Donatella , Panicucci Erica , Valent Francesca , Selli Cesare 
Published: May 2007

AbstractAimsIn this prospective controlled randomized trial we assessed the effects of early, intensive, prolonged pelvic floor exercises (PFE) on urinary incontinence following bladder neck (BN) sparing RRP.MethodsA sample of 152 patients with localized prostate cancer underwent RRP with BN preservation. Out of this group we randomized 107 incontinent patients into 2 groups. We considered incontinent patients with 24 hr Pad test >2 g. The T group received instructions regarding an intensive program of PFE, from 7 days after catheter removal for as long as any degree of incontinence persisted, within a period of 1 year. The control (C) group did not receive instructions. The outcome was assessed using the 24 hr Pad test, a visual analogue scale (VAS) and a single question of QoL. Results at baseline and at 1, 3, 6, and 12 months were available for 54 and 40 patients, respectively.ResultsThe overall spontaneous continence rate after catheter removal was 23.6%. The proportion of men still incontinent was significantly higher in the C group than treatment (T) group at 1 (97.5% vs. 83.3%; P = 0.04), 3 (77.5% vs. 53.7%; P = 0.03), 6 (60% vs. 33.3%; P = 0.01), and 12 months (52.5% vs. 16.6%; P < 0.01). Similarly, the VAS and the response to the QoL question at 12 months significantly differed between the two groups (P = 0.01 and 0.03, respectively).ConclusionsOur study suggests that early intensive prolonged PFE can further increase the number of continent patients and this improvement persists in the first 12 months. The second 6 months following surgery are still useful to recovery. Neurourol. Urodynam. 26:985–989, 2007. © 2007 Wiley‐Liss, Inc.
Functional equations and successive approximations in linear and nonlinear programming
Authors: Bellman Richard 
Published: May 2007

AbstractThe purpose of this paper is to illustrate the applicability of two of the fundamental tools of classical analysis, functional equations and successive approximations, to various classes of multidimensional maximization problems.The advent of the modern digital computer makes it particularly appropriate that this synthesis of new and old be made. Today we can envisage as single steps in an iterative solution the resolution of particular problems which even ten years ago would have been considered as beyond the scope of mathematical power. Since the rules of the game have changed so drastically insofar as what we accept as a feasible solution, it is essential that we revise many of our techniques with this well in mind.Suitably combining classical and modern devices, we can hope to make a start on the solution of the many complex and significant problems that challenge us.
Some accomplishments of logistics research
Authors: Marlow W. H. 
Published: May 2007

AbstractThis is a survey paper drawing from several instances of work by the Logistics Research Project over the past ten years. The selection and treatment of this material has been influenced somewhat by the Conference papers being presented by other Project Members; however this mainly tends to reduce the amount of detail reported for those areas. It is also true that the present paper tends in the direction of a historical record; empirical methods of logistics research are stressed but not to the exclusion of material on the origins of the problems attacked, the course of their formulation as research problems, or the practical application of the results. The principal subjects treated are: operational logistics planning, industrial mobilization, usage data collection and analysis, the Allowance List Test Program, logistics data processing, and some additional instances of logistics research. The rather ambitious aim of the paper is to present an account which will do justice to the many individuals who have been responsible for these accomplishments of logistics research.
Some aspects of mathematics in social sciences
Authors: Tompkins C. 
Published: May 2007

AbstractThe ultimate aim of this paper is to examine the compromises which can be made in order to reach a point where measurement and computation are feasible in some of the quantitative aspects of the social sciences.The basic mathematical theories upon which the social sciences depend include:1. Linear attrition theory including Feller's abstract formulation of parabolic equations.2. Utility theory as a branch of the calculus of variations, described, for example, by G. E. Evans.3. Combination of utility theories and competition in many play games, including Bellman's theory of dynamic programming.Basic empirical aspects of the social sciences include:1. The acquisition of information about probability distributions, such as distribution of demand.2. The testing of hypotheses related to reality, such as a hypothesis of rational behavior as formulated and tested by J. Marschak.3. The intelligent formation of a priori Bayes probabilities and their correction as demanded by L. J. Savage in his The Foundations of Statistics and as carried out by W. A. Smith.4. Observations of value of various competitive situations, based on simulation, experience, or other valid means of practical realization of quantities introduced theoretically in dynamic programming studies.Practical considerations require action after limited observation of existing conditions, and limitations of computational facilities may prohibit complete numerical analysis of situations whose underlying parameters are believed to have been accurately evaluated. This leads to an almost epistemological question as to what can be learned through aggregation of data related to seemingly similar situations and to difficult mathematical questions of reducing the computational extent of problems. Some means of examining these questions will be treated, but the paper will not attempt to present a unified theory covering any substantial set of these problems.
Control of and communication with data‐handling machines
Authors: Orchard‐Hays William 
Published: May 2007

AbstractChange and reworking of systems has become a way of life in the computing or data‐processing field, with nearly a decade of major advances. Both the hardware and the applications of the last few years can elicit only admiration. But mingled with this is a tinge of anxiety that hardware is getting ahead of techniques for utilizing it. Logistics research is a field which offers an extreme technical challenge here. If the equipment is not a responsive “member” of the team, it may be as much of an impediment as a help.Ever larger programming groups as a means of getting the increasingly complex problems “on the air” are becoming more ineffective. There is a definite limit to the availability of expert programmers but, even when they are found, they can solve only one or two of many classes of problems involved. A few basic principles can be set forth to clarify this. Pre‐eminent among these is the fact that the handling of information generates more information which must in turn be handled. This can continue ad infinitum unless restraints are imposed in the nature of policies which reflect the purpose at hand.The over‐all problem seems to be one of communication between people. A particular technical problem that arises is making the hardware responsive to the user's needs without an overburdening programming load. A scheme for accomplishing this is outlined. It will be demanding of the users but hopefully rewarding. Responsibility is a necessary counterpart of responsiveness.As to the supposed dissimilarity between hardware for scientific and for data‐processing applications, it is observed that the really hard problems for both are identical. As always, the primary problem is the proper organization and distribution of human effort.
The reflection of logistics in electronic computer design
Authors: Cannon E. W. 
Published: May 2007

AbstractAnalytical and operational logistics seem, at first glance, to require widely differing computational tools. When one looks more deeply into typical undertakings in logistics, including such varied activities as: fundamental logistics research, the playing of war games, production scheduling, and the determination of supply requirements, appropriate computational techniques do not appear to require markedly differing computational facilities. If differences are deemed essential, they appear to lie in accessibility of storage and the nature and extent of peripheral equipment rather than in the basic organization and mathematical power of the central computer.Representative problems in varied aspects of logistics are discussed briefly. An appropriate mathematical model is displayed, in each case, with perhaps a heuristic derivation, and is viewed from the standpoint of the computational facilities it requires. New applications of electronic computers, such as the mechanical translation of languages and information retrieval (now in the exploratory stage), which promise to have significant logistical implication, are discussed briefly.
An automatic addressing device
Authors: Fennell J. P. 
Published: May 2007

AbstractIn many computations the identification of an item or items requires several decimal digits, an index which cannot be accommodated readily as a machine address. It is characteristic of these indices that the cardinality of the actual range is within the limits determined by conventional high‐speed storage. This fact is exploited by means of the system under discussion.The device1 to be discussed consists chiefly of a magnetic drum with a capacity of about 400,000 decimal digits with variable word lengths of 4 to 64 digits, a register (FR) with capacity varying from 4 to 64 digits, and an address register (FADR). Upon the execution of a SEARCH command, the entire surface (about 30,000 words at WL=12) is scanned in 32 ms, and, if the contents of FR are found anywhere, this information is made available in the form of an output which can be used to cause a transfer—similarly, if this number is not present. When the number is found its location is entered into FADR. This system may be employed as a conventional storage device with the usual READ, WRITE instructions. The various commands and logical elements of the FDS are discussed.
Comments on interindustry economics
Authors: Manne Alan S. 
Published: May 2007

AbstractIn writing “INTERINDUSTRY ECONOMICS” [1], Hollis Chenery and Paul Clark have furnished the profession with a uniquely useful work. Within the same covers, they have succeeded in providing both a readable textbook for the beginner, and at the same time a systematic treatise for the input‐output practitioner. Two chapters are to be singled out for special mention: Chapter 6, “Testing the Validity of Input‐Output Assumptions” and Chapter 7, “A survey of Interindustry Research.” Together, these chapters provide a long‐overdue survey of the literature on empirical implementation of Leontief's model of the economy. Much of this Literature has appeared only in mimeographed form, and has not hitherto been generally accessible.
General simulation model for logistics operation in a randomly damaged system
Authors: Walsh John E. 
Published: May 2007

AbstractThe logistics operation considered is imbedded in a system that is subject to damage. Natural attrition and induced attrition can both occur. This system is concerned with the availability and/or use of several different types of items during a specified period of time. The purpose of logistics is to furnish transportation, reduce natural attrition through maintenance, and return damaged items to operational condition. The capability of the logistics operation is examined by simulating the operation of the entire system for the specified time period. The damage received by the various parts of the system depends on the situation at the start of the time period, the use made of the items, the nature of the induced attrition, and the maintenance procedures, etc. Attrition occurs on a probability distribution basis and is introduced by a Monte Carlo procedure. The time required to return a damaged item to operational condition depends on the type of damage, the damage received by other items, the characteristics of the logistics operation, the damage received by the logistics part of the system, etc. To obtain the simulation model, the over‐all system is divided into subsystems on the basis of the use and location of the items, the properties of the logistics operation, etc. The time scale used is discrete; i.e., all important effects are considered to occur during one of a specified finite set of time intervals. The same form of simulation model is used for representing the operation of each subsystem for each time interval. That is, the mathematical model has the same functional form, but the variables in this functional form can differ with the subsystem and time interval. These subsystems can interact in many ways, e.g., items can be transferred between subsystems, damage received in one subsystem can affect the logistics operations in other subsystems, etc. By using time as the basis for coordination among subsystems, the mathematical model and random assignments for attrition can be programmed on a high‐speed computer. The simulation is performed by obtaining first the operational results for all subsystems at the first time considered; then, by using the first‐time results, the second‐time results are obtained, etc. Examination of the subsystem results for each time interval should furnish a good indication of the capabilities of the logistics operation. Repetitions of this simulation furnish an indication of the effects of statistical variation.
Priority ratings in more than one dimension
Authors: Mellon W. G. 
Published: May 2007

AbstractThis paper presents certain theoretical and empirical results for problems which involve the assignment of priority ratings or indicators of military worth, where either several of these ratings must be aggregated or the outcome is to be evaluated by a multi‐valued criterion. The first portion of the paper contains a discussion of the logic of the problem and the axiomatic structure of a desirable solution. The second section includes the results of an experiment in which random demands were processed by running them through a model supply system using several alternative systems of priorities.
Determining merchant shipping requirements in integrated military planning
Authors: Hunt Ralph B. , Rosholdt Erling F. 
Published: May 2007

AbstractTo establish a perspective, a discussion is made of the over‐all planning process involved in the determination of military requirements for the merchant shipping needed to support a prescribed military plan. Three of the principal parts of the planning process, namely: the determination of “pure” pipeline requirements, ship repair loads, and repair replacement ships, under convoy and nonconvoy conditions, are examined. After this, the newly developed models, assumptions, and methodologies for these are dissected and illustrated by means of figures.Typical characteristics and behavior of both the nonconvoy and convoy‐type pipelines and the effect of the repair policies upon them are presented. Additional logistics problems, which were generated in the planning process and which require further research, are outlined.
An alternative solution to the “lost at sea” problem
Authors: Gluss Brian 
Published: May 2007

AbstractA problem posed by Bellman and considered by Isbell is as follows: Suppose one is a mile from a straight shore with no means whatsoever of ascertaining its direction. What is the optimum path to follow so as to (a) minimize the maximum distance travelled in reaching shore, (b) minimize the statistical expectation of the distance travelled, or (c) maximize the probability of reaching shore within a given distance travelled? Isbell found the solution to (a); in the present paper a sequence of approximations to the optimal policy for (b) is considered.
Replacement when constant failure rate precedes wearout
Authors: Hunter Larry , Proschan Frank 
Published: May 2007

AbstractAssume a component has a constant failure rate during the first τ unit of time following installation. After that, wearout sets in so that failure rate begins to increase sharply. Assume further that replacement is made at the time of component failure or at τ units of time following installation, whichever occurs first. Under these assumptions, we obtain explicit formulas for the distribution and expected value of the number of planned replacements, the number of failures, and the total number of removals due to either planned replacement or failure replacement, corresponding to any specified length of time. Examples are worked to show the application of these formulas. The results obtained in this article are of use in determining the number of spares to stock or the budget required to maintain the equipment.
Constraint qualifications in maximization problems
Authors: Arrow Kenneth J. , Hurwicz Leonid , Uzawa Hirofumi 
Published: May 2007

AbstractMany problems arising in logistics and in the application of mathematics to industrial planning are in the form of constrained maximizations with nonlinear maximands or constraint functions or both. Thus a depot facing random demands for several items may wish to place orders for each in such a way as to maximize the expected number of demands which are fulfilled; the total of orders placed is limited by a budget constraint. In this case, the maximand is certainly nonlinear. The constraint would also be nonlinear if, for example, the marginal cost of storage of the goods were increasing. Practical methods for solving such problems in nonlinear programming almost invariably depends on some use of Lagrange multipliers, either by direct solution of the resulting system of equations or by a gradient method of successive approximations (see [5], Part II). This article discusses a part of the sufficient conditions for the validity of the multiplier method.
Optimal disposal policies
Authors: Fukuda Yoichiro 
Published: May 2007

AbstractIn this paper we analyze the inventory model in which the disposal of surplus items is taken into consideration as well as the purchase of stock in anticipation of future demand. Our main concern is to formulate the optimal ordering and disposal policy in a simple form, and it is assumed that the decision to be made at the beginning of each period is always one of the following: (1) ordering, (2) disposal, (3) no ordering and no disposal. The multiple installation model is treated by the method of implied penalty described by Clark and Scarf. The simple optimal policies are explicitly determined under various sets of assumptions on the cost structure of the inventory model.
A transportation algorithm and code
Authors: Flood Merrill M. 
Published: May 2007

AbstractA FORTRAN II transportation code, using Kuhn's Hungarian Method, was reported upon at the RAND Symposium on Mathematical Programming in March 1959. The algorithm was based upon a proof of the König‐Egervary theorem, presented by the present author at the 1958 Symposium on Combinatorial Problems sponsored by the American Mathematical Society. The code was entirely rewritten (in FORTRAN II), during the 1959 IBM Summer Institute on Combinatorial Problems, and several problems were run at the IBM Research Center to obtain data regarding computing times and frequencies of various internal loops. A CLOCK Subroutine yields readings, in hundredths of minutes, for each time through selected portions of the computing run. The version reported upon at RAND solved a 29 × 116 pseudorandom transportation problem in 8.01 min, as compared with 3.17 min using the fastest competing code (SHARE 464) then available. The present version solved this same problem in 2.87 min, and another 29 × 116 problem in 1.89 min. This paper presents the algorithm and reports upon computing experience.
Approximately optimal one‐dimensional search policies in which search costs vary through time
Authors: Gluss Brian 
Published: May 2007

AbstractConsider a model in which there are N neighboring cells in one of which there is an object that it is required to find. The a priori probabilities of the object being in cells 1, …, N are p1, …, pN respectively, and the costs of examination of these cells are tl, …, tN respectively; the search policy is considered to be optimal when the statistical expectation of the total cost of the search is minimized. For the case in which the ti†s are constant throughout the search, an optimal policy solution has previously been found by Bellman and by Smith. In the present paper it is assumed that the costs comprise a travel cost dependent upon the distance from the last cell examined, in addition to a fixed examination cost: initially, assuming that the searcher is next to cell 1, ti = i + t, where t is constant; and from then onwards, assuming that the jth cell has just been examined, ti = | i ‐ j | + t. An optimal search strategy is found in the case where the pi† s are all equal, and approximately optimal strategies in the case where pi is proportional to i. The latter case has application to defense situations where complete searches occur at successive intervals of time, and hence the enemy objects are thinned out the nearer they come to the defense base.
An approximative algorithm for the fixed‐charges transportation problem
Authors: Kuhn Harold W. , Baumol William J. 
Published: May 2007

AbstractA computationally simple method for approximating the optimal solution to transportation problems is described. Also, a method to deal with fixed charges is proposed. The computational algorithms have been designed primarily to handle very large numbers of transportation problems each involving a small number of origins and destinations as is frequently the situation in the Navy supply system. The results of empirical tests of the effectiveness of the methods are summarized.
Toward a study of bidding processes some constant‐sum games
Authors: Griesmer James H. , Shubik Martin , Watson Thomas J. 
Published: May 2007

AbstractThe study of bidding has presented both economics and psychology with a host of as yet unresolved problems. The lack of understanding of these problems has been manifested in the difficulties confronting policy‐makers in the framing of laws to deal with collusive or restrictive practices in bidding under various market mechanisms. On the one hand, a theory of competitive behavior may call for all competitors to charge the same price for the same product, yet the submission of identical bids may, in fact, be a criterion of collusion.This paper, the first of a series on bidding, gives a general and preliminary discussion of several of the factors entering into the construction of models of the bidding process.Following this discussion, a number of bidding situations, formulated as two‐person constant‐sum games are examined. A number of open questions, suggested during the investigation of such games. are mentioned.Succeeding papers will be devoted to the more important cases of bidding models formulated as non‐constant‐sum games, both for single‐shot bids and for sequences of bids.