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A class of synthetic problems for testing multidisciplinary design optimization (MDO) approaches is presented. These test problems are easy to reproduce because all functions are given as closed-form mathematical expressions. They are constructed in such a way that the optimal value of all variables and the objective is unity. The test problems involve three disciplines and allow the user to specify the number of design variables, state variables, coupling functions, design constraints, controlling design constraints, and the strength of coupling. Several MDO approaches were executed on two sample synthetic test problems. These approaches included single-level optimization approaches, collaborative optimization approaches, and concurrent subspace optimization approaches. Execution results are presented, and the robustness and efficiency of these approaches an evaluated for these sample problems.

A class of synthetic problems for testing multidisciplinary design optimization (MDO) approaches is presented. These test problems are easy to reproduce because all functions are given as closed-form mathematical expressions. They are constructed in such a way that the optimal value of all variables and the objective is unity. The test problems involve three disciplines and allow the user to specify the number of design variables, state variables, coupling functions, design constraints, controlling design constraints, and the strength of coupling. Several MDO approaches were executed on two sample synthetic test problems. These approaches included single-level optimization approaches, collaborative optimization approaches, and concurrent subspace optimization approaches. Execution results are presented, and the robustness and efficiency of these approaches an evaluated for these sample problems.

A class of synthetic problems for testing multidisciplinary design optimization (MDO) approaches is presented. These test problems are easy to reproduce because all functions are given as closed-form mathematical expressions. They are constructed in such a way that the optimal value of all variables and the objective is unity. The test problems involve three disciplines and allow the user to specify the number of design variables, state variables, coupling functions, design constraints, controlling design constraints, and the strength of coupling. Several MDO approaches were executed on two sample synthetic test problems. These approaches included single-level optimization approaches, collaborative optimization approaches, and concurrent subspace optimization approaches. Execution results are presented, and the robustness and efficiency of these approaches an evaluated for these sample problems.

A class of synthetic problems for testing multidisciplinary design optimization (MDO) approaches is presented. These test problems are easy to reproduce because all functions are given as closed-form mathematical expressions. They are constructed in such a way that the optimal value of all variables and the objective is unity. The test problems involve three disciplines and allow the user to specify the number of design variables, state variables, coupling functions, design constraints, controlling design constraints, and the strength of coupling. Several MDO approaches were executed on two sample synthetic test problems. These approaches included single-level optimization approaches, collaborative optimization approaches, and concurrent subspace optimization approaches. Execution results are presented, and the robustness and efficiency of these approaches an evaluated for these sample problems.

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Optimization research at NASA Glenn Research Center has addressed the design of structures, aircraft and airbreathing propulsion engines. During solution of the multidisciplinary problems several issues were encountered. This paper lists four issues and discusses the strategies adapted for their resolution: (1) The optimization process can lead to an inefficient local solution. This deficiency was encountered during design of an engine component. The limitation was overcome through an augmentation of animation into optimization. (2) Optimum solutions obtained were infeasible for aircraft and air-breathing propulsion engine problems. Alleviation of this deficiency required a cascading of multiple algorithms. (3) Profile optimization of a beam produced an irregular shape. Engineering intuition restored the regular shape for the beam. (4) The solution obtained for a cylindrical shell by a subproblem strategy converged to a design that can be difficult to manufacture. Resolution of this issue remains a challenge. The issues and resolutions are illustrated through six problems: (1) design of an engine component, (2) synthesis of a subsonic aircraft, (3) operation optimization of a supersonic engine, (4) design of a wave-rotor-topping device, (5) profile optimization of a cantilever beam, and (6) design of a cvlindrical shell. The combined effort of designers and researchers can bring the optimization method from academia to industry.

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Investigations carried out at STL on three current problems involving instability of thin shells in applications to aerospace vehicles are discussed. The first concerns the experimental determination of the buckling behavior of longitudinally stiffened pressurized cylinders; the\nsecond, the analytic prediction and experimental confirmation of the buckling behavior of multi-layer cylinders and the third involves the behavior of cylinders under combined axial load and lateral pressure. In each case the background of the application is reviewed, followed by a short description of the work. It is indicated that the longitudinally stiffened cylinder shows considerable promise in taking maximum advantage of the strengthening effect of internal pressure, that the use of an external low modulus layer as an insulator can have a significant effect on the buckling capability of a shell, and that the assumption of a linear interaction for\npressure and axial load is unnecessarily conservative.

A class of optimal shape design problems is studied in this paper. The boundary shape of a domain is determined such that the solution of the underlying partial differential equation matches, as well as possible, a given desired state. In the original optimal shape design problem, the variable domain is parameterized by a class of functions in such a way that the optimal design problem is changed to an optimal control problem on a fixed domain. Then, the resulting distributed control problem is embedded in a measure theoretical form, in fact, an infinite-dimensional linear programming problem. The optimal measure representing the optimal shape is approximated by a solution of a finite-dimensional linear programming problem. The method is evaluated via a numerical example.

A class of optimal shape design problems is studied in this paper. The boundary shape of a domain is determined such that the solution of the underlying partial differential equation matches, as well as possible, a given desired state. In the original optimal shape design problem, the variable domain is parameterized by a class of functions in such a way that the optimal design problem is changed to an optimal control problem on a fixed domain. Then, the resulting distributed control problem is embedded in a measure theoretical form, in fact, an infinite-dimensional linear programming problem. The optimal measure representing the optimal shape is approximated by a solution of a finite-dimensional linear programming problem. The method is evaluated via a numerical example.

The specific electrical discharge problems that can directly affect the shuttle vehicle and its payloads are addressed. General design guidelines are provided to assist flight hardware managers in minimizing these kinds of problems. Specific data are included on workmanship practices and system testing while in low pressure environments. Certain electrical discharge problems that may be unique to the design of the shuttle vehicle itself and to its various mission operational models are discussed.

An account of the approach used in design of a large sandwich construction nose cone is given. The areas in which analytical methods are needed are discussed and a theoretical procedure is proposed.

The parachute was originally conceived as a life-saving device to safely and reliably lower personnel from balloons and aircraft to the ground in the event of an emergency, Because it was fabricated of textile materials, inflated and achieved its shape due to aerodynamic forces resulting from its velocity of movement through the air, it was lighter in weight, lower in cost and could be stowed in a smaller space than any other means of accomplishing the same end. The continued use of the parachute today and in the future is dependent upon these same factors of reliability, low weight, cost and volume. Other factors which are very important in most applications and mandatory in others are stability, low opening forces, good structural design, and durability to withstand repeated use under severe service conditions.

The U.S. Army at Natick (NLABS) is presently conducting a program to develop a nuclear hardened, mobile, tactical shelter which would be used to house C3 systems. As part of this program, a prototype shelter was designed to withstand a blast loading corresponding to a 10.0 psi (68.9-kPa) incident overpressure. The hardened shelter was then constructed, instrumented and subjected to a simulated nuclear blast loading at the MILL RACE test, White Sands Missile Range, New Mexico. The principal objectives of the test were to evaluate analytical methods for predicting shelter structural effects and shelter overturning effects induced by blast loading and to assess the validity of a particular design concept using conventional materials. Comparison of measured predicted values of shelter wall strain and shelter overturning motion confirm the validity of the analytical methods used. Test results demonstrated that a design featuring shear stiffened sandwich panels with aluminum face materials could withstand a nominal 10.0 psi incident shock loading. (Author)

Viscoelasticity comprises an irreversible relation between stress and strain which is governed by the irreversibility embodied in viscoelasticity which leads to the production of a beneficial residual stress distribution following loading is discussed. Temperature has a marked effect on viscoelastic characteristics, and thus supplies an additional controlling variable in selecting a design solution. Cooling slows down rate processes so that it may be possible to eliminate deleterious aspects of viscoelasticity in a particular design problem by selecting an appropriate temperature history. The example of the production of toughened glass by the interaction of viscoelasticity and temperature effects is cited. Although viscoelastic stress analysis is usually applied to polymers and glasses, its influence also arises in design problems for metals in the creep range.

The aerodynamic design problems for the Pioneer Venus mission are discussed for a small probe shape that enters the atmosphere, and exhibits good stability for the subsonic portion of the flight. The problems discussed include: heat shield, structures and mechanisms, thermal control, decelerator, probe communication, data handling and command, and electric power.

Source: Digital Library of India Scanning Centre: C-DAC, Noida Source Library: Central Library, Bits- Pilani Date Accessioned: 7/10/2015 22:05 The Digital Library of India was a project under the auspices of the Government of India.

Source: Digital Library of India Scanning Centre: C-DAC, Noida Source Library: Central Library, Bits- Pilani Date Accessioned: 7/10/2015 22:05 The Digital Library of India was a project under the auspices of the Government of India.

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This project has two objectives. The first is to determine whether linear programming techniques can improve performance when handling design optimization problems with a large number of design variables and constraints relative to the feasible directions algorithm. The second purpose is to determine whether using the Kreisselmeier-Steinhauser (KS) function to replace the constraints with one constraint will reduce the cost of total optimization. Comparisons are made using solutions obtained with linear and non-linear methods. The results indicate that there is no cost saving using the linear method or in using the KS function to replace constraints.

Three important purposes--description, policy, and design--of theories of foreign policy are examined. Problems in using existing theories to accomplish these objectives are delineated and suggestions for new modes of theory construction are offered.

Streams in which sedimentation problems are encountered are extremely complex and developments within these streams depend on many factors, most of which are interrelated. Few basic principles are available to the design engineer in the solution of problems concerned with channel improvement and stabilization, and many of the plans and types of structures used have been based on experience and general judgment. Because of the difficulties and costs involved in experimenting with the actual river and the impracticality of comparing the effectiveness of various concepts and designs under the same conditions, the development of new principles and procedures or the optimum solution to many problems have to depend to a considerable extent on river model investigations coordinated with results in the field. This report is a general guide for laboratory engineers and technicians concerned with model invesitgations of sedimentation problems in alluvial streams. The report describes many of the principles and procedures used in the design, adjustment, and operation of movable-bed models and the factors to be considered in the development of improvement plans and in the interpretation of model results. Appendices cover the characteristics of model bed material, slopes required, and check list for model design and operation.

Antiradiation missiles (ARM) have become serious threats to military radar. It is an extremely important and complicated research task for counteracting ARM. The problems of counteracting ARM system design are discussed in this paper. It is extremely important to discover ARM and give warning as early as possible. The dynamic range of a warning receiver should satisfy such requirement radar section of a plane, radar section area of ARM. This paper has also analyzed the effect of two interference sources. Both the coherent interferences and incoherent interferences could cause the angle deviation of radar homing head of ARM. The formulas of angle deviation which could be caused by the interferences are given in this paper. (SDW)

Physiological Psychology has always been the scientific approach most likely to provide in aircraft design the alleviation of environmental stress, the design of protective equipment, the planning of optimal cycles at work and rest, as well as the solution of many special problems relating to seats, lighting systems, safety devices, etc. With the dramatic conceptual changes intervening in aerospace, all performance measurements should indicate the manner in which the human is responding in order to allow the interpretation of data obtained in laboratory conditions. The AGARDograph is a general survey of existing capabilities of, as well as the possible contributions to be made by, psychophysiological measurements techniques in applied settings.

This report describes results of research on factorial designs during a two-year period ending in February 1965. These include (a) characterizations of orthogonal and two classes of non-orthogonal designs as solutions to linear constraints, (b) optimality properties of orthogonal designs, (c) development of a general class of non-orthogonal sequential factorial designs, (d) results on certain families of 2(n) designs, and (e) description of a special-purpose linear programming computer routine for combinatorial problems in experimental design. (Author)

The working environment in which an antenna is installed may substantially modify such antenna parameters as radiation efficiency, impedance, bandwidth, power handling capacity, pattern, etc. The need for more accurate antenna design, combined with the continuing growth of computational techniques, are complementing the more traditional approaches of measurement and analysis to vastly broaden the breadth and depth of problems that are now quantifiable. Computers are being used not only for numerical modelling/simulation, but also for measurement, data acquisition, and subsequent transformation of data. The newly available computational techniques are changing the way we think about, formulate, solve and interpret problems. The subject to be addressed is that of modern antenna design computers and measurement, with emphasis on application to antenna problems of military interest. Computer models, using Moment Method and GTD computer codes, complemented by scale model measurement, and measurement in full scale can provide the essential performance information on which design decisions can be based, over the broad frequency band VLF to EHF. NATO furnished. (RRH)

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This study aims to replicate the study design used by Akca et al. (2023) with the German version of the Inventory of Problems-29 in a community sample. The aim is to conduct an initial investigation of the effectiveness of the German version and to examine the cross-cultural validity of the instrument between the language versions using the same study design.

This article is from BMC Geriatrics , volume 13 . Abstract Background: Due to the ageing of the population, the number of frail older people who suffer from multiple, complex health complaints increases and this ultimately threatens their ability to function independently. Many interventions for frail older people attempt to prevent or delay functional decline, but they show contradicting results. Recent studies emphasise the importance of embedding these interventions into existing primary care systems and tailoring care to older people’s needs and wishes. This article presents the design of an evaluation study, aiming to investigate the effects and feasibility of the early detection of health problems among community-dwelling older people and their subsequent referral to appropriate care and/or well-being facilities by general practices. Methods/Design: A longitudinal, quasi-experimental study is designed comparing 13 intervention practices with 11 control practices. General practices select eligible community-dwelling older people (≥ 75 years). Practice nurses from intervention practices (1) visit older people at home for a comprehensive assessment of their health and well-being; (2) discuss results with the GP; (3) formulate – if required – a care and treatment plan together with the patient; (4) refer patient to care and/or well-being facilities; and (5) monitor and coordinate care and follow-up. Control practices provide usual care and match the intervention practices on the presence of different primary care professionals within the practice. Primary outcome measures are health-related quality of life and disability. Additionally, attitude towards ageing, care satisfaction, health care utilisation, nursing home admission and mortality are measured. Some outcomes are assessed by means of a postal questionnaire (at baseline and after 6, 12, and 18 months follow-up), others through continuous registration over the 18-month period. A profound process evaluation will provide insight into barriers and facilitators for implementing the intervention protocol within general practices from both the patient and caregiver perspective. Discussion: The proposed approach requires redesigning care delivery within general practices for accomplishing appropriate care for older people. A quasi-experimental design is chosen to closely resemble a real-life situation, which is desirable for future implementation after this innovation proves to be successful. Results of the effect and process evaluation will become available in 2013. Trial registration: The Netherlands National Trial Register NTR2737

This article is from BMC Geriatrics , volume 13 . Abstract Background: Due to the ageing of the population, the number of frail older people who suffer from multiple, complex health complaints increases and this ultimately threatens their ability to function independently. Many interventions for frail older people attempt to prevent or delay functional decline, but they show contradicting results. Recent studies emphasise the importance of embedding these interventions into existing primary care systems and tailoring care to older people’s needs and wishes. This article presents the design of an evaluation study, aiming to investigate the effects and feasibility of the early detection of health problems among community-dwelling older people and their subsequent referral to appropriate care and/or well-being facilities by general practices. Methods/Design: A longitudinal, quasi-experimental study is designed comparing 13 intervention practices with 11 control practices. General practices select eligible community-dwelling older people (≥ 75 years). Practice nurses from intervention practices (1) visit older people at home for a comprehensive assessment of their health and well-being; (2) discuss results with the GP; (3) formulate – if required – a care and treatment plan together with the patient; (4) refer patient to care and/or well-being facilities; and (5) monitor and coordinate care and follow-up. Control practices provide usual care and match the intervention practices on the presence of different primary care professionals within the practice. Primary outcome measures are health-related quality of life and disability. Additionally, attitude towards ageing, care satisfaction, health care utilisation, nursing home admission and mortality are measured. Some outcomes are assessed by means of a postal questionnaire (at baseline and after 6, 12, and 18 months follow-up), others through continuous registration over the 18-month period. A profound process evaluation will provide insight into barriers and facilitators for implementing the intervention protocol within general practices from both the patient and caregiver perspective. Discussion: The proposed approach requires redesigning care delivery within general practices for accomplishing appropriate care for older people. A quasi-experimental design is chosen to closely resemble a real-life situation, which is desirable for future implementation after this innovation proves to be successful. Results of the effect and process evaluation will become available in 2013. Trial registration: The Netherlands National Trial Register NTR2737

Iterative majorize-minimize (MM) (also called optimization transfer) algorithms solve challenging numerical optimization problems by solving a series of "easier" optimization problems that are constructed to guarantee monotonic descent of the cost function. Many MM algorithms replace a computationally expensive Hessian matrix with another more computationally convenient majorizing matrix. These majorizing matrices are often generated using various matrix inequalities, and consequently the set of available majorizers is limited to structures for which these matrix inequalities can be efficiently applied. In this paper, we present a technique to algorithmically design matrix majorizers with wide varieties of structures. We use a novel duality-based approach to avoid the high computational and memory costs of standard semidefinite programming techniques. We present some preliminary results for 2D X-ray CT reconstruction that indicate these more exotic regularizers may significantly accelerate MM algorithms.

Document number CIA-RDP88-00904R000100100022-6 declassified and released through the CIA's CREST database. Previously available only on four computers located outside of Washington D.C., the Agency was successfully pressured into putting the files online as a result of a MuckRock lawsuit and the efforts of Emma Best. The metadata was collected by Data.World, and the files are now being archived and made text searchable by the Internet Archive.

Document number CIA-RDP88-00904R000100100022-6 declassified and released through the CIA's CREST database. Previously available only on four computers located outside of Washington D.C., the Agency was successfully pressured into putting the files online as a result of a MuckRock lawsuit and the efforts of Emma Best. The metadata was collected by Data.World, and the files are now being archived and made text searchable by the Internet Archive.

Thesis (Nav. Engr.)--Massachusetts Institute of Technology, 1960

We address the problem of optimal experimental design (OED) for Bayesian nonlinear inverse problems governed by PDEs. The goal is to find a placement of sensors, at which experimental data are collected, so as to minimize the uncertainty in the inferred parameter field. We formulate the OED objective function by generalizing the classical A-optimal experimental design criterion using the expected value of the trace of the posterior covariance. We seek a method that solves the OED problem at a cost (measured in the number of forward PDE solves) that is independent of both the parameter and sensor dimensions. To facilitate this, we construct a Gaussian approximation to the posterior at the maximum a posteriori probability (MAP) point, and use the resulting covariance operator to define the OED objective function. We use randomized trace estimation to compute the trace of this (implicitly defined) covariance operator. The resulting OED problem includes as constraints the PDEs characterizing the MAP point, and the PDEs describing the action of the covariance operator to vectors. The sparsity of the sensor configurations is controlled using sparsifying penalty functions. We elaborate our OED method for the problem of determining the sensor placement to best infer the coefficient of an elliptic PDE. Adjoint methods are used to compute the gradient of the PDE-constrained OED objective function. We provide numerical results for inference of the permeability field in a porous medium flow problem, and demonstrate that the number of PDE solves required for the evaluation of the OED objective function and its gradient is essentially independent of both the parameter and sensor dimensions. The number of quasi-Newton iterations for computing an OED also exhibits the same dimension invariance properties.

State-of-the-art technology regarding critical solid mechanics problems for designing various systems and structures used for military applications is reviewed in 27 Conference papers. The main areas of study were on shcok and impact effects; fatigue and fracture; fiber reinforced composites; and strucutural design. Nine of the papers, concerning the structural design of composites for particular applications (rotor blades, compressor blades and other weapon system components are of most interest to Plastec. Reliability studies, and non destructive procedures for quality assurance of these designed structures are also of interest to Plastec.

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We present MENDER, a knowledge based system that implements software design techniques that are specialized to automatically compile generate-and-patch problem solvers that satisfy global resource assignments problems. We provide empirical evidence of the superior performance of generate-and-patch over generate-and-test: even with constrained generation, for a global constraint in the domain of '2D-floorplanning'. For a second constraint in '2D-floorplanning' we show that even when it is possible to incorporate the constraint into a constrained generator, a generate-and-patch problem solver may satisfy the constraint more rapidly. We also briefly summarize how an extended version of our system applies to a constraint in the domain of 'multiprocessor scheduling'.

Basic research has been conducted in the design and analysis of algorithms. Fundamental questions in computer software and systems research have been addressed, concentrating on two particularly promising areas: (1) practical approaches to problems for which only the existence of asymptotically fast algorithms is guaranteed and (2) efficient strategies for parallel computing in realistic, resource-bounded environments. The former is motivated by dramatic recent results in discrete mathematics. The latter is driven by continuing advances in parallel computer architectures.

A number of key problems in wireless communication, ranging from the physical layer to the data transport layer, were investigated. The key results are as follows: (a) A new Quality of Service (QoS) framework, and new schedulers, were developed for supporting heavy-tailed Internet traffic over wireless, without conservative resource provisioning. Related results include analysis and design prescriptions for supporting TCP over wireless, and joint scheduling and link layer optimization for support of real-time traffic over wireless. (b) New techniques in multiuser detection, interference suppression and equalization were invented. These include the patented Differential Minimum Mean Squared Error (DMMSE) technology that is a promising approach for the design of antijam GPS receivers. (c) A framework was developed for efficient noncoherent communication over time varying channels, using joint channel and data estimation rather than suboptimal pilot-based channel estimation followed by demodulation and decoding. Fundamental information-theoretic limits for time-varying channels were developed.

Historical data from completed construction projects are not always efficiently used when planning a future project because the data are rarely reviewed and synthesized into useful information. In this dissertation, the data from a completed industrial project are examined, with particular emphasis on the design-related problems discovered during the construction phase of the project. The problems were identified and classified into eight categories through the Inter-Office Memos which originated from the construction site. Problems are graphically displayed for each problem category, organization of the problem originator, and discipline for each of the four process areas. The results show that the timing and number of problems for each unit are similar throughout the construction phase of the project. Problems dependencies between problem categories, organization, and discipline are shown through the use of contingency tables. Problem deviations are analyzed by testing the hypothesis that the percentage of problems are linearly proportional to the percentage of discipline progress complete. Equipment and Structural problems followed a pattern which showed problems developing at the end of the discipline's activities. Instrumentation, a changing technology, showed the most scatter, but tended to follow the same type of pattern as Equipment. Forecasting models are developed using regression analysis. Three models are developed to predict the potential number of design-related problems: 1) a model using design manhours, 2) a model using construction manhours, and 3) a model using the discipline's progress schedule. A time series model is tried, but the results indicate that this method is not appropriate to analyze these problems.

THIS REVIEW OF THE PROBLEMS IN DESIGN AND INTERPRETATION OF RESEARCH ON HUMAN RELATIONS TRAINING, PARTICULARLY THAT USING T GROUPS AND SENSITIVITY TRAINING, REFERS TO STUDIES IN THE FIELD. PROBLEMS CONSIDERED ARE--THE PROBLEM OF CONTROLS (VOLUNTEER PARTICIPANTS, PREDICTION OF OUTCOMES), TEMPORAL CHANGE IN TRAINING OUTCOMES (RELATIONSHIP OF CHANGE TO TIME), DIMENSIONS AND DIRECTIONS OF CHANGE, CLASSIFICATION SCHEMES FOR TRAINING OUTCOMES (NORMATIVE, RESTRICTIVE, PRESCRIPTIVE), VARIABILITY IN THE TRAINING EXPERIENCE (TRAINER STYLE, GROUP COMPOSITION), TIMING OF DATA COLLECTION (BY MAIL OR IN THE LABORATORY), EXPERIMENTER-PARTICIPANT RELATIONSHIPS IN THE LABORATORY SETTING, AND STATISTICAL PROBLEMS IN TRAINING RESEARCH. THE PAPER CONTAINS 14 BIBLIOGRAPHIC REFERENCES. IT WAS PRESENTED AT THE RESEARCH SEMINAR OF THE VETERAN'S ADMINISTRATION HOSPITAL (WEST HAVEN, CONNECTICUT, JANUARY 27, 1967). (AJ)

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