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1.
《Ergonomics》2012,55(2):235-236
Abstract

Industrial Design is a discipline which, despite an early pre-occupation with styling and making technology saleable, is now centrally concerned with user needs. This is reflected in Coventry's unique degree course in the Industrial Design/Transport Department at Lanchester Polytechnic. The course contains a significant commitment to Human Factors and this is evident in the range of design projects which are undertaken either by students or as sponsored research. The emphasis in these projects is on practical designs which meet user requirements.

This paper describes the following typical course projects:

1. The competition winning design for a dinghy which can be used as an emergency life-raft.

2. An adaptation of a standard front-wheel-drive car with a transverse slide seat to allow easy access for a wheel chair user.

3. The design for a bus seat which can be used either as a conventional seat or as a standee ‘lean’ seat.

4. Design of a vehicle for use by spina bifida children.

5. Design for a pedal driven power unit for transport and machine uses in Developing Countries.

6. The design of adult tricycles for the transport of mothers plus children under 5 yr.

It is concluded that greater collaboration between industrial designers and ergonomists would be possible if the latter published their data in a more accessible form, and that designers must place greater emphasis on the product evaluation aspect of their work.  相似文献   

2.
Crop classification is a key issue for agricultural monitoring using remote-sensing techniques. Synthetic aperture radar (SAR) data are attractive for crop classification because of their all-weather, all-day imaging capability. The objective of this study is to investigate the capability of SAR data for crop classification in the North China Plain. Multi-temporal Envisat advanced synthetic aperture radar (ASAR) and TerraSAR data were acquired. A support vector machine (SVM) classifier was selected for the classification using different combinations of these SAR data and texture features. The results indicated that multi-configuration SAR data achieved satisfactory classification accuracy (best overall accuracy of 91.83%) in the North China Plain. ASAR performed slightly better than TerraSAR data acquired in the same time span for crop classification, while the combination of two frequencies of SAR data (C- and X-band) was better than the multi-temporal C-band data. Two temporal ASAR data acquired in late jointing and flowering periods achieved sufficient classification accuracy, and adding data to the early jointing period had little effect on improving classification accuracy. In addition, texture features of SAR data were also useful for improving classification accuracy. SAR data have considerable potential for agricultural monitoring and can become a suitable complementary data source to optical data.  相似文献   

3.
In high mountainous areas, such as the Himalayan Range where snow melt run-off contributes substantially to streamflow, information on snow depth and snow areal extent is vital for the estimation of streamflow and for water resources management. Microwave radiationpenetrates through clouds and snowpacks and is thus considered an important tool for providing water equivalent information on snow fields. The scanning multichannel microwave radiometer (SMMR) on board the NIMBUS-7 satellite acquired passive microwave data for 9 years (1978-1987). These SMMR data are used to test a snow algorithm that is applicable for high elevation areas (>3500m) in the Himalayan Range. The study demonstrates promising results, suggesting the application of SMMR data to derive snow-depth and snow-extent information for the Himalayan region. The generated snow maps can be used for various hydrological applications. The limited availability of field data and its comparison with the SMMR data (which are areal in nature), are major limitations in achieving close correlations between two observations. This is the first application of SMMR data for the determination of snow parameters in the Indian Himalayas. Thus, such an application sets a pace for further research and application of passive microwave data in the most rugged terrains of the world.  相似文献   

4.

Possibility distribution introduced by Zadeh ["Fuzzy sets as a basis for a theory of possibility theory", Fuzzy Sets Syst. 1 (1978) 3-28] in his introductory paper of possibility theory assumes a normal distribution, in the sense that it supposes the existence of at least one element s 0 of the universe of discourse U , for which the distribution ~ is fully compatible with the context of interest: ~ (s 0 )=1. However, when such element does no longer exist, it leads to a subnormal possibility distribution. This situation may arise from incomplete data, inconsistent statements, or contradictory beliefs. To deal with such case, many authors like Yager ["On the relationships of methods of aggregation evidence in expert systems", Cybern. Syst. , 16 (1985) 1-21; "A modification of the certainty measure to handle subnormal distributions", Fuzzy Sets Syst. , 20 (1986) 317-324], Dubois and Prade ["An alternative approach to the handling of subnormal possibility distributions--A critical comment on a proposal of Yager", Fuzzy Sets Syst. , 24 (1987) 123-126] have put forward some proposals in order to keep track of the consistency of the basic axioms attached to possibility and necessity measures. In this paper, the proposals are reviewed in the light of new results regarding some appealing criteria. Particularly, when subnormal distribution and normal distribution are encountered in the same level, intuitively, two approaches are possible: Either the subnormal distributions are risen up to a normal distribution level, or the normal ones are flatted down to agree with the normal ones. In both cases there is a sort of gaining or losing information. We review some of the proposal solutions. The flatting approach is mainly related to fuzzy arithmetic calculus while the rising effect is motivated by Dempster-Shafer theory of evidence and its normalization paradigm. The two approaches will also be investigated with respect to some appealing criteria like preference preservation, distance minimization, entropy, minimum/maximum specificity, and, further, particular interest is focused on information based uncertainty preservation. Later on, the proposals are discussed according to the f -certainty qualification where the greatest value h of the subnormal distribution is understood as a degree of certainty that must be attached to the resulting normal distribution.  相似文献   

5.
The greatest portion of papers dealing with the Dempster-Shafer theory consider the case when the basic universe is a finite set, so that all the numerical characteristics introduced and investigated in the D-S theory, including the believeability and plausibility functions as the most important ones, can be easily defined by well-known combinatoric formulas outgoing from a simple probability distribution (basic belief assignment, in the terms of D-S theory) on the power-set 𝒫(S) of all subsets of S. The obvious fact that these numerical characteristics can be equivalently defined also by appropriate set-valued random variables becomes to be of greater importance in the case when S is infinite. We investigate, in this paper, the case when the power-set 𝒫(S) over an infinite set S is equipped by a nonempty σ-field  ? 𝒫(𝒫(S)) andwhen the belief and plausibility functions are defined by a set-valued random variable (i.e., -measurable mapping) which takes a given probability space into the measurable space (𝒫(S),) In general, the values of the two functions in question need not be defined for each subset T of S. Therefore, we define four extensions of these functions to whole the (S) based on the well-known concepts of inner and outer measure, and investigate their properties; interesting enough, just one of them respect the philosophy of the D-S approach to uncertainty quantification and processing and keeps the properties possessed by believeability and plausibility functions defined over finite spaces.  相似文献   

6.
This paper presents CMOS circuit designs of a ternary adder and a ternary multiplier,formulated usingtransmission function theory.Binary carry signals appearing in these designs allow conventional look-aheadcarry techniques to be used.Compared with previous similar designs,the circuits proposed in this paperhave advantages such as low dissipation,low output impedance,and simplicity of construction.  相似文献   

7.
This paper utilizes trapezoidal rule together with Genetic Algorithm (GA) to convert a continuous-time system with input and state delays to an equivalent discrete-time one. A new method has been proposed to construct the hybrid control of sampled-data system with state and input delays via digital redesign which transforms the control law of a continuous-time system with state and input delays into an equivalent one of a sampled-data system so that the states of the digitally controlled sampled-data system closely match those of the originally well-designed continuous-time system for a relatively longer sampling period. An example is given to demonstrate that the proposed digital redesign is superior to the existing ones under a longer sampling period.  相似文献   

8.
9.
A nonlinear state-space model representing the robot dynamics and containing a disturbance term due to gravitational loading is presented. An adaptive model-following control problem satisfying the matching conditions is formulated using a suitable linear time-invariant reference model. The control input is designed to have two components: a non-adaptive linear component to do the task of model-following and a nonlinear unit-vector component based on hyperstability theory to do the adaptive task. An additional integral feedback term is further added and then the overall asymptotic hyperstability is established. Simulation experiments on the first three joints of a PUMA 560 robot manipulator have indicated the potential of our design approach.  相似文献   

10.
11.
This paper explores the problems that are associated with building a model (representation) of two systems which are central to the field of policy analysis. The systems are the Lockean and Dialectical Inquiring Systems (ISs). Given two or more belief systems, a Lockean IS will attempt to secure maximum agreement between them, whereas a Dialectical IS will attempt to secure maximum disagreement as the basis for forming a policy.

It is shown that a representation of these two systems necessitates a notion of probability assignment in which the law of conditional probabilities, p(A)p(B\A) = p(B)p(A\B), does not hold. Cross impact analysis provides such a notion of probability and hence is necessary to the representation of what happens as a decision-maker goes from a Lockean state to a Dialectical state. The movement from a Lockean to a Dialectical state is termed Conflict Production or Generation whereas the movement from a Dialectical to a Lockean state is termed Conflict Resolution or Reduction. It is argued that the representation of these two systems is basic to the foundation of a mathematical approach to policy analysis.  相似文献   


12.
13.
The paper presents new refinements of homomorphisms that are needed in order to deal with partial algebraic systems; namely, weak, strong and Very strong homomorphisms and the laws of their compositions. Further, it describes loose and tight congruences and the canonical factorization of various kinds of homomorphisms. The results have important applications in cognitive modelling, general systems relational models, knowledge representation schemes in Expert Systems and formal methods of Software Engineering,  相似文献   

14.
15.
《Ergonomics》2012,55(4):405-406
The extension force against resistance was recorded in 23 postures for 12 subjects to find explanations for the decrease in back strength in asymmetric postures. A reduction in muscle force in asymmetric postures was found up to 40%, but was strongly dependent on the plane in which asymmetry occurred, and on the posture to which it referred. A quantitative relationship between the forces exerted in different asymmetric postures is discussed, as a basis for formulating universal ergonomic guidelines for optimal working postures. The reduction in force in different asymmetric postures can be explained by length of the muscle, the activation of the muscle, and the moment angle of the muscle.  相似文献   

16.
It is common that experts involved in complex real-world decision problems use natural language for expressing their knowledge in uncertain frameworks. The language is inherent vague, hence probabilistic decision models are not very suitable in such cases. Therefore, other tools such as fuzzy logic and fuzzy linguistic approaches have been successfully used to model and manage such vagueness. The use of linguistic information implies to operate with such a type of information, i.e. processes of computing with words (CWW). Different schemes have been proposed to deal with those processes, and diverse symbolic linguistic computing models have been introduced to accomplish the linguistic computations. In this paper, we overview the relationship between decision making and CWW, and focus on symbolic linguistic computing models that have been widely used in linguistic decision making to analyse if all of them can be considered inside of the CWW paradigm.  相似文献   

17.
18.
《Ergonomics》2012,55(5):801-803
Abstract

In order to evaluate the efficiency of various commercial chemical fabric softeners, a technique of obtaining subjective assessment known as ‘magnitude estimation’ was used to estimate the fabric softness. Particular emphasis was given to subjective scaling and limits of human perception. Comparison between softness and compression ( a physical measure) was demonstrated  相似文献   

19.
《Ergonomics》2012,55(11):1589-1593
The physical work performance of eight fit fire fighters wearing fire brigade uniforms and wearing breathing apparatus was assessed. They were tested in a climatic chamber set at temperatures of 15 and 45°C respectively. The test was performed with and without fire fighting equipment. The subjects walked on a treadmill at a speed of 3.5km/h, which produce a workload equivalent of 20% of the subjects' maximal oxygen uptake without equipment, and 30% with equipment. The test lasted for 60 min. Heart rate, oxygen uptake, skin and deep body temperatures were measured during the test. The subjects estimated perceived physical exertion and perceived temperature. Wearing fire fighting equipment increased the oxygen uptake by 0.4 1min-1. Heart rate at the end of the experiments reached near-maximum levels when the temperature was 45°C with equipment, and deep body temperature increased to an average of 38.7°C. The subjects' ratings of perceived exertion were highly correlated to heart rate. The loading induced by heat and protective equipment reduced the ability to perform strenuous work. The combination of thick clothing and heavy breathing apparatus was found to have a significant limiting effect on the endurance of fire fighters.  相似文献   

20.
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