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1.
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In this study, the performance of air conditioning system and the level of thermal comfort are determined in a state hospital located in Kermanshah city in the west of Iran in winter and summer using the Predicted Mean Vote (PMV) model which has been presented by ISO-7730 (2005). The Predicted Mean Vote (PMV) and the Predicted Percentage Dissatisfied (PPD) indices were computed using the data acquired from the experimental measurements performed in the building. The results showed that the values of PMV in some parts of the building, both for men and women, are not within the standard acceptable range defined by ISO. It was found that the most thermal problems in winter occur in morning work shift, and the worst thermal conditions in summer occur in noon work shift. The t-test results revealed that there is no noticeable difference between the thermal conditions of some rooms and those of the surroundings.  相似文献   

3.
In this study, three methods were used to determine the thermal insulation values of different school clothing worn by 6 to 17 year old girls and boys in Kuwait classrooms for both summer and winter seasons. The different clothing ensembles' insulations were determined by 1: measurement using adult-sized versions of the clothing on thermal manikins, 2: estimations from adult clothing data obtained from the standards tables in ISO 9920 and ASHRAE 55, and 3: calculations using a regression equation from McCullough et al. (1985) that was adapted to accommodate children's sizes for ages 6-17 years. Values for the clothing area factor, f(cl), were also determined by measurement and by using a prediction equation from ISO 9920. Results in this study suggested that the clothing insulation values found from the measured and adapted data were similar to the adult's data in standards tables for the same summer and winter seasons. Further, the effect of the insulation values on the different scholars' age groups were investigated using the clothing temperature rating technique and compared to the scholars' comfort temperature found in recent field studies. Results showed that the temperature ratings of the clothing using the three methods described above are close and in agreement with the scholars' comfort temperature. Though estimated and measured f(cl) data differed, the impact on the temperature ratings was limited. An observed secular change in the children's heights and weights in the last few decades implies that, for adolescents, the children's body surface areas are similar to those of adults, making the use of adult clothing tables even more acceptable. In conclusion, this study gives some evidence to support the applicability of using adults' data in ASHRAE 55 and ISO 9920 standards to assess the thermal insulation values of different children's clothing ensembles, provided that careful selection of the garments, ensembles material and design takes place.  相似文献   

4.
Plant three-dimensional (3D) computer-aided design (CAD) models typically consist of logical configuration, equipment specifications and ports, and 3D shapes. Because 3D CAD models are used as master information throughout a plant’s entire lifecycle and many stakeholders are involved in such lifecycle, providing a method for sharing plant 3D CAD models among various stakeholders is very important. Standard 15926 from the International Organization for Standardization (ISO 15926) is a family of standards that is intended to support the sharing and integrating of all information during the life of a process plant. Therefore it is important for ISO 15926 to support plant 3D CAD models. In order to address this issue, this study investigates a standardized method to exchange plant 3D CAD models using ISO 15926. Information requirements regarding plant 3D CAD models are established, and then ISO 15926 reference data (classes, attributes, and templates) are extended to cover information requirements. For demonstration of the proposed method, we developed a prototype platform where plant 3D CAD models in ISO 15926 are loaded and retrieved.  相似文献   

5.
《Computer aided design》1987,19(7):368-374
Manufactured features generally deviate in size, form and relations with respect to other features from the features desired by the designer. Designers specify certain limits for these deviations that depend on functional requirements. The specification of different form errors is dealt with by the International Organization for Standardization (ISO). ISO also specifies that an ideal geometric feature must be established from the actual measurements such that the maximum deviation between it and the actual feature concerned is the least possible value. In practice, the least squares (LS) method is sometimes used for establishing the ideal feature, as this method is based on sound mathematical principles. However, the least squares procedure does not yield a minimum value. Therefore some attempts have been made to arrive at a form error based on the minimum deviation (MD) principles. A stray peak or valley on the actual feature introduces considerable variation in the results obtained by the minimum deviation method. This paper suggests a new approach based on the minimum average deviation (MAD). In this method, the ideal feature is established by using a search technique for different geometric features such as straight lines, circles, planes, cylinders and spheres. Using simple numerical examples, the values obtained by this approach are compared with the values obtained by the least squares and minimum deviation methods.  相似文献   

6.
This paper describes the basic concepts for the Image Interchange Format (IIF) for the first International Image Processing and Interchange Standard (IPI), which is under elaboration by ISO/IEC JTC1/SC24 (International Standards Organization/International Electronics Commission, Joint Technical Committee, Computer Graphics)—i.e., “information processing”/“computer graphics”—committee work. Starting with a discussion of existing image formats and current image interchange practices, this study outlines the need for a new approach to a general image interchange format. A requirements list and corresponding design goals for the IIF are presented. Finally, the relation to the other parts of the IPI standard are described. The authors are coworkers and contributors to the relevant committees within the ISO/IEC and the DIN German Institute for Standardization (DIN Deutsches Institut für Normung).  相似文献   

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The International Standard ISO 7933 (1989) Hot environments--Analytical determination and interpretation of thermal stress using calculation of required sweat rate has been proposed for the evaluation of climatic stress within the European system of CEN standards. Comparison of results of studies performed in climatic chambers and those in the field with the predictions of ISO 7933 show that there are considerable problems in using this index in practice. In its present state of development, ISO 7933 seems to be rather a step towards a useable index for evaluating climatic conditions rather than an established climatic index which is applicable in practice. Within the CEN standards, the deficiencies of ISO 7933 are reflected mainly by a restriction of the limits of application within EN 12 515 (1997) which is based on ISO 7933.  相似文献   

9.
Virtual reality (VR) has provoked enormous interest in the medical community. In particular, VR offers therapists new approaches for improving rehabilitation effects. However, most of these VR assistant tools are not very portable, extensible or economical. Due to the vast amount of 3D data, they are not suitable for Internet transfer. Furthermore, in order to run these VR systems smoothly, special hardware devices are needed. As a result, existing VR assistant tools tend to be available in hospitals but not in patients' homes. To overcome these disadvantages, as a case study, this paper proposes a Web-based Virtual Ticket Machine, called WBVTM, using VRML [VRML Consortium, The Virtual Reality Modeling Language: International Standard ISO/IEC DIS 14772-1, 1997, available at ], Java and EAI (External Authoring Interface) [Silicon Graphics, Inc., The External Authoring Interface (EAI), available at ], to help people with acquired brain injury (ABI) to relearn basic living skills at home at a low cost. As these technologies are open standard and feature usability on the Internet, WBVTM achieves the goals of portability, easy accessibility and cost-effectiveness.  相似文献   

10.
For International Standard ISO 7933 (Hot environments-analytical determination and interpretation of thermal stress using calculation of required sweat rate. International Organization for Standardization, Geneva, 1989) it has been questioned whether the heat stress index "required sweat rate" is applicable in environments where mean radiant temperature (t(r)) exceeds dry air temperature (t(a)). Based on a re-analysis of 556 climatic chamber experiments on 16 subjects the observed sweat rates were compared with required sweat rates predicted according to the ISO standard. Under climatic conditions with t(r) > t(a) the predictions overestimate the observed sweat rates on average by 86% in clothed subjects and by 25% in nude subjects. In climates with t(r) = t(a) the predictions highly agreed with the observed sweat rates in nude subjects and were slightly overestimated (13%) in clothed subjects. The misjudgement of the present ISO standard is obviously caused by an inappropriate calculation of radiative heat exchange. Corrections are proposed to improve the validity concerning climates with t(r) > t(a).  相似文献   

11.
Vollman  T.E. 《Computer》1993,26(6):118-120
The development of software product-quality assessment methods is reviewed. Much of the software quality standards work has been performed under the aegis of international organizations such as the IEEE Computer Society and the International Standard Organization/International Electrotechnical Committee Joint Technical Committee No.1 Subcommittee on Software Engineering (ISO JTC1 SC7). An alternative approach that defines a set of requirements for members of a class of software product and certifies those that meet the requirements is described  相似文献   

12.
The International Organization for Standardization evacuation alarm (ISO 8201: 2017) is ineffective in initiating evacuation, particularly when people are engaged in pre-evacuation activities, and it is not easy to conduct experiments for evaluating evacuation behavior due to ethical and cost issues. A virtual building emergency where alarms went off while participants were performing activities was created to study the effect of redundancy on evacuation effectiveness. Three alarms were studied: (i) a regular nonverbal ISO alarm, (ii) a speech-inserted ISO alarm, and (iii) a technology-based ISO alarm concept (sound, visual, and haptic information). Evacuation behavior, perceived urgency, and delay time were measured. Results confirmed the effect of redundancy on measurements, and participants complied better with the speech-inserted and technology-based alarms, but there were no differences in evacuation effectiveness between them. Participants perceived higher urgency from the technology-based solution, which can be more adaptive in complicated environments where background noise and language/education barriers are problems. Otherwise, the speech-inserted alarm is more cost-effective.  相似文献   

13.
The paper presents research results of the vibration transmitted from the steering wheel of the small tractor with a 4-wheel drive to the driver's hands. The vibration measurements were carried out on the tractor randomly chosen from the producer's store-house. Before testing the tractor was examined and adjusted following the producer's recommendations. The vibration levels were measured at idling and at full load. The vibration level on the steering wheel was measured and analyzed and the frequency spectra for the chosen working conditions were obtained. The frequency-weighted acceleration, given in m/s(-2), was calculated. The vibration total value was defined as the root-mean-square of the three component values. The obtained values are graphically represented in accordance with ISO/DIS 5349-1979 and ISO5349-1-2001. The vibration exposure for the predicted 10% prevalance of vibration-induced white finger in accordance with Annex C of the same standard was also tested.  相似文献   

14.
This paper motivates on redesigning the traditional management style of global shipping firms in order to originally establish an Integrated Process Management System (IPMS) on the basis of quality aspects, environmental concerns, and occupational health and safety requirements. The requirements of ISO 9001:2000, ISO 14001:2004, and OHSAS 18001:2007 are comparatively assessed with respect to International Safety Management (ISM) Code clauses via using Fuzzy Axiomatic Design (FAD) while Analytic Network Process (ANP) enables to identify critical managerial processes of shipping business. Consequently, the fundamental structure of IPMS is proposed based on the quantitative outcomes of FAD and ANP approaches. In practice, the IPMS can be adopted into shore-based organizations in accordance with the prior principles of ship management companies.  相似文献   

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Most models used in land surface hydrology, vadose zone hydrology, and hydro-climatology require an accurate representation of soil thermal properties (soil thermal conductivity and volumetric heat capacity). Various empirical relations have been suggested to estimate soil thermal properties. However, they require many input parameters such as soil texture, mineralogical composition, porosity and water content, which are not always available from laboratory experiments and field measurements. In this paper, to overcome the above challenge, a hybrid numerical method, Genetic Algorithm–Finite Difference (GA–FD), is proposed to estimate soil thermal properties using land surface temperature (LST) as the only input. The genetic algorithm (GA) optimization method coupled with the finite difference (FD) modeling technique is a viable hybrid approach for estimating soil thermal properties. The finite difference method is employed to solve the heat diffusion equation and simulate LST, while a robust optimization technique (GA) is used to retrieve soil thermal properties by minimizing the difference between observed and simulated LST. Furthermore, a generalization of the hybrid model is developed for inhomogeneous soil, in which soil thermal properties are not constant throughout the soil slab. The proposed model is applied to the First International Satellite Land Surface Climatology Project (ISLSCP) Field Experiment (FIFE). The results show that the proposed hybrid numerical method is able to estimate soil thermal properties accurately, and therefore effectively eliminate the need for the unavailable soil parameters which are required by empirical methods for determining the soil thermal conductivity and volumetric heat capacity. Remarkably, the temporal variation of the retrieved soil thermal conductivity is consistent with the volumetric water content, even though no water content information is used in the model.  相似文献   

17.
Bamford  R.C. Deibler  W.J.  II. 《Computer》1993,26(10):68-70
The Carnegie Mellon University Software Engineering Institutes's (SEI's) five-level framework for engineering practices in a successful software development organization and the International Organization for Standardization's ISO 9000 series of standards, which describes the key requirements for companies and organizations doing business in the European Community, are reviewed. The origins of the models are discussed, and the two models are compared and contrasted  相似文献   

18.
The introduction of standards will hopefully ensure that users can access particular computer resources through a communications network for their own purposes without major problems. The International Standards Organisation (ISO) has developed a seven-layer reference model which is to be used for the purpose of incorporating standards relating to the interconnection of open systems (OSI). It is important that the human factors requirements are considered in relation to this model if the aim of generality of use is to be achieved. This paper considers some of the major human factors requirements and describes an approach to translating them into design standards which can be implemented. The approach starts from a consideration of user activity and develops into a language interface which could reside in layers of the reference model.  相似文献   

19.
《Ergonomics》2012,55(11):1599-1614
Four influential models which make predictions of human response to hot or cold environments have been described and their predictions compared. The models considered were the Givoni and Goldman prediction equations. ISO/DIS 7933, the J. B. Pierce Lab. 2-node and the Stolwijk and Hardy 25-node models of human thermoregulation. The models integrate the important environmental variables, (air temperature, mean radiant temperature, air speed and relative humidity) with subject variables (insulation of clothing worn and metabolic heal production), in order to make predictions such as core and skin temperature response and allowable exposure times. The models' predictions have been compared for a range of hot and cold environments. This comparison has shown that while for some environments the models' predictions are similar, for other environments they are very different. These differences would result in different practical decisions being made. The models should be used with caution until further evaluation for. a wide range of subjects and environmental conditions has determined the accuracy of the models and for which environments they are most appropriate.  相似文献   

20.
分布交互仿真的发展经历了从最早的SimNet到DIS以及目前的HLA等多种体系结构,采用HLA结构是日前分布交互仿真发展的趋势。但是目前还存在许多基于DIS的仿真系统,为了能够利用这些已有的仿真资源,有必要使这些DIS系统能够与基于HLA的分布交互仿真系统相连接。因此需要研究DIS/HLA之间的转换和互联技术。该文分析了几种常用的DIS/HLA转换技术方案,指出对于一个具体的DIS与HLA互联问胚,采用转换器的方案是比较容易实现的,给出了相关的开发思路和程序实现,并对所开发的转换器的延时特性进行了测试。开发和应用表明采用转换器不需要对原有的DIS系统进行修改,具有使用方便且容易实现的特点。  相似文献   

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