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This article, the first in a series of four, views the application of systems anal ysis and design as a method of problem solving for documents librarians. Par ticular emphasis is placed on the use of systems analysis as a major, first step in applying computer based technology to problem areas common to U.S. government publication collections. The specific problem areas amenable to the application of this methodology include (1) bibliographic control, (2) col lection development, (3) collection integration, and (4) improved documents reference service. The steps required for its application to these problem areas are described in sequential fashion, and are augumented by actual examples. Several sources of supplementary information are noted for further references.  相似文献   
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The purpose of this study was to determine the effects of short-term normoxic and hypoxic exercise on plasma endothelin-1 and nitric oxide levels, and the relationship of arterial compliance and pulmonary artery pressure to endothelin-1. Seven endurance-trained males completed two incremental and two steady-state exercise tests performed at ventilatory threshold in normoxia and hypoxia (fraction of inspired oxygen = 0.14). Plasma endothelin-1was measured throughout steady-state tests. Arterial compliance using applanation tonometry, plasma nitric oxide and pulmonary artery pressure using Doppler echocardiography were measured before and after exercise. Small arterial compliance and pulmonary artery pressure significantly increased following exercise. There were no main effects of condition or time for plasma endothelin-1and nitric oxide levels. There were no significant relationships between plasma endothelin-1 and arterial compliance or pulmonary artery pressure. In conclusion, mechanisms other than the endothelial system may play a role in the exercise-induced changes in small artery compliance in this study population. Moderate hypoxia and a 30-minute steady-state exercise have limited effects on plasma endothelin-1 in endurance-trained males.  相似文献   
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Nowadays, some virtual museums include 3D room scenes to show the models of its pieces, just like in real museums. Nevertheless, the generation and maintenance of this kind of scenes is generally difficult and should be done by an expert. For example, any change such as including a new piece or modifying the position of an existing fragment usually requires a different design and the creation of a new scene. In this paper we present a case study on the development of a web-based application to automatize this process. To this end, a database to store both graphic and non-graphic information about the pieces, and some 3D rooms to show them has been created. The designed scenes only contain some pieces of furniture to exhibit the fragments, which will be subsequently included. Thus, when a room is loaded in the web page, its associated pieces are obtained through a query in the database and its models are dynamically included in the original scene. Therefore, the position changes or the inclusion of new pieces are not performed in the 3D model, but in the database. Our application makes the transmission of the knowledge to the general public easier because any new discovered piece can be included in a existing museum effortlessly.  相似文献   
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Solihull's development of delegated budgets began in 1981. The experiences of schools and Centre led to the acceptance by Council in 1987 of a scheme for general implementation. The detailed scheme is included in an Appendix to the article, together with examples of vital financial management systems. In his article, the Director of Education explores the effects of delegation of the budget, and with it, the decision‐making process. The school heads’ role gains the natural extension of facility to implement management decisions, but what of the role of the Centre?  相似文献   
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