"Software engineering" is a term which was coined in the late 1960's as the theme for a workshop on the problems involved in producing software that could be developed economicaLly and would run reliably...
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ISBN:
(数字)9781461298984
ISBN:
(纸本)9780387902166
"Software engineering" is a term which was coined in the late 1960's as the theme for a workshop on the problems involved in producing software that could be developed economicaLly and would run reliably on real machines. Even now, software engineering is more of a wish than a reality, but the last few years have seen an increased awareness of the need to apply an engineering-type discipline to the design and construction of software systems. Many new proposals have been made for the management of software development and maintenance and many methodologies have been suggested for improving the programming process. As these problems and solutions become better understood, there is a growing need to teach these concepts to students and to practicing professionals. As a prelude to the educational process, it is necessary to gain an understanding of the software design and development process in industry and government, to define the appropriate job categories, and to identify the fundamental content areas of soft ware engineering. The need for quality education in software engineering is now recognized by practitioners and educators alike, and various educational endeavors in this area are now being formulated. Yet, discussions we had had over the past year or so led us to believe that there was insufficient contact between practitioners and educators, with the resultant danger that each group would go off in separate ways rather than working together.
Nakano, J. H. and Cole, J. T. (NCDC, Atlanta, Ga. 30333). Antigenic segregation of type 2 poliovirus isolants related and unrelated to Sabin's vaccine strain with Modifled-Wecker Technique. Amer. J. Epid., 1970, 9...
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Nakano, J. H. and Cole, J. T. (NCDC, Atlanta, Ga. 30333). Antigenic segregation of type 2 poliovirus isolants related and unrelated to Sabin's vaccine strain with Modifled-Wecker Technique. Amer. J. Epid., 1970, 97; 317–327.—One hundred and sixty-seven pedigreed vaccine-derived strains and 4 strains from 2 contacts of vaccinees were antigenically characterized. All were vaccine-like except 2 strains from 1 contact. Reciprocal test results suggested that the 2 strains were wild, and antigenically similar to 1 of the 4 wild strains isolated from the same area during the same year. Strains P712KP2 and P712KP5, 2 progenitors of Sabin 2 (P712, ch, 2ab), tested reciprocally with Sabin 2, were antigenically homologous. Antigenic characterization of 157 wild isoIants, obtained from clinical cases and asymptomatic individuals, revealed that 152 (96.9%) were nonvaccine-like, 4 (2.5%) were intermediate and 1 (0.6%) was vaccine-like. The vaccine-like strain was probably vaccine-derived since it was isolated after the initiation of oral polio vaccination. The data establish the stability of the antigenic character of Sabin 2 upon passage in human intestinal tracts and the rare occurrence of vaccine-like wild strains in nature. Reciprocal tests performed with antisera prepared against 9 selected strains showed the interrelationships of their antigenic characteristics. The formulation and use of antigenic and antibody profiles are discussed.
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