Measurements and Predictions of Laminar Mixed Convection Flow Adjacent to a Vertical Surface

Measurements and predictions of laminar mixed forced and free convection airflo

Attitudes Toward Computer Software aid Its Exchange ii tie Pressure f esse! Industry 1

Introduction The widespread use of computer software in modern pressure vessel engineering, for example, is well known (see, e.g. [1)2). Analysis and design tasks which formerly involved great difficullies have now become routine. Others, which were too complex to consider have become feasible. Within the constraints of lime, funding and machine capacity engineers can now contemplate just about any type of calcualtion. This fortunate situation has not, of course, arrived without an attendant set of new problems. Thus, the engineer is now faced with considerations such as access to software, verification of software, user qualification, duplication of effort and a host of others. These indicate that the computer has necessitated a shift from purely technical and theoretical concerns to management and administrative concerns. The verification of software and the qualification of the user have been actively described in several publications of the ASME Pressure Vessels and Piping Division A "dynamic" type of technology transfer effort for software has recently been presented for discussion. In particular representatives of the civil engineering community met in Boulder, Colorado in 1971 to discuss such an effort for their profession. The National Science Foundation sponsored this "Workshop on Engineering Software Coordination" In principle, the Special Workshop on Engineering Software Coordination recommends the establishment of a national effort to optimize common use of engineering software. We further recommend the immediate establishment of a demonstration pilot program, initially limited to software for the civil engineering profession and the related construction community, to: 1) collect, evaluate, and verify software from all available sources; 2) to encourage the development of new programs; and, if necessary, 3) to initiate the development of new programs in order to advance the state-of-the-art. Programs determined to possess transferable merit would be improved as required, would be translated into such form as will facilitate their use by the engineering profession, and would be made generally available to the profession. Later on, the National Science Foundation sponsored a survey of the ASCE by K. Medearis in which the feasibility of a socalled National Civil Engineering Software Center was explored He concluded that the respondents to his questionnaire favored no more than a center that provides information concerning available software. He recommended further that the ASCE establish such a center. Thus, the conclusions of this particular survey were certainly not in accord with those of the Boulder conference. This could be attributed to a difference in population. The attendees at Boulder were the most active users and writers of software in the industry while the Medearis questionnaire went to the general ASGE membership. As a result it became of interest to the NSF to expand the investigation of the feasibility of the transfer effort further. Consequently, it was decided to carry out the survey of the pressure vessel industry whose results are reported here. Since analysts and designers in that industry tend to be affiliated with ASME such a study would also bring a segment of that society into the picture along with ASCE. To fix our ideas it is appropriate at this point to describe in some detail the technology transfer effort for software that is being presented for consideration: In contrast to much of recent experience with passive library functions the currently envisioned technology transfer effort would be more dynamic in structure and philosophy. It would be endowed with the personnel, policy making, physical and monetary resources that are required to accomplish the following objectives: 1 To collect all engineering software developed under publicly supported activities as well as through donation or contractural agreements with private individuals and organizations. 2 In cooperation with recognized technical-professional committees, to separate those elements having a distinct utility. These would be validated and then transformed by a variety of processes such as documentation, translation, testing and continued maintenance into packages suitable for use in a wide variety of operational environments. 3 For other elements having a lower degree of general utility, to provide cataloging and abstracting services. 4 To provide an effective distribution system (perhaps including network and/or satellite concepts) with feedback loops for all collected software elements. 5 To provide a reference source of documentation standards suitable for voluntary adoption. 6 To conduct professional educational activities of the type and level required to assure a continued and broad scale growth of national capability in the practice of engineering as related to utilization of the computer. 7 To provide a discernible, responsible entity to which hardware and computer science specialists can turn for the definition of new needs. With this description in mind we turn to the results of our survey. These will be presented in four parts. First, we discuss the gathering of the data. Second, we present a summary of the data. Third, we give statistically significant correlations in the data and, fourth, we discuss the conclusions that are indicated by the data. Gathering The Data In order to gain the desired information on the attitudes toward software use and its exchange in the pressure vessel industry a five-part questionnaire was designed and is reproduced in the Appendix. This was sent to the most active engineers in the field of pressure vessel analysis and design as covered by the memberships of the following professional groups: As could be expected the memberships of these groups overlap widely. After the duplications were eliminated a mailing of 707 questionnaires was sent out in February 1973. By the end of August 1973, after two reminders had been sent out, the tot.il number of filled-in responses reached 249 or 36.0 percent. The rate of return is itself interesting because it is virtually the same as that obtained by Medearis in his previously cited survey After a consideration of several factors it was concluded that the filled-in forms were received from persons who are actually involved with computer software either as direct users and/or writers or as supervisors of such people. The nonrespondents are essentially uninvolved and, therefore, reluctant to fill in the fairly long questionnaire. This conclusion was reached as follows: First, the ASME Boiler and Pressure Vessel Committee is known to have a large number of members who are in vessel inspection, insurance or fabrication or who work for regulatory agencies concerning labor and safety in various state governments. These are not likely to be conversant with, or interested in, software and its exchange. Second, one of our questions asks the respondent to indicate the scope of his involvement with software. The answers to that question indicate that 198 of the respondents write and/or use programs or supervise persons who do; that is 79.5 percent of the persons who filled in the form. Furthermore, Medearis [9] found a similar percentage for the rate of return (83 percent) on a preliminary questionnaire that he sent to 89 individuals who were actively involved with computer software, that is, the attendees of the Special Workshop in Boulder to which we referred previously. As a result we reached our conclusions that our forms were filled in and returned by most of the individuals in our audience who had direct involvement with computer programs. Apparently our survey and those of Medearis Summary of the Response Data The frequencies of response to each choice on the 148 multiple choice questions are listed on the sample questionnaire that appears in the Appendix. These data will now be discussed with the goal of determining the background of the respondents, the extent of their involvement with computer software, how they feel about software and their reactions to the proposed technology transfer effort. After presenting the broad picture of the responses here we will, in the next section, present statistically significant Transactions of the ASME While t hen~ is It large spread in t heir ages most. of t.he re-,p01lllen ts are bet ween ;3:) and ;-)() yr old. Correspondingly, more Iha n half have lip to It) yr of pressllre vessel experien!:e. ~ The highest. degree earned by most of t.he respondents is the .\1:-; while the rest are almost equally divided between the B:-; and the PhD. Virt ually all respondents st.lIdied engineering. :\ Airnost. all of t.he respondents arc employed by !:orporat.ions in the power generating equipment indllst-ry. :'Ilost, of these arc con('emed with nlldl'ar, as opposed to ('ollvt",tiollal, power generation. However, mallY illdi('ated both, The sillgle ()(TlIpational description that. describes their work is technieal management·. ([OIl'eVer, whell design ellgineerillg and H&D engineerillg are ('olllbilled t.he total is greater than for mallagemellt.. ·1 Tlw vessels dealt. wit h by the respondent.s are of the advan('ed t.ype whi('h operate at· elevated temperatllres, in a radiation envirollIllent. at· pressures above 1000 psi. ,) The professiollal involvemellt of t.he respolldents is high. ~Iore t,han half belong to I to a professional eOlllmitlees, while four out of five belong to at least, one. Abollt. half of them attend I to :\ techni('al ('onferen!:es per yeal". They read a t.echllieal plIblicat iOIl at least weekly and mallY do so daily. Abollt half of t hem at tended a formal com."e wit hin a year prior to t.he snrve,v. In this seetion we sought, to determine some details of t lw respondents' involvement. with ('ompllter software. Hen, we fOllnd that 1Il0st of them aetually use (,omputer programs or supen'ise people who do, :'IIoreo\"er, t he~' an' ill\'o!\'cd both in writing progl"llIll" and in lIsing programs wrillen by "t hers. The)' lmve been doing t his well over three years. Ot her, very general, ('onclllsions follow: They lire in\"o!\'cd with programs of all sizes and besides writ ing programs and using ot her people's programs many abo modify ot.her people'., progl'ams. ~ :'Ilost. of the respondents learned !:ompllter program writing lind u", Oil t heir own. :'I1'lIl), also learned from ('ollrses in their organizatioll or in IIniversilies. :\ :'Ilany of the re'IHJllllents "'1' the ('omp"ter daily, their prohlems rlln moslly ill minlltes and t.hey perfer to receive t.heir I"(·sulh the same day or the next· day. The ('omputer t.hey lise is generally lo('atcd in I heir own building or nellrby, it. is ae-cessed hy taking the deek to it 01' by terminal and it is nol· operated by t.hei I' departll1t'1l t·. When the respondents lise programs writt.cn elsewhere t.he following fllds are noteworlhy: They find Ollt abollt· sll('h programs moslly from colleagllt's, technical pllbli(,lIlions and ('onfprences, 2 The programs are most ly pllrchased or givcn to t hcm hy I'ollpaglles. '. The lise of tllP programs is leaJ'lwd b,Y st udy of the manllal or hy obtaining instrllction from the colleague. .\ The validity of the de('k is generall~' verified by rllnning a pl'ohll'm solvt'd previously or by performing an experiment. '. :'Ilany problems lire encountered when other peoplt·'s deck . ..; al"(' IISt'11. The main ones appt~ar to be dlwunH'ntation m'll'hinl' I'ollipatihility, progr:lInming errors, input preparation lind olltPllt intt'rpretation. \\"hl'II till' rt'''polldl'nts writl' tht'ir own programs Ihis takes lip to 12 man-monlhs of tdIort ill moo;t ('ases, They tend not to train 11"1'1'."; of de('ks IHlhide of Iheir orgallizalions, :'Ilort)ovt'l', their dl'l'k, telld not to he IIsed too nlltdl olltside of t.heir org:lIlizalions. WI' al,,) ,ollght to determine whil'h compllting eqllipmt'nt waht'illg 11"l'd i(1 the pres";\Il"e ve""Pl indllstry. :-lot all rpspondl'lIts Journal of Pressure Vessel Technology supplied t his information while many used more than one machine. Thlls, t he Central Proeessor Unils IIsed by respondent Univac: All -2(i UE-Iloncywcll: All -22 DEC: All -(i !Jurrollghs: III Attitudes Toward Use of Software. In thi~ section the respondents' at.\.i\.udes toward software were sought by making eertain ~tatements about. it and asking for reactions on a fourstep scale labelle<1 "agree st.rongly," "agree," "disagree," "disagree s\.rongly." First., wc observe t.hat on the whole the respondenls "agree strongly" only with the statement that. the eomplexi ty of model"ll pressure vessels makes computerized finalysis and design a neeessit.y, There is no statemcnt in part. III with which t.hey "disagree strongly." They t.end t.o agree \.hat.: improved aeeess to softwarc will make their work easier 2 software developers make reasonable dairns for the capabilit ies of their programs :3 management generally favors computerized analysis and design 4 engineers need aides 10 do computerized analysis and design ,-) t.he engineering department, has too litt.le to say about whidl <'()lnputcr gets purcha;;ed (i comput.er programs shoud he proprietary 7 (:omput.er programs should be eompletely debugged before release X professional jOl\l'nals do not. pay enough attention to computer programs !l articles whieh describe eomputer programs are worthy contributions t.o t.he litemture and should be published by leal"llcd joul"llais 10 programs should be endorsed by some reput.able neutral body in t.he industry II the industry needs a eertifieal,ion seheme to insure the qualifications of software users I~ t he available short eourses on general purpose finite element. programs are \"aillable to I·he Hoflware uscr. Note that some of the disagreements are with negative statements. These were phrased in this maimer to insure that the questions were being read carefully. These responses indicate a rather positive outlook regarding the respondents' experience with software. They feel that it could be given greater status via publications, they are in favor of some type of neutral endorsement of programs and certification of users. They are not satisfied with program manuals. While they agree (slightly) that software can be proprietary, they do not think it should be patentable. IV Attitudes Towards a Technology Transfer Effort for Software. Given the background, the computer involvement and the attitudes toward software that were elicited in the first three parts of the questionnaire this section was meant to determine the respondents' feelings toward a technology transfer effort for software of the type that was described previously. Using the same scale of responses that was used in part III it was found that on the whole there was no sense of strong agreement or disagreement with a collection of statements that describe the activities of the contemplated effort. The respondents did not tend to agree with only one of the statements; namely, that the staff of the effort should write programs to fill gaps. The respondents tended to agree that: 1 absence of such an effort is a barrier to wider use of computer programs in the industry 2 the effort should deal only in fully debugged programs 3 it should put on courses for the use of programs it stores 4 all programs selected should be written in the same language 5 the effort should give financial support for the writing of new programs to fill gaps 6 the effort should encourage the development of programs to fill gaps 7 it should charge its clients for services 8 it should publish program manuals 9 it should publish a journal of articles pertaining to software 10 the effort should buy programs from developers. The responses to the other questions in part IV indicated that there were mixed feelings about sharing programs with the effort. Half said they would share most or all of their decks while half said they would share a few or none with it. It was also felt that the effort should deal in programs of all complexities, that it should maintain the decks that it holds, that there should be one national effort per technical field and that all types of organizations of various sizes would benefit from it. As to its operation the respondents felt mainly that programs held by the effort should be accessed either by remote terminals or by the mailing of decks to subscribers. They felt that the effort ought to be run by a professional society although many favored an industrial cooperative. Finally, in response to a question on whether or not they favor, in general, the creation of such an effort the respondents voted yes 209 to 23 with 17 giving no response. It thus appears that the effort and its various features and activities have been endorsed by the writers and users of software in the pressure vessel industry. ¥ General Comments. Some additional insight to the response was gained from the remarks made by 116 of the respondents under Part V General Comments. For the sake of brevity we shall not quote all of these comments. We will, however, give our own summary of them. We found that the general comments tend to express the same feelings whether the respondent favored the creation of the effort or not. The main sense of the comments is that: 1 Organizations will not wish to relinquish their competitive edge by sharing their latest software. Thus, the effort will be limited to programs that are behind the times. 2 Many were concerned with the problem of verification which plagues the most sincere and honest efforts to share soft, ware. One never really knows when the last bug is out of a deck 3 Some felt that current efforts such as COSMIC, IITltl etc., are sufficient. 4 Many expressed the fear that one would never be able tu obtain the level of funding that would be required to do the joh properly, especially at the outset. These reactions constitute a significant modification of the generally positive attitudes toward software and its exchange that were shown by the answers to the multiple choice questions;. Statistically Significant Correlations Among the Response Data At this point it is interesting to consider the possibility that there are some statistically meaningful correlations among the responses given to the questions on the survey. To determini; the existence of such correlations we applied the standard chisquared test to all of the questions two at a time. Using IBM Scientific Subroutine CHISQ [11] on the IBM-1130 computer we sought correlations at the 90 percent level of confidence and higher. We will not go into the details of the chi-squared tes-i as its description would be beyond the practical scope of thi< discussion. It is well described in many texts, e.g., Siegel In applying the statistical tests for significance we noted the small numbers of response to many of the choices on the questionnaire. To maximize the chance of obtaining valid correlations we therefore used the accepted statistical strategy of combining response categories in many questions. For example, in the questions which asked for reactions on a four step scale from "strongly agree" to "strongly disagree" we combined the twn categories of agreement into one. Similarly, the two categories of disagreement were combined into one. As a further illustration we revised the age categories in the first question to three groups: 20-35, 35-50, over 50. In view of the fact that there were 148 questions on the form it is obvious that the number of correlations to be tested was extremely large. Thus, it was necessary to limit this phase of the study to a manageable yet important and interesting number of questions. As a result we will discuss the correlation of the responses with three basic questions. The first concerns the identification of the typical individual's involvement with software. The second pertains to his willingness to share programs with the contemplated effort. The third establishes his feeling toward the establishment of the effort. In each case the study is limited further by making correlations only with questions that appear on the form before each of the three cited questions. 4/ FEBRUARY 1975 Transactions of the ASME Downloaded From: https://pressurevesseltech.asmedigitalcollection.asme.org on 06/28/2019 Terms of Use: http://www.asme.org/about-asme/terms-of-use I,,") have more than 10 yr of experience 1J 7 serve on 3 to 5 professional committees 1,19 attended a formal course more than a year prior to the survey. Those respondents who are uninvoived with software use and/or writing generally, 1.1 are more than 50 yr old 1.17 serve on more than 5 professional committees 1,19 attended a course more than a year prior to the survey. Thus, we observe that software is being written and/or used in [he industry by young highly educated persons with some professional involvement. The supervisors of such people are older, less educated but more experienced and professionally involved than they are. Correlations between responses to this question and others preceding it in the survey led us to conclude that: Those wh