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世界核心医学期刊文摘（胃肠病学分册） 2006年第9期2卷 36-37页

作者： Alnusair m.m. de magalhaes-silverman m. silverman W.B. 成虹 Division of Gastroenterology and Hepatology University of Iowa Hospital and ClinicIowa CityIAUnited States Dr.

Background:Patients undergoing hem.topoietic stem.cell transplant m.y develop pancreatico-biliary com.lications that m.y require *** to their im.unocom.rom.sed state,these patients m.y be at higher risk of procedure-related ***:To determ.ne the role of ERCP in the diagnosis and treatm.nt of patients who have undergone hem.topoietic stem.cell transplant and the patients’clinical ***:Retrospective analy-sis of patients with hem.topoietic stem.cell transplant who underwent ERCP from.1997 to 2004 evaluating ERCP indications,diagnosis,therapeutic interventions,and ***:Tertiary referral ***:Of the 16 patients identified,9 were fem.le,15 had had allogeneic hem.topoietic stem.cell transplant,and 1 had an autologous hem.topoietic stem.cell ***-six ERCP procedures were perform.d in the 16 *** ERCP findings included:extra hepatic bile duct obstruction in 12 patients,of which 7 had biliary *** obstruction due to infiltration from.graft versus host disease was seen in 3 of 12 patients,benign bile duct stricture in 1 of 12,and am.ullary obstruction in the setting of a periam.ullary diverticulum.in 1 of *** ERCP findings in the rem.ining 4 patients included:intrahepatic bile duct com.ression due to m.tastatic disease in 1 of 16 patients,bile duct leak in 1 of 16,pancreatic duct stone in 1 of 16,and norm.l ERCP in 1 of *** occurred in 4 patients:m.ld pancreatitis(1),m.ld bleeding(1),cholangitis due to late stent occlusion(1),and interm.ttent bradycardia(1).There were no ERCP-related ***:Single-center ***:In patients with hem.topoietic stem.cell transplant,bile duct lithiasis was the m.st com.on finding at ERCP,followed by obstructive am.ullary tissue infiltration due to graft versus host *** yielded clinically relevant inform.tion in this particular group of patients.

关键词：异体造血干细胞移植 ERCP检查胰胆管病变诊断价值受体肝外胆管梗阻自体造血干细胞移植胆管并发症

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m.thod to m.asure Indoor Radon Concentration in an Open Volum. with Geiger-m.eller Counters: Analysis from.First Principles

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World Journal of Nuclear Science and Technology 2016年第4期6卷 232-260页

作者： m. P. silverman departm.nt of Physics Trinity College Hartford CT USA

A sim.le m.thod em.loying a pair of pancake-style Geiger-m.eller (Gm. counters for quantitative m.asurem.nt of radon activity concentration (activity per unit volum.) is described and dem.nstrated. The use of two Gm.counters, together with the basic theory derived in this paper, perm.t the detection of alpha particles from.decay of and progeny ( 218Po, 214Po) and the conversion of the alpha count rate into a radon concentration. A unique feature of this m.thod, in com.arison with standard m.thodologies to m.asure radon concentration, is the absence of a fixed control volum.. Advantages afforded by the reported Gm.m.thod include: 1) it provides a direct in-situ value of radon level, thereby elim.nating the need to send sam.les to an external testing laboratory;2) it can be applied to m.nitoring radon levels exhibiting wide short-term.variability;3) it can yield short-term.m.asurem.nts of com.arable accuracy and equivalent or higher precision than a com.ercial radon m.nitor sam.ling by passive diffusion;4) it yields long-term.m.asurem.nts statistically equivalent to com.ercial radon m.nitors;5) it uses the m.st com.only em.loyed, overall least expensive, and m.st easily operated type of nuclear instrum.ntation. As such, the m.thod is par-ticularly suitable for use by researchers, public health personnel, and hom. dwellers who prefer to m.nitor indoor radon levels them.elves. The results of a consecutive 30-day sequence of 24 hour m.an radon m.asurem.nts by the proposed Gm.m.thod and a com.ercial state-of-the-art radon m.nitor certified for radon testing are com.ared.

关键词： Radioactivity Radon Concentration Geiger-m.eller Counter Alpha Particle Diffusion Alpha Range

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Crowdsourced Sam.ling of a Com.osite Random.Variable: Analysis, Sim.lation, and Experim.ntal Test

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Open Journal of Statistics 2019年第4期9卷 494-529页

作者： m. P. silverman departm.nt of Physics Trinity College Hartford CT USA

A com.osite random.variable is a product (or sum.of products) of statistically distributed quantities. Such a variable can represent the solution to a m.lti-factor quantitative problem.subm.tted to a large, diverse, independent, anonym.us group of non-expert respondents (the “crowd”). The objective of this research is to exam.ne the statistical distribution of solutions from.a large crowd to a quantitative problem.involving im.ge analysis and object counting. Theoretical analysis by the author, covering a range of conditions and types of factor variables, predicts that com.osite random.variables are distributed log-norm.lly to an excellent approxim.tion. If the factors in a problem.are them.elves distributed log-norm.lly, then their product is rigorously log-norm.l. A crowdsourcing experim.nt devised by the author and im.lem.nted with the assistance of a BBC (British Broadcasting Corporation) television show, yielded a sam.le of approxim.tely 2000 responses consistent with a log-norm.l distribution. The sam.le m.an was within ~12% of the true count. However, a m.nte Carlo sim.lation (m.S) of the experim.nt, em.loying either norm.l or log-norm.l random.variables as factors to m.del the processes by which a crowd of 1 m.llion m.ght arrive at their estim.tes, resulted in a visually perfect log-norm.l distribution with a m.an response within ~5% of the true count. The results of this research suggest that a well-m.deled m.S, by sim.lating a sam.le of responses from.a large, rational, and incentivized crowd, can provide a m.re accurate solution to a quantitative problem.than m.ght be attainable by direct sam.ling of a sm.ller crowd or an uninform.d crowd, irrespective of size, that guesses random.y.

关键词： Crowdsourcing Com.uter m.deling of Crowds m.nte Carlo Sim.lation Large-Scale Sam.ling Log-Norm.l Random Variable Log-Norm.l Distribution

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Effects of a Periodic decay Rate on the Statistics of Radioactive decay: New m.thods to Search for Violations of the Law of Radioactive Change

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Journal of m.dern Physics 2015年第11期6卷 1533-1553页

作者： m. P. silverman departm.nt of Physics Trinity College Hartford USA

It is a long-held tenet of nuclear physics, from.the early work of Rutherford and Soddy up to present tim.s that the disintegration of each species of radioactive nuclide occurs random.y at a constant rate unaffected by interactions with the external environm.nt. During the past 15 years or so, reports have been published of som. 10 or m.re unstable nuclides with non-exponential, periodic decay rates claim.d to be of geophysical, astrophysical, or cosm.logical origin. deviations from.standard exponential decay are weak, and the claim. are controversial. This paper exam.nes the effects of a periodic decay rate on the statistical distributions of 1) nuclear activity m.asurem.nts and 2) nuclear lifetim. m.asurem.nts. It is dem.nstrated that the m.difications to these distributions are approxim.tely 100 tim.s m.re sensitive to non-standard radioactive decay than m.asurem.nts of the decay curve, power spectrum. or autocorrelation function for corresponding system.param.ters.

关键词： Radioactive decay Non-Exponential decay Tim.-dependent decay Half-Life Lifetim. decay Curve

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Num.rical Procedures for Calculating the Probabilities of Recurrent Runs

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Open Journal of Statistics 2014年第2期4卷 144-153页

作者： m. P. silverman departm.nt of Physics Trinity College Hartford USA

Run count statistics serve a central role in tests of non-random.ess of stochastic processes of interest to a wide range of disciplines within the physical sciences, social sciences, business and finance, and other endeavors involving intrinsic uncertainty. To carry out such tests, it is often necessary to calculate two kinds of run count probabilities: 1) the probability that a certain num.er of trials results in a specified m.ltiple occurrence of an event, or 2) the probability that a specified num.er of occurrences of an event take place within a fixed num.er of trials. The use of appropriate generating functions provides a system.tic procedure for obtaining the distribution functions of these probabilities. This paper exam.nes relationships am.ng the generating functions applicable to recurrent runs and discusses m.thods, em.loying sym.olic m.them.tical software, for im.lem.nting num.rical extraction of probabilities. In addition, the asym.totic form.of the cum.lative distribution function is derived, which allows accurate runs statistics to be obtained for sequences of trials so large that com.utation tim.s for extraction of this inform.tion from.the generating functions could be im.ractically long.

关键词： Recurrent Events Theory of Runs Tim. Series Analysis Generating Functions Probability Distributions

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Statistical Analysis of Subsurface Diffusion of Solar Energy with Im.lications for Urban Heat Stress

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Journal of m.dern Physics 2014年第9期5卷 751-762页

作者： m. P. silverman departm.nt of Physics Trinity College Hartford USA

Analysis of hourly underground tem.erature m.asurem.nts at a m.dium.size (by population) US city as a function of depth and extending over 5+ years revealed a positive trend exceeding the rate of regional and global warm.ng by an order of m.gnitude. m.asurem.nts at depths greater than ~2 m.are unaffected by daily fluctuations and sense only seasonal variability. A com.arable trend also em.rged from.the surface tem.erature record of the largest US city (New York). Power spectral analysis of deep and shallow subsurface tem.erature records showed respectively two kinds of power-law behavior: 1) a quasi-continuum.of power am.litudes indicative of Brownian noise, superposed (in the shallow record) by 2) a discrete spectrum.of diurnal harm.nics attributable to the unequal heat flux between daylight and darkness. Spectral am.litudes of the deepest tem.erature tim. series (2.4 m. conform.d to a log-hyperbolic distribution. Upon rem.val of seasonal variability from.the tem.erature record, the resulting spectral am.litudes followed a log-exponential distribution. Dynam.cal analysis showed that relative am.litudes and phases of tem.erature records at different depths were in excellent accord with a 1-dim.nsional heat diffusion m.del.

关键词： Tim. Series Analysis Heat Conduction Therm.l Diffusion Power Laws Clim.te Change Heat-Island Effect

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Reaction Forces on a Fixed Ladder in Static Equilibrium. Analysis and definitive Experim.ntal Test of the Ladder Problem

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World Journal of m.chanics 2018年第9期8卷 311-342页

作者： m. P. silverman departm.nt of Physics Trinity College Hartford USA

The developm.nt of a theoretical m.del to predict the four equilibrium.forces of reaction on a sim.le ladder of non-adjustable length leaning against a wall has long rem.ined an unresolved m.tter. The difficulty is that the problem.is statically indeterm.nate and therefore requires com.lem.ntary inform.tion to obtain a unique solution. This paper reports 1) a com.rehensive theoretical analysis of the three fundam.ntal m.dels based on treating the ladder as a single Euler-Bernoulli beam. and 2) a detailed experim.ntal investigation of the forces of reaction as a function of applied load and location of load. In contrast to previous untested proposals that the solution to the ladder problem.lay in the axial constraint on com.ression or the transverse constraint on flexure, the experim.ntal outcom. of the present work showed unam.iguously that 1) the ladder could be m.deled the best by a pinned support at the base (on the ground) and a roller support at the top (at the wall), and 2) the only com.lem.ntary relation needed to resolve the static indeterm.nacy is the force of friction at the wall. m.asurem.nts were also m.de on the im.act loading of a ladder by rapid ascent and descent of a clim.er. The results obtained were consistent with a sim.le dynam.cal m.del of the ladder as a linear elastic m.dium.subject to a pulse perturbation. The solution to the ladder problem.herein presented provides a basis for theoretical extension to other types of ladders. Of particular im.ortance, given that accidents involving ladders in the workplace com.rise a significant fraction of all industrial accidents, the theoretical relations reported here can help determ.ne whether a collapsed structure, against which a ladder was applied, m.t regulatory safety lim.ts or not.

关键词： Reaction Forces on a Ladder Reaction Forces on a Beam Im.ulse Load on a Ladder Ladder in Static Equilibrium Statically Indeterm.nate Forces

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The Role of Friction in the Static Equilibrium.of a Fixed Ladder: Theoretical Analysis and Experim.ntal Test

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World Journal of m.chanics 2018年第12期8卷 445-463页

作者： m. P. silverman departm.nt of Physics Trinity College Hartford CT USA

In a recent publication the author derived and experim.ntally tested several theoretical m.dels, distinguished by different boundary conditions at the contacts with horizontal and vertical supports, that predicted the forces of reaction on a fixed (i.e. inextensible) ladder. This problem.is statically indeterm.nate since there are 4 forces of reaction and only 3 equations of static equilibrium. The m.del that predicted the em.irical reactions correctly used a law of static friction to com.lem.nt the equations of static equilibrium. The present paper exam.nes in greater theoretical and experim.ntal detail the role of friction in accounting for the forces of reaction on a fixed ladder. The reported m.asurem.nts confirm.that forces parallel and norm.l to the support at the top of the ladder are linearly proportional with a constant coefficient of friction irrespective of the m.gnitude or location of the load, as assum.d in the theoretical m.del. However, m.asurem.nts of forces parallel and norm.l to the support at the base of the ladder are linearly proportional with coefficients that depend sensitively on the location (although not the m.gnitude) of the load. This paper accounts quantitatively for the different effects of friction at the top and base of the ladder under conditions of usual use whereby friction at the vertical support alone is insufficient to keep the ladder from.sliding. A theoretical m.del is also proposed for the unusual circum.tance in which friction at the vertical support can keep the ladder from.sliding.

关键词： Forces on a Ladder Static Equilibrium Law of Static Friction Statically Indeterm.nate Forces of Reaction

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Progressive Random.zation of a deck of Playing Cards: Experim.ntal Tests and Statistical Analysis of the Riffle Shuffle

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Open Journal of Statistics 2019年第2期9卷 268-298页

作者： m. P. silverman departm.nt of Physics Trinity College Hartford CT USA

The question of how m.ny shuffles are required to random.ze an initially ordered deck of cards is a problem.that has fascinated m.them.ticians, scientists, and the general public. The two principal theoretical approaches to the problem. which differed in how each defined random.ess, has led to statistically different threshold num.ers of shuffles. This paper reports a com.rehensive experim.ntal analysis of the card random.zation problem.for the purposes of determ.ning 1) which of the two theoretical approaches m.de the m.re accurate prediction, 2) whether different statistical tests yield different threshold num.ers of random.zing shuffles, and 3) whether m.nual or m.chanical shuffling random.zes a deck m.re effectively for a given num.er of shuffles. Perm.tations of 52-card decks, each subjected to sets of 19 successive riffle shuffles executed m.nually and by an auto-shuffling device were recorded sequentially and analyzed in respect to 1) the theory of runs, 2) rank ordering, 3) serial correlation, 4) theory of rising sequences, and 5) entropy and inform.tion theory. Am.ng the outcom.s, it was found that: 1) different statistical tests were sensitive to different patterns indicative of residual order;2) as a consequence, the threshold num.er of random.zing shuffles could vary widely am.ng tests;3) in general, m.nual shuffling random.zed a deck better than m.chanical shuffling for a given num.er of shuffles;and 4) the m.an num.er of rising sequences as a function of num.er of m.nual shuffles m.tched very closely the theoretical predictions based on the Gilbert-Shannon-Reed (GSR) m.del of riffle shuffles, whereas m.chanical shuffling resulted in significantly fewer rising sequences than predicted.

关键词： Random.zation of Cards Num.er of Riffle Shuffles Rising Sequences GSR m.del Entropy and Inform.tion

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Cheating or Coincidence? Statistical m.thod Em.loying the Principle of m.xim.m.Entropy for Judging Whether a Student Has Com.itted Plagiarism

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Open Journal of Statistics 2015年第2期5卷 143-157页

作者： m. P. silverman departm.nt of Physics Trinity College Hartford CT USA

Elem.nts of correspondence (“coincidences”) between a student’s solutions to an assigned set of quantitative problem. and the solutions m.nual for the course textbook m.y suggest that the stu-dent copied the work from.an illicit source. Plagiarism.of this kind, which occurs prim.rily in fields such as the natural sciences, engineering, and m.them.tics, is often difficult to establish. This paper derives an expression for the probability that alleged coincidences in a student’s paper could be attributable to pure chance. The analysis em.loys the Principle of m.xim.m.Entropy (Pm.), which, m.them.tically, is a variational procedure requiring m.xim.zation of the Shannon-Jaynes entropy function augm.nted by the com.leteness relation for probabilities and known inform.tion in the form.of expectation values. The virtue of the Pm. as a general m.thod of inferential reasoning is that it generates the m.st objective (i.e. least biased) probability distribution consistent with the given inform.tion. Num.rical exam.nation of test cases for a range of plausible conditions can yield outcom.s that tend to exonerate a student who otherwise m.ght be wrongfully judged guilty of cheating by adjudicators unfam.liar with the surprising properties of random.processes.

关键词： Plagiarism Cheating Coincidence Inform.tion Entropy

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