Plausibility Considerations Research Articles

The price/acceptance function: perspectives of a pricing policy in European telecommunication markets

Success in innovation management of telecommunication products depends not only on sales, but also, and primarily so, on actual call times by subscribers (e.g. on their mobile phones). It is not only the purchase price that plays a major role for this type of service, but also call and rental charges. This study investigates two potential subscribers’ decisions, using the graphic device of a price/acceptance function and a charge/acceptance function. The first decision is to buy telecommunications products (accepting the purchase price), and the second decision is to use these products (accepting the charges for using the product). In particular, an attempt is made to describe the general profile of the price/acceptance function through considerations of plausibility. Based on an empirical experiment, conclusions are drawn for the pricing policy of telecommunication products, which point to abandoning fixed basic charges and to giving away end‐user sets (e.g. mobile phones) free of charge.

Water Resources Implications of Global Warming: A U.S. Regional Perspective

The implications of global warming for the performance of six U.S. water resource systems are evaluated. The six case study sites represent a range of geographic and hydrologic, as well as institutional and social settings. Large, multi-reservoir systems (Columbia River, Missouri River, Apalachicola-Chatahoochee-Flint (ACF) Rivers), small, one or two reservoir systems (Tacoma and Boston) and medium size systems (Savannah River) are represented. The river basins range from mountainous to low relief and semi-humid to semi-arid, and the system operational purposes range from predominantly municipal to broadly multi-purpose. The studies inferred, using a chain of climate downscaling, hydrologic and water resources systems models, the sensitivity of six water resources systems to changes in precipitation, temperature and solar radiation. The climate change scenarios used in this study are based on results from transient climate change experiments performed with coupled ocean-atmosphere General Circulation Models (GCMs) for the 1995 Intergovernmental Panel on Climate Change (IPCC) assessment. An earlier doubled-CO2 scenario from one of the GCMs was also used in the evaluation. The GCM scenarios were transferred to the local level using a simple downscaling approach that scales local weather variables by fixed monthly ratios (for precipitation) and fixed monthly shifts (for temperature). For those river basins where snow plays an important role in the current climate hydrology (Tacoma, Columbia, Missouri and, to a lesser extent, Boston) changes in temperature result in important changes in seasonal streamflow hydrographs. In these systems, spring snowmelt peaks are reduced and winter flows increase, on average. Changes in precipitation are generally reflected in the annual total runoff volumes more than in the seasonal shape of the hydrographs. In the Savannah and ACF systems, where snow plays a minor hydrological role, changes in hydrological response are linked more directly to temperature and precipitation changes. Effects on system performance varied from system to system, from GCM to GCM, and for each system operating objective (such as hydropower production, municipal and industrial supply, flood control, recreation, navigation and instream flow protection). Effects were generally smaller for the transient scenarios than for the doubled CO2 scenario. In terms of streamflow, one of the transient scenarios tended to have increases at most sites, while another tended to have decreases at most sites. The third showed no general consistency over the six sites. Generally, the water resource system performance effects were determined by the hydrologic changes and the amount of buffering provided by the system's storage capacity. The effects of demand growth and other plausible future operational considerations were evaluated as well. For most sites, the effects of these non-climatic effects on future system performance would about equal or exceed the effects of climate change over system planning horizons.

Cytosolic Ca2+ and H+ buffers in green algae: A reply

The explanation of the coupling between butyrateinduced changes in cytosolic pH and pCa by means of a H+/Ca2+ exchange buffer as proposed by Plieth et al. [Protoplasma (1997) 198: 107–124; 199: 223] was questioned by Schonknecht and Bethmann [Protoplasma (1998) 203: 206–209]. They suggested an allosteric control of binding similar to the Hill equation. Fitting the measured pH-pCa coupling shows that a distinction between the models requires data which would be outside the experimentally accessible range. Plausibility considerations provide a support for the exchange buffer. The Hill equation is just a phenomenological approach which does not account for the diversity of allosteric mechanisms. The benefits of the exchanger model are firstly its mechanistic simplicity and secondly its flexibility as the same set of equations can also be used for an allosteric interaction between H+- and Ca2+-binding sites. The model can easily be extended to include future more detailed data. Finally, the cytosolic buffer capacities for H+ and Ca2+ are discussed.

Ion microprobe studies of Efremovka CAIs: II. Potassium isotope composition and 41Ca in the early Solar System

The potassium isotope composition of refractory phases in Efremovka CAIs has been measured by an ion microprobe. Extensive studies of terrestrial standards were carried out to ensure that the experimental procedures adopted for potassium isotope studies provide accurate 41K/ 39K ratios of the analysed phases. Excess 41K is found to be present in refractory phases with high Ca/K ratios (>3 × 10 5) in all the four Efremovka CAIs analysed in this study. The excess 41K in these phases correlates well with their 40Ca/ 39K ratios. Several possible causes for this excess have been considered and it is concluded that in situ decay of 41Ca can best explain our observations. The results obtained in this work substantiate the conclusion drawn from our initial study (Srinivasan et al., 1994) and confirm the presence of the short-lived nuclide 41Ca (τ ~ 0.15 Ma) in the early Solar System with an initial 41Ca/ 40Ca value of (1.41 ±0.14) × 10 −8 at the time of formation of the Efremovka CAIs. We have considered several processes that may lead to the presence of 41Ca in the early Solar System. These include, production by energetic particles from an active early Sun, low energy particle induced reactions in a molecular cloud complex of which the proto-solar cloud was a part and freshly synthesized material from suitable stellar source(s). The last alternative turns out to be the best one from plausibility considerations. The Efremovka CAIs with excess 41K also have excess 26Mg that can be attributed to the decay of the short-lived nuclide 26Al(τ ~ 1 Ma) within these objects. The presence of both 26Al and 41Ca in Efremovka CAIs is used to infer the most probable stellar site(s) for the synthesis of these nuclides in a self consistent manner. Our observations coupled with predicted stellar production rates suggest an asymptotic giant branch (AGB) star to be a plausible source. However, we cannot completely rule out a supernova or a Wolf-Rayet star as being responsible for the synthesis and subsequent injection of these nuclides to the solar nebula. In spite of this inability to pinpoint the exact stellar source, our result constrains the time interval between the injection of freshly synthesized 41Ca and 26Al to the solar nebula and the formation of first Solar System solids (CAIs) to less than a million year.

Plausibility of structural constitutive equations for swelling tissues--implications of the C-N and S-E conditions.

The mechanically important constituents of swelling tissues are fibers embedded in an osmotically active fluid. The tissues' response to external loading is the sum of contribution of the axial stresses in the fibers and of the fluid pressure. The fluid osmotic properties play a key role in determining its equilibrium response. The present study examines the conditions under which the elastic response of tissues as modeled by structural constitutive equations, is thermodynamically plausible. The analysis shows that plausibility is ensured if the fibers' axial force increases monotonically with stretch and if the fluid osmotic pressure increases convexly with concentration. Published data shows that both conditions prevail in swelling tissues. Plausibility considerations seem to pose no specific restrictions on the structure of the tissues' fibrous network. It is thus concluded that in swelling tissues, structural constitutive formulation is compatible with thermodynamically plausible response.

Multinational Naval Cooperation in Northeast Asia: Some Plausible Considerations for 2010 Based on What We Know in 1994

The future of the US-Korean security relationship is very solid, but it will have more multilateral dimensions and less of a purely bilateral focus in the future than it had in the past. US-Korean relations could evolve under any of three primary scenarios: a stalemate on the Korean peninsula in which a divided Korea continues with neither peace nor war; a bloody reunification which might take the peninsula perhaps a decade from which to recover; or a peaceful reunification a fa Germany. The United States hopes to induce changes in the North Korean side by drawing Pyongyang into the international economic and security community, breaking down its isolation and, in the process, paving the way for peaceful reunification. The multi lateralization of the security dialogue in Northeast Asia could take many forms: an enlarged and strengthened APEC; a security-focused ASEAN regional forum; an Asian Pacific treaty organization a La NATO; a trilateral US-Japan Korea security pact; or, most likely, a building block approach of overlapping, multilateral institutions. Multilateral naval cooperation could take several forms involving formalized alliance relationships, situational cooperation associated with a specific crisis or war, coordinated peacetime activities, and in the form of regional policy support. Enhancing transparency of naval operations and exchanging confidence and security-building measures would be important elements. The net effect of these measures would be to enhance Korean security and also to maintain the US role as a vital Asia-Pacific power.

Relative-error-based non-linear inversion: application to seismic traveltime tomography

SUMMARY The aim of geophysical inversion is to infer information about the subsurface model parameters subject to certain constraints and plausibility considerations. It is achieved through a systematic adjustment of model parameters along a solution path to the minimum of an objective function. The objective function is related to both the observations (data) and the a priori information about the subsurface model parameters (model). When different statistics are assumed for the data and the a priori information about the model, different objective functions are constructed and different solution models become inevitable. Traditionally, data residuals are used directly in constructing the objective function. If the residuals are statistically proportional to the data magnitudes, a least-squares (LS) method often leads to a solution model biased towards (i.e. which emphasizes) observations of large magnitude, whereas a least absolute deviation (LAD) method can reduce this datamagnitude-dependent effect. An alternative is to formulate the objective function in terms of relative differences. It completely eliminates the possible solution bias due to the intrinsic magnitude-dependent discrepancies in the objective function. The solution path is altered in such a way that.data residuals are reduced in a more uniform manner. The idea is illustrated through a seismic traveltime tomographic inversion. Traveltime residuals are often correlated with ray-path lengths. Greater residuals of long ray paths dominate the objective function in the traditional tomographic formulation. The solution path is thus strongly affected by those long ray paths, and short ray paths play a reduced role in the inversion. The final solution is biased toward longer ray paths. The new alternative formulation eliminates this bias by exploiting the relative-error measure to give equal weights to data of the same quality regardless of their ray-path lengths.

Multinational Naval Cooperation in Northeast Asia: Some Plausible Considerations for 2010 Based on What We Know in 1994

Multinational Naval Cooperation in Northeast Asia: Some Plausible Considerations for 2010 Based on What We Know in 1994

Parsing arguments: Phrase structure and argument structure as determinants of initial parsing decisions

Two experiments measured reading times for sentences with prepositional phrases whose syntactic analyses were disambiguated by plausibility considerations (e.g., “The saleswoman tried to interest the man in the wallet during the storewide sale” vs. “The saleswoman tried to interest the man in his fifties during the storewide sale.”) Reading times immediately upon encountering the disambiguating information were faster when the prepositional phrase modified a verb than when it modified a noun, suggesting an initial preference for the former analysis. However, reading times later in the sentence were faster when the prepositional phrase was a syntactic argument rather than a syntactic adjunct of whatever word it modified, suggesting a final preference for arguments over adjuncts. The results were discussed in terms of their implications for theories of parsing that claim initial decisions are made on the basis of information about the part of speech of words together with phrase structure rules, and for theories of parsing that claim that the specific syntactic frames associated with individual lexical items guide parsing.

On the Possibility of Lawful Explanation in Archaeology

El trabajo consiste en examinar la posibilidad de que, en la arqueología, se den explicaciones que recurran a leyes. Muchos arqueólogos trataron de convencer a sus colegas de que adoptaran el modelo nomológico-deductivo de explicación y el modelo hipotético deductivo de confirmación, siguiendo la propuesta de Hempel. Otros arqueólogos, como Tuggle, han recurrido a un modelo alternativo de explicación basado en el llamado “acercamiento de sistemas”; este último modelo supone regularidades en lugar de leyes.
 Los arqueólogos han tratado de responder a la pregunta de por que un objeto o una característica de un objeto se encuentran en un contexto arqueológico dado. Las respuestas a menudo se dan recurriendo a “la función” del objeto o de la característica del objeto. De este manera, la adscripción de una función provee el nexo fundamentalmente entre los objetos que persisten y la conducta de las personas que nos son conocidas a través de esos objetos.
 Los problemas acerca de la justificación de la adscripción de funciones están relacionados con la cuestión sobre la posibilidad de explicar recurriendo a leyes. Para algunos autores, que no siguen el modelo hempeliano, explicar recurriendo a leyes es explicar “causalmente”. Uno de los autores que defiende esta posición es Larry Wright, quien afirma que cuando adscribimos una función a un artefacto hecho por humanos estamos diciendo que el objeto fue seleccionado, diseñado, creado, o modificado para llevar a cabo una consecuencia deseada. Esta afirmación nos dice algo acerca de por que el objeto es o llegó a ser, o tiene la forma que tiene. De esta manera, las adscripciones funcionales nos dicen algo sobre la historia causal del objeto, es decir, las explicaciones funcionales recurren a una etiología causal.
 La fuerza explicativa de las adscripciones funcionales depende de la distinción entre la función de un objeto o de una característica del objeto y un uso propositivo, pero que es accidental o incidental. Una pregunta que surge después de haber analizado lo que significa adscribir una función es: ¿Ias explicaciones de adscripción de función dependen de leyes? Una manera de contestar la pregunta es tratar de ajustar las explicaciones de adscripción de función al modelo hempeliano. El problema con este modelo es que siempre pueden surgir equivalentes funcionales.
 Otra respuesta la da Wright, para quien el problema de las leyes esta conectado con la causalidad y no con la característica estructural de la explicación. Ahora bien, para Wright una relación causal no tiene por que ser entendida en términos de condiciones necesarias y suficientes. Esta posición nos permite afirmar que las leyes causales no tienen que ser detenninistas, sino que admiten cláusulas ceteris paribus.
 Muchos críticos del uso de leyes en ciencias sociales han afirmado que las cláusulas ceteris paribus, en esas disciplinas, son demasiado vagas y ambiguas.
 Otros arqueólogos han recurrido, en la arqueología, a las leyes físicas y biológicas para evitar los problemas relacionados con las leyes de la conducta, sin embargo este intento ha fracasado porque al arqueólogo le interesan las acciones humanas propositivas. Por esta razón el proyecto de explicar los materiales arqueológicos en términos de la conducta de los hombres no es errado. Prácticamente el debate actual se ha dado dentro de esta posición.
 El debate lo han llevado a cabo dos grupos de arqueólogos: los nuevos arqueólogos científicos, que buscan explicaciones recurriendo a leyes y los arqueólogos posprocesalistas humanistas, que buscan “entender”, ignorando el asunto de las leyes. El desacuerdo entre estos dos grupos es acerca de la evidencia que se necesita para fundamentar una adscripción de función.
 Los dos grupos no están de acuerdo en los puntos siguientes:
 (1) la importancia de los aspectos simbólicos o expresivos de la conducta humana para adquirir una comprensión o explicación de las personas que nos son conocidas por sus objetos persistentes;
 (2) la viabilidad y la calidad de la evidencia que tenemos para fundamentar las generalizaciones (o leyes) que necesitarnos para comprender o explicar los hallazgos arqueológicos en términos de una conducta simbólica.
 Ahora bien, esta disputa no puede ser interpretada como una falta de interés de los arqueólogos en los modelos de explicación de la ciencia. Más bien, podemos interpretar el abismo que separa a estos grupos como un profundo desacuerdo entre dos clases de leyes que pueden explicar el fenómeno arqueológico.
 [Paulette Dieterlen]

Visual contrast detection by a single channel versus probability summation among channels.

It is now generally accepted that the human visual system consists of subsystems ("channels") that may be activated in parallel. According to some models of detection, detection is by probability summation among channels, while in other models it is assumed that detection is by a single channel that may even be tuned specifically to the stimulus pattern (detection by a matched filter). So far, arguments in particular for the hypothesis of probability summation are based on plausibility considerations and on demonstrations that the data from certain detection experiments are compatible with this hypothesis. In this paper it is shown that linear contrast interrelationship functions together with a property of a large class of distribution functions (strict log-concavity or log-convexity on the relevant set of contrasts/intensities) uniquely point to detection by a single channel. In particular, models of detection by probability summation based on Quick's Model are incompatible with linear contrast interrelationship functions. Sufficient (and observable) conditions for the strict log-concavity/log-convexity of distribution functions are presented.

Some new evidence on correlates of political violence: income inequality, regime repressiveness, and economic development

Sociological research on political protest and violence either attempts to explain violence by absolute or relative deprivation or by rational action, resource mobilisation and political power (or by some combination of these factors). Although the connection between these theoretical approaches and crossnational studies rests on little more than considerations of plausibility, monotonic linkages between the level of economic development or income inequality and violence seem to fit with deprivation approaches, whereas a curvilinear relationship between regime repressiveness and violence fits easily with a rational action or political power explanations. Taking the disagreement between previous cross-national studies as a starting point, but analysing a new compilation of data, which covers up to 47 nations and the mid-1960s, the following conclusions are reached. First, inequality does not contribute to violence. Second, the level of economic development does not affect violence. Third, there is a rather weak curvilinear relationship between regime repressiveness and violence. Thus while deprivation explanations of violence receive no support at all in this study, there is at least some weak support for rational action or political power explanations.

Historical labial-velar changes in Germanic: A study of the counter-directional sound changes in English and Netherlandic By Veronica Bonebrake (review)

BOOK NOTICES 711 Historical labial-velar changes in Germanic : A study of the counterdirectional sound changes in English and Netherlandic. By Veronica Bonebrake. (Umeâ studies in the humanities, 29.) Umeâ, Sweden: Acta Universitatis Umensis, 1979. Pp. x, 222. B's study is laudable in so many other ways that one must lament the fact that its cover and spine bear only the first part of its full title; this may lead potential readers to expect an investigation of the behavior of PGmc. labiovelars like /w kw gw/, rather than B's unusually detailed consideration of the frequent change of IxJ > IiI in English and West Flemish, and ofIiI > Ix/ in Dutch. Her most important contribution is her use of a mass of painstakingly gathered historical /documentary and dialectal evidence to establish conclusively that the two directions of change had quite different conditioning, and so presumably occurred via rather different mechanisms of phonological diachrony. This is significant because it incontrovertibly disproves the earlier claim of numerous scholars (including this reviewer) that the Eng. and Du. developments in some sense constitute mirror-image substitutions and are therefore strong evidence thatbidirectionalphonologicalchangeispossible. In most ways methodologically exemplary, B's book establishes with great philological care the nature of several long-past sound changes: it also invokes modern phonetics (even instrumental studies)—plus modern theories of morphology , semantics, and sociolinguistics—in an attempt to explain those changes within the framework ofan over-all model ofphonological and even general-linguistic diachrony. In addressing the why of the developments in question , B is not so completely successful as in her dealings with the what. Nevertheless, one wishes that her meticulous attention to a variety of theories, methods, and sources of evidence might be emulated by other synchronic and diachronic linguists. B's brief Ch. I, 'Introduction', concerns "The significance of the labial-velar problem in studies oflanguage change'. A somewhat longer Ch. II, 'Method', surveys her various sources ofevidence —primarily spellings (especially inversions ), rhymes, dialectal variants (including Scots), and considerations of phonetic plausibility . Ch. Ill, 'The velar-to-labial change in English ', is the most solid and conclusive part of the book. When all the evidence is considered, it emerges that the shift ofIxJ to IiI in words like cough regularly occurred only in the environment ofa precedingrounded vowel and afollowing word boundary. This change (dated between 1400and 1700) tookplace when speaker/listeners both reinterpreted the secondary, assimilatory labialization of final IxI after rounded vowels as a primary articulation and eliminated the velar component of the sound in question. That is, roughly, (V'x# >) \wx# > V*V# (... >) V"y# (> V/#). Exceptional forms like slough 'bog' resulted from a desire to avoid homophony —here with slough 'to desquamate'; exceptions like laughter arose because of the analogical connection perceived with related words like laugh. Although B acknowledges the role of both acoustic/auditory and articulatory factors in the change just mentioned, and recognizes that it has abrupt as well as gradual aspects, she regrettably does not really resolve the issue of whether the velar component of [xw] was lost gradually (via an intermediate stage like [x^if]) or abruptly (by a direct change to [f])—hence the parenthesized ellipsis above. Ch. Ill would also have been more cogent if B had systematized and made more comprehensive her presentation of the set of environments where IxI occurred in OE and ME, in addition to discussing how the conditioning vowels first became rounded and then were altered in the Great Vowel Shift. (Thus she does not mention how OE hleahanlhliehhan 'to laugh' came to have a rounded vowel in ME and an unrounded vowel again in NE—hence the parenthesized first and last steps above.) In general, B's meticulous discussions of the data, especially the pages devoted to individual lexical items, tend to overwhelm the passages which present summaries and conclusions. However, the forest is still visible among the trees, and a coherent picture of the Eng. velar-to-labial change does indeed emerge, in terms of both description and explanation . (Later, B briefly treats an almost identical change which occurred ca. 1700 in West Flemish dialects of Netherlandic.) Ch. IV, "The labial-velar changes in Netherlandic ', is again descriptively...

Sex assignment in gestational trophoblastic neoplasia

A retrospective survey was performed in 205 cases of gestational trophoblastic neoplasia with the use of routine tissue sections and quinacrine stain after hydrolysis and pronase pretreatment. The method allows scoring of nuclei simultaneously for either Y chromatin or X chromatin (Barr body) and has proved to be a valid test for sex assignment in tissue sections. Y-chromatin positivity (indicating gamete heterozygosity) was found in 16 of 182 cases (9%) of hydatidiform mole, two of four cases (50%) of invasive mole, and 14 of 19 cases (74%) of choriocarcinoma. The cytogenetic literature of 173 cases of complete hydatidiform mole indicates 8.1% have been 46,XY. Our unexpectedly high incidence of Y chromatin in malignant gestational trophoblastic neoplasia would suggest that homozygosity for a recessive mutant oncogene is not an important factor in pathogenesis of choriocarcinoma. The partial allograft theory of pathogenesis after nonmolar antecedents with attendant diminished host immunoreactivity remains a plausible consideration.

Numerical Modeling of Wet Cooling Towers—Part 2: Application to Natural and Mechanical Draft Towers

This paper presents several applications of the mathematical model described in Part 1 of the paper. Natural and mechanical draft towers of counterflow and crossflow arrangement have been considered. Predicted thermal performances compare well with the available data from operating towers. The distributions of air velocities, pressure, temperature, moisture fraction, and water temperature have been assessed from the considerations of physical plausibility only, since no experimental data are available for comparison. Some sample parametric computations for a mechanical draft crossflow tower are also presented. The parameters studied are: (a) air travel dimension of fill; (b) aspect ratio of fill; (c) fan power; and (d) atmospheric pressure. The results are self-consistent and demonstrate the applicability of the model as an analysis tool.

Archaeological Inference and Inductive Confirmation

The limitations of the hypothetico‐deductive (H‐D) method of inductive confirmation are described, and an alternate method, the hypothetico‐analog (H‐A) method is described in detail. The H‐A method can be characterized as a modified and supplemented form of the simple H‐D method, and is proposed as being more appropriate for archaeological inference. Aspects of the H‐A method that are given particular attention include the establishment of boundary conditions for reference classes, plausibility considerations, multiple working hypotheses, bridging arguments, and criteria for selecting alternative hypotheses. [scientific method, archaeological inference, hypothetico‐analog method, inductive confirmation]

Über einige Grundbegriffe der Informationstheorie

The author explains the basic ideas of thetheory of information, in particular Starting from simple examples and considerations of plausibility these conceptions are formulated in an elementary mathematical language, trying to avoid too much generality in the interest of an easier understanding. For further studies, reference is made to the bibliography on information theory byL. Schmetterer, published in this journal on the following pages.