Thermodynamic study of capillary pressure curves based on free energy minimization

This paper presents a new method for pore level network simulation of the distribution of two immiscible phases in a permeable medium. The method requires that the Helmholtz free energy of the system — the medium and the two phases contained within the pore space — be a minimum at all saturation states. We describe the method here and show some typical results from a computer algorithm that implements it. The results include (i) an explanation of the ‘scanning’ behaviour of capillary pressure curves based wholly on the free energy minimization, (ii) predictions of capillary pressure at arbitrary wetting states, including negative capillary pressures, and (iii) illustrations of how the minimized free energy changes along the scanning curves. The method also predicts the known dependency of the capillary pressure on the pore size distribution and interfacial tension. The current work is restricted to two‐dimensional networks, but the free energy minimization appears to be generalizable to three dimensions and to more than two fluid phases. Moreover, functions generated through the minimization, specifically contact areas between the medium surface and the phases, appear to have applications predicting other multiphase petrophysical properties.     

Number estimation in vertebrate samples

Methods of quantifying bone samples are discussed and the minimum numbers approach criticized. A technique based upon number estimation of game populations is put forward, and some of the practical difficulties of this method are examined. Consideration is given to the underlying statistical assumptions involved in quantified analysis of bone samples, and a method of calculating confidence limits for death population numbers proposed.     

Taphonomy and sample size estimation in paleoethnobotany

This paper investigates how to gain quantitative comparability of macroscopic plant remains by estimating sample sizes representative to each population. First, this study reviews taphonomic pathways of plant remains to clarify how far we can draw cultural implications from the retrieved remains. The target population is defined here as the deposited assemblage, that is, plants that were deposited into the soil matrix. Through time, the deposited assemblage becomes reduced to the fossil assemblage, which is subject to being sampled (sampled population). The relation between the sampled population and samples is a statistical issue. A systematic recovery and a well-designed sampling strategy can help maintaining the same degree of representativeness of samples to the sampled population. The paper thus focuses on a statistical measure that estimates the sample sizes, based on a relative error and a confidence level of a small number of pilot samples. Data for the test is the plant remains recovered from the Nam River sites in south-central Korea, dating to the Early and Middle Mumun periods (3400-2400 BP). This measure ensures that quantitative differences between the plant remains in the two samples were due to real differences between the populations from which they were drawn rather than due only to variation within a single population. Thus this method strengthens cultural interpretations on quantitative differences in plant remains.     

发生学方法与历史研究

发生学方法兴起于自然科学研究领域,随后被人文社会科学研究领域所采用。唯物史观和唯物辩证法使这一方法走向科学,从而形成了具有普遍意义的科学的马克思主义发生学方法。它是对现实及其发生前提和发生过程进行研究的方法,具有科学性、革命性和实践性特征,在马克思主义的历史研究方法体系中处于支配地位。然而,这并非意味着它是历史研究的唯一方法。这对我们加深理解唯物史观与历史学理论方法之间的关系,具有重要启示意义。     

Age estimation by tooth/pulp ratio in canines by peri-apical X-rays: reliability in age determination of Spanish and Italian medieval skeletal remains

Estimation of age at death is an unavoidable step in the process of human identification, both in forensic practice and in the anthropological and palaeopathological study of skeletal remains. In several cases, in which medical or demographic records are completely lacking, a reliable estimation of the age at death becomes very important. Skeletal remains from archaeological contexts suffer from several biasing factors such as post-mortem changes, taphonomy and various burial practices depending on age, sex and social status of the deceased persons.     

Cranial suture closure and its implications for age estimation

Three age estimation techniques using ectocranial and/or endocranial suture closure are tested on a sample of known age from Spitalfields, London in order to determine the value of cranial suture closure as an indicator of age at death. The three techniques are those proposed by Acsádi and Nemeskéri, Meindl and Lovejoy and Perizonius. Results indicate that the Acsádi and Nemeskéri technique, which is based on endocranial sutures, can be used to distinguish young and middle-aged individuals in the Spitalfields sample but gives no information for crania over the age of 50 years. Age estimation using the Meindl and Lovejoy and Perizonius (Old system) techniques, which use ectocranial sutures, was found to be subject to a number of complicating factors, of which sexual dimorphism in the rate and pattern of closure is the most significant. A method of estimating age at death based on both endocranial and ectocranial suture closure is developed on the basis of the Spitalfields sample. The technique attempts to overcome some of the problems associated with both intra- and interpopulation variation in cranial suture closure. For a truly accurate age-estimation technique based on cranial suture closure we would need to know more about the causes and functions of suture closure in human populations.     

庄浪出土汉代铜环权实测对比初探

权衡是我国古代衡器的总称,汉代权衡的器形分鼻钮形和圆环形两种。在甘肃省出土的汉代权衡文物中,鼻钮形的较多,且多为石质。圆环形权衡文物,以1972年定西口镇出土的5件环权(其1为石权,余皆铜权)最具代表,除此,未见相关出土报道。1967年在农田水利基本建设中,甘肃省庄浪县朱店镇吴沟村村民张东仓在一土坑汉墓中挖出一件灰陶“魂瓶”,从中发现铜环权11枚,五铢铜钱4枚,全部上缴县博物馆收藏。由于当时文物管理上的混乱,把后来零星收藏来的另外4枚铜环权混在一起,分不清楚,所以共有15枚(见图),环权全系青铜质地,呈扁平状环形,外径,厚度不一。…     

An Evolutionary Algorithm for Site Search Problems

The goal of solving a site search problem is to allocate a contiguous set of land parcels such that the total land acquisition cost, or other objectives, are optimized. This article describes the design and implementation of an evolutionary algorithm (EA) that can be used to solve site search problems. In this article, a graph representation is used to define the spatial structure of solutions to the problem. By using this representation, the contiguity of a site is maintained during the initialization, mutation, and local search operations of the EA. The effectiveness of the EA in finding optimal or near-optimal solutions is demonstrated by testing it on a series of problems whose optimal solutions are known.     

人类基因工程面临的道德问题

基因工程已经用于人类克隆并因此引起了极大的关注和争议。比如道德灾难、基因歧视以及转基因产品的不确定性。因此人类克隆应该受到限制,用于治疗目的的人类克隆应该严格受控。     

The estimation of the relative frequencies of mammalian species: Khirokitia 1972

The difficulties in the estimation of relative frequencies of species are discussed and a new approach to the recording of bone is proposed. This approach eliminates various biases and allows minimum numbers of individuals and counts of identified specimens to be derived from the same data. Sieved material from Khirokitia is used to provide a comparison of different methods and to illustrate possible ways of recording the information.     

A comparison of different non-destructive methods of age estimation in skeletal material

The skeletal remains of unidentifiable persons, recovered in recent years from the churchyard adjoining the House of Correction in Oslo, included 91 instances in which the maxillae and/or mandibles had been preserved, and these were examined. The length of the apical translucent zone in unsectioned teeth and the amount of secondary dentine deposit have been regarded as two of the most reliable factors in odontological age estimation. This study has used two methods, each using one of these factors, on single-rooted teeth from, respectively, 78 and 76 individuals. The distribution of age at death, as estimated from the two dental methods and from anthropological criteria, was then compared with the distribution of age at death of 380 individuals recorded in the church register for the House of Correction. Age calculations from secondary dentine, measured indirectly on dental radiographs of premolars, and estimates based on anthropological criteria both seemed to approximate to the chronological age distribution better than age estimates based on the length of the apical translucent zone. Statistical analyses indicated that all three methods of age estimation were significantly different (p<0.05). When compared with the church register, each method assigned a lower percentage of individuals to the younger and older age-groups and a higher percentage to those in the middle. No statistical difference could be found between the age distribution from the church register and estimates from either anthropological criteria or dental radiographs; but when age estimates based on these two latter methods were compared, 39.5 per cent differed by more than 10 years.     

A New Algorithm for Graph-theoretic Nodal Accessibility Measurement

Accessibility is a useful concept in the study of the spatial structure of a region, if it can be calibrated appropriately. While graph-theoretic analysis has been used widely as a measurement scheme for the nodal accessibility in various transport networks, several limitations have been pointed out in the existing graph-theoretic accessibility measurements. This study proposes a new algorithm for deriving the nodal accessibility measure, as an attempt to improve the conventional graph-theoretic accessibility measurements. Corrections are made in such a way that irrelevant loops are excluded and relevant indirect connection paths are included selectively. In particular, the new algorithm is developed for intraurban subway networks, and includes the characteristics of intraurban subway traffic behavior. The concept of inconvenience of transfer is introduced, which is one of the most influential factors in the intraurban subway traffic. Nodal differentiation is allowed, if the nodes play different roles in the travel behavior and eventually in the accessibility. For this purpose, we employ a weighting procedure, according to which the influence of transfer on a sequence of linkages is taken into account. The new accessibility measurement scheme is then applied to the Seoul subway network. Here GIS techniques are utilized to generate accessibility surfaces from the discrete nodal accessibility values, and the changes in the spatial structure of the nodal accessibility are analyzed. Finally, based on the resulting changes in the spatial structure of accessibility in the subway network, the direction of changes in the land value and the land use pattern in Seoul is discussed.     

Using Simple Genetic Algorithms to Calibrate Spatial Interaction Models

The paper investigates the use of two genetic algorithms in an attempt to obtain globally optimal parameter estimates for a mix of simple and complex spatial interaction models. The genetic algorithms work well and are strongly advocated as a more robust approach particularly for use with the more complex multiparameter models where the differences in both performance and parameter values are judged to be significant.     

Age estimation from the pars basilaris of the fetal and juvenile occipital bone

The pars basilaris of the human occipital bone is reported to be of considerable value for age estimation in juvenile skeletal remains between early fetal periods and 6 years of age, when it fuses to the remainder of the bone. The aim of this investigation was to examine the relationship between various dimensions of the pars basilaris, and assess their reliability for accurate age estimation. The results confirm the usefulness of the bone in this respect and they are discussed in the light of differential growth of the pars basilaris, and in the increase in dimensions of the boundaries of the foramen magnum.     

Noninferior Bandwidth Line Simplification: Algorithm and Structural Analysis

Digital line simplification operators are an important preprocessing component of a spatial data handling system. Simplification operators are used to generalize digital line files because these files are encoded at one scale but the objects they represent can be displayed at many other scales. Most line simplification algorithms are heuristics that caricaturize lines by eliminating points representing redundant data or conversely retaining the characteristic points of a line that have a high informational content. This paper presents a noninferior simplification algorithm that produces an optimal caricature of an encoded line with respect to the bandwidth criterion that all deleted points must be within a prespecified distance of the simplified line. Results show that it is a practical alternative to existing bandwidth heuristics.