Bi‐objective Model for Optimal Number and Size of Circular Facilities

This article presents a bi‐objective model for determining the number and size of finite size facilities. The objectives are to minimize both the average closest distance to facilities and the probability that a random line intersects facilities. The former represents the accessibility of customers, whereas the latter represents the interference to travelers. The average closest distance and the probability of intersecting facilities are derived for circular facilities randomly distributed in a circular city. The analytical expressions for the average closest distance and the probability of intersecting facilities demonstrate how the number and size of facilities affect the accessibility of customers and the interference to travelers. The model focuses on the tradeoff between the accessibility and interference, and the tradeoff curve provides planners with alternatives for the number and size of facilities.     

Characteristics of ESR signals and TLCLs of quartz included in various source rocks and sediments in Japan: A clue to sediment provenance

The variation of electron spin resonance (ESR) signal intensities and thermoluminescence colour images (TLCIs) of quartz was investigated in the present study for various rocks and sediments in Japan, to discuss the possibilities of identifying the sediment provenance. The ESR signal intensity of the E₁’ centre in the same grain size in granitic quartz varies from sample to sample, except for that in Quaternary samples of volcanic sediment, which is very low, close to the noise level. It was found that the diagram, ESR intensities of Al versus Ti-Li centre signal intensities, distinguish volcanic from the same grain size in granitic quartz as well as distinguish individual tephra from another. The TLCIs from volcanic quartz and some granitic quartz samples is almost red and that from the rest of granitic and metamudstone quartz is blue as results of TLCIs although the emission intensities are different. Our results suggest that examining the multiple-centre signal intensities of ESR and the TLCIs are effective to identify the source of quartz and to estimate the sediment provenance.     

Spinal degenerative lesions and spinal ligamentous ossifications in ancient Chinese populations of the Yellow River Civilization

Rheumatological diseases, whether inflammatory or degenerative, are ubiquitous among modern Asian people but very few palaeopathological studies have been performed in Asia on this subject. Since 1996, we have been carrying out a palaeoepidemiological survey of rheumatic diseases in ancient Chinese and Japanese skeletal populations. Findings on the spinal column in ancient Chinese populations (ca. 5000 bc –ad 1644) in Henan Province (centre of the Yellow River Civilization) are reported in this study. The examined number of the people over 20 years old was 365 (185 males, 169 females and 11 unsexed). Of these, 248 were young adults, 98 were middle adults and 19 were old adults. Crude prevalence (number/100) in total population of vertebral osteophytosis/facet osteoarthritis was 17.5/7.7, 17/3.7 and 44.6/21.1 at the cervical, thoracic and lumbar spine, respectively. That of ossified anterior longitudinal ligament (OALL) or Forestier's disease was around 3 at each of the cervical, thoracic and lumbar spine. Ossification of the posterior longitudinal ligament (OPLL) of the cervical spine was observed in five out of 114 skeletons with cervical spine preserved, while it did not exist in any thoracic and lumbar segment. Ossification of the ligamentum flavum (OLF) was predominantly observed in the thoracic spine, the crude prevalence of which was 36.7. Overall spinal degenerative lesions seemed to have been more prevalent and spinal ligament ossifications less prevalent in ancient Chinese populations than in modern people. None of the inflammatory lesions like rheumatoid spondylitis, as well as seronegative spondyloarthropathies, were detected. This is the first palaeopathological study in which the prevalence of OPLL and OLF, the two clinically important spinal ligamentous ossifications causing myelopathy in modern mankind, was surveyed in ancient skeletons. Copyright © 2000 John Wiley & Sons, Ltd.     

Order Distance in Regular Point Patterns

This article examines the k th nearest neighbor distance for three regular point patterns: square, triangular, and hexagonal lattices. The probability density functions of the k th nearest distance and the average k th nearest distances are theoretically derived for k =1, 2, …, 7. As an application of the k th nearest distance, we consider a facility location problem with closing of facilities. The problem is to find the optimal regular pattern that minimizes the average distance to the nearest open facility. Assuming that facilities are closed independently and at random, we show that the triangular lattice is optimal if at least 68% of facilities are open by comparing the upper and lower bounds of the average distances.     

Erosive peripheral polyarthritis in ancient Japanese skeletons: A possible case of rheumatoid arthritis

The antiquity of rheumatoid arthritis (RA) is still in dispute, due to the difficulty of conclusively differentiating peripheral polyarthritis, especially from spondyloarthropathy, in archaeological populations. In view of the importance of genetic factors in developing spondyloarthropathy and of the far lower prevalence of the disease in modern Japanese, a rarity of peripheral polyarthritis would be anticipated in the ancient Japanese population, given that RA had not been present there. One hundred and sixty adult Japanese skeletons of the late and final Jomon period (3400–2400 years bp ) were examined to find peripheral polyarthritis. There was one male skeleton with peripheral polyarthritis, showing marginal and surface erosions in the joints of the hands, feet, ankle and zygoapopheseal joints of the thoracic vertebrae. RA is suggested as the most probable cause of this pathology. This report raises the significance of further studies to consider whether more cases than anticipated exist in skeletal populations that would have been resistant to developing spondyloarthropathy. Copyright © 1999 John Wiley & Sons, Ltd.     

Healed bone fractures in a jomon skeletal population from the Yoshigo shell mound,Aichi Prefecture,Japan

Healed bone fractures were quantitatively analyzed in an ancient Japanese population. The sample studied consisted of the skeletal remains of 160 adult individuals from the Yoshigo shell mound (ca. BP 3400‐2400), Aichi prefecture, Japan. Healed fractures were diagnosed from the presence of callus formation and/or angular deformity. Fractures were frequently seen in small bones of the hand and foot such as the metacarpals, rather than in large long bones such as the clavicle, humerus, radius, ulna, femur, tibia and fibula. Of a total of 517 intact large long bones, only four fractures (0.8%) were recognized. The prevalence and pattern of bone fractures in the Yoshigo population reflects the relative lack of stress in their life‐style. Copyright © 1999 John Wiley & Sons, Ltd.     

Distribution of the Sum of Distances to the First and Second Nearest Facilities

This article presents a derivation of the distribution of the sum of the distances to the first and second nearest facilities. Facilities are represented as points configured in regular and random patterns, and distance is measured as the Euclidean and rectilinear distances on a continuous plane. The sum of the distances represents the service level of facility location when customers are serviced by the first and second nearest facilities. Thus, the distribution of the sum is useful for facility location problems with nonclosest facility service. The distribution of the sum of road network distances also is calculated to evaluate the efficiency of actual facility locations. Este artículo presenta una derivación de la distribución de la suma de las distancias a la primera y segunda instalación más cercana. Las instalaciones son presentadas como puntos en configuraciones espaciales regulares y aleatorias, y la distancias son medidas usando el método euclidiano y el rectilínea sobre un plano continuo. La suma de las distancias representa el nivel de servicio en cada punto, en los casos en los que los clientes son atendidos en la instalación primera y segunda más cercana. El uso de la distribución de la suma de distancias es útil para resolver problemas de localización para casos en los que los clientes son atendidos por las instalaciones de servicios que nos son las más cercanas. Como demostración se calcula la distribución de la suma de las distancias de una red de carreteras para evaluar la eficiencia de la localización de instalaciones en un caso del mundo real. 本文讨论了一种最邻近距离总和与次邻近设施距离总和分布情况的推导方法。具体设施以规则和随机两种模式的点状要素来表示,距离采用连续平面中的欧氏及直线距离测度。距离之和反映了最邻近及次邻近设施为用户提供该设施区位的服务水平。因此,距离和的分布在无最邻近设施服务的设施选址问题中具有参考价值。路网距离和的分布也可计算用于现有设施区位的效率评估。