Dinosaur tracks from the Cretaceous of South Korea: Distribution, occurrences and paleobiological significance

Abstract   Abundant dinosaur fossils including dinosaur footprints, eggs and nests, teeth and bones have been found from the Cretaceous non-marine deposits of Korea. Among them, dinosaur tracks are the most distinctive, and some track sites are among the most famous in the world. Until now, 27 dinosaur track localities have been discovered from the Cretaceous strata in the Gyeongsang Basin and several small basins. Ornithopod tracks are most abundant at most Korean track sites, and most of them are identified as Caririchnium ; that is, large ornithopod footprints with wide hoof impressions. Most theropod tracks are found in Neungju Basin and they consist of various types of small or medium-sized bird-like footprints, and other large footprints. Sauropod tracks are also abundant in the Gyeongsang Basin. The sauropod tracks vary in size, shape, and pattern of trackway, and suggest that diverse sauropods existed in this area. These diverse tracks in South Korea suggest that various dinosaurs flourished at the margins of lakes distributed in the southern part of the Korean Peninsula during the Cretaceous.     

Landslide susceptibility analysis using GIS and artificial neural network

The purpose of this study is to develop landslide susceptibility analysis techniques using an arti?cial neural network and to apply the newly developed techniques to the study area of Yongin in Korea. Landslide locations were identi?ed in the study area from interpretation of aerial photographs, ?eld survey data, and a spatial database of the topography, soil type and timber cover. The landslide‐related factors (slope, curvature, soil texture, soil drainage, soil effective thickness, timber age, and timber diameter) were extracted from the spatial database. Using those factors, landslide susceptibility was analysed by arti?cial neural network methods. The landslide susceptibility index was calculated by the back‐propagation method, which is a type of arti?cial neural network method, and the susceptibility map was made with a geographic information system (GIS) program. The results of the landslide susceptibility analysis were veri?ed using landslide location data. The validation results showed satisfactory agreement between the susceptibility map and the existing data on landslide location. A GIS was used to ef?ciently analyse the vast amount of data, and an arti?cial neural network to be an effective tool to maintain precision and accuracy. The results can be used to reduce hazards associated with landslides and to plan land use and construction. Copyright © 2003 John Wiley & Sons, Ltd.     

基于先验知识的GIS路径寻优算法

针对地理信息系统中特定的两点路径寻优问题,提出了一种基于先验知识的快速搜索算法。该算法模拟人脑寻找路径的思维过程,首先针对实际问题建立先验知识库,在路径搜索过程中,利用知识库中的信息剪去不可能的搜索路径,构造出简化的查询树,从而大大提高最优路径的搜索速度。     

闪长岩强风化带做高层建筑天然地基的可行性研究

借助于中国工商银行山东省分行营业办公楼的工程实践,将常规勘察与原位测试相结合,运用野外钻探、室内试验、原位测试多种手段,对闪长岩强风化带的物理力学性质进行了测试分析和深入地研究,并通过对承载力、沉降变形的验算,得出其作为高层建筑的天然地基是可行的。实践证明,与桩基础处理方案相比,节省资金近200万元,大大加快了施工进度,减少了基础施工难度,取得了巨大的经济效益与社会效益;同时,也提出了研究岩石风化带所遇到的问题:由于采取原状试样及制样难,导致对其物理力学性质了解不够。     

淇、卫河流域“96·8”致洪暴雨过程的数值模拟

应用LASGREMM模式 ,对淇、卫河流域“96·8”致洪暴雨过程进行了模拟预报分析。结果表明 ,LAS GREM模式不仅能较准确地预报淇、卫河流域暴雨落区 ,而且可以进一步分析天气过程的特点及演变情况     

震级加权四指标Blade算法及在地震带识别中的应用

Blade算法的产生是根据地震点的分布寻找地震断层，其优势在于能从较稀疏的点分布中找出线型条带模式，但不足的是完全不考虑地震的震级屑性。针对Blade算法的几个不足之处逐步改进，提出了震级加权四指标Blade算法。算法主要的改进体现在：①引入以震级为变量的权重函数，体现了高震级地震的控制作用，通过模拟与实例比较了三种权重函数的效果；②改进原方法中所挑出的Blade中心必须有地震点，引入四指标评价体系代替原方法的二指标评价体系，同时还根据指标值将挑选出的线型条带修正到更淮确的位置。将原算法与改进算法应用于华北地区4级以上的地震数据集以按寻地震带，结果表明，震级加权四指标Blade算法较Blade算法有显改进，取得了较好的应用效果。     

斜底面上的表面波理论

考察了任意倾斜底面上的Kelvin波问题，并用线性化的控制方程分别研究了相应于垂直刚壁的和无限倾斜底面上的表面波频散关系。文中还对任意斜坡上的浅水表面波做了尺度分析，并把决定其频散关系的特征值问题简化为该斜坡上气压扰动的常微分方程，且用数值方法进行了求解。     

数字化地震遥测台网不间断供电系统研制

本文介绍一种适用于数字化遥测地震台网的不间断供电系统，它具有交直流不间断切换，输出满足数据采集系统及数据传输设备所需的各种电压要求，并能对备份蓄电池自动恒流、恒压转换充电及过放电保护，冗余量大、可靠性高。解决了无人值守遥测地震台的供电问题。对其它数字设备也有广泛的应用价值。     

Pressures on an intensive irrigated cash-crop system in coastal Ghana

This paper outlines the results of recent interdisciplinary fieldwork in Anloga on Keta Lagoon, Ghana. Vegetable production has been undertaken at Anloga since the nineteenth century and is now highly intensive and carefully regulated. Farmers produce shallots and other crops utilising irrigation water, mostly from wells which tap a shallow fresh-water perched aquifer. However, farmers have been expanding their cultivation activities from the lagoon-side, encouraged by a World Bank supported programme which provides for well-sinking and some electric pumps. The project has environmental and socio-economic implications which give cause for concern. The research employs field investigation to explore both the physical and political economy context and implications of recent change and considers the opportunities for community-based water and crop regulation.     

锶,硼和氟联合作用的亚急性毒理实验及环境意义

本文以自由饮水给药方式进行了锶、硼和氟联合作用的亚急性实验，以探讨锶、硼对氟的拮抗作用。实验结果，给予小鼠200×l0^-6 F 六个月后，可使其骨氟含量显著升高(P<0.01)，肾碱性磷酸酶活力(ALP)显著增高(P<0.01)，4、5个月后血清碱性磷酸酶(ALP)活力亦显著增高(P<0.O1)，同时给予80×l0^-1 B3+、100×l0^-6Sr2+ 时，可以显著降低骨氟含量，抑制血清、肾碱性磷酸酶的活力，表明锶与硼对氟存在拮抗作用。