Comparison of Different Height Systems

Geopotential, dynamic, orthometric and normal height systems and the corrections related to these systems are evaluated in this paper. Along two different routes, with a length of about 5 kilometers, precise leveling and gravity measurements are done. One of the routes is in an even field while the other is in a rough field. The magnitudes of orthometric, normal and dynamic corrections are calculated for each route. Orthometric, dynamic, and normal height differences are acquired by adding the corrections to the height differences obtained from geometric leveling. The magnitudes of the corrections between the two routes are compared. In addition, by subtracting orthometric, dynamic, and normal heights from geometric leveling, deviations of these heights from geometric leveling are counted.

快速静态GPS在koyulhisar滑坡监测中的应用——一种消除垂向速度误差的方法

全球定位系统常用于自然灾害或其他地球物理现象的监测。滑坡监测是一个对各种GPS方法进行测试并解译各种系统误差来源的领域。在以往的研究中，快速静态GPS的系统误差来源的解译受GPS位置高差的显著影响。在这项研究中，我们进一步探讨使用快速静态测量中监测点高差对GPS监测快速测量的影响程度。为了证明其影响，我们在土耳其中部的koyulhisar滑坡中使用了静态GPS测量。快速静态GPS方案与静态GPS方案在BERNESE5．0中的运行结果对比表明，当监测基准点之间高差较大时系统误差主要表现在快速静态GPS变形率的估算值上。其中垂直分量的效果尤为显著，尽管它在水平分量上微不足道。减少地面参考站和流动站之间的高差，15分钟后快速静态方案即显示出与静态定位方案的高度相关性和近似变形率。

Modelling the Urban Interface by Using Fuzzy Logic

This paper discusses the validity of the urban interface dichotomy in the urban planning and scientific literature by means of a new approach and proposes a new model. Although the concept of “Urban Interface” (UI) is discussed widely in the context of urban-rural and/or natural-artificial environment, UI has been used in the computer and communication disciplines, as well as in economy, geography, regional planning, city planning and architecture. UI has also been used in relation to electronic traffic control systems in urban transportation. UI between buildings and city is a relatively new issue in the literature. UI is defined with variant paradigms since the phenomenon is uncertain. This article reports on the use of fuzzy logic to create a kind of expert system for evaluating architectural elements in the context of UI. Fuzzy is the mathematical models of verbal expression on the area of specialization. This study is useful because this study shows a way to transform non-intuitive and precise concepts to the measurable and accurate results into a model. In order to create a model, the definition of UI in literature is evaluated and according to this evaluation a definition in terms of architecture is determined. The model of this new definition is created with using fuzzy logic using the Fuzzy Tec software. The predictions and experiences of a designer are represented in the model, which has been designed to behave like an expert person. Therefore, it has been shown that the definition of “expert system” can be added to architectural software. Lastly, a model that can give a fuzzy logic system for determining the quality of Urban Interface with sixteen parameters has been presented to the scientific field.

2-D delineation of individual citrus trees from UAV-based dense photogrammetric surface models

One of the challenges of remote sensing and computer vision lies in the three-dimensional(3-D)reconstruction of individual trees by using automated methods through very high-resolution(VHR)data sets.However,a successful and complete 3-D reconstruction relies on precise delineation of the trees in two dimensions.In this paper,we present an original approach to detect and delineate citrus trees using unmanned aerial vehicles based on photogrammetric digital surface models(DSMs).The symmetry of the citrus trees in a DSM is handled by an orientationbased radial symmetry transform which is computed in a unique way.Next,we propose an efficient strategy to accurately build influence regions of each tree,and then we delineate individual citrus trees through active contours by taking into account the influence region of each canopy.We also present two efficient strategies to filter out erroneously detected canopy regions without having any height thresholds.Experiments are carried out on eight test DSMs composed of different types of citrus orchards with varying densities and canopy sizes.Extensive comparisons to the state-of-the-art approaches reveal that our proposed approach provides superior detection and delineation performances through supporting a nice balance between precision and recall measures.

Outlier detection by means of robust regression estimators for use in engineering science

This study compares the ability of different robust regression estimators to detect and classify outliers. Well-known estimators with high breakdown points were compared using simulated data. Mean success rates (MSR) were computed and used as comparison criteria. The results showed that the least median of squares (LMS) and least trimmed squares (LTS) were the most successful methods for data that included leverage points, masking and swamping effects or critical and concentrated outliers. We recommend using LMS and LTS as diagnostic tools to classify outliers, because they remain robust even when applied to models that are heavily contaminated or that have a complicated structure of outliers.