Segmentation and classification of individual tree crowns

By segmentation and classification of individual tree crowns in high spatial resolution aerial images, information about the forest can be automatically extracted. Segmentation is about finding the individual tree crowns and giving each of them a unique label. Classification, on the other hand, is about recognising the species of the tree. The information of each individual tree in the forest increases the knowledge about the forest which can be useful for managements, biodiversity assessment, etc. Different algorithms for segmenting individual tree crowns are presented and also compared to each other in order to find their strengths and weaknesses. All segmentation algorithms developed in this thesis focus on preserving the shape of the tree crown. Regions, representing the segmented tree crowns, grow according to certain rules from seed points. One method starts from many regions for each tree crown and searches for the region that fits the tree crown best. The other methods start from a set of seed points, representing the locations of the tree crowns, to create the regions. The segmentation result varies from 73 to 95 % correctly segmented visual tree crowns depending on the type of forest and the method. The former value is for a naturally generated mixed forest and the latter for a non-mixed forest. The classification method presented uses shape information of the segments and colour information of the corresponding tree crown in order to decide the species. The classification method classifies 77 % of the visual trees correctly in a naturally generated mixed forest, but on a forest stand level the classification is over 90 %

A conditional marker gene allowing both positive and negative selection in plants

Selectable markers enable transgenic plants or cells to be identified after transformation. They can be divided into positive and negative markers conferring a selective advantage or disadvantage, respectively. We present a marker gene, dao1, encoding D-amino acid oxidase (DAAO, EC 1.4.3.3) that can be used for either positive or negative selection, depending on the substrate. DAAO catalyzes the oxidative deamination of a range of D-amino acids. Selection is based on differences in the toxicity of different D-amino acids and their metabolites to plants. Thus, D-alanine and D-serine are toxic to plants, but are metabolized by DAAO into nontoxic products, whereas D-isoleucine and D-valine have low toxicity, but are metabolized by DAAO into the toxic keto acids 3-methyl-2-oxopentanoate and 3-methyl-2-oxobutanoate, respectively. Hence, both positive and negative selection is possible with the same marker gene. The marker has been successfully established in Arabidopsis thaliana, and proven to be versatile, rapidly yielding unambiguous results, and allowing selection immediately after germination

"Stratification and Mortality - A Comparison of Education, Class, Status and Income"

In many analyses of social inequality in health, different dimensions of social stratification have been used more or less interchangeably as measures of the individual’s general social standing. This procedure, however, has been questioned in previous studies, most of them comparing education, class and/or income. In the present article, the importance of education and income as well as two aspects of occupation – class and status – are examined. The results are based on register data and refer to all Swedish employees in the age range 35-59 years. There are clear gradients in total death risk for all socioeconomic factors except for income from work among women. The size of the independent effects of education, class, status and income differ between men and women. For both sexes, there are clear net associations between education and mortality. Class and income show independent effects on mortality only for men and status shows an independent effect only for women. While different stratification dimensions – education, social class, income, status – all can be used to show a “social gradient” with mortality, each of them seems to have a specific effect in addition to the general effect related to the stratification of society for either men or women.-

Prospects of long-time-series observations from Dome C for transit search

The detection of transiting extrasolar planets requires high-photometric quality and long-duration photometric stellar time-series. In this paper, we investigate the advantages provided by the Antarctic observing platform Dome C for planet transit detections during its long winter period, which allows for relatively long, uninterrupted time-series. Our calculations include limiting effects due to the Sun and Moon, cloud coverage and the effect of reduced photometric quality for high extinction of target fields. We compare the potential for long time-series from Dome C with a single site in Chile, a three-site low-latitude network as well as combinations of Dome C with Chile and the network, respectively. Dome C is one of the prime astronomical sites on Earth for obtaining uninterrupted long-duration observations in terms of prospects for a high observational duty cycle. The duty cycle of a project can, however, be significantly improved by integrating Dome C into a network of sites.Comment: 10 pages, 9 figures, accepted by PAS

Marital Partner and Mortality: The Effects of the Social Positions of Both Spouses

Background Individual education, social class, social status and income are all associated with mortality, and this is likewise the case for the position of the marital partner. We investigate the combined effect on mortality of own and partner’s positions regarding these four factors. Methods Prospective follow-up of information in the 1990 Census of the Swedish population aged 30-59 (N=1 502 148). Data on all-cause mortality and deaths from cancer and circulatory disease for the period 1991-2003 were collected from the Cause of Death Register. Relative mortality risks were estimated by Cox regression. Results All-cause mortality of both men and women differs by women’s education and status and by men’s social class and income. Men’s education has an effect on their own mortality but not on their partner’s, when other factors are included in the models. Women’s education and men’s social class are particularly important for women’s deaths from circulatory diseases. Conclusions The partner’s social position has a clear effect on individual mortality, and women’s education seems to be particularly important. The results appear above all to support hypotheses about the importance of lifestyle and economic resources for socio-economic differences in mortality.-

Getting expert systems off the ground: Lessons learned from integrating model-based diagnostics with prototype flight hardware

As an initial attempt to introduce expert system technology into an onboard environment, a model based diagnostic system using the TRW MARPLE software tool was integrated with prototype flight hardware and its corresponding control software. Because this experiment was designed primarily to test the effectiveness of the model based reasoning technique used, the expert system ran on a separate hardware platform, and interactions between the control software and the model based diagnostics were limited. While this project met its objective of showing that model based reasoning can effectively isolate failures in flight hardware, it also identified the need for an integrated development path for expert system and control software for onboard applications. In developing expert systems that are ready for flight, artificial intelligence techniques must be evaluated to determine whether they offer a real advantage onboard, identify which diagnostic functions should be performed by the expert systems and which are better left to the procedural software, and work closely with both the hardware and the software developers from the beginning of a project to produce a well designed and thoroughly integrated application

McIntosh and Munk's Supposed Test of the Validity of the E-G Class Schema: A Comment

--

A Comparison Of Characteristics Of Forest and Farm Cooperative Members

The forest owner cooperatives in Sweden were established almost a century ago with the aim to improve the private forest owners’ bargaining situation and improve silviculture (the study, cultivation, and management of forest trees). The characteristics of today’s private forest owners and forest industry are changing, something which should encourage the forest owner cooperatives to consider adaptations of their organizations. The aims of this paper are, first, to describe characteristics of forest owner cooperative members and second, to probe the applicability of farm cooperative research in this venture. The statements that are tested are based on characteristics established in farm cooperative research and refer to (i) a negative relation between forest cooperative member’s age and property size, (ii) a positive relation between member’s age and proportion of trade accomplished through the cooperative, (iii) a positive relation between member’s age and membership in cooperative boards and committees, and, finally, (iv) a positive relation between property size and resignation from the forest cooperative. The hypotheses were tested on data from Norra Skogsägarna, a forest cooperative in northern Sweden. None of the propositions found support in the data. The results thus indicate that forest cooperative members may differ from farm cooperative members in several respects. The premise is put forward that this may be due to differences between forest and farm owners’ situations with respect to market characteristics and investment intensity, something that can affect membership expectations.Private forest owners, cooperative theory, statistical analysis, member’s age, property size, transaction, Agribusiness,

Tracking and data relay satellite fault isolation and correction using PACES: Power and attitude control expert system

The Power and Attitude Control Expert System (PACES) is an object oriented and rule based expert system which provides spacecraft engineers with assistance in isolating and correcting problems within the Power and Attitude Control Subsystems of the Tracking and Data Relay Satellites (TDRS). PACES is designed to act in a consultant role. It will not interface to telemetry data, thus preserving full operator control over spacecraft operations. The spacecraft engineer will input requested information. This information will include telemetry data, action being performed, problem characteristics, spectral characteristics, and judgments of spacecraft functioning. Questions are answered either by clicking on appropriate responses (for text), or entering numeric values. A context sensitive help facility allows access to additional information when the user has difficulty understanding a question or deciding on an answer. The major functionality of PACES is to act as a knowledge rich system which includes block diagrams, text, and graphics, linked using hypermedia techniques. This allows easy movement among pieces of the knowledge. Considerable documentation of the spacecraft Power and Attitude Control Subsystems is embedded within PACES. The development phase of TDRSS expert system technology is intended to provide NASA with the necessary expertise and capability to define requirements, evaluate proposals, and monitor the development progress of a highly competent expert system for NASA's Tracking and Data Relay Satellite Program