| 1. |
- Eshagh, Mehdi, 1977-
(författare)
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Sequential Tikhonov Regularization : an alternative way for inverting satellite gradiometric data
- 2011
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Ingår i: Zfv. - Germany : Wissner Verlag. - 1618-8950. ; 136:2, s. 113-121
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Tidskriftsartikel (refereegranskat)abstract
- Numerous regularization methods exist for solving the ill-posed problem of downward continuation of satellite gravity gradiometry (SGG) data to gravity anomaly at sea level. Generally, the use of a dense set of data is recommended in the downward continuation. However, when such dense data are used some of the regularization methods are not efficient and applicable. In this paper, a sequential way of using the Tikhonov regularization is developed for solving large systems and compared to methods of direct truncated singular value decomposition and iterative methods of range restricted minimum residual, algebraic reconstruction technique, and conjugate gradient for recovering gravity anomaly at sea level from the SGG data. Numerical studies show that the sequential Tikhonov regularization is comparable to the conjugate gradient and yields similar result.
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| 2. |
- Granath Hansson, Anna, 1971-
(författare)
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Combatting the housing shortage through institutional reform: The parallel cases of Germany and Sweden
- 2018
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Ingår i: Zeitschrift für Geodäsie, Geoinformation und Landmanagement. - Augsburg. - 1618-8950. ; 2, s. 93-99
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Tidskriftsartikel (refereegranskat)abstract
- Both Germany and Sweden are currently experiencing affordable housing shortage, mainly in cities and university towns, and central and local governments are investigating reform initiatives that could help alleviate the situation. This article outlines four reform initiatives that are currently being investigated in Sweden and draws parallels to the situation in Germany. The four reforms are related to urban planning, the building code, local government policy related to housing construction and inclusionary zoning (Baulandmodelle). Parallel German and Swedish case studies show that reforms aiming at expanding the overall housing supply are transferable between Germany and Sweden. However, initiatives targeting lower-income households, which are implemented in Germany i.a. through inclusionary zoning, are difficult to implement in Sweden due to its unitary housing system which does not allow reserving certain housing for lower-income groups.
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| 3. |
- Lösler, Michael, et al.
(författare)
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Bestimmung von Messunsicherheiten mittels Bootstrapping in der Formanalyse
- 2018
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Ingår i: ZFV - Zeitschrift für Geodasie, Geoinformation und Landmanagement. - 1618-8950. ; 143:4, s. 224-232
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Tidskriftsartikel (refereegranskat)abstract
- The methods of the Guide to the Expression of Uncertainty in Measurement, e.g. Law of propagation of uncertainty or Monte-Carlo simulations, are the most applied guidelines in the framework of measurement sciences. These methods require a-priori knowledge of the statistical distribution of the taken sample. However, in some practical cases, this condition cannot be fulfilled. In descriptive statistics, analysis methods are known that do not required knowledge of the underlying distribution of the data. One well-known algorithm is the bootstrapping. In this contribution, the bootstrap algorithm is applied to the surface analysis to derive confidence intervals of estimated parameters, exemplified by the adjustment of an elliptic ring-focus paraboloid. Introducing kernel density estimation, the unknown probability density functions of the estimates are approximated and transformed to the resulting focal area to derive the level of confidence of the intervals.
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| 4. |
- Lösler, Michael, et al.
(författare)
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Kongruenzanalyse auf der Basis originärer Beobachtungen
- 2017
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Ingår i: ZFV - Zeitschrift für Geodasie, Geoinformation und Landmanagement. - 1618-8950. ; 142:1, s. 41-52
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Tidskriftsartikel (refereegranskat)abstract
- The congruence analysis is one of the major tasks in the field of applied engineering geodesy. The stability of an object is tested and evaluated based on statistical hypothesis testing. Especially in the 1970s and 1980s the necessary mathematical and statistical background was derived by several institutes. Based on these scientific fundamentals algorithms and software packages were developed and compared to each other. Although modern metrology allows today continual observations, for economic reasons the discontinuous or routine deformation analysis still plays a key role in applied geodesy today, because the instruments are not setup permanently. Usually, deformations are derived from the results of independent single adjustments. This article presents an analysis concept that combines the different original observation sets and furthermore integrates deformation analysis into one unified model. Based on Baarda's Data-Snooping method, a generalised hypothesis testing is introduced to detect questionable observations as well as object deformations. More-Over, shift and strain parameters can be estimated by extend-ing the functional model of the least-squares algorithm. The approach is demonstrated on a synthetic horizontal network presented in 1983, followed by the analysis of a levelling network, which was observed at the Onsala Space Observatory in 2014 and 2015.
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| 5. |
- Paasch, Jesper M.
(författare)
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Vergleich und internationale klassifizierung von liegenschaftsrechten und öffentlich-rechtlichen festlegungen
- 2012
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Ingår i: Zeitschrift für Geodäsie, Geoinformation und Landmanagement. - 1618-8950. ; 137:1, s. 32-36
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Tidskriftsartikel (refereegranskat)abstract
- Real property rights and public regulations are vital for effective land management They are part of a nation's legal system. The applied national terminology and descriptions may therefore not be used as basis for an international information interchange. A neutral and legal system independent model describing real property rights and public regulations would further an international use of information based on standardized descriptions. The Legal Cadastral Domain Model (LCDM) is an attempt to facilitate such descriptions.
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| 6. |
- Reshetyuk, Yuriy, 1980-
(författare)
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Direct Georeferencing with GPS in Terrestrial Laser Scanning
- 2010
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Ingår i: Zeitschrift für Geodäsie, Geoinformation und Landmanagement. - Augsburg, Tyskland : Wissner-Verlag. - 1618-8950. ; 135:3, s. 151-159
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, a combined terrestrial laser scanning survey system is presented, where GPS can be used for direct georeferencing of the point clouds. The results of investigations of this system show that it is possible to achieve the coordinate accuracy of better than 1 cm in the point cloud, both in plane and height, at the object distance of up to about 70 m.
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| 7. |
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| 8. |
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| 9. |
- Sjöberg, Lars Erik, 1947-
(författare)
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Comments H. Schmidt's remarks on Sjöberg
- 2006
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Ingår i: Zeitschrift für Geodäsie, Geoinformation und Landmanagement. - Germany. - 1618-8950. ; 131:3, s. 155-
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Tidskriftsartikel (refereegranskat)
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| 10. |
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