Institut für Raumbezogene Informations- und Messtechnik
Hochschule Mainz - University of Applied Sciences

Dr. Ashish Karmacharya

Dr. Ashish Karmacharya

Fachbereich Technik –
Geoinformatik & Vermessung
Raum: C2.22
Telefon: +49 6131-628-1477
Fax: +49 6131-628-91477

Funktionen

  • – Wissenschaftlicher Mitarbeiter
Anzeigename: 
Dr. Ashish Karmacharya

E-Mail

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Telefon: 
+49 6131-628-1477
Fax: 
+49 6131-628-91477
Raum: 
C2.22
Funktionen: 
Wissenschaftlicher Mitarbeiter

Projekte

The KnowDIP project aims at the conception of a framework for an automatic object detection in unstructured and heterogeneous data. This framework uses a representation of human…
Wissensbasierte Detektion von Objekten in Punktwolken für Anwendungen im Ingenieurbereich.

Publikationen

Ontology-based Knowledge Representation for Recommendation of Optimal Recording Strategies - Photogrammetry and Laser Scanning as Examples.

2017

Wefers, S.,
Karmacharya, A.,
Boochs, F.

BibTex

gis.Science

Experts’ knowledge about optical technologies for spatial and spectral recording is logically structured and stored in an ontology-based knowledge representation with the aim to provide objective recommendations for recording strategies. Besides operational functionalities and technical parameters such as measurement principles, instruments, and setups further factors such as the targeted application, data, physical characteristics of the object, and external influences are considered creating a holistic view on spectral and spatial recording strategies. Through this approach impacting factors on the technologies and generated data are identified. Semantic technologies allow to flexibly store this knowledge in a hierarchical class structure with dependencies, interrelations and description logic statements. Through an inference system the knowledge can be retrieved adapted to individual needs.


Development of a platform recommending 3D and spectral digitisation strategies.

2016

Wefers, S.,
Karmacharya, A.,
Boochs, F.

BibTex

Virtual Archaeology Review

Spatial and spectral recording of cultural heritage objects is a complex task including data acquisition, processing and analysis involving different technical disciplines. Additionally, the development of a suitable digitisation strategy satisfying the expectations of the humanities experts needs an interdisciplinary dialogue often suffering from misunderstanding and knowledge gaps on both the technical and humanities sides. Through a concerted discussion, experts from the cultural heritage and technical domains currently develop a so-called COSCH KR (Colour and Space in Cultural Heritage Knowledge Representation) platform that will give recommendations for spatial and spectral recording strategies adapted to the needs of the cultural heritage application. The platform will make use of an ontology through which the relevant parameters of the different domains involved in the recording, processing, analysis, and dissemination of cultural heritage objects are hierarchically structured and related through rule-based dependencies. Background and basis for this ontology is the fact that a deterministic relation exists between (1) the requirements of a cultural heritage application on spatial, spectral, as well as visual digital information of a cultural heritage object which itself has concrete physical characteristics and (2) the technical possibilities of the spectral and spatial recording devices. Through a case study which deals with the deformation analysis of wooden samples of cultural heritage artefacts, this deterministic relationship is illustrated explaining the overall structure and development of the ontology. The aim of the COSCH KR platform is to support cultural heritage experts finding the best suitable recording strategy for their often unique physical cultural heritage object and research question. The platform will support them and will make them aware of the relevant parameters and limitations of the recording strategy with respect to the characteristics of the cultural heritage object, external influences, application, recording devices, and data.


Semantic based Structuring of 3D technologies for their optimized use in cultural heritage documentation.

2015

Karmacharya, A.,
Wefers, S.,
Boochs, F.

BibTex

43rd Conference of Computer Applications and Quantitative Methods in Archaeology, CAA 2015, Siena, Book of Abstracts.

Constant technological progress results in new possibilities to produce reliable and rich spatial data of cultural heritage objects: for instance, museums have started to digitize their collections, more and more archaeological excavations or features and entire CH buildings have been documented in 3D. It is now necessary to establish connections among different CH disciplines and several technical disciplines, and to work on collaborative projects.

Technicians and CH experts together evaluate the best technique for specific CH object documentation, implementation and use. This discussion arises from the knowledge gaps of each counterpart in respect to the other discipline. Projects such as Agora 3D (see below) clearly demonstrate the need for an evaluation of the different available techniques.

In order to make optimal use of these technological capabilities, it is important to identify and name the information required to best serve the reasoning processes in these application fields. Correspondingly it is necessary to know about the characteristics of digitization techniques producing the content adapted to the needs of the applications. Due to the considerable complexity of instruments and processes producing the data, it is helpful to have a clear structure which relates the capabilities of the instruments to the requirements of the applications.

The COST Action TD1201 “Colour and Space in Cultural Heritage (COSCH)” takes this need into account, aiming to enhance the understanding among these disciplines. We will focus on the already listed, structured and evaluated available 3D technologies. At the same time, experts in spectral and CH research started to list, structure, and evaluate their knowledge. These evaluations yield a structure of technologies, and ultimately the techniques and instruments using their characteristics. The understanding of these characteristics provides insights for their potential applications. The ontology knowledge model accessible through so-called “COSCHKR App” provides a knowledge structure. It benefits from the development of semantic technologies from the Semantic Web framework. Semantics, which provide meanings, are captured through the conceptual structure and are defined through the ontology. The overall aim of this ontology is the development of a software tool to enable a better understanding of data acquisition techniques and their support to optimally realize cultural heritage applications.


Towards a knowledge model bridging technologies and applications in cultural heritage documentation

2014

Boochs, F.,
Trémeau, A.,
Murphy, O.,
Gerke, M.,
Lerma, J.L.,
Karmacharya, A.,
Karaszewski, M.

BibTex

ISPRS Technical Commission V Symposium

This paper documents the formulation of an international, interdisciplinary study, on a concerted European level, to prepare an innovative, reliable, independent and global knowledge base facilitating the use of today’s and future optical measuring techniques for the documentation of  cultural heritage. Cultural heritage professionals, color engineers and scientists share similar goals for the documentation, curation, long-term preservation and representation of cultural heritage artifacts. Their focus is on accuracy in the digital capture and remediation of artefacts through a range of temporal, spatial and technical constraints. A shared vocabulary to interrogate these shared concerns will transform mutual understanding and facilitate an agreed movement forward in cultural heritage documentation here proposed in the work of the COST Action Color and Space in Cultural Heritage (COSCH). The goal is a model that captures the shared concerns of professionals for a standards-based solution with an organic Linked Data model. The knowledge representation proposed here invokes a GUI interface for non-expert users of capture technologies, facilitates, and formulates their engagement with key questions for the field.


Characterisation of Spatial Techniques for Optimised Use in Cultural Heritage Documentation.

2014

Wefers, S.,
Karmacharya, A.,
Boochs, F.,
Wiemann, A.K.

BibTex

Digital Heritage Progress in Cultural Heritage: Documentation, Preservation, and Protection. 5th International Conference, EuroMed 2014 Limassol, Cyprus, November 3-8, 2014 Proceedings

Constant technological progress results in new possibilities to produce reliable and rich spatial data of cultural heritage objects. In order to make optimal use of these capabilities, it is important to identify and name the information required to best serve the reasoning processes in these application fields. Correspondingly it is necessary to know about the characteristics of digitization techniques producing the content adapted to the needs of the applications. Due to the considerable complexity of instruments and processes producing the data, it is helpful to have a clear structure which relates the capabilities of the instruments to the requirements of the applications. This paper addresses this topic and shows a way of structuring spatial techniques as well as how this structure can be related to applications in the field of cultural heritage.


Automatic object detection in point clouds based on knowledge guided algorithms

2013

Truong, H.Q.,
Karmacharya, A.,
Mordwinzew, W.,
Boochs, F.,
Chudyk, C.,
Habed, A.,
Voisin, Y.

BibTex

SPIE Optical Metrology, International Society for Optics and Photonics, 2013

The modeling of real-world scenarios through capturing 3D digital data has been proven applicable in a variety of industrial applications, ranging from security, to robotics and to fields in the medical sciences. These different scenarios, along with variable conditions, present a challenge in discovering flexible appropriate solutions. In this paper, we present a novel approach based on a human cognition model to guide processing. Our method turns traditional data-driven processing into a new strategy based on a semantic knowledge system. Robust and adaptive methods for object extraction and identification are modeled in a knowledge domain, which has been created by purely numerical strategies. The goal of the present work is to select and guide algorithms following adaptive and intelligent manners for detecting objects in point clouds. Results show that our approach succeeded in identifying the objects of interest while using various data types.


Semantics – Supportive Element for the Cooperative Evaluation of Geographical and Historical Information

2013

Karmacharya, A.,
Kohr, T.,
Boochs, F.,
Bruhn, K.C.,
Cruz, C.

BibTex

zfv - Zeitschrift für Geodäsie, Geoinformation und Landmanagement

The emergence of the Semantic Web and its underlying knowledge technologies has brought changes in data handling. Transferring expert knowledge to machines through knowledge formalization provides us the required support in managing huge datasets like the information in the World Wide Web. In the field of geospatial technology semantic technologies not only entail the capability to achieve higher degree of data integration but also infer semantics to discover new and hidden knowledge. This is of particular interest in the field of archaeology, where complex interrelations among heterogeneous datasets exist. Although researches on semantics are active areas in geospatial communities, their initial use is mainly for spatial data integration. This article tries to go one step further and imply semantics for spatial knowledge discovery through spatial built-ins within SWRL and SPARQL. The work resembles the approach of the Open Geospatial Consortium (OGC) to define standards for ­GeoSPARQL.


Spatialization of the Semantic Web

2012

Boochs, F.,
Karmacharya, A.,
Cruz, C.,
Afzal, M.T.

PDF / BibTex

Advances in Theories and Mathematical Models

The abstraction of the real world melds the semantics of its objects with the spatial characteristics seamlessly. This is visible in a way the human perceives the real world where it is often difficult to pin point the spatial characteristics of the objects from their semantics. In other words the spatial characteristics are generally hidden with the semantics of the objects. As for example, describing relations of objects the terms near, far or touching are often used which are spatial relations but in general considered as semantic properties which is not true. Hence, it is a trend to consider that the spatial behaviors of objects are parts of its semantics. Similar approaches where the spatial properties are considered as part of semantics have been translated in technical advancements made by the technologies. There is a general trend to mix up spatial components in the semantics or the semantics in the spatial components within technologies. For instance, a classic GIS ignores semantics of objects to focus on the spatial components whereas a non GIS uses spatial components as the semantic parameters of the objects. As the technology is getting matured, it is moving closer to the human perception of the real world. Today, the knowledge management is being researched in real sense to model and to manage knowledge possessed by humans which is basically the perception of the real world.