--- _id: '5617' abstract: - lang: eng text: CAPTCHAs are challenge-response tests that aim at preventing unwanted machines, including bots, from accessing web services while providing easy access for humans. Recent advances in artificial-intelligence based attacks show that the level of security provided by many state-of-the-art text-based CAPTCHAs is declining. At the same time, techniques for distorting and obscuring the text, which are used to maintain the level of security, make text-based CAPTCHAs diffcult to solve for humans, and thereby further degrade usability. The need for developing alternative types of CAPTCHAs which improve both, the current security and usability levels, has been emphasized by several researchers. With this study, we contribute to research through (1) the development of two new face recognition CAPTCHAs (Farett-Gender and Farett-Gender&Age), (2) the security analysis of both procedures, and (3) the provision of empirical evidence that one of the suggested CAPTCHAs (Farett-Gender) is similar to Google's reCAPTCHA and better than KCAPTCHA concerning effectiveness (error rates), superior to both regarding learnability and satisfaction but not effciency. author: - first_name: Guido full_name: Schryen, Guido id: '72850' last_name: Schryen - first_name: Gerit full_name: Wagner, Gerit last_name: Wagner - first_name: Alexander full_name: Schlegel, Alexander last_name: Schlegel citation: ama: 'Schryen G, Wagner G, Schlegel A. Development of two novel face-recognition CAPTCHAs: a security and usability study. Computers & Security. 2016;60(July):95-116.' apa: 'Schryen, G., Wagner, G., & Schlegel, A. (2016). Development of two novel face-recognition CAPTCHAs: a security and usability study. Computers & Security, 60(July), 95–116.' bibtex: '@article{Schryen_Wagner_Schlegel_2016, title={Development of two novel face-recognition CAPTCHAs: a security and usability study}, volume={60}, number={July}, journal={Computers & Security}, publisher={Elsevier}, author={Schryen, Guido and Wagner, Gerit and Schlegel, Alexander}, year={2016}, pages={95–116} }' chicago: 'Schryen, Guido, Gerit Wagner, and Alexander Schlegel. “Development of Two Novel Face-Recognition CAPTCHAs: A Security and Usability Study.” Computers & Security 60, no. July (2016): 95–116.' ieee: 'G. Schryen, G. Wagner, and A. Schlegel, “Development of two novel face-recognition CAPTCHAs: a security and usability study,” Computers & Security, vol. 60, no. July, pp. 95–116, 2016.' mla: 'Schryen, Guido, et al. “Development of Two Novel Face-Recognition CAPTCHAs: A Security and Usability Study.” Computers & Security, vol. 60, no. July, Elsevier, 2016, pp. 95–116.' short: G. Schryen, G. Wagner, A. Schlegel, Computers & Security 60 (2016) 95–116. date_created: 2018-11-14T14:00:47Z date_updated: 2022-01-06T07:02:10Z ddc: - '000' department: - _id: '277' extern: '1' file: - access_level: open_access content_type: application/pdf creator: hsiemes date_created: 2018-12-07T11:38:19Z date_updated: 2018-12-13T15:07:36Z file_id: '6029' file_name: cose_991_final.pdf file_size: 2983143 relation: main_file file_date_updated: 2018-12-13T15:07:36Z has_accepted_license: '1' intvolume: ' 60' issue: July keyword: - CAPTCHA - Usability - Facial features - Gender classiffcation - Age classification - Face recognition reverse Turing test language: - iso: eng oa: '1' page: 95-116 publication: Computers & Security publisher: Elsevier status: public title: 'Development of two novel face-recognition CAPTCHAs: a security and usability study' type: journal_article user_id: '61579' volume: 60 year: '2016' ... --- _id: '11892' abstract: - lang: eng text: For an environment to be perceived as being smart, contextual information has to be gathered to adapt the system's behavior and its interface towards the user. Being a rich source of context information speech can be acquired unobtrusively by microphone arrays and then processed to extract information about the user and his environment. In this paper, a system for joint temporal segmentation, speaker localization, and identification is presented, which is supported by face identification from video data obtained from a steerable camera. Special attention is paid to latency aspects and online processing capabilities, as they are important for the application under investigation, namely ambient communication. It describes the vision of terminal-less, session-less and multi-modal telecommunication with remote partners, where the user can move freely within his home while the communication follows him. The speaker diarization serves as a context source, which has been integrated in a service-oriented middleware architecture and provided to the application to select the most appropriate I/O device and to steer the camera towards the speaker during ambient communication. author: - first_name: Joerg full_name: Schmalenstroeer, Joerg id: '460' last_name: Schmalenstroeer - first_name: Reinhold full_name: Haeb-Umbach, Reinhold id: '242' last_name: Haeb-Umbach citation: ama: Schmalenstroeer J, Haeb-Umbach R. Online Diarization of Streaming Audio-Visual Data for Smart Environments. IEEE Journal of Selected Topics in Signal Processing. 2010;4(5):845-856. doi:10.1109/JSTSP.2010.2050519 apa: Schmalenstroeer, J., & Haeb-Umbach, R. (2010). Online Diarization of Streaming Audio-Visual Data for Smart Environments. IEEE Journal of Selected Topics in Signal Processing, 4(5), 845–856. https://doi.org/10.1109/JSTSP.2010.2050519 bibtex: '@article{Schmalenstroeer_Haeb-Umbach_2010, title={Online Diarization of Streaming Audio-Visual Data for Smart Environments}, volume={4}, DOI={10.1109/JSTSP.2010.2050519}, number={5}, journal={IEEE Journal of Selected Topics in Signal Processing}, author={Schmalenstroeer, Joerg and Haeb-Umbach, Reinhold}, year={2010}, pages={845–856} }' chicago: 'Schmalenstroeer, Joerg, and Reinhold Haeb-Umbach. “Online Diarization of Streaming Audio-Visual Data for Smart Environments.” IEEE Journal of Selected Topics in Signal Processing 4, no. 5 (2010): 845–56. https://doi.org/10.1109/JSTSP.2010.2050519.' ieee: 'J. Schmalenstroeer and R. Haeb-Umbach, “Online Diarization of Streaming Audio-Visual Data for Smart Environments,” IEEE Journal of Selected Topics in Signal Processing, vol. 4, no. 5, pp. 845–856, 2010, doi: 10.1109/JSTSP.2010.2050519.' mla: Schmalenstroeer, Joerg, and Reinhold Haeb-Umbach. “Online Diarization of Streaming Audio-Visual Data for Smart Environments.” IEEE Journal of Selected Topics in Signal Processing, vol. 4, no. 5, 2010, pp. 845–56, doi:10.1109/JSTSP.2010.2050519. short: J. Schmalenstroeer, R. Haeb-Umbach, IEEE Journal of Selected Topics in Signal Processing 4 (2010) 845–856. date_created: 2019-07-12T05:30:16Z date_updated: 2023-10-26T08:10:18Z department: - _id: '54' doi: 10.1109/JSTSP.2010.2050519 intvolume: ' 4' issue: '5' keyword: - audio streaming - audio visual data streaming - context information speech - face identification - face recognition - image segmentation - middleware - multimodal telecommunication - online diarization - service oriented middleware architecture - sessionless telecommunication - software architecture - speaker identification - speaker localization - speaker recognition - steerable camera - telecommunication computing - temporal segmentation - terminal-less telecommunication - video streaming language: - iso: eng main_file_link: - open_access: '1' url: https://groups.uni-paderborn.de/nt/pubs/2010/ScHa10.pdf oa: '1' page: 845-856 publication: IEEE Journal of Selected Topics in Signal Processing quality_controlled: '1' status: public title: Online Diarization of Streaming Audio-Visual Data for Smart Environments type: journal_article user_id: '460' volume: 4 year: '2010' ...