2,001 research outputs found
Evaluation of binocular eye trackers and algorithms for 3D gaze interaction in virtual reality environments
No full textPfeiffer T, Latoschik ME, Wachsmuth I. Evaluation of binocular eye trackers and algorithms for 3D gaze interaction in virtual reality environments. JVRB - Journal of Virtual Reality and Broadcasting. 2008;5(16):1660.Tracking user's visual attention is a fundamental aspect in novel human-computer interaction paradigms found in Virtual Reality. For example, multimodal interfaces or dialogue-based communications with virtual and real agents greatly benefit from the analysis of the user's visual attention as a vital source for deictic references or turn-taking signals. Current approaches to determine visual attention rely primarily on monocular eye trackers. Hence they are restricted to the interpretation of two-dimensional fixations relative to a defined area of projection. The study presented in this article compares precision, accuracy and application performance of two binocular eye tracking devices. Two algorithms are compared which derive depth information as required for visual attention-based 3D interfaces. This information is further applied to an improved VR selection task in which a binocular eye tracker and an adaptive neural network algorithm is used during the disambiguation of partly occluded objects
Managing Technology Risks Through Technological Proficiency: Guidance for Local Governments
No full textLike most organizations, local governments face challenges managing technology, the critical resource to meet evolving public service expectations. But benefits associated with adapting the latest technology come with risks, some more apparent than others.
This report details the problems facing municipal officials as they try to maximize the benefits of technology for their communities and constituents in the face of cybersecurity, legal, operational, financial, reputational and societal risks.
The report concludes that top municipal officials must create and maintain an environment of “technological proficiency.” That includes creating a process for making technology decisions, developing an annually reviewed technology plan that is tied to the budget, instituting a “cyber hygiene” training program for all employees in proper computer security practices, and making sure that agency technology is competently managed.
The report is supplemented by a "Best Practices and Resources Guide" that organizations can use to achieve technology proficiency. It provides best practices based on an organization's technology profile.Report and Supplement were prepared for the Municipal Excess Liability Fund, a joint insurance fund of over 600 New Jersey local government agencies
Anselm C. Hagedorn, Henrik Pfeiffer (éd.), Die Erzväter in der biblischen Tradition. Festschrift für Matthias Köckert, (Beihefte zur Zeitschrift für die alttestamentliche Wissenschaft, 400) Berlin – New York, Walter de Gruyter, 2009
No full textHunziker-Rodewald Regine. Anselm C. Hagedorn, Henrik Pfeiffer (éd.), Die Erzväter in der biblischen Tradition. Festschrift für Matthias Köckert, (Beihefte zur Zeitschrift für die alttestamentliche Wissenschaft, 400) Berlin – New York, Walter de Gruyter, 2009. In: Revue d'histoire et de philosophie religieuses, 90e année n°3, Juillet-Septembre 2010. pp. 382-383
Orion Aft Side Thermal Protection (XTP) Subsystem - Challenges, Design and Implementation
No full textMatthias Pfeiffer, Airbus Defence and Space GmbH, GermanyDirk Labuhn, Airbus Defence and Space GmbH, GermanyPatrick Oger, Airbus Defence and Space GmbH, GermanyICES103: Thermal Control of Commercial and Exploration
Spacecraft and Surface HabitatsThe 54th International Conference on Environmental Systems was held in Prague, Czechia, on 13 July 2025 through 17 July 2025.The European Service Module (ESM) for the Orion spacecraft
is equipped with high-thrust engines on its aft side, which
generate significant heat loads during prolonged firing.
This paper addresses the technical challenges associated
with managing these heat loads, including the distribution
of heat across the ESM and the selection of appropriate
thermal protection technologies. It details the systems
implemented to sustain these extreme conditions, focusing
on the integration and performance of the thermal
protection in the context of the ESM 1 and 2. The
discussion highlights key design decisions, lessons
learned, and the effectiveness of the chosen solutions in
ensuring the thermal integrity of the ESM during mission
operations
Why people with disabilities might really be leaving work : an exemplar case with lessons for managers
No full textThe author explores the 'silent' problem of unseen illness at work
Dezentrale Nutzung von partiell aufbereitetem Biogas als Kraftstoff für landwirtschaftliche Fahrzeuge
No full textParachondria (Chondropomorus) caricae Pfeiffer 1858
No full textParachondria (Chondropomorus) caricae (Pfeiffer, 1858) Figures 1 P–W, 5 A Type material. Chondropoma caricae Pfeiffer, 1858: not located. Chondropoma (Chondropomorus) caricae navarretense Bartsch, 1946: NMNH 471990 (2 specimens in lot, holotype listed as 12.2 mm long specimen). Chondropoma (Chondropomorus) caricae sosuense Bartsch, 1946: NMNH 336770, holotype. Type locality. Chondropoma caricae Pfeiffer, 1858: “ Prope Santiago insulae Haiti.” Chondropoma (Chondropomorus) caricae navarretense Bartsch, 1946: “Above Navarrete Station on the railroad running from Puerto Plata to Santiago, Dominican Republic.” See Distribution below. Chondropoma (Chondropomorus) caricae sosuense Bartsch, 1946: “At Sosúa, 17 miles east of Puerto Plata, Dominican Republic.” Type figured. Chondropoma caricae Pfeiffer, 1858: unfigured. Chondropoma (Chondropomorus) caricae navarretense Bartsch, 1946: Bartsch, 1946: pl. 3, fig. 5. C hondropoma (Chondropomorus) caricae sosuense Bartsch, 1946: Bartsch, 1946: pl. 3, fig. 4. Chresonymy. Chondropoma caricae Pfeiffer in Hjalmarson & Pfeiffer, 1858: 142; Bland, 1861: 355; Pfeiffer, 1865: 156–157; Pfeiffer, 1876: 196; Kobelt, 1880: 277; Crosse, 1891: 174; Watters, 2006: 192–193. Chondropoma (Chondropomorus) caricae Pfeiffer, 1858. Henderson & Bartsch, 1920: 61; Clench & Aguayo, 1937: 65. Chondropoma (Chondropomorus) caricae caricae Pfeiffer, 1858. Bartsch, 1946: 20 –22, pl. 3, fig. 2. Chondropoma (Chondropomorus) caricae navarretense Bartsch, 1946: 21 –22, pl. 3, fig. 5; Ruhoff, 1973: 102; Watters, 2006: 193. Chondropoma (Chondropomorus) caricae sosuense Bartsch, 1946: 20 –21, pl. 3, fig. 4; Ruhoff, 1973: 128; Watters, 2006: 193. Parachondria (Parachondria) caricae caricae (Pfeiffer, 1858). Watters, 2006: 46, 192– 193. Parachondria (Parachondria) caricae navarretensis (Bartsch, 1946). Watters, 2006: 46, 193. Parachondria (Parachondria) caricae sosuensis (Bartsch, 1946). Watters, 2006: 46, 193. Distribution and habitat. Authors have identified the habitat of this species as living on papaya trees (Pfeiffer in Hjalmarson & Pfeiffer, 1858; 1865; Crosse, 1891). Pfeiffer (in Hjalmarson & Pfeiffer, 1958: 142) specifically reported specimens “under fallen leaves on the roots of Carica papaya, usually in pairs” (translated here from German). However, papayas are not native to Hispaniola and other records place this species on limestone outcrops in evergreen forests. There are very few records of this species and its actual range is unknown. It is currently known only from the vicinity of Santiago de Los Caballeros in Santiago Province and from Puerto Plata and Sosúa in Puerto Plata Province. Bartsch’s type locality description of C. c. navarretense is somewhat misleading. He implied that Navarrete Station was on the railroad between Puerto Plata and Santiago. Navarrete is now called Bisonó and is located on the railroad that runs from Puerto Plata through Santiago to Bisonó some 25 km further west. It is located in the Cibao Valley between the Cordillera Central and the Cordillera Septentrional. Material examined (17 specimens). Dominican Republic. OSUM 22087 (2), Tacagera [not located], Santiago Province; UF 216562 (15), 3 km W of Puerto Plata, Puerto Plata Province. Redescription. Shell solid, opaque, high-spired, elongate conic. Maximum adult size: 16.1 mm, decollate. Minimum adult size: 9.9 mm, decollate. Adult shell decollated. Protoconch of 1.5 pale tan, smooth whorls. Teleoconch of 4.25–5.25 whorls. Axial sculpture of final whorl of numerous (ca. 100–120) very fine, narrowly spaced, weak threads of varying width. Growth stoppage lines usually present. Spiral sculpture of final whorl outside of umbilicus of ca. 20–30 irregularly sized, weak threads, widely spaced near suture, narrowly spaced elsewhere. Intersections of sculpture form very weak, axially elongated beads. Overall sculpture appearing as weak, irregular fenestrations or scallops. Umbilicus smooth within or with few very indistinct threads. Suture indented but not channeled. 1–3 threads are narrowly expanded at suture into sharp denticles or cusps; these are irregularly spaced. Aperture oval, lip double. Inner lip slightly exserted, thickened. Outer lip thickened, narrowly expanded, except narrower facing umbilicus, slightly recurved abaperturally. Adnate or narrowly detached from body whorl within same population. Weak posterior auricle broad and low. Color pattern pale and not well-defined. Base color off-white or tan. Smudged, pale tan and white axial zig-zags or dots that mark leading edge of growth stoppage areas; bands continue as brown bands on both sides of outer lip, tending to few narrow, weak spiral bands near umbilicus; umbilicus without bands. Beads and sutural denticles white. Operculum paucispiral with granular deposit. Variation in specimens. The few specimens seen differ primarily in having the outer lip either adnate or narrowly detached from the previous whorl. Specimens with a solute outer lip were named C. c. sosuense Bartsch, 1946, but this feature occurs along with adnate outer lipped individuals in a single population. Bartsch (1946) also named C. c. navarretense for specimens having fine sculpture but this is also a variable characteristic. Comparison with other species. This small, pale species is most similar to P. s i l v at i c u s. That species differs in its much coarser sculpture: 70–80 axial threads in P. silvaticus vs. 100–120 threads in P. caricae; 14–16 spiral threads in P. silvaticus vs. 20–30 threads in P. caricae. Remarks. Although the description appeared in Hjalmarson & Pfeiffer (1858) the species was listed as “ Chondropoma Caricae Pfr. ” and Pfeiffer is considered the sole author of the taxon. The species was not figured by Pfeiffer and the type has not been located. Bartsch (1946) identified his specimens based on the locality and the brief description given by Pfeiffer. This is reasonable as this is one of the few members of the complex recorded near Santiago and the description adequately matches Bartsch’s specimens. Original descriptions. Chondropoma caricae Pfeiffer, 1858. Pfeiffer in Hjalmarson & Pfeiffer (1858: 142) (translated here from Latin): “Shell slightly perforate, oblong-turret, solid, spiral raised lines and longitudinally subequally granular-decussated, pale brown, red spots and white variegated streaks; spire regularly narrowed, truncate; suture irregularly and widely crenulated; remaining 5 whorls convex, last not solute; aperture vertical, subangulate-oval; peristome double: inner slightly prominent, outer produced on top, right side shortly expanded, left obsolete.—Operculum flat, cartilaginous.” Chondropoma (Chondropomorus) caricae navarretense Bartsch, 1946: See Bartsch (1946: 21–22). Chondropoma (Chondropomorus) caricae sosuense Bartsch, 1946: See Bartsch (1946: 20–21). Etymology. Chondropoma caricae Pfeiffer, 1858: L. carica, fig or papaya [“ Ad radicae Caricae Papayae,” fide Pfeiffer, 1865: 156–157]. Chondropoma (Chondropomorus) caricae navarretense Bartsch, 1946: Navarrete Station, Dominican Republic. Chondropoma (Chondropomorus) caricae sosuense Bartsch, 1946: Sosúa, Dominican Republic.Published as part of Watters, G. Thomas, 2016, Review of the Hispaniolan Parachondria (Chondropomorus) complex (Gastropoda: Littorinoidea: Annulariidae), pp. 245-275 in Zootaxa 4127 (2) on pages 250-251, DOI: 10.11646/zootaxa.4127.2.2, http://zenodo.org/record/27177
Dietmar K. Pfeiffer / Carsten Püttmann: Methoden empirischer Forschung in der Erziehungswissenschaft. Eine Einführung. Münster: Waxmann 2018 (220 S.) [Rezension]
No full textRezension von: Dietmar K. Pfeiffer / Carsten Püttmann: Methoden empirischer Forschung in der Erziehungswissenschaft. Eine Einführung. Münster: Waxmann 2018 (220 S.; ISBN 978-3-8309-3848-4; 19,90 EUR)
How Dr. Ehrenfried Pfeiffer Contributed to Organic Agriculture in Australia
No full textEhrenfried Pfeiffer (1899-1961) was 25 years old when Rudolf Steiner (1861-1925) delivered his eight lectures on agriculture from 7th June to 16th June 1924. In those eight lectures at Koberwitz, Rudolf Steiner laid the basis for biodynamic agriculture. Steiner advocated an agriculture informed by anthroposophy, and that the ideas he expounded in the eight agriculture lectures should be developed by experiments, practice and observation. Ehrenfried Pfeiffer took up this task and he spent the rest of his life in the pursuit. Pfeiffer published his book ‘Bio-Dynamic Farming and Gardening’ in 1938. It was the first popular account of bio-dynamic agriculture. In that book Pfeiffer presented the practical results of more than a decade of farming practice and experimentation. Pfeiffer was a major contributor to Australia’s first organic farming journal, the 'Organic Farming Digest' (1946-1955); he was the leading contributing author from the USA. Pfeiffer's lecture tour to Australia planned for 1953, and visiting the states of NSW, Victoria, and South Australia, was cancelled at short notice due to his ill health
- …
