Deficient signaling in mice devoid of double-stranded RNA-dependent protein kinase (2007)
Yang, Y. L., Reis, L. F., Pavlovic, J., Aguzzi, A., Schafer, R., Kumar, A., ...
Double-stranded RNA-dependent protein kinase (PKR) has been implicated in interferon (IFN) induction, antiviral response and tumor suppression. We have generated mice devoid of functional PKR (Pkr%)....
Hamrle, J., Blomeier, S., Gaier, O., Hillebrands, B., Schafer, R., Jourdan, M.
Magnetic anisotropies and magnetization reversal properties of the epitaxial Heusler compound Co$_2$Cr$_{0.6}$Fe$_{0.4}$Al (CCFA) deposited on Fe and Cr buffer layers are studied. Both samples...
DXB-a system concept for the mobile broadcast services of tomorrow (2006)
Two standards for the transfer of television signals to mobile units are currently being evaluated in Germany: 1. DVB-H (handheld) conceptually derived from digital television DVB-T (terrestrial). 2....
ACCELERATED RELIABILITY TESTING FOR NONELECTRONIC PARTS. (2005)
This study was conducted to develop techniques to reduce test time, sample size and cost involved in the demonstration of the reliability of long lived nonelectronic parts. It was also the purpose of...
Video compression for integrated digital video broadcasting (DVB-H) (2005)
Schierl, T., Suhring, K., Wiegand, T., Schafer, R., Schwiertz, J., Zurek-Terhard, G.
This paper discusses the integrated DVB-H video playout systems with efficient compression. Reports on a project ISyP to study digital video transmission (DVB-H) capacities. This paper reviews video...
High definition television (HDTV): Markets and applications (2000)
Anticipates the co-existence of various generations of TV formats, and refers to the availability of flat displays, low cost HDTV integrated circuits and the need for displaying sport and...
Improving image compression - is it worth the effort? (2000)
Schafer, R., Heising, G., Smolic, A.
This paper presents some arguments in favour of further research in video compression because of scarce spectrum resources for mobile applications and the lack of powerful tools for scalable coding....
MPEG-4: A multimedia compression standard for interactive applications and services (1998)
The Moving Pictures Experts Group (MPEG), which produced the MPEG-1 and MPEG-2 video and audio compression standards, is developing the MPEG-4 standard. MPEG-4 targets interactive multimedia...
Multimedia communication on integrated networks and terminals-the MINT Project results (1998)
Presents a short overview of the overall project "Multimedia communication on integrated networks and terminals (MINT)" sponsored by the Ministry for Education, Science, Research and...
Cooperating to Be Noncooperative: The Dialog System PRACMA (1997)
A. Jameson, A. Ndiaye, R. Schafer, J. Simons, T. Weis, D. Zimmermann
. The modeling of noncooperative dialogs, as opposed to dialogs in which the goals of the participants coincide, presents novel challenges to a pragmatically oriented dialog system. PRACMA models...
Cooperating to Be Noncooperative: The Dialog System PRACMA (1997)
A. Jameson, A. Ndiaye, R. Schafer, J. Simons, T. Weis, D. Zimmermann
. The modeling of noncooperative dialogs, as opposed to dialogs in which the goals of the participants coincide, presents novel challenges to a pragmatically oriented dialog system. PRACMA models...
Cooperating to Be Noncooperative: The Dialog System PRACMA (1997)
A. Jameson, A. Ndiaye, R. Schafer, J. Simons, T. Weis, D. Zimmermann
. The modeling of noncooperative dialogs, as opposed to dialogs in which the goals of the participants coincide, presents novel challenges to a pragmatically oriented dialog system. PRACMA models...
Cooperating to Be Noncooperative: The Dialog System PRACMA (1997)
A. Jameson, A. Ndiaye, R. Schafer, J. Simons, T. Weis, D. Zimmermann
. The modeling of noncooperative dialogs, as opposed to dialogs in which the goals of the participants coincide, presents novel challenges to a pragmatically oriented dialog system. PRACMA models...
Cooperating to Be Noncooperative: The Dialog System PRACMA (1997)
A. Jameson, A. Ndiaye, R. Schafer, J. Simons, T. Weis, D. Zimmermann
. The modeling of noncooperative dialogs, as opposed to dialogs in which the goals of the participants coincide, presents novel challenges to a pragmatically oriented dialog system. PRACMA models...
MPEG-4: A new data compression standard for interactive applications and services (1997)
MPEG-4 is to standardize interactive multimedia applications, including image manipulation, storage and transmission, for bit rates up to 4 Mbit/sec. Interactive graphical applications of MPEG-2 are...
MPEG-2 video coding with an adaptive selection of scanning path and picture structure (1996)
Zhou, M., De Lameillieure, J., Schafer, R.
In MPEG-2 video coding an interlaced frame can be encoded as either a frame-picture or two field-pictures. The selection of picture structure (frame/field) has a strong impact on picture quality. In...
The status of HDTV in Europe (1996)
High-definition television (HDTV) has been intensively developed in Europe since the early '80s, but no regular service has been started. The author reviews some ongoing European R & D...
Cooperating to Be Noncooperative: The Dialog System PRACMA (1995)
A. Jameson, A. Ndiaye, R. Schafer, J. Simons, T. Weis, D. Zimmermann
. The modeling of noncooperative dialogs, as opposed to dialogs in which the goals of the participants coincide, presents novel challenges to a pragmatically oriented dialog system. PRACMA models...
Cooperating to Be Noncooperative: The Dialog System PRACMA (1995)
A. Jameson, A. Ndiaye, R. Schafer, J. Simons, T. Weis, D. Zimmermann
. The modeling of noncooperative dialogs, as opposed to dialogs in which the goals of the participants coincide, presents novel challenges to a pragmatically oriented dialog system. PRACMA models...
Cooperating to Be Noncooperative: The Dialog System PRACMA (1995)
A. Jameson, A. Ndiaye, R. Schafer, J. Simons, T. Weis, D. Zimmermann
. The modeling of noncooperative dialogs, as opposed to dialogs in which the goals of the participants coincide, presents novel challenges to a pragmatically oriented dialog system. PRACMA models...
Digital video coding standards and their role in video communications (1995)
The efficient digital representation of image and video signals has been subject of considerable research over the past 20 years. With the growing availability of digital transmission links, progress...
Schafer, R., De Lameillieure, J.
In the German collaborative project "hierarchical digital television transmission-HDTVT" an integrated broadcast system for TV and HDTV over satellite, cable and terrestrial channels is...
Mobile telecommunication is a rapidly growing market. Second generation systems such as GSM, DECT and ERMES, which are actually in an evolving status will be replaced by the third generation UMTS...
Recent advances in digital transmission of HDTV (1993)
This paper reviews some of the latest developments in image compression. Besides a description of the coding schemes of already implemented systems or systems under development, it focuses on...
Flexible bit rate coding for satellite transmission of HDTV (1993)
Guillemot, C., Guirao, F., Perron, C., Schafer, R., Stierle, H.
Describes coding schemes for HDTV with flexible bit rates between 34 and 70 Mbit/s. DCT and subband schemes have been investigated and compared and finally a DCT scheme based on a modified ETSI-codec...
A codec for digital studio recording of HDTV (1992)
Kauff, P., Stammnitz, P., Schafer, R.
The digital recorder is one of the most important components in the HDTV studio. However, the main problem of digital HDTV recording is the enormous tape consumption, which is given by the high bit...
A comparison of different HDTV-standards using subjective and objective criteria (1990)
Schafer, R., Chen, S.C., Kauff, P., Leptin, M.
Progressive or sequential scan (HDP) has been proposed by the EUREKA 95 project for worldwide production and program exchange. However technology seems not yet ready for this standard and therefore...
Colorimetry and constant luminance coding in a compatible HDMAC system (1988)
Chen, S.C., Goff, F.Le., Melwig, R., Schafer, R.
The authors consider the establishment of a new colorimetric standard due to the advent of HDTV, and discuss the parameters to be reconsidered. Constant luminance coding is described, and nonlinear...
Considerations on new primaries for high definition television (1988)
A constant-luminance-coding (CIELAB) codec is presented for high-definition TV (HDTV) use that offers the possibility of enlarging the reproducible color TV spectrum by selecting a new set of primary...
Technical solutions for a sequential HDTV-production standard with todays technology (1987)
Schafer, R., Kauff, P., Chen, S.C.
The authors discuss the problems of sequential scanning and present a 4-channel camera-system which avoids these problems. A signal format for storing sequentially scanned HDTV signals without...
HDTV colorimetry and gamma considering the visibility of noise and quantization errors (1987)
Three methods of color processing for HDTV-conventional, linear, and CIELAB coding-have been investigated, considering different color primaries, different characteristics for precorrection, and the...
Schafer, R., Kauff, P., Golz, U.
The conventional method of generation and processing color components causes image defects, which can be avoided in a future HDTV-system: loss of sharpness and resolution by violation of the constant...
High-definition television production standard-an opportunity for optimal color processing (1985)
To justify the enormous investments necessary to establish a new HDTV system, the gain in quality over enhanced TV, based on the digital standard for studios (CCIR Rec. 601), must be substantial. The...
Several DPCM Coding schemes for the chrominance components were investigated with regard to their suitability to the transmission of broadband TV signals at 34 Mbits/s. While luminance adaptive...
Design of adaptive and nonadaptive quantizers using subjective criteria (1983)
Several properties of visual masking have been investigated with a view to their application to adaptive quantization in DPCM-coding. Quantization characteristics for adaptive and nonadaptive...
Optical transmission of 16 digitized TV-channels (1979)
Baack, C., Elze, G., Enning, B., Feddersen, E., Heydt, G., Knupke, H., ...
16 digitized TV channels will be transmitted with an optical link at a pulse rate of 1.12 Gb/s using a graded-index fiber of 3 km length.
Natural killer cells mediate protection induced by a Salmonella aroA mutant.
We have previously shown that an avirulent strain of Salmonella typhimurium, SL3235, blocked in aromatic synthesis, confers high levels of resistance to challenge with virulent Salmonella as early as...
Tarleton, R L, Schafer, R, Kuhn, R E
Extracts of epimastigotes of Trypanosoma cruzi were examined for the ability to augment or suppress in vivo and in vitro responses of mouse spleen cells. When administered to mice 4 days before...
Bravo, R, Schafer, R, Willecke, K, MacDonald-Bravo, H, Fey, S J, Celis, J E
Gene expression at the level of polypeptide synthesis has been investigated in a somatic cell hybrid (20 BW-4) isolated after fusion of spontaneously transformed, tumorigenic Chinese hamster lung...
Natural killer cells mediate protection induced by a Salmonella aroA mutant.
We have previously shown that an avirulent strain of Salmonella typhimurium, SL3235, blocked in aromatic synthesis, confers high levels of resistance to challenge with virulent Salmonella as early as...
Tarleton, R L, Schafer, R, Kuhn, R E
Extracts of epimastigotes of Trypanosoma cruzi were examined for the ability to augment or suppress in vivo and in vitro responses of mouse spleen cells. When administered to mice 4 days before...
Bravo, R, Schafer, R, Willecke, K, MacDonald-Bravo, H, Fey, S J, Celis, J E
Gene expression at the level of polypeptide synthesis has been investigated in a somatic cell hybrid (20 BW-4) isolated after fusion of spontaneously transformed, tumorigenic Chinese hamster lung...