bluuebunny/crossref_metadata_2025 huggingface dataset:
The effects of different forms of feedback on fuzzy and verbatim memory of science principles
Authors: Clariana Roy B. , Koul Ravinder
Published: May 2006

Background. Previous models of the effects of feedback account for lower‐order learning outcomes but do not adequately describe experimental findings for higher‐order learning.

Aims. Based on a connectionist model of feedback effects, this investigation aims to show that feedback that allows only one learner response facilitates proposition‐specific verbatim encoding, while feedback that requires the learner to try again on error facilitates relational fuzzy encoding.

Sample and methods. Volunteer high school students were randomly assigned to one of 5 print‐based lesson treatments that consisted of four science expository texts with adjunct inference‐level questions covering science principles. The five treatments included delayed feedback, single‐try immediate feedback, multiple‐try immediate feedback, and two control treatments, questions without feedback, and text only. A post‐test given 5 days after instruction was designed to measure both verbatim and fuzzy outcomes.

Results. Multiple‐try immediate feedback was best for paraphrased post‐test questions (fuzzy) and worse for verbatim post‐test questions.

Conclusions. Fuzzy trace theory complements a connectionist model of feedback, and may provide a fruitful approach for describing the effects of feedback on different learning outcomes.
Confirmatory factor analysis of the Approaches to Teaching Inventory
Authors: Prosser Michael , Trigwell Keith
Published: May 2006

Background. The Approaches to Teaching Inventory (ATI) was developed to explore the relationship between students' approaches to learning, and teachers' approaches to teaching, in the physical sciences in higher education. It is increasingly being used in other contexts.

Aim. To analyse the factor structure of the ATI.

Method. Confirmatory factor analysis.

Sample. Inventory responses from over 1,000 university teachers, from 4 different countries and a wide range of disciplines, experience, and teaching level (year of students' study) were used as the sample.

Results. Cronbach's alpha values of the 2‐scale inventory were acceptable for scale reliability, but not for the 4‐scale structure. A good fit to the intended 2‐factor structure was obtained by confirmatory factor analysis. Both Information transmission/teacher‐focused and conceptual change/student‐focused scales had well identified intention and strategy subscales.

Conclusion. The ATI has been developed as a relational indicator of 2 dimensions of approaches to teaching. It is not intended for use in gathering a full, rich self‐report of teaching, or in non‐relational contexts. However, it has now been used in a number of different contexts, including different subject areas and cultures. There is evidence in this paper that in those contexts its factor structure is, in the main, consistent with the original design. This analysis also suggests ways that the ATI could be improved.
Royal French Women in the Ottoman Sultans' Harem: The Political Uses of Fabricated Accounts from the Sixteenth to the Twenty-first Century
Authors: Isom-Verhaaren Christine
Published: May 2006

The Ottoman sultans' harem has provided fertile ground for the invention of tales that have been incorporated into the historical tradition. The purported presence of royal French women in the harem has been used for political purposes since the sixteenth century. These tales fall into two groups: myths about a fictional fifteenth-century French princess and fantasies concerning Nakshidil, a nineteenth-century valide sultan who some authors claim was a relative of Napoleon's wife Josephine. The earlier myths explained the alliance between the Ottoman sultan and the king of France. Fables about Nakshidil have come to symbolize the oppression of women by Islam.
American Missionaries and the Opium Trade in Nineteenth-Century China
Authors: Lazich Michael C
Published: May 2006

America's earliest missionaries to China in the mid-nineteenth century played a key role in the formulation of early Sino-American relations. This paper explores the changing influence missionaries had on American policy toward the opium trade as reflected in the provisions of the Treaty of Wangxia (1844) and the American Treaty of Tianjin (1858). As missionary attitudes toward the opium issue shifted in a subtle but significant manner in the years following the Opium War, so too did the official position of the American government as embodied in the provisions of these treaties and supplemental commercial agreements.
Homo sapiens Populates the Earth: A Provisional Synthesis, Privileging Linguistic Evidence
Authors: Manning Patrick
Published: May 2006

Information on historical linguistics can make a substantial contribution to the understanding of early migrations of Homo sapiens within Africa and throughout the world. This essay summarizes the distribution of language groups around the world and applies basic techniques for analyzing the paths of migration associated with language evolution. The analysis relies on the approach of Joseph H. Greenberg to language classification, but it also reviews the continuing differences among linguists on the classification of languages and calls for more study to resolve those differences. The interpretation distinguishes between an initial human colonization of the tropics along Indian Ocean shores and a later occupation of temperate Eurasia and the Americas.
To Capture a Face: A Novel Technique for the Analysis and Quantification of Facial Expressions in American Sign Language
Authors: Grossman Ruth B , Shepard-Kegl Judy Anne
Published: May 2006

American Sign Language uses the face to express vital components of grammar in addition to the more universal expressions of emotion. The study of ASL facial expressions has focused mostly on the perception and categorization of various expression types by signing and nonsigning subjects. Only a few studies of the production of ASL facial expression exist, and those rely mainly on descriptions and comparisons of individual sentences. The purpose of this article is to present a novel and multilevel approach for the coding and quantification of ASL facial expressions. The technique combines ASL coding software with novel postcoding analyses that allow for graphic depictions and group comparisons of the different facial expression types. This system enables us to clearly delineate differences in the production of otherwise similar facial expression types.
How Many People Use ASL in the United States? Why Estimates Need Updating
Authors: Mitchell Ross E , Young Travas A , Bachleda Bellamie , Karchmer Michael A
Published: May 2006

This article traces the sources of the estimates of the number of American Sign Language users in the United States. A variety of claims can be found in the literature and on the Internet, some of which have been shown to be unfounded but continue to be cited. In our search for the sources of the various (mis)understandings, we have found that all of the data-based estimates of the number of people who use ASL in the United States have their origin in a single study published in the early 1970s, which inquired about signing in general and not ASL use in particular. There has been neither subsequent research to update these estimates nor any specific study of ASL use. The article concludes with a call to action to rectify this problem.
Inferring Population Parameters From Single-Feature Polymorphism Data
Authors: Jiang Rong , Marjoram Paul , Borevitz Justin O , Tavaré Simon
Published: May 2006

This article is concerned with a statistical modeling procedure to call single-feature polymorphisms from microarray experiments. We use this new type of polymorphism data to estimate the mutation and recombination parameters in a population. The mutation parameter can be estimated via the number of single-feature polymorphisms called in the sample. For the recombination parameter, a two-feature sampling distribution is derived in a way analogous to that for the two-locus sampling distribution with SNP data. The approximate-likelihood approach using the two-feature sampling distribution is examined and found to work well. A coalescent simulation study is used to investigate the accuracy and robustness of our method. Our approach allows the utilization of single-feature polymorphism data for inference in population genetics.
Cumulative Mutations Affecting Sterol Biosynthesis in the Yeast Saccharomyces cerevisiae Result in Synthetic Lethality That Is Suppressed by Alterations in Sphingolipid Profiles
Authors: Valachovic Martin , Bareither Bart M , Bhuiyan M Shah Alam , Eckstein James , Barbuch Robert , Balderes Dina , Wilcox Lisa , Sturley Stephen L , Dickson Robert C , Bard Martin
Published: May 2006

UPC2 and ECM22 belong to a Zn(2)–Cys(6) family of fungal transcription factors and have been implicated in the regulation of sterol synthesis in Saccharomyces cerevisiae and Candida albicans. Previous reports suggest that double deletion of these genes in S. cerevisiae is lethal depending on the genetic background of the strain. In this investigation we demonstrate that lethality of upc2Δ ecm22Δ in the S288c genetic background is attributable to a mutation in the HAP1 transcription factor. In addition we demonstrate that strains containing upc2Δ ecm22Δ are also inviable when carrying deletions of ERG6 and ERG28 but not when carrying deletions of ERG3, ERG4, or ERG5. It has previously been demonstrated that UPC2 and ECM22 regulate S. cerevisiae ERG2 and ERG3 and that the erg2Δ upc2Δ ecm22Δ triple mutant is also synthetically lethal. We used transposon mutagenesis to isolate viable suppressors of hap1Δ, erg2Δ, erg6Δ, and erg28Δ in the upc2Δ ecm22Δ genetic background. Mutations in two genes (YND1 and GDA1) encoding apyrases were found to suppress the synthetic lethality of three of these triple mutants but not erg2Δ upc2Δ ecm22Δ. We show that deletion of YND1, like deletion of GDA1, alters the sphingolipid profiles, suggesting that changes in sphingolipids compensate for lethality produced by changes in sterol composition and abundance.
Rapid Evolution of Major Histocompatibility Complex Class I Genes in Primates Generates New Disease Alleles in Humans via Hitchhiking Diversity
Authors: Shiina Takashi , Ota Masao , Shimizu Sayoko , Katsuyama Yoshihiko , Hashimoto Nami , Takasu Miwa , Anzai Tatsuya , Kulski Jerzy K , Kikkawa Eri , Naruse Taeko , Kimura Natsuki , Yanagiya Kazuyo , Watanabe Atsushi , Hosomichi Kazuyoshi , Kohara Sakae , Iwamoto Chie , Umehara Yumi , Meyer Alice , Wanner Valérie , Sano Kazumi , Macquin Cécile , Ikeo Kazuho , Tokunaga Katsushi , Gojobori Takashi , Inoko Hidetoshi , Bahram Seiamak
Published: May 2006

A plausible explanation for many MHC-linked diseases is lacking. Sequencing of the MHC class I region (coding units or full contigs) in several human and nonhuman primate haplotypes allowed an analysis of single nucleotide variations (SNV) across this entire segment. This diversity was not evenly distributed. It was rather concentrated within two gene-rich clusters. These were each centered, but importantly not limited to, the antigen-presenting HLA-A and HLA-B/-C loci. Rapid evolution of MHC-I alleles, as evidenced by an unusually high number of haplotype-specific (hs) and hypervariable (hv) (which could not be traced to a single species or haplotype) SNVs within the classical MHC-I, seems to have not only hitchhiked alleles within nearby genes, but also hitchhiked deleterious mutations in these same unrelated loci. The overrepresentation of a fraction of these hvSNV (hv1SNV) along with hsSNV, as compared to those that appear to have been maintained throughout primate evolution (trans-species diversity; tsSNV; included within hv2SNV) tends to establish that the majority of the MHC polymorphism is de novo (species specific). This is most likely reminiscent of the fact that these hsSNV and hv1SNV have been selected in adaptation to the constantly evolving microbial antigenic repertoire.
Evolutionary Divergence of Exon Flanks: A Dissection of Mutability and Selection
Authors: Xing Yi , Wang Qi , Lee Christopher
Published: May 2006

The intronic sequences flanking exon–intron junctions (i.e., exon flanks) are important for splice site recognition and pre-mRNA splicing. Recent studies show a higher degree of sequence conservation at flanks of alternative exons, compared to flanks of constitutive exons. In this article we performed a detailed analysis on the evolutionary divergence of exon flanks between human and chimpanzee, aiming to dissect the impact of mutability and selection on their evolution. Inside exon flanks, sites that might reside in ancestral CpG dinucleotides evolved significantly faster than sites outside of ancestral CpG dinucleotides. This result reflects a systematic variation of mutation rates (mutability) at exon flanks, depending on the local CpG contexts. Remarkably, we observed a significant reduction of the nucleotide substitution rate in flanks of alternatively spliced exons, independent of the site-by-site variation in mutability due to different CpG contexts. Our data provide concrete evidence for increased purifying selection at exon flanks associated with regulation of alternative splicing.
Mapping Quantitative Trait Loci by an Extension of the Haley–Knott Regression Method Using Estimating Equations
Authors: Feenstra Bjarke , Skovgaard Ib M , Broman Karl W
Published: May 2006

The Haley–Knott (HK) regression method continues to be a popular approximation to standard interval mapping (IM) of quantitative trait loci (QTL) in experimental crosses. The HK method is favored for its dramatic reduction in computation time compared to the IM method, something that is particularly important in simultaneous searches for multiple interacting QTL. While the HK method often approximates the IM method well in estimating QTL effects and in power to detect QTL, it may perform poorly if, for example, there is strong epistasis between QTL or if QTL are linked. Also, it is well known that the estimation of the residual variance by the HK method is biased. Here, we present an extension of the HK method that uses estimating equations based on both means and variances. For normally distributed phenotypes this estimating equation (EE) method is more efficient than the HK method. Furthermore, computer simulations show that the EE method performs well for very different genetic models and data set structures, including nonnormal phenotype distributions, nonrandom missing data patterns, varying degrees of epistasis, and varying degrees of linkage between QTL. The EE method retains key qualities of the HK method such as computational speed and robustness against nonnormal phenotype distributions, while approximating the IM method better in terms of accuracy and precision of parameter estimates and power to detect QTL.
The Effect of Gap Length on Double-Strand Break Repair in Drosophila
Authors: Johnson-Schlitz Dena M , Engels William R
Published: May 2006

When a double-strand break has a gap between the broken ends, the missing information can be restored through synthesis from a homologous template. Here we address the question of how long such a gap can be before this process fails. We measured the frequency of homologous repair in the Drosophila germ line following the creation of gaps of specific sizes ranging from 3.8 to 210 kb. We found that gaps of ≤11 kb can be repaired with approximately the same efficiency as breaks with no gap at all. However, a gap of 44 kb was repaired only rarely, and one of 210 kb was not repaired at a measurable frequency. We conclude that DNA gap repair is a length-limited process, but that this limitation is critical only for gaps ≫11 kb.
A 30,000‐cd/m2, 50‐lm/W, and 92%‐luminance‐uniformity flat discharge fluorescent lamp for LCD backlights
Authors: Shiga T. , Hirayama K. , Hashimoto K. , Mikoshiba S. , Shinoda S.
Published: May 2006

Abstract— A 5.2‐in.‐diagonal simple‐structured argon‐mercury cold‐cathode flat discharge fluorescent lamp has been developed for LCD backlighting. A pair of insulated electrodes is provided at the top and bottom ends of the inner surface of the front glass plate. Phosphor is deposited on both the front and rear glass plates. A luminance of 30,000 cd/m2 and a luminous efficacy of 50 lm/W were obtained with a luminance uniformity of 92% without the use of a diffuser sheet. A mechanism for obtaining the high luminous efficacy is described. Luminance can be dimmed down to 4% of the peak value by extending the pulse interval and/or by reducing the pulse amplitude.
Two approaches to the luminance enhancement of backlighting units for LCDs
Authors: Suzuki Masaru
Published: May 2006

Abstract— Two approaches to the luminance enhancement of a backlighting unit for a LCD have been followed. One uses a light‐collimating sheet, which changes the light direction from an oblique angle to the normal angle, resulting in higher luminance intensity at the normal direction. By optimizing its refractive index and the apex angle, a luminance enhancement of 30% was achieved. This collimating sheet has a light distribution whose angles at half luminous intensity were the same as the LCD's viewing angles. The other approach uses a reflective polarizer sheet, which reflects one of the polarization components and recycles it to the other polarization component in order to increase the total amount of light. This sheet also has a luminance enhancement of 30%. The designs and the measured data obtained through each approach are presented.
An intelligent inverter for a high‐power LCD backlight
Authors: Yana T. , Hanzawa F. , Watanabe Y.
Published: May 2006

Abstract— To resolve some of the problems encountered in developing a high‐power inverter for an LCD backlight with multiple cold‐cathode fluorescent lamps (CCFLs), we developed an intelligent dc‐ac inverter unit with the following special functions: (1) stabilization of the power consumption within several minutes of power‐on, (2) dispersion of the inrush current at power‐on, and (3) low switching noise on the power‐source line.
An inverter with a quasi‐synchronous dimming function
Authors: Suzuki Mikio , Hiratsuka Eiichi
Published: May 2006

Abstract— We have developed a high‐dimming‐ratio inverter, which is controlled by a digital circuit. The dimming function is synchronized with a half‐cycle of a Buck‐Royer inverter. A dimming ratio of 100:1 was obtained by using this technique.
Design considerations for a CCFL and its surroundings
Authors: Watanabe Yoshiteru
Published: May 2006

Abstract— A TFT‐LCD module includes a backlight unit, which normally uses one or more thin cold‐cathode fluorescent lamps (CCFLs). Since a CCFL is driven at high frequency and high voltage, there is a leakage current. In recent years, TFT‐LCD modules have been getting thinner, with a wider screen size and a narrower frame; consequently, the leakage current has come to have a significant influence on the design of the LCD module and the dc/ac inverter unit that generates the high‐voltage ac to drive the CCFL. It is actually impossible to probe the inside of a working CCFL because of the high voltage, high frequency, and low electric discharge current. This fact adds to the difficulty of the analysis and the design. This paper proposes an electrical model of a CCFL and a simulation method using the model, making it possible to analyze the inside of the CCFL and to provide some important parameters that are required for the basic design of the LCD module and the dc/ac inverter, before the construction and measurement of actual samples.
A study of the virtual screen image of flat‐faced CRTs
Authors: Saito Tsunenari
Published: May 2006

Abstract— Simulation of a CRT with a flat outer surface and a spherical inner surface was performed to determine the virtual screen image made by refraction in the glass panel. The simulation calculated the radius of the panel inner surface for the flat‐faced CRT to make a perfectly flat virtual screen image at each eye position. With H as the screen height, display‐monitor CRTs used with eye positions closer than 1H show that the radius of the panel inner surface R = 18H is the most appropriate. On the other hand, for TV CRTs with a normal eye distance of 3H or greater, a radius of R = 40H or more is required to obtain a flat virtual image. The paper also clarifies the influence of panel glass thickness T on the distortion of the screen image.
A high‐luminance and high‐resolution CRT for projection HDTV display
Authors: Wang Qionghua , Cheng Jianbo , Lin Zulun , Yang Gang
Published: May 2006

Abstract— We have developed a 3‐in. YAG (yttrium aluminum garnet) projection CRT for an HDTV display. The densely packed phosphor screen with a multi‐layer interference filter is prepared by depositing phosphor on a YAG faceplate using a centrifugal sedimentation method. The tube's envelope is made from a glass whose expansion coefficient is well‐matched with that of YAG. The focusing characteristics of an optimally designed pre‐focusing electron gun and focusing magnet are improved for a HDTV display application. As a result, the green, red, and blue tubes reached luminances of 1.4 × 105, 6.2 × 104, and 8 × 103 cd/m2 at a cathode current of 1.0 mA and an anode voltage of 29 kV, respectively, with a half‐intensity linewidth of 85 μm. An experimental 48‐in. rear‐projection TV set using the YAG projection tubes achieves more than 1000‐TV‐lines horizontal resolution and 300‐cd/m2 mean white luminance.
Motion and stereoscopic tilt perception
Authors: Pierce Byron J. , Arrington Karl Frederick , Moreno Miguel A.
Published: May 2006

Abstract— Stereoscopic perception of tilt about a vertical or horizontal axis is influenced by size and shear disparities, respectively. Other researchers have reported that, under certain conditions, stereoscopic perception deficits occur when the dots in a random‐dot stereogram move at a velocity that produces optokinetic nystagmus. Here we examine how size disparity and shear disparity affect stereoscopic tilt perception under various motion conditions. We hypothesized that visual stimulus motion may interact with these disparities to affect tilt perception. Our results indicate that shear disparity and size disparity effects under static conditions are maintained under motion conditions. A possible explanation for the conflict between the current and previous results is discussed, as are implications for binocular head‐mounted display applications.
Theoretical and quantitative evaluation of the cuttability of AMLCD glass substrates using a four‐point‐bending test
Authors: Ono Toshihiko , Tanaka Koichi
Published: May 2006

Abstract— Glass cutting is one of the important processes in liquid‐crystal display (LCD) manufacturing. Glass cutting consists of two processes, scribing and breaking. However, both processes have evolved through manufacturing experience and have not been analyzed theoretically. In particularly, no studies have been found which relate to the breaking process. In this study, theoretical and quantitative analysis is performed for the breaking process using a four‐point‐bending test of scribed sheet. From the results of the four‐point‐bending test, the breaking load of a scribed sheet was 40% lower than that of the theoretically calculated load due to the residual stress created by indentation and by sheet forming. For median crack depths greater than 100 μm, the breaking load increased to close to the calculated load due to stress relaxation by lateral crack growth. The four‐point‐bending lest of scribed glass sheet is effective in identifying the breaking process, and is necessary to understand glass “cuttability”.
Mechanism and electro‐optic properties of multidomain vertically aligned mode LCDs
Authors: Konovalov V. A. , Minko A. A. , Muravski A. A. , Timofeev S. N. , Yakovenko S. Ye.
Published: May 2006

Abstract— We considered the electro‐optical properties of twisted and non‐twisted modes in vertically aligned (VA) nematic liquid crystals with the main objective of improving their viewing angle, response speed, and luminance. Several modes appropriate for applications in multidomain and amorphous VA textures are outlined. Mechanisms of multidomain texture formation in displays with dielectric patterns between the electrodes are analyzed by computer simulations and verified with experimental samples. It is shown that by depositing dielectric patterns on the electrodes it is possible to fabricate multidomain liquid‐crystal displays without inversion of gray levels, sacrificing only 20% of the luminance of conventional single‐domain displays.
Organic LED full‐color passive‐matrix display
Authors: Miyaguchi Satoshi , Ishizuka Shinichi , Wakimoto Takeo , Funaki Jun , Fukuda Yoshinori , Kubota Hirofumi , Yoshida Kenji , Watanabe Teruichi , Ochi Hideo , Sakamoto Tsuyoshi , Tsuchida Masami , Ohshita Isamu , Tohma Teruo
Published: May 2006

Abstract— A full‐color 5.2‐inch 1/4‐VGA passive‐matrix organic LED display has been developed, adopting selective deposition for the different emitting materials. The display features 320 (×3) × 240 pixels with an equivalent pixel size of 0.33 × 0.33 mm, white peak luminance of over 150 cd/m2, and power consumption of 6 W.
Improving PDP picture quality by means of a motion‐dependent equalizing‐pulse technique
Authors: Yamaguchi Takahiro , Toda Kosaku , Zhu Yi‐Wen , Shiga Tomokazu , Mikoshiba Shigeo , Ueda Toshio , Kariya Kyoji , Shinodat Tsutae
Published: May 2006

Abstract— When moving images are displayed on color plasma displays, motional artifacts such as dynamic false contours with disturbances of gray scales and colors are often observed. Reduction of the disturbances is essential to achieve PDPs with acceptable picture quality for TV use. The moving‐picture quality can be improved to some extent by using an equalizing‐pulse technique which augments or suppresses light‐emission to compensate for the lack or surplus from the original signal. The disturbances, however, become significant as the speed of motion increases. In order to reduce the disturbances, the equalizing pulses are weighted according to the speed and direction of motion. The improvement can be enhanced further by combining the technique with a modified‐binary‐coded light‐emission‐period scheme. Disturbance is thus reduced by 82 dB. The technique is applicable to images moving at any speed in any direction. It can also be used for any pixel arrangement and any light‐emission scheme.
Evaluating the resolution of ultra‐fine‐grain phosphor screens
Authors: Sluzky Esther , Avalos Teresa , Hesse Kenneth R.
Published: May 2006

Abstract— This paper describes a method of measuring the resolution of a very‐fine‐grain phosphor screen without having to build a cathode‐ray tube. The method is based on contact‐printer technology and makes use of a master resolution pattern. This pattern is contact focused onto the screen under investigation. The resulting image is examined under a microscope to determine the finest resolution that can be detected visually in the manner of the shrinking‐raster technique used for tube evaluation. Data collected through this method are compared to data taken from 1‐in. high‐resolution tubes made for airborne applications. It is shown that the method produces results closely matched by the tube data. Several examples are given of the use of this method in measuring resolution of screens of various particle sizes and screen densities, and also the effect of fiber‐optic faceplates on resolution.
Computer simulation of double‐mussel deflection‐coil winding
Authors: Penninga Hans
Published: May 2006

Abstract— A new program package, DUCAD‐C, has been developed to assist in computer‐aided design of double‐mussel deflection coils. In contrast with the very abstract model of our existing package, DUCAD‐Y, this new package, DUCAD‐C, gives an exact description of a deflection coil based on the simulation of winding this coil in the mandrels. Since the coils calculated by DUCAD‐C agree very well with the corresponding real coil, DUCAD‐C is a very powerful tool for the development of new deflection coils.
Fabrication technique for a full‐color non‐phosphor plasma display device with vertically aligned RGB colors
Authors: Andreadakis Nicholas C. , Wullert John R. , Shirokmann Howard F.
Published: May 2006

Abstract— This paper describes the device structure and novel fabrication techniques for an experimental full‐color ac plasma display. This device is composed of three vertically stacked twin‐substrate single‐color ac plasma display devices, each containing a gas mixture whose discharge emits one of the primary (red‐green‐blue) visible colors. In this unique arrangement, unlike any other emissive color‐display device, each color pixel consists of three coaxially viewed and separately addressable single‐color subcells.
A large‐screen visual telecommunications device using a liquid‐crystal screen to provide eye contact
Authors: Shiwa Shinichi
Published: May 2006

Abstract— A device that uses a video camera mounted behind an alternately transparent and opaque display screen is described. Eye contact is provided by synchronizing the camera shuttering and the transparent period of the screen.
A 5‐Mpixel overhead projection display utilizing a nematic‐cholesteric phase‐transition liquid crystal
Authors: Yabe Yoshikazu , Yamada Hisatake , Hoshi Toshihiro , Yoshihara Toshiaki , Mochizuki Akihiro , Yoneda Yasuhiro
Published: May 2006

Abstract— A multiplexed high‐luminance liquid‐crystal projection display with 5 Mpixels (2240 × 2240 dots) at a luminance level of 800 cd/m2 using a conventional overhead projector has been developed. This display exhibits the bistability of a nematic‐cholesteric phase‐transition liquid crystal without the use of polarizers, and can display 5‐Mpixel data which matches the output of a high‐resolution printer, using a conventional overhead projector. A 4:1 contrast ratio and 2.2‐ms line‐addressing time was achieved.
A high‐contrast multiplexed dot‐matrix FELCD using naphthalene‐based FELC and conductive polymer films for orientation
Authors: Mochizuki Akihiro , Motoyoshi Katsusada , Yoneda Yasuhiro , Nakatsuka Masakatsu , Yoshida Masaaki , Kobayashi Shunsuke
Published: May 2006

Abstract— A direct‐multiplexed ferroelectric liquid‐crystal display, having a contrast ratio as high as 35:1 without showing zigzag defects, has been realized by using an electrical conductive orientation polymer: a polypyrrole film together with a special material containing naphthalene‐based ferroelectric liquid crystals. The polypyrrole orientation films can effectively suppress the formation of depolarization fields, resulting in a stable memory capability and a high contrast ratio.
Droplet‐size effects and lighting techniques in direct‐view PDLC displays
Authors: Erdmann John H. , Lackner Anna M. , Sherman Elena , Margerum J. David
Published: May 2006

Abstract— By varying liquid‐crystal droplet sizes in designated regions, direct‐view polymer‐dispersed liquid‐crystal (PDLC) displays with simpler addressing schemes are constructed. A multiple‐droplet‐size PDLC is used to hide addressing‐line voltage effects in a segmented display which requires a clear (non‐scattering) region surrounding the segments. Edge lighting improves the contrast ratio of these direct‐view displays.
Noncrossing TFT matrix with reduced dc level shift and crosstalk
Authors: Yanai Ken‐ichi , Tanaka Tsutomu , Hoshiya Takayuki , Kakehi Tatsuya , Ohgata Kohji , Oki Ken‐ichi , Okabe Masahiro
Published: May 2006

Abstract— A noncrossing TFT matrix and drive scheme that eliminates dc level‐shift differences among data and reduces crosstalk without a storage capacitor is proposed. To compensate for the dc level shift, an extra TFT is added to each pixel. By applying a compensation pulse to the TFT, the dc level‐shift differences among data are reduced to less than 0.01 V. The compensating TFT also provides redundancy. The peak‐to‐peak data voltage amplitude is lowered by changing the reference voltage according to the LC cell voltage polarity. By using the lowered data voltage and the shielded reference bus structure, crosstalk is reduced sufficiently to allow for 64 gray levels.
An analysis of source bus‐line to common‐electrode coupling effect in large‐area TFT‐LCDs
Authors: Yachi Shigeru , Ikemoto Tetsuya , Takahashi Seiki , Matsukawa Fumio , Ishizu Akira , Takasago Hayato , Yamazaki Teruhiko
Published: May 2006

Abstract— The source (or data) bus‐line to common (or backplane) electrode coupling effect in TFT‐LCDs has been investigated through experiment and simulation using a new model. The important feature of this simulated model is that the common electrode consists of a network of discrete resistors. The horizontal crosstalk is caused by this coupling effect, and the mechanism of the crosstalk has become clear by the simulation of 5‐in. TFT‐LCDs. By adopting this simulation, useful information for large‐area TFT‐LCD designs can be obtained. As an example, this simulation has been performed for 10‐ and 15‐in. TFT‐LCDs and the requirement for a common resistance has been illustrated.
New high‐quality drive methods for high‐resolution LCTVs
Authors: Okumura Haruhiko , Fujiwara Hisao
Published: May 2006

Abstract— New flicker‐reduction and high‐speed drive methods are proposed for use in high‐resolution liquid‐crystal TVs. The new flicker‐reduction delta‐inversion drive method changes the drive polarity in every line and field. In addition, one of the three color pixels in the same line is driven in reverse polarity. In this method, the plain flicker due to field‐inversion driving is transformed into a column flicker similar to the column‐inversion drive method. The column‐flicker spatial frequency in our method is the highest of that in any other flicker‐reduction drive method for high‐resolution LCTVs with more than 1000 horizontal pixels. The high‐speed preparatory drive method is achieved by driving individual pixels twice per field. The first drive is a dummy drive made two lines before the actual drive. The second drive is the actual drive. The drive time can be virtually twice as long as that for conventional methods, if the vertical image correlation is strong. The combination of these two methods yields high‐quality images for large‐size and high‐resolution LCTVs.
Influence of pixel‐structure noise on image resolution and color for matrix display devices
Authors: Chen Li‐Ming , Hasegawa Shin
Published: May 2006

Abstract— In matrix display devices, image quality is influenced by pixel‐structure noise (fixed‐pattern noise) originating from the pixel arrangement. The influence of this noise on image resolution and color is investigated for four types of color pixel arrangements. Spatial Nyquist limits (SNLs) based on pixel reciprocal lattices are first applied to determine the primary resolution of these devices. Then actual visual resolution limits (VRLs), which are obtained by subjectively evaluating sinusoidal patterns displayed on simulated displays, are compared to the SNLs in order to assess quantitatively the color pixel arrangements. The ratios of VRLs to SNLs (corresponding to the Kell factors) are 0.6–0.7 for white patterns, but only 0.5–0.6 for patterns of one of the three primary colors due to pixel‐structure noise. A subjective evaluation of color‐bar patterns of ten colors shows that image colors, especially greenish colors, are influenced by the pixel‐structure noise.
Hypermedia‐based rapid interface prototyping
Authors: Greitzer Frank L. , Wunderlich Dana , Weinberg Mark J.
Published: May 2006

Abstract— Methods and tools used to produce rapid prototypes of human‐computer interfaces are discussed, with primary focus on hypermedia‐based tools. Rapid prototyping should begin early in the design definition process to focus on user‐interface requirements and issues that might otherwise be overlooked by more‐traditional approaches. Hypermedia products such as HyperCard and SuperCard are extremely useful in this process because of their flexibility and powerful user‐interface design features. In addition to providing insights and initial concept definition, the prototyping process can be enhanced by adding automated software‐engineering support functions that increase productivity. This paper describes the development and use of the rapid interface prototyping (RIP) system, which supports the design, prototyping, and development of large computer‐based information systems at McDonnell Douglas Training Systems. Built upon hypermedia tools, the RIP System fosters consistency of displays/interactions, automates some of the time‐consuming aspects of user‐interface software development, and reduces software coding errors.
Analysis of ZnS:Mn‐Type ac Thin‐Film Electroluminescent Display Devices with Bulk Traps
Authors: Singh Vijay P. , Majid Wan Z. , Morton David C.
Published: May 2006

Abstract— Analysis of a ZnS:Mn‐type ac thin‐film electroluminescent device with a deep level in the bulk of the phosphor layer was performed. Both donor‐ and acceptor‐type levels were considered. Calculations of field, current, and luminescence as a function of the interface‐state‐level energy (ECD) showed that a trailing‐edge peak in the luminescence waveform appears when ECD is less than 0.5 eV. It was found that an acceptor‐type bulk level can, under certain conditions, lead to oscillations in the electron flux and the device current. A reasonable match between theoretical and experimental luminescence waveforms could be obtained for ECD = 0.8 eV. However, theory and experiment could not be matched simultaneously at three different drive conditions consisting of three different slew rates for the drive pulses. Further refinement of the model is necessary for predicting the ACTFEL drive response for all drive conditions. These refinements include the energy distribution of hot electrons, probability of impact excitation, and carrier multiplication in the phosphor layer.
Silicon field‐emitter arrays for cathodoluminescent flat‐panel displays
Authors: Gray H. F. , Sune C. T. , Jones G. W.
Published: May 2006

Abstract— Cathodoluminescent flat‐panel displays can be made with field‐emitter arrays (FEAs). Using orientation‐dependent etching and a linear thermal‐oxidation process, uniform and reproducible FEAs which yield more than 10 μA per tip with less than 140‐Vdc extraction voltages have been fabricated. Modulation voltages are in the 40‐V region. These FEAs can be the basis for a simple and inexpensive cathodoluminescent flat‐panel display.
Application of the Mueller matrix method to optically retarded liquid‐crystal cells for C.I.E. color‐coordinate calculations
Authors: Fair D. C. , Tilton M.
Published: May 2006

Abstract— The 4 × 4 matrix method is a commonly used technique for calculating the transmission through liquid‐crystal displays. Here, the Mueller 4 × 4 method is extended to the optically retarded liquid‐crystal cell by including the 4 × 4 matrix for the retardation film in the calculation. By doing so, the transmission of the cell is found and the C.I.E. color coordinates are calculated by utilizing the weighted ordinate method. By applying this method we can optimize the cell configuration for contrast, color, and backlighting conditions. We describe this method and show some sample calculations for several types of liquid‐crystal devices.
Simultaneous measurement of twist angle and cell gap of a twisted‐nematic cell by an optical method
Authors: Lien A.
Published: May 2006

Abstract— An optical method is presented which allows one to measure simultaneously the twist angle and cell gap of a filled twisted‐nematic liquid‐crystal display (TN‐LCD) that has an arbitrary unknown twist angle between 0 and 360°. It can also determine the sense of handedness of the twist and the two rubbing directions of an unknown panel. Using this method, the measurement uncertainty of the cell gap is within 1% and the measurement uncertainties of the twist angle and rubbing directions are within 1°.
A novel surface‐stabilized monostable ferroelectric LCD
Authors: Nito K. , Matsui E. , Miyashita M. , Arakawa S. , Yasuda A.
Published: May 2006

Abstract— A new type of analog gray‐scale display based on a surface‐stabilized ferroelectric LCD is presented. A SmC* phase with a long pitch was employed so that the alignment direction of the liquid‐crystal molecules shows monostability along the rubbing direction for the uniaxial orientation of the substrate. Modulation with an electric field produces an analog gray‐scale display. An antiparallel cell shows regular arrays of stripes (2.3‐μm pitch) which are parallel to the rubbing direction and show monostable behavior. Due to the two types of stripes aligning alternately in the cell, the optical transmission increases with increasing voltage in two stages: a linear response and small transmission change from 0 to 5 V, and a stepwise and large response in the range of greater than 5 V. By eliminating the striped texture in the cell with an electrical treatment, the contrast ratio (>80), the linearity (the analog gray scale in the low‐driving‐field region <4 V/2 μm), and the response times (on the order of 1 ms) of the surface‐stabilized monostable ferroelectric LCD (SSMFLCD) can be improved significantly.
Electro‐optical properties of a double‐layer ECB‐LCD with a wide viewing‐angle cone
Authors: Seki Hidehiro , Itoh Yasuhisa , Uchida Tatsuo , Masuda Yoichiro
Published: May 2006

Abstract— An electrically controlled birefringence (ECB) LCD often has the limitation of a narrow viewing angle. To solve this problem, a double‐layer ECB (D‐ECB) LCD with a wide viewing‐angle cone is proposed. In this device, each layer compensates the variation of retardation of the other over a wide range of viewing angles.
Batch processing of high‐performance a‐Si/SiN TFTs using a low‐temperature hot‐wall CVD method
Authors: Ahn Byung‐chul , Kanoh Hiroshi , Sugiura Osamu , Matsumura Masakiyo
Published: May 2006

Abstract— A chemical‐vapor‐deposition (CVD) method has been applied, for the first time, to a batch process for a‐Si/SiN TFTs. The maximum process temperature was 500°C. High‐performance TFTs with mobilities of 1.2 cm2/V‐s, a threshold voltage of 4 V, and a subthreshold slope of 0.6 V/decade have been fabricated with good reproducibility and uniformity over a wide range of CVD conditions. This feature makes the a‐Si/SiN TFT batch process practical.
A polymer‐network liquid‐crystal poly‐CdSe TFT active‐matrix display
Authors: De Baets J. , Capon J. , De Rycke I. , De Smet H. , Doutreloigne J. , Van Calster A. , Vanfleteren J. , Fujisawa T. , Ogawa H. , Takatsu H.
Published: May 2006

Abstract— A polymer‐network liquid‐crystal (PNLC) display with a poly‐CdSe thin‐film‐transistor active matrix is presented. This first‐published AMPNLCD combines high transmission (>80%) and large viewing angles with low‐driving‐voltage capability (5 V).
Analysis of dynamic characteristics in a‐Si TFT structures
Authors: Kitazawa Tomoko , Shibusawa Makoto , Higuchi Toyoki
Published: May 2006

Abstract— The dynamic characteristics of a‐Si TFTs in terms of level shift in pixel voltage have been investigated in various TFT structures, such as back‐channel‐etched (BCE) TFTs, tri‐layered (TL) TFTs, and self‐aligned (SA) TFTs. The dependence of the level‐shift voltage on drain voltage and on gate‐pulse delay was measured. The results were compared to that of SPICE simulation. When the gate‐pulse delay is zero, the drain‐voltage dependence of the level shift for the BCE TFT is larger than that of the level shifts for the TL TFT and the SA TFT. On the other hand, when the gate‐pulse delay increases, the level shift drastically decreases, and the magnitude of the decrease is independent of the three TFT structures.
A 9.5‐in. 1.3‐Mpixel low‐temperature poly‐Si TFT‐LCD fabricated by solid‐phase crystallization of very thin films and an ECR‐CVD gate insulator
Authors: Little Thomas W. , Koike Hideki , Takahara Ken‐ichi , Nakazawa Takashi , Ohshima Hiroyuki
Published: May 2006

Abstract—A unique combination of solid‐phase crystallization (SPC) and gate‐insulator technology has been used to fabricate low‐temperature poly‐Si TFTs. Using this technology, a high‐resolution 9.5‐in. TFT‐LCD with 1.3 Mpixel has been realized. This is believed to be the largest and highest‐resolution LCD employing low‐temperature poly‐Si TFTs fabricated to date.
Display performance improvement in a TFD‐LCD with reduced image‐sticking
Authors: Kamagami S. , Sunohara K. , Tanaka Y. , Morita H.
Published: May 2006

Abstract— Image‐sticking in a TFD‐LCD was examined and found to be dependent on the bias ratio in the driving waveforms and on temperature. Consequently, image‐sticking can be diminished by optimizing the bias ratio and by temperature compensation.
The use of Lorentzian functions in the analysis of non‐Gaussian CRT spots
Authors: Infante Carlo
Published: May 2006

Abstract— The spot profile of the CRT electron beam is Gaussian at low currents, but exhibits tails at higher currents, such as those used by modern high‐resolution color CRTs. Lorentzian functions are proposed as an analytic model to represent these distributions. Experimental evidence is given and the effect on the resultant picture quality analyzed. The flexibility of the Lorentzian functions make them useful in simulation and modeling tasks.
Geometric design of lensless photoconductive contact‐type image sensors
Authors: Capon J. , De Baets J. , De Rycke I. , De Smet H. , Doutreloigne J. , Van Calster A. , Vanfleteren J.
Published: May 2006

Abstract— Two figures of merit of the imaging process in a lensless photoconductive contact‐type image sensor are described. One figure is proportional to the signal‐to‐noise ratio and the other figure is a measure of the strength of aliasing effects. A simple analytical model, based on a realistic “one‐strip” geometry, is presented. Using this model, the effects of five geometric parameters on these figures are analyzed. It is shown that in optimizing the geometry, trade‐offs will have to be made between a high signal‐to‐noise ratio and a good suppression of aliasing effects. The model described can be used to carry out first‐order calculations in order to optimize the sensor geometry.
Design criteria for polyimide alignment layers in surface‐stabilized ferroelectric LCDs
Authors: Myrvold Bernt O.
Published: May 2006

Abstract— The mass production of surface‐stabilized ferroelectric liquid‐crystal (SSFLCD) displays has been an elusive goal for several years. In this paper, some of the effects that structural and process variations in the alignment polymer can have in an SSFLC cell are considered. From the examples given here and in previous work, the general requirements for the design of alignment layers used in SSFLC devices are outlined.
Influence of spontaneous polarization and polyimide surface treatment on layer tilt angle in SSFLC cells
Authors: Okada Hiroyuki , Ninomiya Norihiro , Murashiro Katsuyuki , Onnagawa Hiroyoshi , Miyashita Kazuo
Published: May 2006

Abstract— The influence of the spontaneous polarization of liquid‐crystal materials and polyimide surface treatments on layer tilt angle in surface‐stabilized ferroelectric liquid‐crystal (SSFLC) cells has been studied by x‐ray diffraction. For the case of liquid‐crystal molecules with the same core structure, the layer tilt angle is not influenced by the magnitude of the spontaneous polarization of the liquid crystals (Ps). Three kinds of polyimides which result in different pre‐tilt angles for the typical nematic material result in the same layer tilt angle for the ferroelectric liquid‐crystal materials. The layer tilt angle vs. molecular tilt angle characteristics are expressed by a universal straight line and its slope is less than unity.
Ferroelectric liquid‐crystal mixtures containing new chiral γ‐lactone compounds
Authors: Koden Mitsuhiro , Shiomi Makoto , Tamai Kazuhiko , Wada Tomio , Sakaguchi Kazuhiko , Shiomi Yutaka
Published: May 2006

Abstract— New chiral γ‐lactone compounds were developed as chiral dopants for ferroelectric liquid‐crystal (FLC) mixtures. They were found to induce fast response times when they were doped into achiral liquid‐crystal host mixtures. In addition, the effect of the molecular structure on the melting point and the helical twist properties in the nematic phase were investigated. Some FLC mixtures and their applications to FLC devices are described.