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Coding Scheme (coding + scheme)

Distribution by Scientific Domains

Medical Sciences	40%
Engineering	26%
Psychology	13%
Information Science and Computing	10%
Humanities and Social Sciences	10%

Selected Abstracts

Maternal limit-setting in toddlerhood: Socialization strategies for the development of self-regulation

INFANT MENTAL HEALTH JOURNAL, Issue 4 2006
Elizabeth LeCuyer
Early findings from the Prohibition Coding Scheme (PCS; Houck & LeCuyer, 1995; LeCuyer-Maus & Houck, 2002; Medvin & Spieker, 1985) revealed that maternal limit-setting styles with toddlers were differentially related to later child social competence, self-concept, and delay of gratification. For this study, the PCS was revised to provide more information about the specific strategies mothers used during limit-setting in relation to those outcomes. Results from the PCS-Revised (PCS-R; LeCuyer & Houck, 2004) included that the more time mothers spent actively distracting their toddlers away from a prohibited object during limit-setting, as early as 12 months, the longer their children could delay gratification at age 5 years. Mothers who spent more time sensitively following and being engaged in their toddler's own interests (other than the prohibited object), again as early as 12 months, had more socially competent children with more developed self-concepts at age 3 years. Maternal use of reasoning statements later in toddlerhood also related to higher levels of social competence. Maternal limits and prohibitions were not related to these outcomes, and appeared to contribute to the development of self-regulation mainly by creating the opportunity for the use of other, less directive strategies. The findings indicate that these strategies may be important to include in intervention programs for the promotion of toddler and child development of self-regulation. [source]

Maternal limit setting during toddlerhood, delay of gratification, and behavior problems at age five

INFANT MENTAL HEALTH JOURNAL, Issue 1 2004
Gail M. Houck
In this study, self-regulation was examined in relation to maternal limit setting during toddlerhood. Observational coding of limit-setting interactions was carried out at 12, 24, and 36 months using the Prohibition Coding Scheme (Houck & LeCuyer, 1995; LeCuyer-Maus & Houck, 2002). At five years, self-regulation was assessed by observation of self-imposed delay-of-gratification (Shoda, Mischel, & Peake, 1990), and behavior problems were measured by maternal report on a behavior checklist (CBCL; Achenbach, 1991). Maternal limit-setting patterns at every age differentiated subsequent duration of delay, but not behavior problems. A power-based maternal pattern in limit setting adversely affected later self-imposed delay. Although an indirect limit-setting pattern optimized the child's delay duration, a teaching-based pattern yielded more consistently positive outcomes at 36 months and normative delay durations at age five years. ©2004 Michigan Association for Infant Mental Health. [source]

The Impact of Injury Coding Schemes on Predicting Hospital Mortality After Pediatric Injury

ACADEMIC EMERGENCY MEDICINE, Issue 7 2009
Randall S. Burd MD
Abstract Objectives:, Accurate adjustment for injury severity is needed to evaluate the effectiveness of trauma management. While the choice of injury coding scheme used for modeling affects performance, the impact of combining coding schemes on performance has not been evaluated. The purpose of this study was to use Bayesian logistic regression to develop models predicting hospital mortality in injured children and to compare the performance of models developed using different injury coding schemes. Methods:, Records of children (age < 15 years) admitted after injury were obtained from the National Trauma Data Bank (NTDB) and the National Pediatric Trauma Registry (NPTR) and used to train Bayesian logistic regression models predicting mortality using three injury coding schemes (International Classification of Disease-9th revision [ICD-9] injury codes, the Abbreviated Injury Scale [AIS] severity scores, and the Barell matrix) and their combinations. Model performance was evaluated using independent data from the NTDB and the Kids' Inpatient Database 2003 (KID). Results:, Discrimination was optimal when modeling both ICD-9 and AIS severity codes (area under the receiver operating curve [AUC] = 0.921 [NTDB] and 0.967 [KID], Hosmer-Lemeshow [HL] h-statistic = 115 [NTDB] and 147 [KID]), while calibration was optimal when modeling coding based on the Barell matrix (AUC = 0.882 [NTDB] and 0.936 [KID], HL h-statistic = 19 [NTDB] and 69 [KID]). When compared to models based on ICD-9 codes alone, models that also included AIS severity scores and coding from the Barell matrix showed improved discrimination and calibration. Conclusions:, Mortality models that incorporate additional injury coding schemes perform better than those based on ICD-9 codes alone in the setting of pediatric trauma. Combining injury coding schemes may be an effective approach for improving the predictive performance of empirically derived estimates of injury mortality. [source]

Multiresolution Random Accessible Mesh Compression

COMPUTER GRAPHICS FORUM, Issue 3 2006
Junho Kim
This paper presents a novel approach for mesh compression, which we call multiresolution random accessible mesh compression. In contrast to previous mesh compression techniques, the approach enables us to progressively decompress an arbitrary portion of a mesh without decoding other non-interesting parts. This simultaneous support of random accessibility and progressiveness is accomplished by adapting selective refinement of a multiresolution mesh to the mesh compression domain. We present a theoretical analysis of our connectivity coding scheme and provide several experimental results. The performance of our coder is about 11 bits for connectivity and 21 bits for geometry with 12-bit quantization, which can be considered reasonably good under the constraint that no fixed neighborhood information can be used for coding to support decompression in a random order. Categories and Subject Descriptors (according to ACM CCS): I.3.5 [Computer Graphics]: Computational Geometry and Object Modeling [source]

Effect of self-monitoring on binge eating: treatment response or ,binge drift'?

EUROPEAN EATING DISORDERS REVIEW, Issue 1 2006
Tom Hildebrandt
Abstract The current study aimed to determine if subjective bulimic episodes (SBEs) and objective bulimic episodes (OBEs) have different reactive effects to self-monitoring. Fourteen women with bulimia nervosa (57%) or binge eating disorder (43%) were diagnosed using the Eating Disorder Examination (EDE; version 12.0). During the 7-days post-interview, participants filled out daily self-monitoring records indicating the food consumed and any episodes of loss of control over eating. These records were reviewed and coded for OBEs and SBEs using the EDE coding scheme. Paired samples t -tests indicated that participants' average number of daily OBEs significantly decreased from baseline to the period of self-monitoring (t,=,2.41, p,<,0.05, Cohen's d,=,0.90), whereas there was a significant increase from baseline to self-monitoring in their average number of SBEs (t,=,,2.41, p,<,0.05, Cohen's d,=,0.86). Of the 12 participants who showed a decrease in OBEs, 75% showed a concurrent increase in SBEs. The data suggest that the reactivity of OBEs to minimal or brief interventions may in part be due to binge drift, or the reduction of OBEs at the expense of increasing SBEs. Copyright © 2006 John Wiley & Sons, Ltd and Eating Disorders Association. [source]

Issue salience in regional party manifestos in Spain

EUROPEAN JOURNAL OF POLITICAL RESEARCH, Issue 1 2009
LISELOTTE LIBBRECHT
It is based on a content analysis of the party manifestos of the Spanish PP and PSOE in eight regional elections held between 2001 and 2003. It provides an innovative coding scheme for analysing regional party manifestos and on that basis seeks to account for inter-regional, intra-party and inter-party differences in regional campaigning. The authors have tried to explain the inter-regional variation of the issue profiles of state-wide parties in regional elections on the basis of a model with four independent variables: the asymmetric nature of the system, the electoral cycle, the regional party systems and the organisation of the state-wide parties. Three of their hypotheses are rejected, but the stronger variations in the regional issue profiles of the PSOE corroborate the assumption that parties with a more decentralised party organisation support regionally more diverse campaigning. The article concludes by offering an alternative explanation for this finding and by suggesting avenues for further research. [source]

CGU-frame-based representations and their connection with Reed,Solomon and DCT/DST coding schemes

EUROPEAN TRANSACTIONS ON TELECOMMUNICATIONS, Issue 1 2009
Fatma Abdelkefi
We investigate the use of overcomplete frame representations to correct errors occurring over burst-based transmission channels or channels leading to isolated errors. We show that when the overcomplete signal representation is based on a class of frames, called cyclic geometrically uniform (CGU) finite frames, the family of frames containing finite harmonic frames (both in and ), this representation becomes equivalent to a Reed--Solomon (RS) coding scheme. Hence, introducing an RS decoding procedure at the receiver, leads to remove the errors introduced by the transmission channel and consequently results in a quasi-perfect reconstructed signal. The advantage of this approach is to exploit the RS coding scheme without using it explicitly at the transmitter, which would lead to a robust and low complexity transmission. Furthermore, we prove that the discrete cosine transform (DCT) coding is a special case of CGU-frame-based representations and this property holds also true for the discrete sine transform (DST) coding scheme. Simulation results are presented to confirm our claims. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Managed Behavioral Health Care: An Instrument to Characterize Critical Elements of Public Sector Programs

HEALTH SERVICES RESEARCH, Issue 4 2002
M. Susan Ridgely
Objective. To develop an instrument to characterize public sector managed behavioral health care arrangements to capture key differences between managed and ,unmanaged" care and among managed care arrangements. Study Design. The instrument was developed by a multi-institutional group of collaborators with participation of an expert panel. Included are six domains predicted to have an impact on access, service utilization, costs, and quality. The domains are: characteristics of the managed care plan, enrolled population, benefit design, payment and risk arrangements, composition of provider networks, and accountability. Data are collected at three levels: managed care organization, subcontractor, and network of service providers. Data Collection Methods. Data are collected through contract abstraction and key informant interviews. A multilevel coding scheme is used to organize the data into a matrix along key domains, which is then reviewed and verified by the key informants. Principal Findings This instrument can usefully differentiate between and among Medicaid fee-for-service programs and Medicaid managed care plans along key domains of interest. Beyond documenting basic features of the plans and providing contextual information, these data will support the refinement and testing of hypotheses about the impact of public sector managed care on access, quality, costs, and outcomes of care. Conclusions. If managed behavioral health care research is to advance beyond simple case study comparisons, a well-conceptualized set of instruments is necessary. [source]

Towards a distinctive body of knowledge for Information Systems experts: coding ISD process knowledge in two IS journals

INFORMATION SYSTEMS JOURNAL, Issue 4 2004
Juhani Iivari
Abstract., This paper introduces the idea of coding a practically relevant body of knowledge (BoK) in Information Systems (IS) that could have major benefits for the field. In its main part, the paper focuses on the question if and how an underlying body of action-oriented knowledge for IS experts could be distilled from the IS research literature. For this purpose the paper identifies five knowledge areas as the most important parts for an IS expert's BoK. Two of these are claimed as distinct areas of competence for IS experts: IS application knowledge and IS development (ISD) process knowledge. The paper focuses particularly on ISD process knowledge because it allows the organizing of practically relevant IS knowledge in an action-oriented way. The paper presents some evidence for the claim that a considerable body of practically relevant IS process knowledge might, indeed, exist, but also notes that it is highly dispersed in the IS literature. It then argues that the IS research community should take stock of this knowledge and organize it in an action-oriented way. Based on results from prior work it proposes a four-level hierarchical coding scheme for this purpose. In order to test the idea of coding action-oriented knowledge for IS experts, the paper reports the results of a coded literature analysis of ISD research articles published from 1996 to 2000 in two leading IS journals , Information Systems Journal and MIS Quarterly. The results suggest that ISD approaches form a useful framework for organizing practically relevant IS knowledge. [source]

A new progressive coding scheme for halftone dithered images using bit-interleaving

INTERNATIONAL JOURNAL OF IMAGING SYSTEMS AND TECHNOLOGY, Issue 4 2006
Jing-Ming Guo
Abstract A novel progressive coding scheme is presented for the efficient display of dithered images. Dithered images are the results of thresholding original gray-level images with dithering screens. After the preprocessing of bit-interleaving, this algorithm utilizes the characteristic of reordered image to determine the transmitting order and then progressively reconstructs the dithered image. In addition, the dithered images are further compressed by lossy and lossless procedures. The experimental results demonstrate high-quality reconstructions while maintaining low transmitted bit rates. Moreover, an objective error criterion obtained by LMS optimization is also presented in this study. As documented in the experiments, the error criterion is quite consistent to the basic characteristic of human visual system. © 2007 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 16, 121,127, 2006. [source]

Image coding based on wavelet feature vector

INTERNATIONAL JOURNAL OF IMAGING SYSTEMS AND TECHNOLOGY, Issue 2 2005
Shinfeng D. Lin
Abstract In this article, an efficient image coding scheme that takes advantages of feature vector in wavelet domain is proposed. First, a multi-stage discrete wavelet transform is applied on the image. Then, the wavelet feature vectors are extracted from the wavelet-decomposed subimages by collecting the corresponding wavelet coefficients. And finally, the image is coded into bit-stream by applying vector quantization (VQ) on the extracted wavelet feature vectors. In the encoder, the wavelet feature vectors are encoded with a codebook where the dimension of codeword is less than that of wavelet feature vector. By this way, the coding system can greatly improve its efficiency. However, to fully reconstruct the image, the received indexes in the decoder are decoded with a codebook where the dimension of codeword is the same as that of wavelet feature vector. Therefore, the quality of reconstructed images can be preserved well. The proposed scheme achieves good compression efficiency by the following three methods. (1) Using the correlation among wavelet coefficients. (2) Placing different emphasis on wavelet coefficients at different decomposing levels. (3) Preserving the most important information of the image by coding the lowest-pass subimage individually. In our experiments, simulation results show that the proposed scheme outperforms the recent VQ-based image coding schemes and wavelet-based image coding techniques, respectively. Moreover, the proposed scheme is also suitable for very low bit rate image coding. © 2005 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 15, 123,130, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ima.20045 [source]

Wavelet-based adaptive vector quantization for still-image coding

INTERNATIONAL JOURNAL OF IMAGING SYSTEMS AND TECHNOLOGY, Issue 4 2002
Wen-Shiung Chen
Abstract Wavelet transform coding (WTC) with vector quantization (VQ) has been shown to be efficient in the application of image compression. An adaptive vector quantization coding scheme with the Gold-Washing dynamic codebook-refining mechanism in the wavelet domain, called symmetric wavelet transform-based adaptive vector quantization (SWT-GW-AVQ), is proposed for still-image coding in this article. The experimental results show that the GW codebook-refining mechanism working in the wavelet domain rather than the spatial domain is very efficient, and the SWT-GW-AVQ coding scheme may improve the peak signal-to-noise ratio (PSNR) of the reconstructed images with a lower encoding time. © 2002 Wiley Periodicals, Inc. Int J Imaging Syst Technol 12, 166,174, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ima.10024 [source]

A study of argumentation in a causal probabilistic humanistic domain: Genetic counseling

INTERNATIONAL JOURNAL OF INTELLIGENT SYSTEMS, Issue 1 2007
Nancy Green
We present the results of an in-depth qualitative analysis of argumentation in two genetic counseling patient letters. In addition to argumentation techniques designed for medical experts, we found other types of causal argumentation designed for lay readers, reflecting the educational and supportive counseling functions of these letters. Analysis was facilitated by use of a coding scheme for representing causal probabilistic biomedical content of the letters as Bayesian networks. We define the argument techniques used in the letters in terms of Bayesian network, semantic network, argumentation theory, and user model concepts rather than in terms of genetics concepts. © 2007 Wiley Periodicals, Inc. Int J Int Syst 22: 71,93, 2007. [source]

Robust and efficient quantization and coding for control of multidimensional linear systems under data rate constraints

INTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 10-11 2007
K. Li
Abstract Recently, we reported results on coding strategies for scalar feedback systems with data-rate-limited feedback channels in which the data-rate constraints are time varying. Such rate-varying channels are typically encountered in communication networks in which links between nodes are subject to noise, congestion, and intermittent disruption. The present paper describes results of extending this research into the multidimensional domain. An important consideration is that for systems of dimension greater than one, many classical feedback designs cannot be realized for operation near the theoretical minimum possible data rate. A novel control coding scheme will be presented, and in terms of this, it will be shown that the advantages of coarse signal quantization that had been reported earlier for scalar systems remain in the multidimensional case. The key is to allocate the communication bandwidth efficiently among faster and slower modes. We discuss various strategies that allocate bandwidth by scheduling the time slots assigned to each mode. In particular, we propose a ,robust attention varying' technique, whose merit will be discussed in terms of its robustness with respect to time-varying communication channel capacity and also in terms of how well it operates when the feedback channel capacity is near the theoretical minimum data rate. Copyright © 2006 John Wiley & Sons, Ltd. [source]

An Evaluation of How Well Research Reports Facilitate the Use of Findings in Practice

JOURNAL OF NURSING SCHOLARSHIP, Issue 2 2006
Jennifer Leeman
Purpose: To analyze how research is reported in journal publications as a potential barrier to use of research findings in practice. Design: Content analysis of 46 reports of diabetes self-management interventions published between 1993 and 2004. Methods: Data were extracted from the publications using a coding scheme based on concepts from Rogers' theory of the diffusion of innovations. Findings: Authors provided only some of the information potential users need to progress through Roger's stages of adopting an intervention and implementing it in practice. Authors provided only limited information on the target population; frequency, number, and duration of patient contacts; expertise and training required to deliver the intervention; intervention protocol; and the process of adapting and implementing interventions in practice settings. Conclusions: To close the gap between research and practice, authors should offer more information to help readers decide whether and how to adopt and implement interventions. [source]

Students' and teachers' perceived and actual verbal interactions in seminar groups

MEDICAL EDUCATION, Issue 4 2009
A Debbie C Jaarsma
Objectives, This study set out to examine how much time students and teachers devote to different learning-oriented interactions during seminar sessions and students' and teachers' perceptions about the occurrence and desirability of these interactions. Methods, Students and teachers participating in eight seminar group sessions in Year 4 of an undergraduate veterinary curriculum completed an 11-item questionnaire which asked them to rate, on a 5-point Likert scale, the frequency of occurrence and level of desirability of three learning-oriented types of interaction: exploratory questioning; cumulative reasoning, and handling of conflict about knowledge. The questionnaire also invited positive and negative responses to aspects of group interactions and an overall mark (1,10) for the seminars and group interactions. Four group sessions were video-recorded and analysed using a coding scheme. The amount of time devoted to the different interactions was calculated. Results, Both students and teachers gave scores of 3.0,3.5 for frequency of occurrence of exploratory questioning and cumulative reasoning and < 3.0 for occurrence of handling of conflict about knowledge. The desired occurrences of all interaction types were significantly higher than the actual occurrences according to students and teachers. Teachers were responsible for the majority of the interactions (93%). The percentages of session time devoted to teacher-centred cumulative reasoning, exploratory questioning and handling of conflict about knowledge were 65.8%, 15.6% and 3.1%, respectively. Conclusions, Group interactions in seminar groups are dominated by the posing of questions by teachers to students. The moderate occurrence of group interactions as perceived by students and teachers may be explained by the inadequate preparation of teachers and students to stimulate group interactions. [source]

Do human figure diagrams help alleged victims of sexual abuse provide elaborate and clear accounts of physical contact with alleged perpetrators?

APPLIED COGNITIVE PSYCHOLOGY, Issue 2 2010
Yee-San Teoh
The present study examined whether the use of human figure diagrams (HFDs) within a well-structured interview was associated with more elaborate and clearer accounts about physical contact that had occurred in the course of an alleged abuse. The sample included investigative interviews of 88 children ranging from 4 to 13 years of age. Children were interviewed using the NICHD investigative interview protocol, and were then asked a series of questions in association with unclothed gender-neutral outline diagrams of a human body. A new coding scheme was developed to examine the types and clarity of touch-related information. Use of the HFDs was associated with reports of new touches not mentioned before and elaborations regarding the body parts reportedly touched. The HFDs especially helped clarify reports by the oldest rather than the youngest children. The clarity of children's accounts of touch was also greater when details were sought using recall prompts. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Auditory substitution of vision: pattern recognition by the blind

APPLIED COGNITIVE PSYCHOLOGY, Issue 5 2001
P. Arno
Pattern recognition in a computer environment was investigated in 6 early blind and 6 blindfolded sighted subjects using auditory substitution of vision. Subjects had to scan visual patterns displayed on a PC screen by moving the pen of a graphics tablet, which lead to corresponding displacements of the cursor on the screen. A small screen area centered on the pointer was then translated into sounds according to a visual-auditory transcription code. Subjects were trained to learn this code during 12 one-hour sessions. Performance of both groups significantly increased with practice. This indicates that mental representations of visual patterns can be acquired through the auditory channel, even in the absence of visual experience. Moreover, blind subjects performed significantly better than sighted subjects did. This could be interpreted as a result of partial compensation for their loss of vision. Pattern recognition in a computer environment is thus possible using a fairly natural vision-to-audition coding scheme. Copyright © 2001 John Wiley & Sons, Ltd. [source]

Prognostic ability of simplified nuclear grading of renal cell carcinoma

CANCER, Issue 5 2007
Nathalie Rioux-Leclercq MD
Abstract BACKGROUND. The Fuhrman grading system is an established predictor of survival in patients with renal cell carcinoma (RCC). The predictive accuracy of various Fuhrman grading schemes was tested with the intent of improving the prediction of RCC-specific survival (RCC-SS). METHODS. The analyses targeted 5453 patients from 14 institutions. Univariable, multivariable, and predictive accuracy analyses addressed RCC-SS. The statistical significance of the gain in predictive accuracy was quantified with the Mantel-Haenszel test. RESULTS. The median follow-up time was 4.5 years. In both univariable and multivariable analyses, Fuhrman grade achieved independent predictor status regardless of the coding scheme. When Fuhrman grade was not considered in multivariable analyses, the predictive accuracy was 83.8%. Addition of Fuhrman grade to the multivariable model resulted in predictive accuracy gains of 0.8% for all 3 grading schemes tested. CONCLUSION. Fuhrman grade must to be considered when RCC-SS is assessed. However, modified or conventional Fuhrman grading schemes perform equally well as the conventional grading system. Cancer 2007 © 2007 American Cancer Society. [source]

Reconceptualizing Children's Suggestibility: Bidirectional and Temporal Properties

CHILD DEVELOPMENT, Issue 1 2005
Livia L. Gilstrap
Forty-one children (3 to 7 years) were exposed to a staged event and later interviewed by 1 of 41 professional interviewers. All interviews were coded with a detailed, mutually exclusive, and exhaustive coding scheme capturing adult behaviors (leading questions vs. neutral) and child behaviors (acquiescence vs. denial) in a temporally organized manner. Overall, interviewers' use of leading questions did not result in increased acquiescence as previously found. However, one specific type of leading question (i.e., inaccurate misleading) was followed by acquiescence. Lagged sequential analyses showed that it was possible to predict directly from child-to-child behavior, effectively skipping the intervening adult behavior. This result raises questions about the current conceptualization that suggestibility is driven by adult behaviors. [source]

CGU-frame-based representations and their connection with Reed,Solomon and DCT/DST coding schemes

Improved genetic algorithm for design optimization of truss structures with sizing, shape and topology variables

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 13 2005
Wenyan Tang
Abstract This paper presents an improved genetic algorithm (GA) to minimize weight of truss with sizing, shape and topology variables. Because of the nature of discrete and continuous variables, mixed coding schemes are proposed, including binary and float coding, integer and float coding. Surrogate function is applied to unify the constraints into single one; moreover surrogate reproduction is developed to select good individuals to mating pool on the basis of constraint and fitness values, which completely considers the character of constrained optimization. This paper proposes a new strategy of creating next population by competing between parent and offspring population based on constraint and fitness values; so that lifetime of excellent gene is prolonged. Because the initial population is created randomly and three operators of GA are also indeterminable, it is necessary to check whether the structural topology is desirable. An improved restart operator is proposed to introduce new gene and explore new space, so that the reliability of GA is enhanced. Selected examples are solved; the improved numerical results demonstrate that the enhanced GA scheme is feasible and effective. Copyright © 2005 John Wiley & Sons, Ltd. [source]

Bandwidth-efficient turbo coding over Rayleigh fading channels

INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 7 2002
Stéphane Y. Le Goff
Abstract Introduced in 1993, turbo codes can achieve high coding gains close to the Shannon limit. In order to design power and bandwidth-efficient coding schemes, several approaches have been introduced to combine high coding rate turbo codes with multilevel modulations. The coding systems thus obtained have been shown to display near-capacity performance over additive white Gaussian noise (AWGN) channels. For communications over fading channels requiring large coding gain and high bandwidth efficiency, it is also interesting to study bit error rate (BER) performance of turbo codes combined with high order rectangular QAM modulations. To this end, we investigate, in this paper, error performance of several bandwidth-efficient schemes designed using the bit-interleaved coded modulation approach that has proven potentially very attractive when powerful codes, such as turbo codes, are employed. The structure of these coding schemes, termed ,bit-interleaved turbo-coded modulations' (BITCMs), is presented in a detailed manner and their BER performance is investigated for spectral efficiencies ranging from 2 to 7 bit/s/Hz. Computer simulation results indicate that BITCMs can achieve near-capacity performance over Rayleigh fading channels, for all spectral efficiencies considered throughout the paper. It is also shown that the combination of turbo coding and rectangular QAM modulation with Gray mapping constitutes inherently a very powerful association, since coding and modulation functions are both optimized for operation in the same signal-to-noise ratio region. This means that no BER improvement is obtainable by employing any other signal constellation in place of the rectangular ones. Finally, the actual influence of the interleaving and mapping functions on error performance of BITCM schemes is discussed. Copyright © 2002 John Wiley & Sons, Ltd. [source]

Image coding based on wavelet feature vector

Signal reconstruction in the presence of finite-rate measurements: finite-horizon control applications

INTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 1 2010
Sridevi V. Sarma
Abstract In this paper, we study finite-length signal reconstruction over a finite-rate noiseless channel. We allow the class of signals to belong to a bounded ellipsoid and derive a universal lower bound on a worst-case reconstruction error. We then compute upper bounds on the error that arise from different coding schemes and under different causality assumptions. When the encoder and decoder are noncausal, we derive an upper bound that either achieves the universal lower bound or is comparable to it. When the decoder and encoder are both causal operators, we show that within a very broad class of causal coding schemes, memoryless coding prevails as optimal, imposing a hard limitation on reconstruction. Finally, we map our general reconstruction problem into two important control problems in which the plant and controller are local to each other, but are together driven by a remote reference signal that is transmitted through a finite-rate noiseless channel. The first problem is to minimize a finite-horizon weighted tracking error between the remote system output and a reference command. The second problem is to navigate the state of the remote system from a nonzero initial condition to as close to the origin as possible in finite-time. Our analysis enables us to quantify the tradeoff between time horizon and performance accuracy, which is not well studied in the area of control with limited information as most works address infinite-horizon control objectives (e.g. stability, disturbance rejection). Copyright © 2009 John Wiley & Sons, Ltd. [source]

Relationships between nurse care-giving behaviours and preterm infant responses during bathing: a preliminary study

JOURNAL OF CLINICAL NURSING, Issue 1-2 2010
Jen-Jiuan Liaw
Aims., The purpose of this study was to explore the relationships between specific nurse care-giving behaviours and preterm infant behavioural responses during bathing and to identify nurse behaviours associated with infant ,stress'. Background., Although recent advances in medical technology have improved neonatal intensive care, the high mortality and morbidity rates in preterm infants have not decreased proportionally. As caregivers strive to reduce infant mortality and morbidity, a factor for consideration is which caregiver behaviours are associated with preterm infant well-being. Design., A descriptive correlational design. Method., Convenience samples of 24 preterm infants and 12 nurses were recruited. A total of 120 baths were videotaped. Infant and nurse behaviours were measured using the coding schemes developed by the researchers. Pearson coefficient correlation, non-parametric Kruskal,Wallis test, t -test and generalised linear models were methods for data analysis. Results., As nurses provided more support, stress was reduced in the infants, and their self-regulation during the bath was enhanced especially by the use of ,containment' and ,positional support'. Conversely, non-therapeutic caregiver behaviours including ,rapid and rough handling' of the baby, ,chatting with other people' and ,inappropriate handling' increased infant ,stress' during the bath. Conclusion., The findings provide new information about the link between care-giving and infant responses and how caregivers can better interact with preterm infants during a very sensitive period of brain development. Relevance to clinical practice., How nurses take care of the preterm infants influences their responses to care-giving stimuli. To interact better with the infant during care-giving procedures, nurses need to provide more supportive care-giving behaviours especially ,position support' and ,containment' based on the infant's needs, and avoid care-giving that may be too rough and occur too quickly without attending the baby's stressful signals, positioning the baby in hyperextension posture, or chatting with other people during procedures. [source]