Off-line Processes Research Articles

An Improved Delegation-Based Authentication Protocol for PCSs

A new delegation-based authentication protocol was proposed by Lee and Yeh in 2005, claiming that they have provided users with Portable Communication Systems (PCS), which are anonymity and non-repudiation. However, they have also pointed out that their protocol has a weakness in off-line authentication processes. That is, a malicious who visits location register ( VLR ) can masquerade another mobile user to login to home location register ( HLR ). To solve this weakness, Lee et al. later on proposed an improved protocol, which slightly modified the original one Unfortunately, we found out that Lee et al.’s protocol still cannot achieve user anonymity and does not provide perfect forward secrecy. In this paper, we first utilize Lee et al.’s protocol to demonstrate that Lee-Yeh’s protocol has an instinctive design flaw. Furthermore, we propose a modification to improve Lee et al.’s protocol to overcome these weaknesses. DOI: http://dx.doi.org/10.5755/j01.itc.41.3.857

Valproic acid but not d-cycloserine facilitates sleep-dependent offline learning of extinction and habituation of conditioned fear in humans

The effectiveness of d-cycloserine (DCS), an N-methyl-d-aspartate glutamate receptor partial agonist, and valproic acid (VPA), a histone deacetylase inhibitor, in facilitating the extinction of fear-conditioned memory has been explored in humans and animals. Here, we confirmed whether DCS (100 mg) and VPA (400 mg) act in off-line learning processes during sleep or waking, for further clinical application to anxiety disorders and posttraumatic stress disorder (PTSD). We performed a randomized, blind, placebo-controlled clinical trial in 90 healthy adults. Visual cues and electric shocks were used as the conditioned stimulus (CS) and unconditioned stimulus (US), respectively. The extinction effect was observed not in simple recall after the extinction of coupled CS–US, but was observed in the post-re-exposure phase after unexpected re-exposure to reinstatement CS–US coupling. Newly acquired conditioned fear was also eliminated or habituated by DCS and VPA administration, in line with previous findings. Furthermore, VPA facilitated the off-line learning process of conditioned fear extinction and habituation during sleep, while DCS facilitated this process during waking. These novel findings suggest that DCS and VPA might enhance exposure-based cognitive therapy for anxiety disorders and PTSD by reducing the vulnerability to reinstatement and preventing relapses of fear-conditioned responses, and provide evidence for a peculiarity of the sleep-dependent off-line learning process for conditioned fear extinction.This article is part of a Special Issue entitled ‘Cognitive Enhancers’.

Mirror neurons as a conceptual mechanism?

The functional role of mirror neurons has been assessed in many different ways. They have been regarded, inter alia, as the core mechanism of mind reading, the mechanism of language understanding, the mechanism of imitation. In this paper we will discuss the thesis according to which MNs are a conceptual mechanism. This hypothesis is attractive since it could accommodate in an apparently simple way all the above-mentioned interpretations. We shall take into consideration some reasons suggesting the conceptualist characterization of MNs, as well as some possible replies. We shall figure out how an argument for the conceptualist hypothesis could be deployed, focusing on the notion of off-line processes, which turns out to be the crucial (and maybe problematic for mirror processes) property necessary to ascribe concept possession. Our conclusion will be that, despite of there being some evidence for the conceptualist account, the issue cannot be definitely settled, because there are both experimental shortages and conceptual difficulties. In particular, there are (at least) three distinct senses in which MNs can be regarded as a conceptual mechanism, but we shall argue that only one of these interpretations can be defended.

Real-time stylistic prediction for whole-body human motions

The ability to predict human motion is crucial in several contexts such as human tracking by computer vision and the synthesis of human-like computer graphics. Previous work has focused on off-line processes with well-segmented data; however, many applications such as robotics require real-time control with efficient computation. In this paper, we propose a novel approach called real-time stylistic prediction for whole-body human motions to satisfy these requirements. This approach uses a novel generative model to represent a whole-body human motion including rhythmic motion (e.g., walking) and discrete motion (e.g., jumping). The generative model is composed of a low-dimensional state (phase) dynamics and a two-factor observation model, allowing it to capture the diversity of motion styles in humans. A real-time adaptation algorithm was derived to estimate both state variables and style parameter of the model from non-stationary unlabeled sequential observations. Moreover, with a simple modification, the algorithm allows real-time adaptation even from incomplete (partial) observations. Based on the estimated state and style, a future motion sequence can be accurately predicted. In our implementation, it takes less than 15 ms for both adaptation and prediction at each observation. Our real-time stylistic prediction was evaluated for human walking, running, and jumping behaviors.

Overpressured Layer Chromatography (OPLC) – A Flexible Tool of Analysis and Isolation

This review briefly summarizes the overpressured layer chromatography (OPLC) technique and its progress from the beginning until today. Some theoretical aspects, important technical and methodological solutions, as well as analytical separations and isolations are demonstrated covering the last 30 years. The infusion and transfusion OPLC operations, as well as their combination, and their off-line and on-line processes, and off-line and on-line hyphenations for detection and structure elucidation are presented. The combination of OPLC separation with biological detection by direct bioautography and BioArena as an important solution touches the potential of analysis and isolation based on biological activity.

Brain plasticity related to the consolidation of motor sequence learning and motor adaptation

This study aimed to investigate, through functional MRI (fMRI), the neuronal substrates associated with the consolidation process of two motor skills: motor sequence learning (MSL) and motor adaptation (MA). Four groups of young healthy individuals were assigned to either (i) a night/sleep condition, in which they were scanned while practicing a finger sequence learning task or an eight-target adaptation pointing task in the evening (test) and were scanned again 12 h later in the morning (retest) or (ii) a day/awake condition, in which they were scanned on the MSL or the MA tasks in the morning and were rescanned 12 h later in the evening. As expected and consistent with the behavioral results, the functional data revealed increased test-retest changes of activity in the striatum for the night/sleep group compared with the day/awake group in the MSL task. By contrast, the results of the MA task did not show any difference in test-retest activity between the night/sleep and day/awake groups. When the two MA task groups were combined, however, increased test-retest activity was found in lobule VI of the cerebellar cortex. Together, these findings highlight the presence of both functional and structural dissociations reflecting the off-line consolidation processes of MSL and MA. They suggest that MSL consolidation is sleep dependent and reflected by a differential increase of neural activity within the corticostriatal system, whereas MA consolidation necessitates either a period of daytime or sleep and is associated with increased neuronal activity within the corticocerebellar system.

Phonological loop and central executive contributions to oral comprehension skills of 5.5 to 9.5 years old children

Summary Oral story comprehension in 5.5, 7.5 and 9.5 year old children is examined in relation to working memory (WM) contributions. The phonological loop (PL) of the Baddeley and Hitch WM model was assessed with word, non-word and digit recall and a word list matching task. The central executive (CE) was assessed with listening, counting and backward digit recall tasks. A composite score was calculated for each WM component. Receptive vocabulary and oral comprehension were also assessed. Regression analyses demonstrated CE contributions to oral comprehension overall, and also to comprehension sub-skills (above any vocabulary contributions). Effects were stronger in preschoolers and decreased with age. The PL did not play an important role in oral comprehension. Comprehension control was the comprehension skill best predicted. The study demonstrates the CE importance in off-line comprehension processes during early childhood and the usefulness of assessing CE processes for identifying possible comprehension difficulties later at school. Copyright © 2010 John Wiley & Sons, Ltd.

Enhanced delegation-based authentication protocol for PCSs

Lee and Yeh recently presented a delegation-based authentication protocol for portable communication systems (PCSs), which is claimed to provide non-repudiation in on-line authentication. This investigation indicates that their protocol has a weakness in that a malicious visited location register can forge the authentication messages in off-line authentication processes, preventing mobile users from obtaining non-repudiation in such processes. This study also presents an enhanced protocol, which not only has the same security properties as the original protocol but also avoids the weakness in the original scheme and reduces the computational cost.

Recurrent boosting effects of short inactivity delays on performance: an ERPs study

BackgroundRecent studies investigating off-line processes of consolidation in motor learning have demonstrated a sudden, short-lived improvement in performance after 5–30 minutes of post-training inactivity. Here, we investigated further this behavioral boost in the context of the probabilistic serial reaction time task, a paradigm of implicit sequence learning. We looked both at the electrophysiological correlates of the boost effect and whether this phenomenon occurs at the initial training session only.FindingsReaction times consistently improved after a 30-minute break within two sessions spaced four days apart, revealing the reproducibility of the boost effect. Importantly, this improvement was unrelated to the acquisition of the sequential regularities in the material. At both sessions, event-related potentials (ERPs) analyses disclosed a boost-associated increased amplitude of a first negative component, and shorter latencies for a second positive component.ConclusionBehavioral and ERP data suggest increased processing fluency after short delays, which may support transitory improvements in attentional and/or motor performance and participate in the final setting up of the neural networks involved in the acquisition of novel skills.

Rapid and Accurate Quantification of Right Ventricular Volume and Stroke Volume by Real‐time 3‐Dimensional Triplane Echocardiography

Previous studies have demonstrated that 3-Dimensional (3-D) echocardiography can determine right ventricular (RV) volume accurately. However, this technique has not been feasible in everyday clinical practice because of the necessity of time-consuming off-line processes. A newly developed real-time 3-D triplane echocardiography, which acquires 3 apical rotational cross-sectional images simultaneously, holds the promise to resolve these problems. Sixteen excised formalin fixed porcine hearts and 24 healthy human subjects underwent real-time 3-D triplane echocardiography. In an anatomic in vitro study, the actual volume of RV was obtained by spilling water in the RV cavity into a graduated cylinder for measurement, which served as a reference standard for comparison. For healthy subjects, the RV stroke volume (SV) was measured by triplane echocardiography which was compared with the left ventricular (LV) SV obtained by conventional 2-Dimensional echocardiography (2-DE). Excellent correlation and agreement between 3-D triplane imaging derived RV volume and the actual one for excised porcine hearts were observed (r = 0.979, p < 0.001, mean difference 2.2 mL). In healthy human subjects, good correlation and agreement between 3-D triplane imaging derived RV SV and LV SV measured by 2-DE were obtained (r = 0.970, p < 0.001, mean difference 5.9 mL). Real-time 3-D triplane echocardiography provides us a new method for rapid and accurate quantification of RV volume. Furthermore, this new method holds the promise for evaluating RV volume and SV in routine clinical practice.

Real-time respiration monitoring using the radiotherapy treatment beam and four-dimensional computed tomography (4DCT)—a conceptual study

Real-time knowledge of intra-fraction motion, such as respiration, is essential for four-dimensional (4D) radiotherapy. Surrogate-based and internal-fiducial-based methods may suffer from one or many drawbacks such as false correlation, being invasive, delivering extra patient radiation, and requiring complicated hardware and software development and implementation. In this paper we develop a simple non-surrogate, non-invasive method to monitor respiratory motion during radiotherapy treatments in real time. This method directly utilizes the treatment beam and thus imposes no additional radiation to the patient. The method requires a pre-treatment 4DCT and a real-time detector system. The method combines off-line processes with on-line processes. The off-line processes include 4DCT imaging and pre-calculating detector signals at each phase of the 4DCT based on the planned fluence map and the detector response function. The on-line processes include measuring detector signal from the treatment beam, and correlating the measured detector signal with the pre-calculated signals. The respiration phase is determined as the position of peak correlation. We tested our method with extensive simulations based on a TomoTherapy machine and a 4DCT of a lung cancer patient. Three types of simulations were implemented to mimic the clinical situations. Each type of simulation used three different TomoTherapy delivery sinograms, each with 800 to 1000 projections, as input fluences. Three arbitrary breathing patterns were simulated and two dose levels, 2 Gy/fraction and 2 cGy/fraction, were used for simulations to study the robustness of this method against detector quantum noise. The algorithm was used to determine the breathing phases and this result was compared with the simulated breathing patterns. For the 2 Gy/fraction simulations, the respiration phases were accurately determined within one phase error in real time for most projections of the treatment, except for a few projections at the start and end of the treatment in which beam intensities were extremely low. At 2 cGy/fraction dose level, the method can still determine the respiration phase very well with less than 10% of projections having more than two phases (∼1 s) error. This technique can also be applied in other delivery systems such as orthogonal x-ray systems, although in those cases it would entail the delivery of additional non-treatment radiation.

SU‐DD‐A3‐03: A Dose‐Guided Adaptive Therapy Process for Treatment Evaluation and Correction

Purpose: To develop an adaptive therapy process for off‐line radiotherapy evaluation and modification. Method and Materials: An adaptive therapy process was developed to analyze and adjust a patient treatment. This included:Daily Online Processes• Daily CT imaging• Patient repositioningWeekly Offline Processes• Automatic dose recalculation on each daily image• Automatic deformable registration of each image with the planning image• Automatic deformation‐based recontouring of each image• Automatic deformation‐based dose accumulation• Cumulative plan evaluation• Replanning, as neededThe on‐line imaging and repositioning was performed with the TomoTherapy MVCT system and integrated registration software. The off‐line processes were performed on a standalone workstation.Head and neck cases were studied with this process. Cumulated doses were typically analyzed at the end of each week, and modifications were performed mid‐course. Remaining treatments were then performed with the adapted plan. Results: It was found that CT‐guided soft‐tissue positioning alone did not protect against dosimetric changes due to patient weight loss. Without plan adaptation, the right parotid gland would have received a dose of 10 Gy above the plan, due to its medial motion towards the target region. However, since mid‐course adaptive replanning was used, the dose was only 2.5 Gy above the original plan. The use of an additional plan adaptation could have further reduced this discrepancy. Conclusion: An adaptive therapy process was developed for off‐line contouring, dose recalculation, dose accumulation, and replanning. This process was applied to clinical head and neck patients to evaluate on‐going treatments, adjust plans, and retrospectively assess the results. This process reduced unexpected parotid dose for these patients. This process also indicated that ability to recalculate to accumulate doses on daily CT images is important for addressing systematic errors, such as anatomical changes, that may arise during a treatment.Supported by TomoTherapy, Inc.

Digital Glossing, Its Applications and Performance Evaluation

In Graphic Arts industry, the surface treatment of glossing provides two major functions to the printed sheets. The first is to accentuate the piece giving it more emphasis and the second is to serve as a protecting layer against damage to the information underneath. The common practice of glossing involves both in-line and off-line processes of aqueous, varnish, Ultra Violet (UV) and lamination. Aqueous and varnish could be applied in-line using one of the inking units of an offset press. UV could be applied through a build-in device that's part of the offset press or an offline UV applicator. Aqueous and UV could be done real-time but varnish has to be applied after the printed ink is dry completely, usually overnight. Lamination is an off-line process adhering a layer of glossy thin film material on top of the entire printed sheet to deliver high gloss if so desired and this is gloss lamination. When a layer of matte film is applied to the printed sheet it will give a matte appearance instead of glossy and it's known as matte lamination. Both solid and liquid films are available for lamination processes. The gloss lamination could achieve a gloss level of 80 (G20) or higher.Several attempts were made by the digital printing industry to increase the overall gloss level of electro-photographic prints. They include both in-line and off-line processes. The results were mixed. Gloss lamination and UV coating remain as the two major methods to provide high gloss for electro-photographic prints.1 A novel method to deliver high gloss on these prints is being reported in this article.2 This approach utilizes a belt in fusing a layer of Clear DryInk overcoat on top of a printed sheet to achieve a high level of gloss. It also makes use of barcodes and barcode-scanner to communicate the machine parameters between the digital press and the glossing unit hence an optimized system level near-line solution. Several substrates were tested using this method in comparison to aqueous, varnish, UV and lamination. The achieved gloss level and protection performance were reported in this study.

Memory Processing during Sleep Mechanisms and Evidence from Neuroimaging Studies

————— A growing number of studies support the hypothesis that sleep participates in the off-line processing of recent memories. However, many determinants and outcomes of memory reprocessing during sleep remain to be identified. This review provides a summary description of the main behavioural, neurophysiological and hemodynamic features of sleep, with a special emphasis on sleep mechanisms deemed potentially important to support sleep-related brain plasticity and memory consolidation: PGO-waves, spindles and hippocampal rhythms. Next are presented brain imaging studies having demonstrated the reexpression and modulation of learning-related cerebral activity during posttraining sleep in humans. As a whole, functional neuroimaging results nowadays suggest that learning-dependent modulations in cerebral activity during human sleep reflect the offline processing of recent memory traces, which eventually leads to the plastic changes underlying the subsequent improvement in performance. Circulating blood in the cardiovascular system, respiring and sleeping have in common to be essential for the integrity and survival of most living organisms including humans. What makes unique the latter is that we have no certainty as to the function(s) supported by sleep, despite an increasing knowledge of its semiology, mechanisms and regulation. Nonetheless, the infinite repetition of sleep episodes, from the first to the last night of one’s life, suggests that sleep houses a series of processes necessary for normal brain function. Among several non-exclusive proposals, the hypothesis that sleep is a favourable period for brain plasticity has received increasing attention in the last 25 years (Maquet, Smith, & Stickgold, 2003). We will deal here with the corollary hypothesis that brain plasticity during sleep participates in the off-line processes of learning and memory consolidation.

On the role of peripheral visual afferent information for the control of rapid video-aiming movements

It has been shown that, even for very fast and short duration movements, seeing one’s hand in peripheral vision, or a cursor representing it on a video screen, resulted in a better direction accuracy of a manual aiming movement than when the task was performed while only the target was visible. However, it is still unclear whether this was caused by on-line or off-line processes. Through a novel series of analyses, the goal of the present study was to shed some light on this issue. We replicated previous results showing that the visual information concerning one’s movement, which is available between 40° and 25° of visual angle, is not useful to ensure direction accuracy of video-aiming movements, whereas visual afferent information available between 40° and 15° of visual angle improved direction accuracy over a target-only condition. In addition, endpoint variability on the direction component of the task was scaled to direction variability observed at peak movement velocity. Similar observations were made in a second experiment when the position of the cursor was translated to the left or to the right as soon as it left the starting base. Further, the data showed no evidence of on-line correction to the direction dimension of the task for the translated trials. Taken together, the results of the two experiments strongly suggest that, for fast video-aiming movements, the information concerning one’s movement that is available in peripheral vision is used off-line.

Norman's dual model in a broader context

This commentary suggests how Norman's dual control model of vision can be fitted into a broader general model of the control of behaviour by direct (on-line) and indirect (off-line) processes. Some general principles of behavioural organization, development, and competition are described and their specific application to vision is noted.

Reduction of post exposure delay time and contamination sensitivity in chemically amplified resists: application for lithography using off-line environment

The chemically amplified concept is directly linked to the diffusion capabilities of the photo-generated acid. As a consequence of this principle, delay time effect during processing may affect lithographic performance. This paper discusses the post exposure delay time impact on final image formation. It presents a solution based on inert atmosphere storage for off-line lithographic processes with which sub-50-nm patterns can be resolved even if the wafer is stored for more than 24 h after exposure.

Case‐Base Maintenance in a Multimodal Reasoning System

The definition of suitable case‐base maintenance policies is widely recognized as a major key to success for case‐based systems; underestimating this issue may lead to systems that either do not fulfill their role of knowledge management and preservation or that do not perform adequately under performance dimensions, namely, computation time and competence and quality of solutions. The goal of this article is to analyze some automatic case‐base management strategies in the context of a multimodal architecture combining case‐based reasoning and model‐based reasoning. We propose and compare two different methodologies, the first one, called replace, is a competence‐based strategy aimed at replacing a set of stored cases with the current one, if the latter exhibits an estimated competence comparable with the estimated competence of the considered set of stored cases. The second one, called learning by failure with forgetting (LFF), is based on incremental learning of cases interleaved with off‐line processes of forgetting (deleting) cases whose usage does not fulfill specific utility conditions. Results from an extensive experimental analysis in an industrial plant diagnosis domain are reported, showing the usefulness of both strategies with respect to the maintenance of suitable performance levels for the target system.

High Speed Opti Concept Line for Coated Woodfree Paper

The production of coated fine paper has, until now, mainly been based on separate processes. where base paper coating and calendering were off-line processes. A change has taken place in woodcontaining grades, all-on-line processes are already in production. The benefits are clear. Investment costs are significantly smaller than before, as well as running costs. The total efficiency of the paper making line can also be improved. despite the fact that it is more challenging to maintain time efficiency in an on-line process. Through long and thorough study, we can now present a new member of Opti-Concept family: a high speed OptiConcept line for coated woodfree paper.

Associative priming by targets and distractors during rapid serial visual presentation: Does word meaning survive the attentional blink?

In 5 experiments, 432 college students viewed lists of words containing 2 targets (Target 1 [T1] and Target 2 [T2]) presented by rapid serial visual presentation at 10 words per second. Identification of T1 caused a 500-ms impairment in the identification of T2 (the attentional blink [AB]). Improved recall of T2 was observed throughout the time course of the AB when T2 was a strong associate of either T1 or a priming distractor (PD). When participants ignored T1, the AB was eliminated, but the amount of priming was not affected. Priming of T2 by PD was temporary (100-200 ms after the onset of PD). Although target priming and distractor priming both survived the AB, the 2 forms of priming appeared to have different bases. In contrast to priming by PD, priming by T1 was larger, modulated by backward associative strength, and longer lasting. Priming and the AB are hypothesized to result from on-line attentional processes, but recall from RSVP lists is also influenced by off-line memory processes.