High capacity adaptive image steganography with cover region selection using dual-tree complex wavelet transform

The importance of image steganography is unquestionable in the field of secure multimedia communication. Imperceptibility and high payload capacity are some of the crucial parts of any mode of steganography. The proposed work is an attempt to modify the edge-based image steganography which provides higher payload capacity and imperceptibility by making use of machine learning techniques. The approach uses an adaptive embedding process over Dual-Tree Complex Wavelet Transform (DT-CWT) subband coefficients. Machine learning based optimization techniques are employed here to embed the secret data over optimal cover-image-blocks with minimal retrieval error. The embedding process will create a unique secret key which is imperative for the retrieval of data and need to be transmitted to the receiver side via a secure channel. This enhances the security concerns and avoids data hacking by intruders. The algorithm performance is evaluated with standard benchmark parameters like PSNR, SSIM, CF, Retrieval error, BPP and Histogram. The results of the proposed method show the stego-image with PSNR above 50 dB even with a dense embedding of up to 7.87 BPP. This clearly indicates that the proposed work surpasses the state-of-the-art image steganographic systems significantly.     

Code wars: Steganography,signals intelligence,and terrorism

This paper discusses the process of secret communication known as steganography. The argument advanced here is that terrorists are unlikely to be employing digital steganography to facilitate secret intra-group communication as has been claimed. This is because terrorist use of digital steganography is both technically and operationally implausible. The position adopted in this paper is that terrorists are likely to employ low-tech steganography such as semagrams and null ciphers instead. Her research interests are in the area of terrorism and the Internet. She has published in Current History, the Journal of Information Warfare, and elsewhere. Her research has been facilitated by a grant from the Irish Research Council for the Humanities and Social Sciences.     

Performance based algorithms for video bit transmissions

The usage of video content has increased in past ten decades. As a result, increase in usage of commercial video coding standards called High Efficiency Video Coding (HEVC/H.265). A self-Adaptive N-depth Context Tree Weighting algorithm (SANDCTW) is proposed to overcome the limitations of Context tree weighting (CTW) method, which applied in CABAC know as Context Adaptive Binary Arithmetic Coding. This CABAC uses KT estimators and relies on beginning with the Bayesian approach to determine the true distribution of the next symbol to select for data compression. This approach is suitable only if the true distribution is stationary, the proposed SANDCTW that uses discounted KT estimators, which is suitable if the distribution is non-stationary and it reduces the computation and memory cost. Additionally, Block size sustained intra mode detection (BSSIMD) is proposed based on the mass-center and sub-sampling approach. In this approach, all correlation directions about the entire block associated to the intra-prediction mode and DC mode directions determined by using mass-center vector. Then, the modes corresponding to the determined directions selected as the best intra-prediction candidates during the intra-coding process for computing Rate-Distortion Optimization (RDO) with less complexity. The bit rate of 60–70 frames per second (fps) achieved in this technique based on the different block, size. Thus, the bit rate is also reduced significantly compared with the preceding H.265 standard.     

基于秘密分享的学前儿童对友谊关系的推断

秘密是隐藏在内心深处的东西,人们通常会与亲密的人分享和披露秘密。因此,追踪人们知道彼此的秘密可以作为社会关系的线索。本研究开展两个实验探究秘密分享对学前儿童推断友谊关系的影响。105名和60名幼儿分别参与实验1、实验2。实验1发现5岁以下的儿童大多数认为主角分享物质资源(玩具)的对象是主角的朋友,5～6岁的儿童大多数认为主角分享秘密的对象是主角的朋友,选择被分享秘密的人是分享者更可能的朋友的人数随着年龄的增长而增长; 实验2发现与分享积极的秘密信息和物质资源相比,大部分5～6岁的儿童更倾向于认为分享消极的秘密信息的双方存在友谊关系。研究结果说明至少5～6岁的儿童理解分享秘密的社会意义,并且5～6岁儿童把分享消极的秘密作为友谊关系更有力的标志。     

Culturally Sensitive AIDS Educational Videos for African American Audiences: Effects of Source, Message, Receiver, and Context

The importance of using culturally sensitive educational materials in HIV-related interventions with racial and ethnic minority groups is widely recognized. However, little empirical research has been conducted to assess the relative effectiveness of different techniques for creating culturally sensitive AIDS educational videos. Two field experiments with three samples of African American adults (N = 174, 173, and 143) were conducted to assess how source characteristics (race of communicator), message characteristics (multicultural message vs. culturally specific message), and audience characteristics (racial distrust and AIDS-related distrust) influence proximate (perceptions of the message's credibility and attractiveness) and distal (AIDS-related attitudes, beliefs, and behavioral intentions) output variables for AIDS educational videos. In Study 1, an AIDS video with a culturally specific message was rated as more credible, more attractive, and of higher quality than was a video with a multicultural message. The multicultural message was rated less favorably when delivered by a White announcer than when the announcer was Black. In Study 2, the same pattern was replicated with a second community sample and a campus-based sample. Study 2 also indicated that a multicultural message might be more effective if delivered in a culturally specific context, namely, after audience members watch a culturally specific video. Minimal changes were observed in distal outcome variables. It is argued that influencing proximate output variables is necessary, though not sufficient, for effecting long-term change in AIDS-related attitudes, beliefs, and behaviors.     

Using message framing to motivate HIV testing among low-income, ethnic minority women.

This study compared the effectiveness of 4 videotaped educational programs designed to motivate HIV testing among low-income, ethnic minority women. Four hundred eighty women were assigned randomly to watch one of 2 gain-framed or 2 loss-framed videos. Consistent with prospect theory, participants' perceptions of the certainty of the outcome of an HIV test moderated the effects of framing on self-reported testing behavior 6 months after video exposure. Among participants who reported being certain of the test's outcome, those who saw a gain-framed video reported a higher rate of testing than those who saw a loss-framed message. Among women who perceived the outcome of HIV testing as relatively uncertain, gain- and loss-framed videos led to similar rates of self-reported testing, with some advantage for the loss-framed message.     

Talking about visually perceived events: Communication effects on eyewitness memory

Communicators' tuning of a message about a social target to their audience's evaluation can shape their representation of the target. This audience‐tuning effect has been demonstrated with ambiguous text passages as input material. We examined whether the effect also occurs when communicators learn about the target's behaviours from visual (nonverbal) input material. In Experiment 1, participants watched a soundless video depicting ambiguous behaviours of a target, described the video to an audience who liked (vs. disliked) the target, and subsequently recalled the video. Both message and recall were biased towards the audience's judgement. In Experiment 2, the video depicted a forensically relevant event, specifically ambiguous behaviours of two persons involved in a bar brawl. Participants tuned their event retellings to their audience's responsibility judgement and remembered the event accordingly. In both experiments, the effect of the audience's judgement on recall was statistically mediated by the extent to which the message was tuned to the audience. The more participants experienced a shared reality with their audience the stronger was the message‐recall correlation (Experiment 2). We conclude that the audience‐tuning effect for visually perceived information depends on the communicators' creation of a shared reality with their audience. Copyright © 2011 John Wiley & Sons, Ltd.     

Text On Screen: Can Emotionally Incongruent Combinations of Media Frames and Messages Elicit Coactivation in the Motivational Systems

ABSTRACT

Social media is becoming one of the most common deployment methods for antidrug and risk message campaigns. This is largely due to the low cost and high distribution that social media affords. This article argues that the social media approach to antidrug messaging also results in greater attention to the message over time. This article reports results from a study that examined how the combination of a short gain-or-loss framed text message interacts with a subsequent pleasant or unpleasant antidrug video message to influence motivational activation and information processing. Based on previous work investigating how different emotional trajectories in public service announcements (PSAs) elicit different patterns of motivational activation and cognitive processing, it was predicted, and found, that emotionally incongruent combinations of the text frame and video content resulted in the coactivation of the motivational systems. Placing a gain frame before a video message affects the overall processing of the subsequent message such that even an unpleasant message is rated more positively and results in a pattern of resource availability more like what we see for pleasant messages. Motivational activation and the subsequent effects on cognitive and emotional reactions are discussed within the context of multi-modal anti-drug campaigns.     

Influence of Speech Rate and Information Density on Recognition: The Moderate Dynamic Mechanism

This article analyzes whether recognition in the news may be affected by speech rate and information density and addresses what the optimal level would need to be for information on the radio to be encoded and recognized as effectively as possible. The key question is whether the combination of these two factors has a decisive influence on cognitive processing, especially in the distribution of resources allocated and required to encode the message. The findings indicate that Speech Rate does have a decisive influence on recognition of information since it modifies the resources available for encoding the message. The higher the speed, the lower the information density should be and vice versa. The best result to achieve the greatest recognition is between 170 (high density) and 190 (low density) words per minute, confirming that a moderate dynamic mechanism takes place.     

Will They or Won’t They? Secret Telling in Interpersonal Interactions

This study investigated predictors of within-gender secret telling. Eighty-eight participants were exposed to either a “positive” or a “negative” secret about another individual. Just under 20% of participants told the secret. Conscientiousness, secret condition, empathy, and the conscientiousness by secret condition interaction had effects on the rate of secret telling, χ² (5,82) = 17.78, p = .003, AIC = 80.60. Conscientiousness had a negative effect on secret telling among participants that told the “negative” secret.     

A new approach to the generation of visual stimuli for eye-movement research

An interactive, computer-controlled, visual stimulus generator is described, suitable for both psychophysical and neurophysiological experimentation on human subjects. The system core is a wide-screen electrostatic cathode-ray tube, which can be used both as a television monitor, to display standard video pictures, and as anx-y oscilloscope, so that a bright dot can be moved around the display by electrical signals. In addition, a third working mode is provided, according to which a time-compressed video picture of limited size (fast picture) plays the role that is typical of the spot in a standard oscilloscope. Through computer-assisted time compression, the frame period of the video signal is reduced to about one tenth of its standard value. The fast picture can accordingly be driven by even the fastest eye movements, and it can be displayed as a stabilized image, or, more generally, in the altered retinal feedback condition. Moreover, as compared with a standard video picture, the fast image can be “flashed” over much shorter time periods. Since a standard input video signal is used for both standard and fast video pictures, all the image processing facilities of commercial videographic systems can be fully exploited by the proposed device.     

Fit for persuasion: the effects of nonverbal delivery style,message framing,and gender on message effectiveness

This study examined two experimental variables, delivery style and message framing, that have yet to be examined together in the regulatory fit literature. College students (mean age = 30) watched a video message encouraging regular exercise delivered in an eager or vigilant nonverbal style and framed in terms of gain or loss. Results revealed significant fit effects involving gender, delivery style, and message framing. The eager message was perceived as more effective by men whereas the vigilant message was perceived as more effective by women. A message framing by delivery style fit effect also emerged for perceived message effectiveness. The implications and limitations of these findings are discussed.     

Video playback,affective witnessing,and the mobility of trauma: Video evidence of violent crime in the criminal justice system

In today's technologically mediated society, video is increasingly relied upon as an objective and reliable source of evidence in the investigation and prosecution of violent crimes. The now pervasive presence of violent video in the criminal justice system, however, presents new challenges for understanding repeated work-related exposure to and witnessing of potentially traumatic material and its impacts. Thus, this project seeks to qualitatively examine the relational affective processes that occur among criminal justice professionals when violent crimes are captured on video. We present four key categories organized around the circumstances of exposure and its impacts: 1) playback in the investigative and pre-trial process; 2) sharing videos among colleagues; 3) playing videos for victims, witnesses, and families and; 4) transmission in the broader public. Findings suggest this work involves deeply embodied processes where video evidence of violent crime enables a virtual presence at scenes and an emotional proximity to events through new forms of witnessing. These affective experiences are one relational dynamic that keeps witnessing active, thus expanding the mobility of trauma, its reach and potential impacts.     

Auditory evoked potentials during selective listening to dichotic speech messages

The sensitivity of the scalp-recorded, auditory evoked potential to selective attention was examined while subjects monitored one of two dichotically presented speech passages for content. Evoked potentials were elicited to irrelevant probe stimuli (vowel sounds) embedded in both the right- and the leftear’s message. The amplitude of the evoked potential was larger to probe stimuli embedded in the attended message than to probe stimuli in the unattended message. Recall performance was unaffected by the presence of the probes. The results are interpreted as supporting the hypothesis that this evoked potential sensitivity reflects an initial “input selection” stage of attention.     

Data-driven Q-matrix validation using a residual-based statistic in cognitive diagnostic assessment

In a cognitive diagnostic assessment (CDA), attributes refer to fine-grained knowledge points or skills. The Q -matrix is a central component of CDA, which specifies the relationship between items and attributes. Oftentimes, attributes and Q -matrix are defined by subject-matter experts, and assumed to be appropriate without any misspecifications. However, this assumption does not always hold in real applications. To address this concern, this paper proposes a residual-based statistic for validating the Q -matrix. Its performance is evaluated in a simulation study and compared against that of an existing method proposed in Liu, Xu and Ying (2012, Applied Psychological Measurement, 36, 548). Simulation results indicate that the proposed method leads to a higher recovery rate of the Q -matrix and is computationally more efficient. The advantage in computational efficiency is particularly pronounced when the number of attributes measured by the test reaches five or more. Results also suggest that the two methods have different tendencies in estimating the attribute vector for each item. In cases where the methods fail to recover the correct Q -matrix, the method in Liu et al. (2012, Applied Psychological Measurement, 36, 548) tends to overestimate the number of attributes measured by the items, whereas our method does not show that bias.     

On-line and memory-based modification of attitudes: determinants of message recall-attitude change correspondence

Experiments investigated the impact of message elaboration on attitude change-message recall correspondence when attitude change occurs in an on-line (as attitude-relevant information is received), or memory-based (on the basis of retrieved attitude-relevant information) fashion. In 2 experiments, Ss' processing goals were manipulated to increase or inhibit on-line change and message elaboration. As predicted, Ss reported postexposure attitudes more rapidly in on-line vs memory-based conditions. Decreased message elaboration increased attitude-recall correspondence, regardless of when attitude change occurred. Increased elaboration produced elaboration-attitude judgment correspondence. Results suggest that recall of message content will best predict persuasion when message content is encoded free of elaborations, regardless of when attitude change occurs.     

Examining the Effects of Gain-Framed Messages on the Activation and Elaboration of Possible Sport Selves in Middle-Aged Adults

Using an online cross-sectional randomized design, we explored whether messages emphasizing benefits of sport (sport gain-framed messages) would activate and elaborate hoped-for possible sport selves in 40- to 59-year-olds. One group viewed a video containing sport gain-framed messages, and a comparison group completed a sport and physical activity quiz. Results showed that the message group attended to a health and fitness message most frequently and demonstrated more frequent activation of possible selves than the quiz group. The message group's possible selves also contained more elaborate content related to delaying the effects of aging through sport and the social benefits of sport.     

Web‐based corporate,social and video recruitment media: Effects of media richness and source credibility on organizational attraction

Despite the high use of social media in graduate recruitment campaigns, research has yet to examine how it compares with websites and videos in influencing job seekers’ reactions. Drawing from recruitment, media richness, and source credibility theories, we proposed that the media used to present recruitment material would influence organizational attraction via perceptions of media richness and source credibility. Results of a between‐subjects study, with 342 participants holding or working toward a degree, show that when a standardized recruitment message is delivered via Facebook, video, or text‐based webpage media, there are significant between‐media richness and source credibility differences. Furthermore, particular media richness features were positively related to perceptions of source credibility, and source credibility perceptions were positively related to organizational attraction. Implications for organizations’ online recruitment campaigns are discussed.     

THE MEDIATION OF RESISTANCE TO PERSUASION STRATEGIES BY LANGUAGE VARIABLES AND ACTIVE-PASSIVE PARTICIPATION

This investigation attempted to confer resistance to persuasion by inoculating people with either supportive, refutational, or combination pretreatment messages. Following inoculation, subjects either passively received a high or low intense attack message or actively encoded a message of high or low intensity. As predicted, there was a significant interaction between type of attack and level of language intensity. Discussion centered on the effects of language intensity as a mediator of attitude change in yet another persuasive paradigm.