97 research outputs found

    Exclusion-intersection encryption

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    Identity-based encryption (IBE) has shown to be a useful cryptographic scheme enabling secure yet flexible role-based access control. We propose a new variant of IBE named as exclusion-intersection encryption: during encryption, the sender can specify the targeted groups that are legitimate and interested in reading the documents; there exists a trusted key generation centre generating the intersection private decryption keys on request. This special private key can only be used to decrypt the ciphertext which is of all the specified groups' interests, its holders are excluded from decrypting when the documents are not targeted to all these groups (e.g., the ciphertext of only a single group's interest). While recent advances in cryptographic techniques (e.g., attribute-based encryption or wicked IBE) can support a more general access control policy, the private key size may be as long as the number of attributes or identifiers that can be specified in a ciphertext, which is undesirable, especially when each user may receive a number of such keys for different decryption power. One of the applications of our notion is to support an ad-hoc joint project of two or more groups which needs extra helpers that are not from any particular group. Ā© 2011 IEEE.published_or_final_versionThe 1st IEEE International Workshop on Security in Computers, Networking and Communications (SCNC 2011) in conjuntion with IEEE INFOCOM 2011, Shanghai, China, 10-15 April 2011. In Conference Proceedings of INFOCOM WKSHPS, 2011, p. 1048-1053The 1st IEEE International Workshop on Security in Computers, Networking and Communications (SCNC 2011) in conjuntion with IEEE INFOCOM 2011, Shanghai, China, 10-15 April 2011. In Conference Proceedings of INFOCOM WKSHPS, 2011, p. 1048-105

    Direction-specific impairment of stability limits and falls in children with developmental coordination disorder: Implications for rehabilitation

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    Limit of stability (LOS) is an important yet under-examined postural control ability in children with developmental coordination disorder (DCD). This study aimed to (1) compare the LOS and fall frequencies of children with and without DCD, and (2) explore the relationships between LOS parameters and falls in the DCD population. Thirty primary school-aged children with DCD and twenty age- and sex-matched typically-developing children participated in the study. Postural control ability, specifically LOS in standing, was evaluated using the LOS test. Reaction time, movement velocity, maximum excursion, end point excursion, and directional control were then calculated. Self-reported fall incidents in the previous week were also documented. Multivariate analysis of variance results revealed that children with DCD had shorter LOS maximum excursion in the backward direction compared to the control group (pā€…=ā€…0.003). This was associated with a higher number of falls in daily life (rhoā€…=ā€…āˆ’0.556, pā€…=ā€…0.001). No significant between-groups differences were found in other LOS-derived outcomes (pā€…>ā€…0.05). Children with DCD had direction-specific postural control impairment, specifically, diminished LOS in the backward direction. This is related to their falls in daily life. Therefore, improving LOS should be factored into rehabilitation treatment for children with DCD.postprin

    Differential effect of Taekwondo training on knee muscle strength and reactive and static balance control in children with developmental coordination disorder: A randomized controlled trial

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    This randomized controlled trial aimed to investigate the effect of short-term intensive TKD training on the isokinetic knee muscle strength and reactive and static balance control of children with developmental coordination disorder (DCD). Among the 44 children with DCD (mean age: 7.6 Ā± 1.3 years) recruited, 21 were randomly assigned to undergo daily TKD training for 1. h over three consecutive months, with the remaining 23 children being assigned to the DCD control group. Eighteen typically developing children (mean age: 7.2 Ā± 1.0 years) received no training as normal controls. Knee extensor and flexor muscle strength and reactive and static balance control were assessed using an isokinetic machine (with low, moderate and high movement velocities), a motor control test (MCT) and a unilateral stance test (UST), respectively. A repeated measures MANCOVA revealed a significant group through time interaction effect in isokinetic outcomes at 180Ā°/s and in the UST outcome. Post hoc analysis demonstrated that DCD-TKD children's isokinetic knee muscle strength, specifically at 180Ā°/s, was as high as that of the normal control children (p>0.0083) after TKD training. Moreover, UST body sway velocity was slower in the DCD-TKD group than in the DCD control group (p0.05) after TKD training. However, no such improvement in balance was observed in the MCT (p>0.025). The results show that children with DCD who undergo a 3-month program of intensive TKD training experience improvements in isokinetic knee muscle strength at 180Ā°/s and static single-leg standing balance control, but do not benefit from improved reactive balance control. Ā© 2013 Elsevier Ltd.postprin

    Distributed Random Process for a Large-Scale Peer-to-Peer Lottery

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    Most online lotteries today fail to ensure the verifiability of the random process and rely on a trusted third party. This issue has received little attention since the emergence of distributed protocols like Bitcoin that demonstrated the potential of protocols with no trusted third party. We argue that the security requirements of online lotteries are similar to those of online voting, and propose a novel distributed online lottery protocol that applies techniques developed for voting applications to an existing lottery protocol. As a result, the protocol is scalable, provides efficient verification of the random process and does not rely on a trusted third party nor on assumptions of bounded computational resources. An early prototype confirms the feasibility of our approach

    Theoretical examination of behavioral feedback in the application of teledietetics to weight reduction

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    Introduction Behavioural feedback can be attained through electronic self-monitoring with teledietetics. This study examined the theoretical framework of the theory of planned behaviour, which suggests that behavioural feedback contributes to the intention to initiate and maintain weight loss. Methods A quasi-experiment involving adults aged 20ā€“50 years with a body mass index greater than 23ā€‰kg/m2 was conducted. The experimental group (EG) comprised 25 participants who used electronic dietary records for self-monitoring. The control group (CG) comprised 25 participants who used paper-format dietary records for self-monitoring. Data pertaining to the theory of planned behaviour were obtained using a self-administered questionnaire. After an initial measurement, each participantā€™s body weight was measured again at Week 12 and at Week 24, following a 12-week observation period. Hierarchical regression analyses of planned behaviour components were conducted for each power to predict the participantsā€™ intentions to lose 10% of their body weight. Logistic regression analysis was performed to investigate the odds ratio of intention, perceived behavioural control (PBC) and the group effect (CG vs EG) for predicting the initiation and maintenance of 10% weight loss. Results At Week 12, the odds ratios for intention, the PBC and the group effect were 2.154, 0.330 and 0.654, respectively, and those at Week 24 were 3.255, 0.499 and 24.592, respectively. The group effect contributed significantly to weight-loss maintenance at Week 24. Discussion Behavioural feedback through electronic self-monitoring improved the intention to achieve weight-loss maintenance, which may indicate the importance of behaviour reflection in weight-loss maintenance.postprin

    Pseudolaric acid B as a new class of microtubule destabilizing agent and an effective anti-tumor compound in vivo

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    Secretin facilitates GABA transmission in the cerebellum

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    Secretin was the first hormone discovered in human history, and yet, its function as a neuropeptide has been overlooked in the past. The recent discovery of the potential use of secretin in treating autistic patients, together with the conflicting reports on its effectiveness, urges an in-depth investigation of this issue. We show here that in the rat cerebellar cortex, mRNAs encoding secretin are localized in the Purkinje cells, whereas those of its receptor are found in both Purkinje cells and GABAergic interneurons. Immunoreactivity for secretin is localized in the soma and dendrites of Purkinje cells. In addition, secretin facilitates evoked, spontaneous, and miniature IPSCs recorded from Purkinje cells. We propose that secretin is released from the somatodendritic region of Purkinje cells and serves as a retrograde messenger modulating GABAergic afferent activity.published_or_final_versio

    Separable and anonymous identity-based key issuing

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    In identity-based (ID-based) cryptosystems, a local registration authority (LRA) is responsible for authentication of users while the key generation center (KGC) is responsible for computing and sending the private keys to users and therefore, a secure channel is required. For privacy-oriented applications, it is important to keep in secret whether the private key corresponding to a certain identity has been requested. All of the existing ID-based key issuing schemes have not addressed this anonymity issue. Besides, the separation of duties of LRA and KGC has not been discussed as well. We propose a novel separable and anonymous ID-based key issuing scheme without secure channel. Our protocol supports the separation of duties between LRA and KGC. The private key computed by the KGC can be sent to the user in an encrypted form such that only the legitimate key requester authenticated by LRA can decrypt it, and any eavesdropper cannot know the identity corresponding to the secret key. Ā© 2005 IEEE.published_or_final_versio
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