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1.
Wu Ge Mu Yi Susilo Willy Guo Fuchun Zhang Futai 《International Journal of Information Security》2019,18(3):321-331
International Journal of Information Security - Data integrity is a critical security issue in cloud storage. The data integrity checking schemes by a third-party auditor (TPA) have attracted a lot... 相似文献
2.
In this paper, we describe RanGen, a random network generator for generating activity-on-the-node networks and accompanying data for different classes of project scheduling problems. The objective is to construct random networks which satisfy preset values of the parameters used to control the hardness of a problem instance. Both parameters which are related to the network topology and resource-related parameters are implemented. The network generator meets the shortcomings of former network generators since it employs a wide range of different parameters which have been shown to serve as possible predictors of the hardness of different project scheduling problems. Some of them have been implemented in former network generators while others have not. 相似文献
3.
Study of direct and indirect naphtha recycling to a resid FCC unit for maximum propylene production 总被引:2,自引:0,他引:2
To satisfy the increasing propylene demand, direct and indirect naphtha recycling schemes around an existing resid fluid catalytic cracking (FCC) unit were investigated. To this aim, light cracked naphtha (LCN), heavy cracked naphtha (HCN) and a PolyNaphtha (PN) oligomerisation product were cracked under a wide range of operating conditions over a commercial Y zeolite based equilibrium catalyst. Experimental data were acquired in three different units: a fixed bed bench scale unit, a fixed fluidised bed unit and an adiabatic circulating fluidised bed pilot plant. It was shown that FCC naphthas require high operating severities to crack, and that even then their conversion remains relatively moderate. Hence, direct recycling to the main riser does not seem a viable pathway to increase propylene product. Feeding FCC naphthas to a second reaction zone operating at high severity allows to increase the propylene yield in a significant manner. Increasing conversion, however, not only leads to higher LPG and propylene yields, but also results in very high dry gas yields. An alternative scheme was proposed, in which the olefinic C4 and C5 fractions are converted into a naphtha fraction through oligomerisation in a dedicated unit before being recracked in the secondary riser. As the highly olefinic oligomerised effluent mainly consist of dimerised and trimerised butenes and pentenes, this feed is more easily cracked and high conversions can be achieved. This indirect interconversion of butenes and pentenes into propylene therefore effectively allows to convert these butenes and pentenes into propylene, resulting in a significant increase in propylene yield. Each of the three main naphtha recycle options (directly to the main riser, directly to a secondary riser or indirectly via a light olefin oligomerisation unit) have been analysed and compared to a base case. In the evaluation of each of these schemes, all heat balance effects, both on the riser and the regenerator side, have been accounted for. The proposed process scheme with an indirect recycle via an oligomerisation unit enhances the already inherent flexibility of the FCC unit. The naphtha recycle can be turned on or off, the second reaction zone can be used to crack naphtha or to crack resid feed to maximise throughput, while the effluent of the oligomerisation unit can be recycled to the FCC unit for propylene production or hydrogenated and sent to gasoline and kerosene pool. 相似文献
4.
Henk A. van der Schee Willy B. H. Kennedy Jan-Paul Bouwknegt Renske Hittenhausen-Gelderblom 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1989,188(1):11-15
Summary Linear discriminant analysis of GLC-aromagram data is used to separate several classes of wine distillates, namely cognac, armagnac and brandy. In this paper we demonstrate how this method was used to detect adulteration. The adulteration was confirmed by the presence of ethyl heptanoate and limonene, which are well-known flavour compounds. They were analysed by means of a Purge and Trap headspace technique. Mass spectrometry was used to identify these flavours.
Ein Beispiel für die Verfälschung von Cognac
Zusammenfassung Die Linear-Discriminanz-Analyse von GLC-Aromagramm-Daten wird zur Klassifizierung von Weindestillaten wie Cognac, Armagnac und Brandy verwendet. In dieser Arbeit werden mit dieser Methode Verfälschungen nachgewiesen, die durch die Gegenwart der Ethylester der Heptansäure und des Limonen belegt werden konnten. Diese Substanzen wurden mit der Purge- und Trap-Methode erfaßt und massenspektrometrisch identifiziert.相似文献
5.
The vast majority of the project scheduling research efforts over the past several years have concentrated on the development
of workable predictive baseline schedules, assuming complete information and a static and deterministic environment. During
execution, however, a project may be subject to numerous schedule disruptions. Proactive-reactive project scheduling procedures
try to cope with these disruptions through the combination of a proactive scheduling procedure for generating predictive baseline
schedules that are hopefully robust in that they incorporate safety time to absorb anticipated disruptions with a reactive
procedure that is invoked when a schedule breakage occurs during project execution.
In this paper we discuss the results obtained by a large experimental design set up to evaluate several predictive-reactive
resource-constrained project scheduling procedures under the composite objective of maximizing both the schedule stability
and the timely project completion probability. 相似文献
6.
7.
Jinguang Han Willy Susilo Yi Mu Jun Yan 《International Journal of Information Security》2012,11(6):389-401
Oblivious signature-based envelope (OSBE) schemes have demonstrated their potential applications in the protection of users privacy and rights. In an OSBE protocol, an encrypted message can only be decrypted by the receiver who holds a valid signature on a public message, while the sender (encrypter) does not know whether the receiver has the signature or not. Our major contributions in this work lie in the following aspects. We improve the notion of OSBE so that a valid credential holder cannot share his/her credential with other users (i.e., all-or-nothing non-transferability). We clarify the relationship between one-round OSBE and identity-based encryption (IBE) and show that one-round OSBE and semantically secure IBE against the adaptively chosen identity attack (IND-ID-CPA) are equivalent, if the signature in the OSBE scheme is existentially unforgeable against adaptively chosen message attacks. We propose an oblivious access control scheme to protect user privacy without the aid of any zero-knowledge proof. Finally, we also highlight some other novel applications of OSBE, such as attributed-based encryption. 相似文献
8.
N. De Belie J. Monteny A. Beeldens E. Vincke D. Van Gemert W. Verstraete 《Cement and Concrete Research》2004,34(12):2223-2236
New equipment and procedures for chemical and microbiological tests, simulating biogenic sulfuric acid corrosion in sewerage systems, are presented. Subsequent steps of immersion and drying, combined with mechanical abrasion, were applied to simulate events occurring in sewer systems. Both chemical and microbiological tests showed that the aggregate type had the largest effect on degradation. Concrete with limestone aggregates showed a smaller degradation depth than did the concrete with inert aggregates. The limestone aggregates locally created a buffering environment, protecting the cement paste. This was confirmed by microscopic analysis of the eroded surfaces. The production method of concrete pipes influenced durability through its effect on W/C ratio and water absorption values. In the microbiological tests, HSR Portland cement concrete performed slightly better than did the slag cement concrete. A possible explanation can be a more rapid colonisation by microorganisms of the surface of slag cement samples. A new method for degradation prediction was suggested based on the parameters alkalinity and water absorption (as a measure for concrete porosity). 相似文献
9.
Shams Qazi Raad Raad Yi Mu Willy Susilo 《Journal of Network and Computer Applications》2013,36(2):582-592
A wormhole attack is one of the hardest problems to detect whereas it can be easily implanted in any type of wireless ad hoc network. A wormhole attack can easily be launched by the attacker without having knowledge of the network or compromising any legitimate nodes. Most existing solutions either require special hardware devices or make strong assumptions in order to detect wormhole attacks which limit the usability of these solutions. In this paper, we present a security enhancement to dynamic source routing (DSR) protocol against wormhole attacks for ad hoc networks which relies on calculation of round trip time (RTT). Our protocol secures DSR against a wormhole attack in ad hoc networks for multirate transmissions. We also consider the processing and queuing delays of each participating node in the calculation of RTTs between neighbors which to date has not been addressed in the existing literature. This work provides two test cases that show that not taking multirate transmission into consideration results in miss identifying a wormhole attack. 相似文献
10.
The inherent key escrow problem is one of the main reasons for the slow adoption of identity-based cryptography. The existing
solution for mitigating the key escrow problem is by adopting multiple Private Key Generators (PKGs). Recently, there was
a proposal that attempted to reduce the trust of the PKG by allowing a malicious PKG to be caught if he reveals the user’s
identity-based private key illegally. Nonetheless, the proposal does not consider that the PKG can simply decrypt the ciphertext
instead of revealing the private key itself (in the case of identity-based encryption schemes). The aim of this paper is to
present an escrow-free identity-based signature (IBS) scheme, in which the malicious PKG will be caught if it releases a signature
on behalf of the user but signed by itself. We present a formal model to capture such a scheme and provide a concrete construction. 相似文献