Protecting Business Secrets in an EDI/CALS Environment

ABSTRACT

Communicating with confidential data requires special attention in a mobile agents environment, especially when the other hosts must be prevented from eavesdropping on the communication. We propose a communication model for secured communication between the agents belonging to publishers and consumers data. Confidentiality is ensured using our on-the-fly encryption-decryption sequence using ElGamal system to directly convert the message or plaintext into one that is encrypted directly with the public key of consumer. The scheme ensures that the data possessed by the agents is secured at all times when it is executing at any untrusted host. Our minimal implementation of the model with Aglets agent platform gives the first faithful picture of the happenings in the model. Finally, we also explain how the homomorphic property of ElGamal scheme can be integrated with our model for a Web-based application such as voting involving multiple agents.     

Parallel partitioning for distributed systems using sequential assignment

This paper introduces a method to combine the advantages of both task parallelism and fine-grained co-design specialisation to achieve faster execution times than either method alone on distributed heterogeneous architectures. The method uses a novel mixed integer linear programming formalisation to assign code sections from parallel tasks to share computational components with the optimal trade-off between acceleration from component specialism and serialisation delay. The paper provides results for software benchmarks partitioned using the method and formal implementations of previous alternatives to demonstrate both the practical tractability of the linear programming approach and the increase in program acceleration potential deliverable.     

Quality assessment of SRTM C- and X-band interferometric data: Implications for the retrieval of vegetation canopy height

The Shuttle Radar Topography Mission distinguished itself as the first near-global spaceborne mission to demonstrate direct sensitivity to vertical vegetation structure. Whether this sensitivity is viewed as exploitable signal or unwanted bias, a great deal of interest exists in retrieving vegetation canopy height information from the SRTM data. This study presents a comprehensive application-specific assessment of SRTM data quality, focusing on the characterization and mitigation of two primary sources of relative vertical error: uncompensated Shuttle mast motion and random phase noise. The assessment spans four test sites located in the upper Midwestern United States and examines the dependence of data quality on both frequency, i.e., C-band vs. X-band, and the number of acquired datatakes. The results indicate that the quality of SRTM data may be higher than previously thought. Novel mitigation strategies include a knowledge-based approach to sample averaging, which has the potential to reduce phase noise error by 43 to 80%. The strategies presented here are being implemented as part of an ongoing effort to produce regional- to continental-scale estimates of vegetation canopy height within the conterminous U.S.     

Assessment of the interaction between the Canadian Regional Climate Model and lake thermal–hydrodynamic models

This paper describes our preliminary assessment of the system requirements (data, interface and process) for implementation of terms describing lake effects in the Canadian Regional Climate Model. We demonstrate test results for one-dimensional (1-D) and three-dimensional (3-D) models for lake hydrodynamics that have been tested and prepared for interfacing with atmospheric circulation models. We discuss the use of a physical interface model, Canadian Land Surface Scheme (CLASS), that is under consideration for the air–water interface. Our preliminary assessment indicates that it is technically feasible to apply the combination of small shallow lake (slab) model, 1-dimensional vertical model and 3-dimensional circulation model (for very large lakes), together with the current land–air linkage used in regional climate modelling in Canada. Whether we can discern the necessary conditions for invoking each of the models to the lakes present in individual regional climate grid cells is still to be determined.     

The effect of impact damage on the room-temperature fatigue behavior of γ-TiAl

The relationship between impact damage and the fatigue behavior of γ-TiAl has been examined. Axial fatigue specimens fabricated from cast Ti-47.9Al-2.0Cr-1.9Nb (to be referred to as 48-2-2) and Ti-47.3Al-2.2Nb-0.5Mn-0.4W-0.4Mo-0.23Si (to be referred to as WMS) alloys were damaged by impact under controlled conditions with a 60 deg wedge-shaped indenter to simulate assembly-related damage in low-pressure turbine blades. The level of damage produced was quantified and found to correlate well with the peak load of the impact event. The WMS alloy exhibited a greater resistance to impact damage due to its higher yield strength and lamellar microstructure. A measure of the ambient-temperature fatigue failure stress in the alloys was obtained by standard fatigue testing employing a step-loading approach. The failure stress of the WMS alloy was greater than that of the 48-2-2 alloy in the undamaged state. The relationship between impact damage and failure stress was examined using a threshold-based approach. These studies indicate that, for damage levels below a transitional flaw size, the failure stress is near that for undamaged specimens. At damage levels greater than the transitional flaw size, the failure stress can be adequately approximated using the threshold stress-intensity range (ΔK _TH ) from long-crack growth testing. Fractographic studies were performed to investigate impact damage and crack-advance mechanisms, which match those observed in other alloys tested at room temperature.     

Cloud motion in the GOCI/COMS ocean colour data

The Geostationary Ocean Colour Imager (GOCI) instrument, on Korea’s Communications, Oceans, and Meteorological Satellite (COMS), can produce a spectral artefact arising from the motion of clouds – the cloud is spatially shifted and the amount of shift varies by spectral band. The length of time it takes to acquire all eight GOCI bands for a given slot (portion of a scene) is sufficient to require that cloud motion be taken into account to fully mask or correct the effects of clouds in all bands. Inter-band correlations can be used to measure the amount of cloud shift, which can then be used to adjust the cloud mask so that the union of all shifted masks can act as a mask for all bands. This approach reduces the amount of masking required versus a simple expansion of the mask in all directions away from clouds. Cloud motion can also affect regions with unidentified clouds – thin or fractional clouds that evade the cloud identification process – yielding degraded quality in retrieved ocean colour parameters. Areas with moving and unidentified clouds require more elaborate masking algorithms to remove these degraded retrievals. Correction for the effects of moving fractional clouds may also be possible. The cloud shift information can be used to determine cloud motion and thus wind at the cloud levels on sub-minute timescales. The beneficial and negative effects of moving clouds should be considered for any ocean colour instrument design and associated data processing plans.     

FTC finds internet privacy self-regulation disappointing

After giving private industry the opportunity to self-regulate the collection of personal information from children on the Internet, Federal Trade Commission Chairman Robert Pitofsky, admitted on 4 June 1998 that he was, “surprised how little progress was made”. He added, “industry self-regulation has not worked”. Consequently, Pitofsky called on Congress to enact legislation to provide online privacy protection for children 12 years and under.     

Psychologists in medical schools: Comment.

Comments on the article by S. Williams and J. L. Kohout (see record 1999-10642-004) which presented data from a large survey of psychologists employed by medical schools and concluded that there is a growing marginalization of the psychologists' role in medical schools. The authors note that it is unfortunate that Williams and Kohout based their conclusions on limited evidence from their own survey and disregarded preexisting literature. The authors discuss methodological similarities and differences between their own survey conducted in 1994 and the survey of Williams and Kohout that have direct bearing on the interpretation of the results. (PsycINFO Database Record (c) 2010 APA, all rights reserved)