An evaluation of volcanic cloud detection techniques during recent significant eruptions in the western ‘Ring of Fire’

We examined recent volcanic cloud events in the Western Pacific and Indonesian area, to validate the performance of remote sensing techniques used to support the International Airways Volcano Watch (IAVW). Five events were considered, during which eruptions from eight volcanoes injected ash into the upper troposphere or lower stratosphere. For one of the eruptions, at Miyakejima, Japan, at least five aircraft encountered volcanic ash clouds, and the cost to three operators alone exceeded US $12,000,000 in aircraft repairs, diversions, and lost operating time. We performed ‘reverse’ absorption and ‘pattern analysis’ using GMS-5/VISSR, MODIS and AVHRR data, and we examined TOMS SO₂ and Aerosol Index data, surface-based observations, pilot reports, and dispersion model output. Our results verify that the introduction of ‘reverse’ absorption using the geostationary GMS-5 platform significantly enhanced our capacity to monitor volcanic ash clouds in the region. In one case, we tracked an eruption cloud for approximately 80 h. The primary impediment to remote monitoring is the presence of overlying cloud, or substantial amounts of ice within the volcanic clouds. TOMS data showed success in identifying volcanic clouds during these conditions, but was limited by the infrequency of observations. More effective future operation of the IAVW relies on developing complementary methods of volcanic cloud remote sensing, and greatly increasing the amount and quality of available surface and air observations, including observations of precursor activity. An understanding of the likely future limitations of remote sensing techniques will aid in the refining of IAVW procedures.     

Ant-inspired sorting by robots: the importance of initial clustering.

For engineers the prospect of scalable collective robot systems is very appealing. Such systems typically adopt a decentralized approach in their control and coordination mechanism, which employs local sensing and action as well as limited communication. Under these constraints and informed by research on Temnothorax ants, two puck sorting algorithms were tested in a combination of simulation and with real robots. Both algorithms employed puck density as a cue. Only the overall local density, irrespective of puck type, was found to be required which offers the prospect for a more simple mechanism than had been previously considered. For one algorithm, this density cue was used both for picking up and dropping items and is, therefore, referred to as the 'double density' algorithm (DD). In the second algorithm, density was used as a cue only for picking up. Depositing an item was governed by the distance travelled which was specific to the type of item being carried. This was referred to as the 'single density' algorithm (SD). Unlike the DD it was found that, for the SD, the clustering of items is a necessary pre-condition for sorting. Results from ant experiments also showed that sorting is carried out in two phases: a primary clustering episode followed by a spacing phase. This strongly suggests that clustering may also be a precondition for spacing in ants.     

Validity of the 1994 Strong Interest Inventory with racial and ethnic groups in the United States.

During the revision of the 1994 Strong Interest Inventory (SII; Harmon, Hansen, Borgen & Hammer, 1994), information was obtained about the race–ethnicity and careers of over 55,000 employed adults in 50 different occupations. The national norm group, the general reference sample, contains 18,789 individuals who identified their race–ethnicity in the following manner: 378 African Americans; 363 Asian Americans; 17,365 Caucasian Americans; 349 Hispanic Americans/Latinos (Latinas); and 77 Native Americans/American Indians. Concurrent validity across racial–ethnic groups was examined by typing their 50 occupations into the appropriate Holland (1997) job family. Then the General Occupational Themes, the SII scales corresponding to Holland's (1997) 6 vocational personality types, were examined for their ability to predict Holland (1997) job family in similar ways for the different racial–ethnic groups. Results generally showed comparable validity and interpretive counseling implications in using the SII with these racial–ethnic groups. Some interesting trends and important limitations were also noted. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Diversity and direction in psychoanalytic technique.

Review of book: Fred Pine. Diversity and Direction in Psychoanalytic Technique. New Haven, CT: Yale University Press, 1998, viii + 234 pp. Reviewed by Joseph W. Slap. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Managing network security: Security education in the information age

Computing operates in an almost universally networked environment, but the technical aspects of information protection have not kept up. As a result, the success of information security programs has increasingly become a function of our ability to make prudent management decisions about organizational activities. Managing Network Security takes a management view of protection and seeks to reconcile the need for security with the limitations of technology.     

Managing network security: Returning fire

Computing operates in an almost universally networked environment, but the technical aspects of information protection have not kept up. As a result, the success of information security programmes has increasingly become a function of our ability to make prudent management decisions about organizational activities. Managing Network Security takes a management view of protection and seeks to reconcile the need for security with the limitations of technology.     

Managing Network Security: The limits of cryptography

Computing operates in an almost universally networked environment, but the technical aspects of information protection have not kept up. As a result, the success of information security programs has increasingly become a function of our ability to make prudent management decisions about organizational activities. Managing Network Security takes a management view of protection and seeks to reconcile the need for security with the limitations of technology.     

The DMCA: Why It Is Bad For InfoSec Professionals

Networks dominate today's computing landscape and commercial technical protection is lagging behind attack technology. As a result, protection programme success depends more on prudent management decisions than on the selection of technical safeguards. Managing Network Security takes a management view of protection and seeks to reconcile the need for security with the limitations of technology.     

Water quality characteristics of two reservoir lakes in eastern Connecticut, USA

The Mansfield Hollow Lake (MHL) and Willimantic Reservoir (WR) are two reservoirs located in eastern Connecticut in the north‐eastern USA. The MHL was constructed by the US Army Corps of Engineers in 1952, being primarily fed by the Fenton, Mount Hope and Natchaug Rivers. The WR lies downstream from the Mansfield Hollow Dam. The physical and chemical characteristics of MHL, WR, and the three streams discharging into them were intensively evaluated during four sampling quarters in 2001 and 2002. This study focused on possible sources of eutrophication, and occurrence of trace amounts of selected priority pollutants, in the sediments and waters of MHL and WR. Analytical results for total dissolved nitrogen and phosphorus and chlorophyll‐a indicated that, in terms of eutrophication status, the waterbodies can be classified as mesotrophic. Comparison of the analytical results in this study to historical limnological data reported for lakes in southern New England and eastern Connecticut indicates that the median levels of total nitrogen, total phosphorus, dissolved inorganic carbon, calcium, magnesium, and iron measured in this study were higher than previously reported median values.     

Reduction of Facet Reflectivity of Quantum-Cascade Lasers With Subwavelength Gratings

We demonstrate the reduction of the facet reflectivity of quantum-cascade lasers (QCLs) by using subwavelength gratings. The gratings were fabricated on lambda=4.9- and 9.8-mum QCLs using focused ion beam milling. Reflectivities as low as 1%-3% for the 4.9-mum QCL and as low as 4%-8% for the 9.8-mum QCL are reported