Exploring Effect of Location Number on Map-Based Graphical Password Authentication

Information security and privacy : 22nd Australasian Conference, ACISP 2017, Auckland, New Zealand, July 3-5, 2017Graphical passwords (GPs) that authenticate users using images are considered as one potential alternative to overcome the issues of traditional textual passwords. Based on the idea of utilizing an extremely large image, map-based GPs like PassMap and GeoPass have been developed, where users can select their secrets (geographical points) on a world map. In particular, PassMap allows users to select two locations on a map, while GeoPass reduces the number of locations to only one. At first glance, selecting one location is more vulnerable to attacks, while increasing the location number may add burden on users. In the literature, there is no research exploring this issue. Motivated by this, our purpose in this work is to explore the effect of location number (the number of geographical points) and compare two schemes of PassMap and GeoPass in terms of users’ performance and feedback. In this work, we develop a generic and open platform for realizing map-based schemes, and conduct a user study with 60 participants. The study reveals that selecting two locations would not degrade the scheme performance. Our effort aims to complement exiting research studies in this area.Department of Computing2016-2017 > Academic research: refereed > Chapter in an edited book (author)bcw

Application and properties of aluminum in primary and secondary explosives

Aluminum is an easily available and cheap material, which is widely used in military and civil industries, e.g. in space technology, explosion welding, mining, production of oil and natural gas, manufacture of airbags. Primary and secondary explosives containing aluminum are described in this part of the work. Aluminum is added to high explosives of different shapes and sizes. These parameters influence inter alia detonation velocity (D), explosion heat, detonation pressure, pressure impulse and thermal stability. Detonation parameters of high explosive (HE) containing aluminum have been determined for binary systems consisting of high explosive or oxidizer and aluminum, plastic bonded explosives (PBX), melt cast explosives, thermobaric explosives (TBX), ammonium nitrate fuel oil (ANFO). Aluminum causes different effects on detonation velocity and explosion heat depending on the type of high explosive in binary systems. The dependence of the aluminum content in a mixture with ammonium nitrate with detonation velocity increased for an aluminum range from 0 to 10%, changed little between 10 and 16% of aluminum added and decreased from 16 to 40% of the aluminum content. For an aluminum content higher than 40%, the detonation process was not observed. The performance of explosives can be determined by the shock wave intensity. An increase in the pressure impulse made Al particle react with gaseous products and the air behind the front of detonation wave. The addition of aluminum also influences the thermal stability of high explosive materials

Właściwości reologiczne i termiczne mieszanin polibutadienu z końcowymi grupami hydroksylowymi oraz plastyfikatora

Mixtures of hydroxyl-terminated polybutadiene (HTPB) and dioctyladipate (DOA) as a plasticizer, which after crosslinking are applied as binders in heterogeneous propellants, were studied.The influence of mixture composition on rheological and thermal properties, important from technological and utility viewpoint were specified. The temperature dependence of prepared mixtures viscosity were studied. Systems were subjected to crosslinking and values of pot life (tpl) were determined. It was stated that tpl rose with increasing plasticizer content. Differential scanning calorimetry and thermogravimetry techniques were used toanalyze thermal stability of mixtures. It was concluded that applied component scould not decompose in the temperature range of 290–350 K and studied mixtures did not cause the hazard of thermal explosion.Zbadano mieszaniny polibutadienu z końcowymi grupami hydroksylowymi (HTPB) oraz adypinianu dioktylu (DOA) jako plastyfikatora, które po usieciowaniu wykorzystywane są jako lepiszcza w heterogenicznych paliwach rakietowych. Określono wpływ składu na reologiczne i termiczne właściwości mieszanin, mające istotne znaczenie z technologicznego i użytkowego punktu widzenia. Zbadano zależność lepkości przygotowanych mieszanin od temperatury. Badane układy poddano sieciowaniu i wyznaczono wartości czasu życia technologicznego (tpl).Wykazano, że tpl wydłuża się ze wzrostem zawartości plastyfikatora. Stabilność termiczną mieszanin zbadano za pomocą różnicowej kalorymetrii skaningowej i termograwimetrii. Stwierdzono, że zastosowane składniki nie ulegają rozkładowi w temperaturze od 290 do 350 K i badane mieszaniny nie powodują zagrożenia eksplozją

Application and properties of aluminum in primary and secondary explosives

Aluminum is an easily available and cheap material, which is widely used in military and civil industries, e.g. in space technology, explosion welding, mining, production of oil and natural gas, manufacture of airbags. Primary and secondary explosives containing aluminum are described in this part of the work. Aluminum is added to high explosives of different shapes and sizes. These parameters influence inter alia detonation velocity (D), explosion heat, detonation pressure, pressure impulse and thermal stability. Detonation parameters of high explosive (HE) containing aluminum have been determined for binary systems consisting of high explosive or oxidizer and aluminum, plastic bonded explosives (PBX), melt cast explosives, thermobaric explosives (TBX), ammonium nitrate fuel oil (ANFO). Aluminum causes different effects on detonation velocity and explosion heat depending on the type of high explosive in binary systems. The dependence of the aluminum content in a mixture with ammonium nitrate with detonation velocity increased for an aluminum range from 0 to 10%, changed little between 10 and 16% of aluminum added and decreased from 16 to 40% of the aluminum content. For an aluminum content higher than 40%, the detonation process was not observed. The performance of explosives can be determined by the shock wave intensity. An increase in the pressure impulse made Al particle react with gaseous products and the air behind the front of detonation wave. The addition of aluminum also influences the thermal stability of high explosive materials

Modification of HTPB (α,ω-dihydroxypolibutadiene) by esterification, silanization, epoxidation and hydrogenation

α,ω-Dihydroksypolibutadien (HTPB) jest cennym komonomerem do otrzymywania poliuretanów. Dzięki swoich specyficznym właściwościom, nadaje tym tworzywom mrozoodporność i świetne właściwości mechaniczne, szczególnie w niskich temperaturach. Tak otrzymywane poliuretany znajdują zastosowanie w produkcji stałych paliw rakietowych używanych w napędach rakiet kosmicznych i wojskowych, a także są podstawą mrozoodpornych klejów i lepiszcz oraz materiałów izolacyjnych. Współczesne badania nad doborem lepiszcza wskazują na zastosowanie polimerów wysokoenergetycznych lub modyfikacji dotychczas stosowanych polimerów polepszających ich właściwości. W nowoczesnych rakietowych materiałach pędnych polimerowe lepiszcze, może zostać zastąpione odpowiednim wysokoenergetycznym związkiem chemicznym, czyli polimerem z wbudowanymi grupami energetycznymi, takimi jak azydkowa lub nitrowa. W prezentowanym artykule przedstawione zostaną wyniki badań nad takimi sposobami modyfikacji HTPB, które zapewnią jego rozszerzoną aplikację.HTPB is a valuable comonomer for the preparation of polyurethanes. Thanks to its specific properties, it gives these materials frost resistance and excellent mechanical properties, especially at low temperatures. The polyurethanes thus obtained are used in the production of propellants used in space and military rocket propulsion, and are the basis for frost-resistant adhesives and insulating materials. Research on the selection of binder indicates the use of high energy polymers or modifications of previously used polymers improving their properties. The results of research on ways of changing the properties of HTPB through its modification and thus an increase of application possibilities will be presented

Interactions of Some Organic Solvents: Hydrocarbons and Chloroalkene

Metabolic and toxicodynamic interactions of some organic solvents in rats repeatedly treated with medium dose levels were examined. It was shown that both n-hexane and ethylbenzene significantly inhibited tetrachloroethylene metabolism during a 2-week period. n-Hexane and tetrachloroethylene enhanced metabolism of ethylbenzene whereas ethylbenzene suppressed n-hexane metabolism only at the end of the experiment. Biochemical changes, especially the drop in the level of non-protein sulfhydryl groups in tissues of rats treated with organic solvent mixtures, were significantly less pronounced than those observed after these chemicals were administered separately. These results demonstrate that metabolic interactions between hydrocarbons and chloroalkene may lead to a modification of the biological response to these compounds