Testing of PLL-based True Random Number Generator in Changing Working Conditions

Security of cryptographic systems depends significantly on security of secret keys. Unpredictability of the keys is achieved by their generation by True Random Number Generators (TRNGs). In the paper we analyze behavior of the Phase-Locked Loop (PLL) based TRNG in changing working environment. The frequency of signals synthesized by PLL may be naturally influenced by chip temperature. We show what impact the temperature has on the quality of generated random sequence of the PLL-based TRNG. Thank to analysis of internal signals of the generator we are able to prove dependencies between the PLL parameters, statistical parameters of the generated sequence and temperature. Considering the measured results of experiments we form a new requirement in order to improve the robustness of the designed TRNG

Comparison of Scalable Montgomery Modular Multiplication Implementations Embedded in Reconfigurable Hardware

International audienceThis paper presents a comparison of possible approaches for an efficient implementation of Multiple-word radix-2 Montgomery Modular Multiplication (MM) on modern Field Programmable Gate Arrays (FPGAs). The hardware implementation of MM coprocessor is fully scalable what means that it can be reused in order to generate long-precision results independently on the word length of the originally proposed coprocessor. The first of analyzed implementations uses a data path based on traditionally used redundant carry-save adders, the second one exploits, in scalable designs not yet applied, standard carry-propagate adders with fast carry chain logic. As a control unit and a platform for purely software implementation an embedded soft-core processor Altera NIOS is employed. All implementations use large embedded memory blocks available in recent FPGAs. Speed and logic requirements comparisons are performed on the optimized software and combined hardware-software designs in Altera FPGAs. The issues of targeting a design specifically for a FPGA are considered taking into account the underlying architecture imposed by the target FPGA technology. It is shown that the coprocessors based on carry-save adders and carry-propagate adders provide comparable results in constrained FPGA implementations but in case of carry-propagate logic, the solution requires less embedded memory and provides some additional implementation advantages presented in the paper

A direct urea fuel cell - power from fertiliser and waste

For the first time, a working direct urea and direct urine fuel cell has been developed to generate electricity directly from urea or urine

Righteous Commitment: Renewing, Repairing, and Restoring the World—Wangari Maathai and the Green Belt Movement

This Africentric historical inquiry introduces Wangari Maathai, 2004 Nobel Peace Prize recipient and internationally renowned Kenyan activist, as a visionary adult educator and leader of the liberatory environmental movement -The Green Belt Movement. The Movement addresses decades of mis-education through culturally grounded adult education activities that help communities understand the linkages between environmental degradation and poor governance, and educate people to participate in democracy. The study describes Maathai’s philosophy and how it informed her leadership of environmental, political, and social change. The African philosophical framework of Maat, and the principle of serudj-ta (repairing, renewing and restoring the world) provide a lens and conceptual grounding for understanding Maathai’s philosophy. Maathai’s message, that equitable and sustainable management of natural resources is inextricably bound with issues of governance and social justice, suggests the consciousness that allows exploitation and domination of people is the same consciousness that allows exploitation and domination of nature. Adult education is central to the Movement because of its role in helping people understand and address root causes of injustice, in all its forms. Maathai’s success at mobilizing thousands of people at the grassroots, many marginalized, to both challenge oppressive systems and affect environmental change at the local level speaks to the power of culturally grounded adult education. The Movement employed adult education as a decolonization process and to foster the revitalization of indigenous culture, selfethnic identity, women’s empowerment, and participatory democracy. For adult educators and others concerned with the environment, Maathai’s work teaches us that we must not isolate our work in that domain from the larger, systemic and root causes of environmental problems

Factor V Leiden distribution : could it shed some light on the pre-history of Europe and the Near East?

Polymorphism of clotting factor V, comprising Arg506Gln substitution in the factor V molecule, commonly known as Factor V Leiden, represents the most common heritable risk factor for thrombotic events in Indo-Europeans and some Semitic nations. Although it is suggested that this mutation is associated with a survival advantage that has facilitated the spread of this polymorphism in the human population, in this paper we argue against such a Darwinian evolutionary mechanism responsible for the high prevalence of FV Leiden in some countries. Instead, we propose that cultural, climatic, and geographic factors played a role. Taking into account the current distribution of FV Leiden polymorphism and the results of recent assessments of pre-historic human DNA, we suggest that actually the origin of FV Leiden mutation did not occur in the Near East, as is widely believed, but rather in a small isolated population of so-called Basal Eurasians, probably in northern Africa. This founder group probably migrated to the Near East during the Younger Dryas, a geological period associated with climate cooling. Here, they mixed with local people; still Factor V Leiden mutation remained very prevalent in this population. The invention of agriculture, which took place approximately 2,000 years later, gave the descendants of Basal Eurasians an enormous advantage over hunter-gatherers, and probably enabled a successful spread of FV Leiden polymorphism to Europe, Central Asia, and towards the Indian subcontinent

Porównanie jakości życia i ciężkości objawów klinicznych u chorych z przewlekłą niewydolnością żylną. Czy u wszystkich chorych jakość życia można określać za pomocą jednego uniwersalnego kwestionariusza?

Background. The assessment of the quality of life (QoL) questionnaire based on patients’ opinions and preferences, and to estimate whether QoL of patients with chronic venous insufficiency (CVI) should be assessed in the universal manner, or in the way depending on the progression of the disease, were the aims of the study. Material and methods. Eighty patients with C-2, -3, -4, and -6 according to CEAP classification were estimating their QoL by means of ques-tionnaire assessing: physical complaints, influence of the disease on patient’s activity, and psychological aspects of the disability. Patients were asked to evaluate the severity of each problem, as well as its subjective importance. It was also analyzed whether consideration of severity of each problem, as well as its importance for the patient, instead of the presence or absence of the problem, will result in different final assessment. Results. The statistically significant correlation was revealed between the intensity of majority of the problems and the class of CVI. However, if the subjective importance of the complaint were regarded, the final score would be significant value only for some problems. It was also demonstrated that patients from different classes of CVI did not found the same clinical problems equally important. The final score of QoL assessment depended on the method of evaluation of the questionnaire, these differences however were not statistically significant. Conclusions. It was revealed that a QoL questionnaire presented in this study can be used in the patients with CVI. Different subjective values of clinical problems for the patient with CVI at different clinical stages of the disease were demonstrated. It was not definitively answered whether specific questionnaires for different classes of CVI were necessary. The further studies of this diagnostic tool and its verification in the clinical practice are required.Wstęp. Celem pracy była ocena kwestionariusza jakości życia chorych z przewlekłą niewydolnością żylną (CVI), którego podstawą były opinie i preferencje chorych, jak również zbadanie czy sposób oceny jakości życia tych chorych powinien być uniwersalny, czy też powinien zależeć od stopnia zaawansowania choroby. Materiał i metody. Jakość życia oceniono u 80 chorych ze stopniem klinicznym C-2, -3, -4 i -6 według klasyfikacji CEAP za pomocą kwestionariusza uwzględniającego: dolegliwości fizyczne, ograniczenie aktywności życiowej i problemy psychologiczne związane z chorobą. Chorych proszono, aby oceniali nasilenie każdego z problemów oraz i jego subiektywne znaczenie. Oceniono również wpływ, jaki ma uwzględnienie nasilenia i znaczenia poszczególnych problemów zamiast dostrzegania tylko ich obecności lub braku na końcową ocenę jakości życia chorych. Wyniki. Stwierdzono statystycznie znamienną korelację nasilenia większości problemów z klasą CVI. Wykazano jednak, że uwzględniając również subiektywne znaczenie problemu, ostatecznie tylko kilka problemów ma istotne znaczenie dla chorych. Stwierdzono też, że chorzy należący do klas CVI oceniali różnie subiektywne znaczenie poszczególnych problemów. Końcowy wynik skali jakości życia zależał od sposobu oceny kwestionariusza. Jednak różnice te nie były znamienne statystycznie. Wnioski. Stwierdzono, że opracowany kwestionariusz oceny QoL można stosować u chorych z CVI. Wykazano, że dla chorych z CVI w różnym klinicznym stopniu zaawansowania choroby poszczególne problemy kliniczne mogą mieć różne subiektywne znaczenie. Nie uzyskano jednoznacznej odpowiedzi na pytanie, czy konieczne byłoby zastosowanie specyficznych kwestionariuszy dla poszczególnych klas chorych z CVI. W tym celu konieczne są dalsze prace nad tym narzędziem diagnostycznym, jak również jego weryfikacja w praktyce klinicznej