Remote Policy Enforcement Using Java Virtual Machine

Tanenbaum, A.S. [Promotor]Crispo, B. [Copromotor

étudiants à la médiathèque de Tréfilerie à Saint-Étienne (Les)

The concept of an Ephemerizer system has been introduced in earlier works as a mechanism to ensure that a file deleted from the persistent storage remains unrecoverable. The principle involved storing the data in an encrypted form in the user’s machine and the key to decrypt the data in a physically separate machine. However the schemes proposed so far do not provide support for fine-grained user settings on the lifetime of the data nor support any mechanism to check the integrity of the system that is using the secret data. In addition we report the presence of a vulnerability in one version of the proposed scheme that can be exploited by an attacker to nullify the ephemeral nature of the keys. We propose and discuss in detail an alternate Identity Based cryptosystem powered scheme that overcomes the identified limitations of the original system

Studies on the Thermodynamics of Association of Ions in Aqueous Solutions

The thermodynamics of ion association in aqueous solutions of 1:1 and 2:2 valency type electrolytes have been studied. The thesis is divided into three parts together with an appendix. In part I, the uncharged ion pairs formed by the thallous ion with the aside, nitrate and bromide ions have been studied by solubility measurements on thallous iodate in sodium azide and potassium nitrate solutions at 0, 10, 25 and 40°C. , and on thallous bromide in sodium perchlorate and potassium nitrate solutions at 25 and 40°C. Conductivity measurements of thallous chloride solutions at 40°C and on saturated solutions of thallous bromide at 25 and 40°C have also been made. The heat and entropy of association are compared with data for other uncharged ion pairs. Part II deals with a study of association of bivalent cations with the sulphate ion using the cell H2, Pt HCl I, MSO4 AgCl, Ag in which e. auf. s were measured to an accuracy of +/-0.01 m.v. A detailed investigation of the second dissociation of sulphuric acid, has been made over the temperature range 0°C to 45°C using the cell, H2, Pt | HCl, H2SO4 I AgCl, Ag and the results obtained are discussed and compared the with the available data in literature. The heat of dissociation of bisulphate is in good agreement with values obtained by calorimetric and spectraphotometric methods. The ionic association in solutions of the sulphates of magnesium, zinc, cobalt, nickel and manganese has been studied at various temperatures in the range 0°C to 45°C. , in a range of ionic strength and the thermodynamic functions have been derived. Part III consists of a general discussion of the results. The entropies of the various ion pairs have been estimated, taking into account both translational and rotational terms. The heat and entropy data have been discussed in relation to the factors involved in the association process. A S hydration of the ion-pairs are compared in relation to their size, and a good linear relationship between A S hyd (ion pair) and reciprocal of interionic distance has been observed for the 1:1 ion pairs (including some silver salts). A similar relationship is indicated for the sulphates of the transition metals cobalt, nickel and manganese. An appendix is included dealing with a spectro- photometric study of the equilibrium HCrO4- ↔ H+ +CrO4-- at 25°C, at wavelengths 355, 365, 370, 375 and 385 m.u. A value of 2.97x10e-7 obtained for the dissociation constant is in agreement with the potentiometric value

Thermodynamic structure of the Atmospheric Boundary Layer over the Arabian Sea and the Indian Ocean during pre-INDOEX and INDOEX-FFP campaigns

Spatial and temporal variability of the Marine Atmospheric Boundary Layer (MABL) height for the Indian Ocean Experiment (INDOEX) study period are examined using the data collected through Cross-chained LORAN (Long-Range Aid to Navigation) Atmospheric Sounding System (CLASS) launchings during the Northern Hemispheric winter monsoon period. This paper reports the results of the analyses of the data collected during the pre-INDOEX (1997) and the INDOEX-First Field Phase (FFP; 1998) in the latitude range 14°N to 20°S over the Arabian Sea and the Indian Ocean. Mixed layer heights are derived from thermodynamic profiles and they indicated the variability of heights ranging from 400m to 1100m during daytime depending upon the location. Mixed layer heights over the Indian Ocean are slightly higher during the INDOEX-FFP than the pre-INDOEX due to anomalous conditions prevailing during the INDOEX-FFP. The trade wind inversion height varied from 2.3km to 4.5km during the pre-INDOEX and from 0.4km to 2.5km during the INDOEX-FFP. Elevated plumes of polluted air (lofted aerosol plumes) above the marine boundary layer are observed from thermodynamic profiles of the lower troposphere during the INDOEX-FFP. These elevated plumes are examined using 5-day back trajectory analysis and show that one group of air mass travelled a long way from Saudi Arabia and Iran/Iraq through India before reaching the location of measurement, while the other air mass originates from India and the Bay of Bengal

Bubbling and bistability in two parameter discrete systems

We present a graphical analysis of the mechanisms underlying the occurrences of bubbling sequences and bistability regions in the bifurcation scenario of a special class of one dimensional two parameter maps. The main result of the analysis is that whether it is bubbling or bistability is decided by the sign of the third derivative at the inflection point of the map function.Comment: LaTeX v2.09, 14 pages with 4 PNG figure

EFFECT OF CLASSICAL AYURVEDIC TREATMENT IN THE FUNCTIONAL IMPROVEMENT OF PATIENTS WITH RHEUMATOID ARTHRITIS

Arthritis and various musculoskeletal disorders are the leading causes of disability in persons between 18 to 65 years of age and are common causes of disability related to employment. Among them Rheumatoid arthritis is a common clinical condition characterized by pain, stiffness and inflammation of joints with varying degree of disability. In this study 50 patients (age group between 20-60 yrs) diagnosed as RA after assessing both objective and subjective parameters have undergone the prescribed classical Ayurvedic treatments, both IP and OP level to evaluate its effect in the functional improvement. The study period was totally 57 days which includes 21 days each at inpatient and outpatient basis and 15 days of follow up. Initial course was Ama pachana treatments for 7 days. It includes Pachana medicines internally and Ruksha pottali sweda externally. Next 14 days, Samana medicines internally and Pathra pottali sweda externally were given. Same internal medicines and oil application were continued for next 21 days as outpatient. The response of treatment was assessed periodically with respective parameters and were showed significant effect. The improvement in functional assessment evaluated by using the Das 28 score, disability index, quality of life index -SF36 and global assessment of disease activity scale are all found significant changes. The lab parameters used to evaluate the liver and kidney function did not show any adverse changes that shows the prescribed treatment is safe

CLASSICAL ASHTAVAIDYAN AYURVEDIC THERAPY IN THE FUNCTIONAL IMPROVEMENT OF PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS: CASE STUDY

Background: Systemic lupus erythematosus is a systemic auto immune connective tissue disease that can affect any part of the body. The disease has no direct reference in Ayurvedic texts. Considering the symptomatology, it can be compared with Upadrava of Vatarakta. Methodology: In this study, 3 patients (age group between 15– 60 yrs) diagnosed SLE with the help of ACR criteria after assessing both objective and subjective parameters have undergone the prescribed classical Ayurvedic treatments, in both IP and OP level to evaluate its effect in the functional improvement. The study period was totally 57 days which included 21 days each at inpatient and outpatient basis and 15 days of follow up. Initially Sathaila Shastika Pinda Sweda was done for first 7 days followed by Takradhara for another 7 days. Consecutively Abhyanga with Pinda taila and Thalam with Amalaki were done for next 7 days. Then treatment was done on OP basis with internal medicines. Result: Results shows that the prescribed Ayurvedic treatments helped to control the progressive signs and symptoms. The quality of life and range of movements of the affected joints improved. Major difference showing a good improvement in carrying out the day today life activities was noted. Conclusion: Traditional Ashtavaidyan Ayurveda therapy is found effective in controlling the progressive symptoms of patients and improvement in functional ability of the patients with SLE. More over there was no adverse drug reaction recorded during as well there was significant change observed in liver and renal function tests. This indicates that the therapy is safe without producing any complication or side effects

Classical Ashtavaidyan Ayurvedic Therapy in the functional improvement of patients of Psoriatic Arthritis - An open label, single arm exploratory clinical study

Background: Arthritis and various musculoskeletal disorders are the leading cause of disability in persons between 18 to 65 years of age. Psoriatic arthritis simulates Ayurvedic descriptions of the clinical syndrome - Vatarakta. The study has been designed to evaluate the effectiveness of classical Ashtavaidyan methods of Ayurvedic intervention in the management of psoriatic arthritis and to assess the safety of the therapy. Methodology: Diagnosed cases of psoriatic arthritis (n=30) (20-60 yrs) have undergone the prescribed classical Ashtavaidyan Ayurvedic therapies. The total study period was 57 days which included 21 days each at inpatient and outpatient basis and 15 days of follow up. Initially modified Takradhara was performed along with internal medications for first 14 days; later same internal medication was continued with Sarvanga Abhyanga (therapeutic massage) with Pinda Taila and Vajraka Ghrita in 3:1 ratio externally and Amalaki Thalam for next 7 days. Same internal medicines and oil application were continued for next 21 days as outpatient. Results: The response to treatment was assessed periodically with respective parameters and showed highly significant improvement (P<0.001). There was significant reduction in PASI score and also significant changes in functional parameters related to psoriatic arthritis evaluated by using the visual analogue pain scale, DAS score, disability index scores and SF-36 (quality of life Index). The laboratory parameters used to evaluate the liver and renal functions did not show any significant changes that indicate the prescribed treatment is safe. Conclusion: Traditional Ashtavaidyan Ayurveda therapy is effective in reducing the skin lesions and improving functional ability in Vatarakta vis-à-vis psoriatic arthritis over a period of 42 days. Moreover, there was no adverse drug reaction recorded as well no significant change observed in liver and renal function tests

Phase separation and the effect of quenched disorder in Pr0.5Sr0.5MnO3Pr_{0.5}Sr_{0.5}MnO_3

The nature of phase separation in $Pr_{0.5}Sr_{0.5}MnO_3$ has been probed by linear as well as nonlinear magnetic susceptibilities and resistivity measurements across the 2nd order paramagnetic to ferromagnetic transition ($T_C$) and 1st order ferromagnetic to antiferromagnetic transition ($T_N$). We found that the ferromagnetic (metallic) clusters, which form with the onset of long-range order in the system at $T_C$, continuously decrease their size with the decrease in temperature and coexist with non-ferromagnetic (insulating) clusters. These non-ferromagnetic clusters are identified to be antiferromagnetic. Significantly, it is shown that they do not arise because of the superheating effect of the lower temperature 1st order transition. Thus reveals unique phase coexistence in a manganite around half-doping encompassing two long-range order transitions. Both the ferromagnetic and antiferromagnetic clusters form at $T_C$ and persist much below $T_N$. Substitution of quenched disorder (Ga) at Mn-site promotes antiferromagnetism at the cost of ferromagnetism without adding any magnetic interaction or introducing any significant lattice distortion. Moreover, increase in disorder decreases the ferromagnetic cluster size and with 7.5% Ga substitution clusters size reduces to the single domain limit. Yet, all the samples show significant short-range ferromagnetic interaction much above $T_C$. Resistivity measurements also reveal the novel phase coexistence identified from the magnetic measurements. It is significant that, increase in disorder up to 7.5% increases the resistivity of the low temperature antiferromagnetic phase by about four orders