Since John von Neumann suggested utilizing Logistic map as a random number generator in 1947, a great number of encryption schemes based on Logistic map and/or its variants have been proposed. This paper re-evaluates the security of an image cipher based on transformed logistic maps and proves that the image cipher can be deciphered efficiently under two different conditions: 1) two pairs of kn...

To assess the usefulness of MR in defining the changes of lumbar arachnoiditis, we reviewed retrospectively the MR, plain-film myelographic, and CT myelographic findings in 100 patients referred for evaluation of failed-back-surgery syndrome. In 11 of 12 cases of arachnoiditis demonstrated by plain-film and CT myelography, an abnormal configuration of nerve roots was seen by MR. The correlated ...

BACKGROUND Reports showing high recurrence rates for intralesional curettage and bone grafting have made the current treatment principle for fibrous dysplasia controversial. This study aimed to report the postoperative clinical outcomes from three minimally invasive surgical strategies we use for monostotic fibrous dysplasia (MFD). PATIENTS AND METHODS Twelve patients with MFD presenting with...

OBJECTIVE To evaluate the role of sonography compared to plain radiography in the diagnosis of patients with suspected small bowel obstruction as well as to determine their specificity, sensitivity and accuracy in the Ugandan setting. DESIGN Prospective comparative study. SETTING Mulago Hospital, Uganda's main referal Hospital and Makerere University Medical School. SUBJECTS Seventy patie...

The structure of the monoid of autarkies for clause-sets is investigated (autarkies are generalizations of satisfying (truth) assignments). The notion of a \plain clause-set" is introduced, where every clause is usable by some resolution refutation, and it is shown that a clause-set is plain ii it has no non-trivial autarky. Every clause-set has a unique decomposition into a plain sub-clause-se...