Studies on measuring software

A quality control workshop prototype based on a quantitative approach which is operational from the validation phase was developed. Several telecommunications software systems were analyzed, particularly those areas pertaining to complexity and reliability. The workshop, the methods use to collect, handle, and analyze data, and the tools employed are described. The results allow evaluation of tool usefulness, pertinence of metrics, and validation of the reliability model. It is noted that the research carried out will lead to the application and evaluation of software quality assurance plans and to the evaluation of current beliefs concerning validity, efficiency, and costs     

Gritti's amputation in vascular surgery

Gritti's amputation was performed in 35 patients, mean age 71 years, with vascular disease of leg. There was no immediate postoperative mortality. Of twenty patients fitted with an appliance using a specific technique, only one had a poor functional result. The results obtained in this preliminary series were compared with those after amputations and knee disarticulations. They showed that Gritti's amputation should be considered for patients with arteritis when a functional knee is impossible to conserve.     

Predictive factors of physical disability in a cohort of retired persons in Paris followed during 10 years

OBJECTIVE: The objective of the present study was to examine predictors of physical disability in a survey of retired men and women living in the Paris area followed-up longitudinally for 10 years. METHODS: Subjects were randomly selected in a supplementary retirement pension fund. In all 627 subjects took part in the first phase of the survey (1982-83) and 392 in the follow-up phase (1992-93). At the 10-year follow-up, there were 185 confirmed deaths and 50 subjects refused to participate or could not be traced. Physical disability was measured by difficulties reported by the subjects for seven basic activities of daily life. Possible predictors, socio-demographic, impairments, physical activities, working conditions during working life were explored at T1. RESULTS: The incidence of physical disability was 41.4% for men and 57.6% for women. For disability in mobility, the incidence was 37.1% for men and 54.7% for women. In multivariate analysis, predictors of physical disability were social category (clerks), no physical activities, use of medicine, mental impairment. The predictors of disability in mobility were sex (women), social category (clerks), use of medicine, cardio-respiratory and sensory impairments. On the contrary, subjects with mental impairment had a lower incidence of disability in mobility than subjects without mental impairment. CONCLUSION: The results confirm the two poles of disability: biomedical and social. Working conditions during working life do not seem to play a direct part in incidence of disability at ten years follow-up.     

Pathogens isolated during treatment failures in otitis

OBJECTIVES: A prospective study in the Paris region to evaluate the clinical and bacteriologic epidemiology of acute otitis media in infants in whom oral antibiotic therapy resulted in clinical failure. METHODS: The study included 186 children with a mean age of 17.5 +/- 13.1 months. Two-thirds of them attended a day-care center and 40.8% had a history of recurrent otitis media. The most frequently prescribed prior antibiotics were amoxicillin-clavulanic acid (43% of cases), an oral third generation cephalosporin (22.6%), erythromycin-sulfisoxazole (11.8%) and a first generation cephalosporin (10.2%). The average duration of antibiotic therapy was 6.9 +/- 2.65 days. Specimens for bacterial cultures included 188 samples of middle ear fluid obtained by tympanocentesis and 37 collected from otorrhea fluid. RESULTS: One hundred forty-one samples (62.7%) from 126 children yielded 170 bacterial isolates. In 60 children (32.3%) the culture of the ear pus was sterile. Among the 170 bacterial isolates: 67 (39.4%) were Streptococcus pneumoniae (59 patients), of which 77.6% had reduced susceptibility to penicillin (PRSP with penicillin MIC > or = 0.125 mg/l); 61 (35.9%) were Haemophilus influenzae (56 patients) of which 49.2% were beta-lactamase producers; and 8 were Moraxella catarrhalis (8 patients), of which 87.5% were beta-lactamase producers. Thirty-six patients were infected by S. pneumoniae with penicillin MIC > or =1 mg/l. In our study attending day-care center (P = 0.04), temperature >38 degrees C with signs of otalgia (P = 0.02), age <2 years (P = 0.048) and prior antibiotic treatment with erythromycin-sulfisoxazole (P = 0.006) were independently predictive risk factors for patients infected with penicillin-resistant S. pneumoniae. Pneumococcal serogroups 23, 14 and 19 were predominant (25.4, 25.4 and 23.8%, respectively). Penicillin resistance was mainly associated with serogroups 23 and 14. CONCLUSIONS: Penicillin-resistant S. pneumoniae isolates are frequently responsible for therapeutic failure in cases of acute otitis media in the Paris region.     

An eight-user UMTS channel unit Processor for 3GPP base station applications

We present a multi-user W-CDMA baseband channel unit processor for cellular base station applications. The ASIC is compliant with the 3GPP/UMTS standard and exceeds 3GPP minimum requirements for high-speed data by 2.2-6.2 dB. It supports up to eight users simultaneously, with a mix of voice and data services and a maximum uplink data rate of 384 kb/s and maximum downlink data rate of 2 Mb/s. The ASIC implements preamble detection, searching, demodulation RAKE-finger processing, channel coding/decoding for voice and data services, and transmission functions. It is coupled to a DSP to form a complete channel element for eight users.     

Une expérience de i’utilisation des modéles classiques à croissance de fiabilité du logiciel dans le domaine des télécommunications

Telephone switching systems require using more and more complex and bulky software. Accordingly, before the operational phase France Telecom must evaluate software quality in particular reliability. This paper sets out to present an experiment conducted at the CNET-Lannion A centre. This experiment was based on the use of 3 conventional reliability growth models during the qualification phase of a product (analytical and overall tests) and also during the validation phase of a different product. The future prospects with regards the reliability data book and the use of the different models are also discussed.     

Use of failure-intensity models in the software-validation phasefor telecommunications

Telephone switching systems require the use of more complex and bulky software. It is therefore important for France Telecom to take an interest in software quality before the operational phase. Trend tests show the evolution of detected failures during the validation phase. When these tests show a tendency towards improvement, we can apply software-reliability growth models. This paper describes experiments conducted at CNET, Lannion A Center, concerning the use of failure-intensity models in the software-validation phase of 3 telecommunication products. The experiments show that the logarithmic model is the most accurate. This paper also addresses future perspectives in data collection and use of reliability models