Accountability of work activity in high-consequence work systems: human error in context

Organizational context is now accepted as a central concept in attempts to understand error in human–machine systems. However, accounts which emphasize the processes of everyday organizing, such as accountability and work activity, are needed in order to establish organizational requirements for design. In this article, we provide a framework for the consideration of organizational contexts of human error in high-consequence work systems, with a view to integrating empirical insights and supporting practical design work. We draw on computer-supported cooperative work conceptualizations of the process of everyday organizing, particularly the notion of “accountability for work activity” which is pivotal to our organizational account of error. The conceptual framework is characterized here as a set of dimensions which are expressive concerning the relationship between accountability and work activity in different contexts: (1) explicit–implicit; (2) global–local; (3) stable–transient and (4) dependent–independent. The framework is demonstrated with respect to everyday work practices in a radiology department and its analytical utility validated with respect to two documented aviation system failures. Applying the framework has enabled us to identify and define, in terms of the dimensions, a number of contexts for vulnerability in high-consequence systems: contexts for collusion, violation, deference, loss of control, buck passing and complacency. These are discussed in terms of requirements for error-tolerant design. In the final section of the article, links between the various contexts for vulnerability and the design process are explored.     

Efficient design/simulation algorithms for simultaneous switching noise in leadframe packages

 Two new modeling and simulation approaches for Simultaneous Switching Noise (SSN) are described and compared to “brute force” simulation by SPICE. Both simulation accuracy and simulation run-time are considered. The two new approaches are: 1) the “effective inductance” method, in which an approximate, very efficient method of extracting an SSN L _eff  is utilized; and 2) the “macromodel” method, in which the complex inductance network responsible for SSN is represented by only a few dominant poles in the frequency domain and the time domain response is obtained by an efficient convolution algorithm. Both approaches are shown to be accurate and fast, but only the effective inductance algorithm is robust in numerical convergence. Received: 19 March 1997 / Accepted: 25 March 1997     

Frequency and etiology of calf losses and calf diseases before weaning in cow-calf farms. II. Microbiological and parasitological diagnoses in diarrheic calves]

Diarrhea is the most frequently diagnosed disease in Swiss cow-calf farms. During an longitudinal study conducted in 105 cow-calf farms in Switzerland in 1993-95, blood and fecal samples were collected from diarrheic calves and from calves that died because of diarrhea. Campylobacter spp. were detected in 42%, E. coli (VTEC) in 32%, rotavirus in 33%, coronavirus in 13%, coccidia in 43% and helminths in 8% of the cases. In some samples Yersinia pseudotuberculosis were isolated. The BVD-virus antigen was not detected in any of the calves examined. In most cases concurrent infection with several enteropathogens was diagnosed. Specific causes of diarrhea were therefore difficult to establish. The bacteriological findings of this study have implication for food safety: VTEC, Campylobacter spp. Yersinia spp. and cryptosporidia are considered as potential causes on zoonoses.     

Investigation of driving performance, vection, postural sway, and simulator sickness in a fixed-based driving simulator

This paper reports the results of a pilot study conducted to determine whether there is a relationship between simulator sickness and measures of driver inputs, vection, and postural sway, in a fixed base driving simulator. Seven males and four females performed a series of alternating left and right turns (20 each), with straigth-aways inbetween. The task was designed to promote experiences of circular and linear vection, and associated sway. It was hypothesized that greater driver inputs (i.e., steering wheel and braking activity; deviation from the centerline) would correlate: with reports of vection and measures of postural sway. Ten of the eleven subjects reported moderate sickness, which precluded any statistical comparisons between “sick” and “not sick” however, there was a significant tendency for persons who reported vection to also report sickness. There were no gender differences in reported incidence of vection or sickness, however, males tended to exhibit greater lateral velocity. The next phase of investigation will necessitate reducing the strength of the stimulus (i.e., require less turns) to increase variability of sickness scores amongst subjects and permit comparisons between “sick” and “not sick.” Measurement considerations include increasing the sensitivity of vection ratings, and examination of the timecourse for the development of postural sway.     

"Inflammations of the male adnexa--disorders in fertility?" Report of the IV. Colloquium Andrologicum 15 February 1997 in Jena

An uncommon systemic reaction mimicking sarcoidosis after ligament reconstruction is reported. Clinical and radiological outcome after surgical treatment led to the diagnosis of a a specific injury caused by the ligament reconstruction device.     

Ocular involvement in tuberculoid leprosy--a case report

Leprosy is rarely diagnosed in our part of the world. In our 26-year-old patient, borderline lepromatous leprosy was first diagnosed in 1992 and was treated with Rifoldin, Lemprene and Dapson according to the standard WHO scheme of treatment. Ophthalmic examination showed minor epithelial lesions of the cornea in both eyes, a reduced corneal reflex in the left eye and a scleral leproma nasally and close to the limbus, also in the left eye. In 1995, the patient was examined again and was treated as above for lepromata of the left eyebrow nasally and of both lower legs. Ophthalmic examination revealed conjunctival irritation, anterior uveitis with leprosy pearls on the pupillary margin and secondary glaucoma. The glaucoma was treated with hypotonics, the uveitis was treated with topical cortisone. The intra-ocular pressure normalised and the uveitis improved. Of the two main types of leprosy, lepromatous leprosy and tuberculoid leprosy, our patient had the second, milder form.     

A standardized method for CMOS unit process development

The multipurpose mask set described, which consists of three stepper reticles, contains 95% of all test structures required for CMOS process development and random defect detection, thereby dramatically reducing the stepper reticle inventory and the frequency of reticle changes. Realizing the mask set by two dozen standard unit processes minimizes the feedback loop for defect density data, parametric data and unit process data     

Reciprocal association between insulin sensitivity and the haematocrit in man

BACKGROUND: Granular cell tumor was first described by Abrikossoff in 1926. It is rare and usually presents as a benign solitary lesion. Multifocal and malignant forms are known to occur. METHODS: This presentation illustrates an additional case of granular cell tumor. Clinical and histological features to distinguish malignant and benign forms are presented. RESULTS: Tumor can develop years after therapy for the primary lesion. Treatment recommendations are presented. CONCLUSIONS: Patients diagnosed with granular cell tumor require close follow-up. Radiographic evaluation for the presence of metastatic disease is necessary if a malignant variant is suspected.     

Radio-oncologic therapeutic strategy in curative treatment of non-small-cell bronchial carcinoma

Radiotherapy is an important modality in the postoperative and primary treatment of non-small cell lung cancer. Treatment results are rather unsatisfactory and have not basically changed in the past 15-20 years. In the nearer past, new treatment strategies were developed, which may contribute to a substantial improvement of the poor prognosis. On one hand, novel fractionation schedules using hyperfractionated accelerated radiation show promising results by improving local control. On the other hand, the main interest of many groups is focussed on a combined modality treatment using radiotherapy plus neoadjuvant or concurrent chemotherapy and surgery. There are numerous reports in the literature which document an advantage in survival of combined modalities over radiotherapy alone with improvements concerning local control as well as distant spread. The bases of the encouraging results is the use of a simultaneous or sequential combination of cisplatin-containing chemotherapy and high dose radiation. The following article reviews the relevant data from the literature with main emphasis on radiochemotherapy regimens.     

Performance evaluation of a multichannel transceiver system forADSL and VHDSL services

The authors study the performance of a multichannel modulation method for asymmetric digital subscriber lines (ADSLs) and very high-speed digital subscriber lines (VHDSLs). In the ADSL case, over all unloaded North American subscriber lines in the test set, a unidirectional 1.536 Mb/s data rate service from the end office to the customer premises is possible on a single twisted pair at an error rate of 10^-7 with at least a 6 dB margin used coded multichannel modulation with sufficient transmit power. In the VHDSL case, data rates in excess of 100 Mb/s can be transmitted reliably, at an error rate of 10^-7, using uncoded multichannel modulation on a single twisted pair over a distance ⩽150 ft with a sufficiently high sampling rate (≈24 MHz) and transmit power. It is shown that a cost-effective multichannel transceiver design suggested for high-speed digital subscriber line (HDSL) service will also work well for ADSL and VHDSL services with only minimal modifications