A self-protected colorless WDM-PON with 2.5 Gb/s upstream signal based on RSOA.

In this investigation, we propose and demonstrate a colorless wavelength division multiplexed passive optical network (WDM-PON) at 2.5 Gb/s using reflective semiconductor optical amplifier (RSOA)-based optical networking units (ONUs); together with a self-protected architecture against fiber fault. In the optical line terminal (OLT), we use an array of self-seeding Fabry-Perot laser diodes (FP-LDs) to provide single-longitudinal-mode (SLM) continuous wave (CW) optical sources for the external injection to the RSOA-based ONUs. The self-survivable function for protecting the fiber fault in the distributed fibers and the proposed network performance are investigated and discussed.

Should bleeding tendency deter abdominal paracentesis?

BACKGROUND AND AIMS: This study was conducted to evaluate the complications and bleeding associated with either thrombocytopoenia or prolongation of prothrombin time for ultrasound-guided abdominal paracentesis in the emergency department. STUDY DESIGN AND PATIENTS: In an emergency department of a tertiary centre, patients receiving ultrasound-guided abdominal paracentesis by the emergency physicians were prospectively enrolled. Patient characteristics, the preprocedure international normalised ratio for prothrombin time and the platelet count, and the procedure-related complications were collected and analysed. RESULTS: For a 2-year study period, a total of 410 abdominal paracenteses in 163 patients were investigated. The preprocedure international normalised ratio for prothrombin time was more than 1.5 in 142 paracenteses; the preprocedure platelet count was less than 50 x 10(3) microL(-1) in 55 paracenteses. Only two out of 410 procedures (0.5%, 95% confidence interval=0.1-1.8%) were associated with minor complications of cutaneous bleeding in the same patient (0.6%, 95% confidence interval=0.1-3.4%) at different visits. There was no significant procedure-related bleeding or complications even in patients with marked thrombocytopoenia or prolongation in international normalised ratio. CONCLUSIONS: Bleeding complication of ultrasound-guided abdominal paracentesis is uncommon and appears to be very mild, regardless of preprocedure international normalised ratio or platelet count. Routine correction of prolonged international normalised ratio or thrombocytopoenia before abdominal paracentesis may not be necessary.

Disaster epidemiology and medical response in the Chi-Chi earthquake in Taiwan.

STUDY OBJECTIVE: We examine the mortality and morbidity associated with earthquakes in the Chi-Chi earthquake in Taiwan in 1999. METHODS: Crude casualty data were collected from the reports of the government, local health bureaus, and 97 hospitals. The demographic data from the annual report of the Department of Interior were also employed for data analysis. Cross tables showing incidence of deaths and injuries by age, sex, time, and geographic distribution were generated to compare the mortality among different subgroups. Multiple regression models were established to explore the risk factors related to the mortality caused by earthquakes. RESULTS: The following results were found: the mortality rate increased with proximity to the epicenter, mortality was higher among the elderly than among young people, 30% of the victims died from head injuries caused by the collapse of dwellings, and the peak of medical demand was 12 hours after the earthquake and significantly increased demand for care lasted as long as 3 days. Furthermore, the regression model indicated that 78.5% of the variation of locality-age-sex-specific mortality was explained by the intensity of the earthquake, age, population density, distance to epicenter, medical beds per 10,000 people, and physicians per 10,000 people. CONCLUSION: The results implied that fragile minorities, specifically the elderly and children, require special consideration and attention in regard to disaster rescue and emergency medical care allocation. Epidemiologic analysis can guide disaster response and preparation.

ED overcrowding in Taiwan: facts and strategies.

The objective of this study was to quantity the extent of emergency department (ED) overcrowding in Taiwan and to identify possible solutions. The ED log was reviewed for all patients who presented to the National Taiwan University Hospital's ED from January 16, 1996 through February 15, 1996. Charts from patients held longer than 72 hours were reviewed. Among 5,810 patients, 213 (3.6%) were held in the ED for more than 72 hours (7.1 patients per day). In 149 (70.0%) of them, admission was indicated but delayed (42 because more than one subspecialty were involved, 57 because of unavailability of bed, and 50 because of the disparity in admission priority between the emergency physicians and house staffs). Eighteen (8.4%) patients did not meet admission criteria (13 could have been treated in outpatient clinics, 3 needed placement in nursing homes, 2 because of personal problems). The others (22%) recovered while waiting. Significant overcrowding exists in EDs in Taiwan. Four solutions are proposed: (1) creation of a holding unit; (2) flexible ward assignment; (3) pre-established rules for admission priority-setting; and (4) active interfacility transfer. Only through these efforts can EDs in Taiwan guarantee an optimal level of care in the face of a growing patient demand.

Adaptive document block segmentation and classification.

This paper presents an adaptive block segmentation and classification technique for daily-received office documents having complex layout structures such as multiple columns and mixed-mode contents of text, graphics, and pictures. First, an improved two-step block segmentation algorithm is performed based on run-length smoothing for decomposing any document into single-mode blocks. Then, a rule-based block classification is used for classifying each block into the text, horizontal/vertical line, graphics, or-picture type. The document features and rules used are independent of character font and size and the scanning resolution. Experimental results show that our algorithms are capable of correctly segmenting and classifying different types of mixed-mode printed documents.

Skeletonization for fuzzy degraded character images.

Most skeletonization algorithms are operated on binary images. To avoid information loss and distortion, a topography-based approach is proposed to apply directly on fuzzy or gray scale images. A membership function is used to indicate the degree of membership of each ridge point with respect to the skeleton. Significant ridge points are linked to form strokes of skeleton. Experimental results show that our algorithm can reduce deformation of junction points anti correctly extract the whole skeleton, although a character may be broken into pieces. For merged characters, the breaking positions can be located by searching for the saddle points. A multiple context confirmation is used to increase the reliability of breaking hypotheses.

Pipeline architectures for recursive morphological operations.

Introduces efficient pipeline architectures for the recursive morphological operations. The standard morphological operation is applied directly on the original input image and produces an output image. The order of image scanning in which the operator is applied to the input pixels is irrelevant. However, the intent of the recursive morphological operations is to feed back the output at the current scanning pixel to overwrite its corresponding input pixel to be considered into computation at the following scanning pixels. The resultant output image by recursive morphology inherently depends on the image scanning sequence. Two pipelined implementations of the recursive morphological operations are presented. The design of an application-specific systolic array is first introduced. The systolic array uses 3 n cells to process an nxn image in 6 n-2 cycles. The cell utilization rate is 100%. Second, a parallel program implementing the recursive morphological operations and running on distributed-memory multicomputers is described. Performance of the program can be finely tuned by choosing appropriate partition parameters.

Recursive soft morphological filters.

We present properties of recursive soft morphological filters that use previously filtered outputs as their inputs, cascade combinations of these filters, and the idempotent recursive soft morphological filters. The development allows problems in the implementation of cascaded recursive soft morphological filters to be reduced to the equivalent problems of a single recursive standard morphological filter.