Developing a voltage-stability-constrained security assessment system part I: Determination of power system voltage security operation limits

The method for determining the voltage security operation limits in a practical voltage security analysis (VSA) system based on VSAT software for large power systems is introduced in this paper. These operation limits include bus voltage limits, branch/corridor transfer power limits and P-load limit of the whole system. The voltage security operation limits are determined by the most critical contingency among the studied contingency set. The most critical contingency determines the P-load limit of the whole system, and all kinds of operation parameter limits are operation parameter values corresponding to this P-load limit under pre-contingency. An operation parameter limit is upper limit if the function relationship between this operation parameter and load power is an increasing curve, or lower limit if the function relationship between this operation parameter and load power is an decreasing curve. These operation parameter limits are helpful for operators to monitor the system operation state. © 2005 IEEE.published_or_final_versio

Developing a voltage-stability-constrained security assessment system part II : Structure and function design and technology used

This is the second part in a two-part paper on the development of a voltage stability constrained security assessment system (VSC-SAS). In this part, overall VSC-SAS structure and function design and technology used will be presented. The system is expected to be used in both on-line and off-line modes. In on-line mode, on-line SCADA/EMS data will be used for VSC-SAS use; while in off-line mode (usually day-ahead calculation), historical data can be used for VSC-SAS. Both results (i.e. system operation limits) can be selected to compare with real time operation conditions and supervision power system operation security margin. © 2005 IEEE.published_or_final_versio

Use Of Chinese Medicine Among Colorectal Cancer Patients: A Nationwide Population-Based Study.

Background: Traditional Chinese medicine (CM) appears to be used worldwide, especially by cancer patients. The aim of the present study was to explore CM uses and CM non-users by patients with colorectal cancer (CRC).Materials and methods: A retrospective study was conducted using registration and claims data sets for 2007 from the National Health Insurance Research Database. Patients with colorectal cancer were identified from the Registry for Catastrophic illness Patients. Binary logistic regression was used to estimate odds ratios as the measure of association with the use of CM.Results: A total of 61,211 CRC patients diagnosed in 2007 were analysis. Most CM users preferred to visit private clinics (46.9%) with 306,599 visits. In contrast, the majority of CM non-users preferred to visit private hospitals (42.2%) with 538,769 visits. Among all 176,707 cancer-specific CM visit, there were 66.6% visits to CM outpatient department (OPD) of private hospitals, while in 477,612 non-cancer-specific CM visits, 62.0% was for private clinics. The proportion of expenses for diagnostic fees for CM user in CM visits was much less than that for WM visits and CM non-users (US$4.6 vs. 29.3 vs. 33.5). The average cost for CM user in CM was less than that for WM visits and CM non-users (US$6.3 vs. 25.9 vs. 30.3). Female patients, younger age, and patients not living in the northern region, with higher EC or more comorbidities were more likely to receive CM treatment.Conclusion: The prevalence and costs of insurance-covered CM among CRC patients were low. Further longer longitudinal study is needed to follow up this trend.Key words: Chinese Medicine, Digestive System Neoplasms, Health Insuranc

中文词汇网络:跨语言知识处理基础架构的设计理念与实践

Title in Traditional Chinese: 中文詞彙網路 : 跨語言知識處理基礎架構的設計理念與實踐Journal title in Traditional Chinese: 中文信息學報2009-2010 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Suppression of gas species signals in direct current glow discharge time-of-flight mass spectrometry

The possibility of suppressing gas species in direct current glow discharge mass spectrometry (dc-GDMS) with a linear time-of-flight mass analyzer was investigated. With this tic-GD ion source, a 'clean' mass spectrum rich in analyte could be obtained when the dc-GD was operated under a discharge current of 15-30 mA and a gas pressure of 300-500 Pa, in contrast to the strong signals of gas species in convention dc-GDMS, which operates at lower currents and pressures (typically 1-5 mA and 100 Pa). Such an experimental result is believed to be due to increased sputtering at higher pressures and currents, and the different ionization mechanisms of analyte and gas species. For a possible GD design to eliminate the background gas ions, a new discharge configuration was developed by attaching a TM,,, microwave resonator to the GD ion source. The mass spectrum of the cathode sample showed a low gas species background when the microwave-induced plasma (MIP) discharge was 'off' under different dc-GD parameters. The mass spectra of analyte and gas species obtained with 'MIP + dc-GD' and 'MIP only' modes are also compared and discussed. It was found that the analyte signals decrease and the gas species signals increase in the presence of the MIP, and that the analyte signals nearly disappear in the 'MIP only' mode. Preliminary results suggest that, for specific discharge conditions and with a suitable design of the GD source, an efficient suppression of gas species in dc-GDMS detection could be realized

Knee loading stimulates cortical bone formation in murine femurs

BACKGROUND: Bone alters its architecture and mass in response to the mechanical environment, and thus varying loading modalities have been examined for studying load-driven bone formation. The current study aimed to evaluate the anabolic effects of knee loading on diaphyseal cortical bone in the femur. METHODS: Using a custom-made piezoelectric loader, 0.5-N loads were laterally applied to the left knee of C57/BL/6 mice at 5, 10, 15, and 20 Hz for 3 minutes per day for 3 consecutive days. Animals were sacrificed for examination 13 days after the last loading. The contralateral femur was used as a non-loading control, and the statistical significance of loading effects was evaluated with p < 0.05. RESULTS: Although diaphyseal strains were measured as small as 12 μstrains, bone histomorphometry clearly demonstrated frequency-dependent enhancement of bone formation. Compared to a non-loading control, bone formation on the periosteal surface was significantly enhanced. The loading at 15 Hz was most effective in elevating the mineralizing surface (1.7 x; p < 0.05), mineral apposition rate (1.4 x; p < 0.001), and bone formation rate (2.4 x; p < 0.01). The loading at 10 Hz elevated the mineralizing surface (1.4 x; p < 0.05), mineral apposition rate (1.3 x; p < 0.01), and bone formation rate (1.8 x; p < 0.05). The cross-sectional cortical area and the cortical thickness in the femoral diaphysis were significantly increased by loading at 10 Hz (both 9%) and 15 Hz (12% and 13%, respectively). CONCLUSION: The results support the anabolic effects of knee loading on diaphyseal cortical bone in the femur with small in situ strain, and they extend our knowledge on the interplay between bone and joints. Strengthening the femur contributes to preventing femoral fractures, and the discovery about the described knee loading might provide a novel strategy to strengthen osteoporotic bones. Further analyses are required to understand the biophysical and molecular mechanism behind knee loading

Clinical characteristics of the autumn-winter type scrub typhus cases in south of Shandong province, northern China

<p>Abstract</p> <p>Background</p> <p>Before 1986, scrub typhus was only found endemic in southern China. Because human infections typically occur in the summer, it is called "summer type". During the autumn-winter period of 1986, a new type of scrub typhus was identified in Shandong and northern Jiangsu province of northern China. This newly recognized scrub typhus was subsequently reported in many areas of northern China and was then called "autumn-winter type". However, clinical characteristics of associated cases have not been reported.</p> <p>Methods</p> <p>From 1995 to 2006, all suspected scrub typhus cases in five township hospitals of Feixian county, Shandong province were enrolled. Indirect immunofluorescent assay (IFA) was used as confirmatory serodiagnosis test. Polymerase chain reaction (PCR) connected with restriction fragment length polymorphism (RFLP) and sequence analyses were used for genotyping of <it>O. tsutsugamushi </it>DNAs. Clinical symptoms and demography of confirmed cases were analyzed.</p> <p>Results</p> <p>A total of 480 scrub typhus cases were confirmed. The cases occurred every year exclusively between September and December with a peak occurrence in October. The case numbers were relatively higher in 1995, 1996, 1997, and 2000 than in other years. 57.9% of cases were in the group aged 21–50. More cases occurred in male (56%) than in female (44%). The predominant occupational group of the cases was farmers (85.0%). Farm work was reported the primary exposure to infection in 67.7% of cases. Fever, rash, and eschar were observed in 100.0%, 90.4%, and 88.5% of cases, respectively. Eschars formed frequently on or around umbilicus, abdomen areas, and front and back of waist (34.1%) in both genders. Normal results were observed in 88.7% (WBC counts), 84.5% (PLT counts), and 89.7% (RBC counts) of cases, respectively. Observations from the five hospitals were compared and no significant differences were found.</p> <p>Conclusion</p> <p>The autumn-winter type scrub typhus in northern China occurred exclusively from September to December with a peak occurrence in October, which was different from the summer type in southern China. In comparison with the summer type, complications associated with autumn-winter type scrub typhus were less severe, and abnormalities of routine hematological parameters were less obvious.</p

Microwave-induced plasma boosted microsecond-pulse glow discharge optical emission spectrometry

A microsecond-pulse (mu s-pulse) glow discharge (GD) source boosted by a microwave-induced plasma (MIP) has been developed and studied for optical emission spectrometry (OES), The excitation processes of the tandem GD source were investigated, The analytical characteristics of the GD-OES source in the presence and absence of the MIP were compared, including the operating parameters, signal-to-background ratios (S/B) and relative standard deviation (RSD), The results show that under a relatively low discharge pressure (<180 Pa), the mu s-pulse GD can couple fairly well with the MIP and emit intense analytical lines, When the GD source is operated under a pressure higher than 200 Pa, tao emission peaks appear, independent in time, for a given resonance atomic line, because sample atoms are independently structurally excited, first by the mu s-pulse GD and then by the MIP. The time interval between the tao peaks for Zn I 213.8 nm is longer than that for Cu I 324.7 nm, which is believed to be due to the faster diffusing velocity of copper atoms, When the mu s-pulse GD lamp is operated under a gas pressure higher than 220 Pa, the ion population is so high that Cu II ionic line at 224.7 nm 'becomes' two peaks because of a possible self-absorption. The results show that the supplementary nse of an MIP can eliminate the self-absorption of ionic and atomic lines, When the mu s-pulse GD source is coupled with the MTP, S/Bs are improved by a factor of more than one order of magnitude for several analytical lines. A short-term RSD of 0.2% is achieved for the 'mu s-pulse GD+MIP' configuration compared with that of 1.0% for 'mu s-pulse GD only' mode. The experimental results show that the MIP boosted mu s-pulse GD is a promising technique for solid sample and surface analysis

Skeletal Adaptation to Intramedullary Pressure-Induced Interstitial Fluid Flow Is Enhanced in Mice Subjected to Targeted Osteocyte Ablation

Interstitial fluid flow (IFF) is a potent regulatory signal in bone. During mechanical loading, IFF is generated through two distinct mechanisms that result in spatially distinct flow profiles: poroelastic interactions within the lacunar-canalicular system, and intramedullary pressurization. While the former generates IFF primarily within the lacunar-canalicular network, the latter generates significant flow at the endosteal surface as well as within the tissue. This gives rise to the intriguing possibility that loading-induced IFF may differentially activate osteocytes or surface-residing cells depending on the generating mechanism, and that sensation of IFF generated via intramedullary pressurization may be mediated by a non-osteocytic bone cell population. To begin to explore this possibility, we used the Dmp1-HBEGF inducible osteocyte ablation mouse model and a microfluidic system for modulating intramedullary pressure (ImP) to assess whether structural adaptation to ImP-driven IFF is altered by partial osteocyte depletion. Canalicular convective velocities during pressurization were estimated through the use of fluorescence recovery after photobleaching and computational modeling. Following osteocyte ablation, transgenic mice exhibited severe losses in bone structure and altered responses to hindlimb suspension in a compartment-specific manner. In pressure-loaded limbs, transgenic mice displayed similar or significantly enhanced structural adaptation to Imp-driven IFF, particularly in the trabecular compartment, despite up to ∼50% of trabecular lacunae being uninhabited following ablation. Interestingly, regression analysis revealed relative gains in bone structure in pressure-loaded limbs were correlated with reductions in bone structure in unpressurized control limbs, suggesting that adaptation to ImP-driven IFF was potentiated by increases in osteoclastic activity and/or reductions in osteoblastic activity incurred independently of pressure loading. Collectively, these studies indicate that structural adaptation to ImP-driven IFF can proceed unimpeded following a significant depletion in osteocytes, consistent with the potential existence of a non-osteocytic bone cell population that senses ImP-driven IFF independently and potentially parallel to osteocytic sensation of poroelasticity-derived IFF