Computational Simulation and Comparison of the Effect of Different Surroundings on Wind Loads on Domed Structures

[[abstract]]Mean surface pressures and overall wind loads on domes immersed in a boundary layer were obtained by computational fluid dynamics simulation. The effects of alternative turbulence models, upwind area roughness were examined and compared with wind tunnel studies. Surface pressures on dome structures were calculated in two cases by numerical simulation. One is with surrounding structures to calculate the wind comes from east and west direction, another one is no surrounding structure existing. The results will be evaluated the accuracy of numerical simulation with different roughness types of upwind area and effect of surroundings. Calculated values were compared to wind-tunnel measurements made in equivalent flow conditions.[[notice]]補正完畢[[incitationindex]]EI[[booktype]]紙

An Efficiency Enhanced Cluster Expanding Block Algorithm for Copy-Move Forgery Detection

[[conferencetype]]國際[[conferencetkucampus]]台北校園[[conferencedate]]20150902~20150904[[booktype]]電子版[[iscallforpapers]]Y[[conferencelocation]]Taipei, Taiwa

Data preprocessing for artificial neural network applications in prioritizing railroad projects â a practical experience in Taiwan

[[abstract]]Financial constraints necessitate the tradeoff among proposed railroad projects, so that the project priorities for implementation and budget allocation need to be determined by the ranking mechanisms in the government. At present, the Taiwan central government prioritizes funding allocations primarily using the analytic hierarchy process (AHP), a methodology that permits the synthesizing of subjective judgments systematically and logically into objective consensus. However, due to the coopetition and heterogeneity of railway projects, the proper priorities of railroad projects could not be always evaluated by the AHP. The decision makers prefer subjective judgments to referring to the AHP evaluation re- sults. This circumstance not only decreased the AHP advantages, but also raised the risk of the policies. A method to con- sider both objective measures and subjective judgments of project attributes can help reduce this problem. Accordingly, combining the AHP with the artificial neural network (ANN) methodologies would theoretically be a proper solution to bring a ranking predication model by creating the obscure relations between objective measures by the AHP and subjec- tive judgments. However, the inconsistency between the AHP evaluation and subjective judgments resulted in the inferior soundness of the AHP/ANN ranking forecast model. To overcome this problem, this study proposes the data prepro- cessing method (DPM) to calculate the correlation coefficient value using the subjective and objective ranking incidence matrixes; according to the correlation coefficient value, the consistency between the AHP rankings and subjective judg- ments of railroad projects can be evaluated and improved, so that the forecast accuracy of the AHP/ANN ranking forecast model can also be enhanced. Based on this concept, a practical railroad project ranking experience derived from the Insti- tute of Transportation of Taiwan is illustrated in this paper to reveal the feasibility of applying the DPM to the AHP/ANN ranking prediction model.[[notice]]補正完畢[[journaltype]]國外[[incitationindex]]SCI[[ispeerreviewed]]Y[[booktype]]電子版[[countrycodes]]LT

XOR-Based Progressively Secret Image Sharing

[[abstract]]Secret image sharing technology is a strategy for jointly protecting secret images. The (n, n) secret image sharing problem can be solved by conventional Boolean calculation easily. However, how to recover secret images with progressive steps is not addressed. In this study, we proposed an XOR-based (m, t, Ti) multi-secret image sharing scheme that shares m secret images among m participants and recovers m shared images progressively with t thresholds. The proposed secret images partition strategy (SIPS) partitions m secret images to generate intermediate images for different thresholds in the sharing procedure. Based on progressive recovery property, the proposed recovery method recovers parts of the secret images by gathering consecutive shared images. Moreover, gathering all shared images can perfectly recover all secret images. The experimental results show that the proposed XOR-based multi-secret image sharing method has high security and efficiency.[[notice]]補正完

The X-ray Properties of the Energetic Pulsar PSR J1838-0655

We present and interpret several new X-ray features of the X-ray pulsar PSR J1838-0655. The X-ray data are obtained from the archival data of CHANDRA, RXTE}, and SUZAKU. We combine all these X-ray data and fit the spectra with different models. We find that the joint spectra are difficult to fit with a single power law; a broken power-law model with a break at around 6.5 keV can improve the fit significantly. The photon index changes from $\Gamma$ = 1.0 (below 6.5 keV) to $\Gamma$ = 1.5 (above 6.5 keV); this indicates a softer spectral behaviour at hard X-rays. The X-ray flux at 2-20 keV is found to be 1.6x10^{-11} ergs cm^{-2} s^{-1}. The conversion efficiency from the spin-down luminosity is ~ 0.9% at 0.8-10 keV, which is much higher than that (~ 10^{-3}% - 10^{-4}%) of the pulsars that show similar timing properties. We discuss non-thermal radiation mechanisms for the observed high X-ray conversion efficiency and find that emission from the magnetosphere of a greatly inclined rotator is the most favorable interpretation for the conversion rate and the pulse profiles at X-ray bands. A line feature close to 6.65 keV is also detected in the spectra of SUZAKU/XIS; it might be the K$_\alpha$ emission of highly ionised Fe surrounding the pulsar.Comment: 8 pages, 6 figures and 1 tabl

Investigation of Landslides and Debris Flows in Tachia Watershed Between Maan Dam and Techi Dam

The Chi-Chi earthquake and subsequent typhoon events induced severe landslides and debris flows in the watershed of Tachia river. It inflicted severe damage to the power generation facilities and highway links. For the rehabilitation planning, quantitative assessment of landslides, debris flows and river deposits were conducted by using aerial photos and satellite images obtained at six stages of earthquake and typhoon events. The future trends of landslide and debris flow were also investigated by using empirical models. The long-term deposition or scouring was also conducted by numerical simulation. The results show that over 50,000,000 to 70,000,000m3 of sliding volume were induced in the Chi-Chi earthquake and subsequent typhoon events during 1999 to 2005. By conservative estimation, 60% of the debris still remain in the watershed, which will cause silting of the main river channel in the future. The deposition in the main river channel will increase with decreasing rate in the future, and river channel scouring is not expected to occur in the future 20 to 30 years

How does patent litigation influence dynamic risk for market competitors?

Many recent studies have discussed the appropriateness of various patent measurement indicators, as well as the differences in the positioning of patented technologies, while there is little discussion on the risk transmission of enterprises when faced with infringement litigation. This study used the bivariate EGARCH (Exponential Generalized Autoregressive Conditional Heteroskedasticity) model with DCC (Dynamic Conditional Correlations) to investigate the dynamic risk transmission of patent litigation between market competitors in the smartphone industry. Empirical results revealed that when facing lawsuits from market challengers, the market leader faces fewer risks when handling patent infringement litigations. In addition, the risk reactions of competitors during patent wars may widely differ. Investors should consider the patent infringement litigations when measuring the dynamic risks of share prices, and determining the optimal configuration of asset portfolios in response. First published online: 03 Nov 201

Severe hypoalbuminemia is a strong independent risk factor for acute respiratory failure in COPD: a nationwide cohort study

BACKGROUND: Acute respiratory failure (ARF) is a life-threatening event, which is frequently associated with the severe exacerbations of chronic obstructive pulmonary disease (COPD). Hypoalbuminemia is associated with increased mortality in patients with COPD. However, to date, little is known regarding whether or not hypoalbuminemia is a risk factor for developing ARF in COPD. METHODS: We conducted a retrospective cohort study using data from the National Health Insurance system of Taiwan. A total of 42,732 newly diagnosed COPD patients (age ≥40 years) from 1997 to 2011 were enrolled. Among them, 1,861 (4.36%) patients who had received albumin supplementation were defined as hypoalbuminemia, and 40,871 (95.6%) patients who had not received albumin supplementation were defined as no hypoalbuminemia. RESULTS: Of 42,732 newly diagnosed COPD patients, 5,248 patients (12.3%) developed ARF during the 6 years follow-up period. Patients with hypoalbuminemia were older, predominantly male, had more comorbidities, and required more steroid treatment and blood transfusions than patients without hypoalbuminemia. In a multivariable Cox regression analysis model, being elderly was the strongest independent risk factor for ARF (adjusted hazard ratio [HR]: 4.63, P<0.001), followed by hypoalbuminemia (adjusted HR: 2.87, P<0.001). However, as the annual average dose of albumin supplementation was higher than 13.8 g per year, the risk for ARF was the highest (adjusted HR: 11.13, 95% CI: 10.35–11.98, P<0.001). CONCLUSION: Hypoalbuminemia is a strong risk factor for ARF in patients with COPD. Therefore, further prospective studies are required to verify whether or not albumin supplementation or nutritional support may help to reduce the risk of ARF in patients with COPD

Surgical repair of a complex renal artery aneurysm through bench surgery and autotransplantation

AbstractA 58-year-old woman with underlying medically controlled hypertension presented after an episode of sudden-onset chest pain. Chest computed tomography imaging revealed a left renal artery aneurysm (RAA) measuring 1.6 cm in diameter with mural thrombi in the distal left renal artery at bifurcation level. An interval enlargement of approximately 0.4 cm in diameter was noted within a 6-month period; however, endovascular intervention was not feasible because of the complex RAA pattern. She was hospitalized and received a hand-assisted laparoscopic nephrectomy, ex vivo repair of the RAA, and autotransplantation into the left iliac fossa. The procedure was successful, and the postoperative course went smoothly. The kidney graft was evaluated using a magnetic resonance angiography 1-year postoperatively, which showed no signs of surgical complications or RAA recurrence