Risk-based maintenance strategy for deteriorating bridges using a hybrid computational intelligence technique: a case study

The current bridge inspection and maintenance protocol that is used in most countries focuses primarily on the visible aspects of bridge fitness and underestimates the invisible aspects, such as resistance to scouring and earthquake hazards. To help transportation authorities to better consider both aspects, the present study developed a new computational intelligence system, the so-called risk- based evaluation model for bridge life-cycle maintenance strategy (REMBMS). This model considers the three main risk factors of component deterioration, scouring and earthquakes in order to minimise the expected life-cycle cost of bridge maintenance. Monte Carlo simulation is used to estimate the probability of bridge maintenance. The evolutionary support vector machine inference model (ESIM) was applied to estimate the risk-related maintenance cost using historical data from the Taiwan Bridge Management System (TBMS) database. The time-influenced expected costs were obtained by multiply- ing each maintenance probability with its associated cost. Finally, the symbiotic organisms search (SOS) algorithm is used to identify the bridge maintenance schedule that optimises the life-cycle main- tenance cost. The present study provides to bridge management authorities an effective approach for determining the optimal timing and budget for maintaining transportation bridges

Automatic inspection system for dimensional measurements of the saw blade milling cutter

The demand for measuring equipments of automatic optical inspection has grown rapidly, because of its benefits of promoted efficiency and higher precision. Instead of manual projection measurements, measurement performance and efficiency can be obviously enhanced by the image measurement system. In this investigation, digital image processing and geometrical measurement principles have been integrated to develop a dynamic measurement system for the dimensional measurements of a saw blade milling cutter. The repeatability of the measurement system has been analyzed and its accuracy has been verified by using commercial 3D image measurement system. The analysis results show that the dimensional precision of 25μm and the angular precision of 0.21° can be realized by the self-developed measurement system. Between the results of the developed system and reference standard system, there are 25μm deviation in dimensional measurement and 0.26° in angular measurement. That measuring performances can meet the industrial requirement and the higher measurement efficiency can be achieved.Peer Reviewe

Evaluation of Wood Quality of Taiwania Trees Grown with Different Thinning and Pruning Treatments Using Ultrasonic-Wave Testing

The variations of Vtree, Vlumber, MOEtree, and MOElumber in the thinning and pruning treatments showed the similar trend. Results of this study also demonstrate that the effect of silvicultural practices on wood properties can be identified with the ultrasonic-wave properties of trees. This indicates that this non-destructive ultrasonic-wave technique can be provided basic information for future management practice and wood utilization of Taiwania

Crushing Strength Sampling With Minimal Damage to Taiwania (Taiwania Cryptomerioides) Using a Fractometer

The Fractometer is a device that stresses radial increment cores in the direction of the fiber to measure crushing strength, which can provide a direct wood quality indicator for structural lumber. This study analyzes the pattern of the radial variation in Taiwania (Taiwania cryptomerioides Hay.) trunk wood crushing strength to explore its effect on the precision and efficiency of the sampling procedure in the outer increment core zone as an alternate nondestructive sampling method. A pith-to-bark 0.5-cm caliber core was extracted at breast height (1.3 m above the ground) from each tree and was separated into individual section groups. Then individual crushing strengths were determined using the Fractometer.In this study, the variation in crushing strength in the transverse direction increased from the pith outward to the bark side. An analysis of variance and correlation analysis were used to evaluate the data. The magnitude of the radial variation in crushing strength was smaller than the tree-to-tree variation. Including samples of at least 7.2 cm, 5.4 cm, and 2.4 cm near the bark side was found to be acceptable for the assessment of wood crushing strength for trees of Type A (DBH > 27 cm), Type B (DBH = 23~27 cm), and Type C (DBH > 23 cm), respectively

Effect of Moisture Content on the Drill Resistance Value in Taiwania Plantation Wood

The effect of moisture content (MC) on the drill resistance values during desorption from a watersaturated condition of Taiwania (Taiwania cryptomerioides Hayta) plantation lumber was examined. Results showed that the drill resistance values tended to decrease with the decreasing of MC. Positive significant relationships were found among the MC, bulk density, and drill resistance values. This adjustment of density profiles could help the RESISTOGRAPH® to achieve a better measurement of the drill resistance profile of standing trees

Heparinization on pericardial substitutes can reduce adhesion and epicardial inflammation in the dog

AbstractObjective: Primary concerns about currently available pericardial substitutes include adhesion and epicardial reaction. The purpose of this study is to evaluate host reaction to pericardial substitutes with and without incorporating slow heparin release. Methods: To avoid biologic variation among these pericardial patches, we made a composite of six membranes. The composite membrane consisted of epoxy-fixed patches with (1) or without (2) ionically bound heparin, a glutaraldehyde-fixed patch with (3) or without (4) ionically bound heparin, an expanded polytetrafluoroethylene patch (5), and a polyester polymeric patch (6). Ten recipient dogs weighing from 12 to 19 kg (mean 13.6 kg) were used to assess the composite membranes as pericardial substitutes. The implanted composite membranes were retrieved 1 week (one dog), 2 weeks (one dog), 4 weeks (one dog), 8 weeks (one dog), and 12 weeks (six dogs) after implantation. Results: Overall, the synthetic patches had a more notable inflammatory reaction than the biologic patches with or without ionically bound heparin. The heparin-bound patches caused significantly less inflammation than their nonheparinized counterparts. The heparinized porcine patches cross-linked with different compounds were found to have less fibrous formation than the nonheparinized patches and the synthetic patches. Conclusions: Heparinized pericardial substitutes may cause less adhesion and inflammatory reaction than nonheparinized material. (J Thorac Cardiovasc Surg 1998;115:1111-20

Inhibitory effects of armepavine against hepatic fibrosis in rats

Activation of hepatic stellate cells (HSCs) plays a crucial role in liver fibrogenesis. armepavine (Arm, C19H23O3N), an active compound from Nelumbo nucifera, has been shown to exert immunosuppressive effects on T lymphocytes and on lupus nephritic mice. The aim of this study was to investigate whether Arm could exert anti-hepatic fibrogenic effects in vitro and in vivo. A cell line of rat HSCs (HSC-T6) was stimulated with tumor necrosis factor-α (TNF-α) or lipopolysaccharide (LPS) to evaluate the inhibitory effects of Arm. An in vivo therapeutic study was conducted in bile duct-ligated (BDL) rats. BDL rats were given Arm (3 or 10 mg/kg) by gavage twice daily for 3 weeks starting from the onset of BDL. Liver sections were taken for fibrosis scoring, immuno-fluorescence staining and quantitative real-time mRNA measurements. In vitro, Arm (1-10 μM) concentration-dependently attenuated TNF-α- and LPS-stimulated α-SMA protein expression and AP-1 activation by HSC-T6 cells without adverse cytotoxicity. Arm also suppressed TNF-α-induced collagen collagen deposition, NFκB activation and MAPK (p38, ERK1/2, and JNK) phosphorylations. In vivo, Arm treatment significantly reduced plasma AST and ALT levels, hepatic α-SMA expression and collagen contents, and fibrosis scores of BDL rats as compared with vehicle treatment. Moreover, Arm attenuated the mRNA expression levels of col 1α2, TGF-β1, TIMP-1, ICAM-1, iNOS, and IL-6 genes, but up-regulated metallothionein genes. Our study results showed that Arm exerted both in vitro and in vivo antifibrotic effects in rats, possibly through anti-NF-κB activation pathways

Ray Tracing Simulation in Nonspherically Symmetric Atmosphere for GPS Radio Occultation

A three-dimensional ray tracing model with aiming algorithms for global positioning system (GPS) signal is proposed to make simulations conform to the realistic radio occultation (RO) signal propagation. The two aiming algorithms used in this study ensure the initial and end point ray trajectories are located in the prescribed region. In past studies, the ray tracing techniques applied to the RO signal simulation usually assumed a spherically symmetrical atmosphere for simplicity. The exact GPS and low earth orbit (LEO) satellite locations are not considered in the simulation. These two assumptions make the simulation unrealistic for GPS signal propagation in the RO technique. In the proposed model, the shape of the earth is assumed as an ellipse. The information from European Centre for Medium-Range Weather Forecasts (ECMWF) analysis is used to setup the atmosphere in the simulation. Two aiming algorithms are developed to determine the initial signal propagating direction to make the simulated signal start from the prescribed GPS satellite position and end in the close vicinity of the LEO satellite position. An ideal spherical symmetric atmospheric structure is used to verify the ray tracing model. The fractional difference between real and simulated refractivity results is less than 0.1%. Otherwise, the GPS and LEO satellite position in the Formosat-3/COSMIC observation and the ECMWF analysis, considering the earth¡¦s flattening, is also used to verify the aiming algorithms. All of the simulated signals end in close vicinity to the LEO satellite position in the simulation results

Bronchiolitis Obliterans Organizing Pneumonia in Swine Associated with Porcine Circovirus Type 2 Infection

Bronchiolitis obliterans organizing pneumonia (BOOP) is a chronic respiratory disease. Although the pathogenesis of BOOP is still incompletely understood, BOOP is responsive to steroids and has a good prognosis. In our five pigs with chronic postweaning multisystemic wasting syndrome (PMWS), typical BOOP lesions were revealed. All five porcine lungs showed typical intraluminal plugs, and porcine circovirus type 2 (PCV2) was identified. They also exhibited similar pathologic findings such as proliferation of type II pneumocytes and myofibroblasts (MFBs), extracellular collagen matrix (ECM) deposition, and fragmentation of elastic fibers. MFBs migration correlative molecules, for instance, gelatinase A, B and osteopontin, appeared strongly in the progressing marginal area of polypoid intraluminal plugs of fibrotic lesion. These molecules colocalized with the active MFBs. Both gelatinase activity and intercellular level of active MFBs were significantly increased (P < .05). Porcine chronic bronchopneumonia leads to BOOP and it is associated with PCV2 persistent infection. Swine BOOP demonstrates similar cellular constituents with human BOOP. Perhaps their molecular mechanisms of pathogenesis operate in a similar way. Thus we infer that the swine BOOP can be considered as a potential animal model for human BOOP associated with natural viral infection. Moreover, it is more convenient to obtain samples

Effects of mycophenolate mofetil on cutaneous lupus erythematosus in (NZB × NZW) F1 mice

AbstractBackgroundFew studies have evaluated the effects and precise molecular mechanism of mycophenolate mofetil (MMF) in the treatment of human cutaneous lupus erythematosus (CLE). Our findings shed light on the therapeutic effects of MMF in a UVB-induced NZB × NZW (NZBW) F1 CLE mouse model.MethodsContinuous MMF treatment (60 mg/kg/day) was administered up to Day 50 from the beginning of UVB induction (Day 0; 20 weeks old), as the pathologic features of CLE are present after 50 days. The therapeutic effects of MMF treatment in NZBW lupus mice were examined by comparing histopathological changes, lupus band test (deposition of immune complexes at the dermal–epidermal junction) and colocalization of autoantibodies with a dermal autoantigen Dsg3, and by evaluating the associations of local matrix metalloprotease activities.ResultsMMF improved survival in the NZBW lupus mice from 35.7% to 81.8%. The proteinuria, blood urea nitrogen, and interleukin 6 levels were significantly reduced after MMF treatment. The dermal lymphocytic infiltration, deposition of immune complexes at the dermal–epidermal junction, colocalized autoantibodies with Dsg3, and epidermal matrix metalloprotease activity were also attenuated in MMF-treated NZBW F1 mice.ConclusionThe results confirmed that MMF could substantially attenuate skin damage due to CLE in the NZBW F1 mouse model