Product Development Risk Management in Product Development Process

It is necessary to manage product development risk in new product development process. This paper puts forward a risk management frame combined the traditional risk management framework and establishes a product development risk system in new product development, which provides new patterns for practice. It is helpful to raising the possibility of new product development success.Key words: Product development risk management; Product development Proces

Comprehensive Analysis Method of Acquiring Wall Heat Fluxes in Rotating Detonation Combustors

Accurate perception of the combustor thermal environment is crucial for thermal protection design of a rotating detonation combustor (RDC). In this study, a comprehensive analysis method is established to calculate the non-uniform heat flux distribution of the RDC by utilizing the measured temperature distribution of the combustor outer wall obtained by the high-speed infrared thermal imager. Firstly, in order to determine the inverse heat flux solving method, a physical model based on the geometric characteristics of the RDC is constructed and its thermal conductive process is simulated, given by different heat flux boundary conditions. Then the wall heat fluxes are inversely calculated by the Levenberg-Marquardt (L-M) method based on the above numerical data. Results show that the L-M method can obtain more accurate heat flux distribution even in the zones with large heat flux gradients, considering the axial heat conduction within the combustor outer wall caused by the non-uniform heat flux. Finally, the wall heat flux distribution is analyzed coupling the L-M method together with the experimental measurements in kerosene two-phase RDC. The analyses show that the highest temperature of combustor outer surface and the highest wall heat flux occurs within the region of 20mm from the combustor head, which corresponds to nearly 14% of the combustor length. With the increase of axial distance, the heat flux is rapidly reduced, and then the heat flux distribution is more uniform at the downstream region of the combustor. The heat flux peak and thermal heat rate are positively correlated with the combustor equivalence ratio in the range between 0.44 and 0.64.Comment: 26 pages, 21 figure

Data-driven Topology Optimization of Channel Flow Problems

Typical topology optimization methods require complex iterative calculations, which cannot be realized in meeting the requirements of fast computing applications. The neural network is studied to reduce the time of computing the optimization result, however, the data-driven method for fluid topology optimization is less of discussion. This paper intends to introduce a neural network architecture that avoids time-consuming iterative processes and has a strong generalization ability for topology optimization for Stokes flow. Different neural network methods that have been already successfully used in solid structure optimization problems are mutated and examined for fluid topology optimization cases, including Convolution Neural Networks (CNN), conditional Generative Adversarial Networks (cGAN), and Denoising Diffusion Implicit Models (DDIM). The presented neural network method is tested on the channel flow topology optimization problems for Stokes flow. The results have shown that our presented method has high pixel accuracy, and we gain a 663 times decrease in execution time compared with the conventional method on average

Trifluorobenzamidine prevents allergic rhinitis by regulating IgE, IL-4 and IL-5 in T-cells

Purpose: To investigate the effect of trifluorobenzamidine (TBI) on a mouse model of ovalbumin (OVA)- induced allergic rhinitis. Methods: Allergic rhinitis was established in mice via sensitization on days 1, 5 and 14 through intraperitoneal injection of OVA (100 μg) in PBS. On day 15, the mice were subjected to intranasal exposure to OVA (1.5 mg dissolved in PBS). Prior to 10 days of intranasal exposure to OVA, the micewere treated with TBI at doses of 5, 10 and 20 μg/kg. Cytokine levels were determined using enzymelinked immunosorbent assay (ELISA) kits, while cyclooxygenase (COX)-2 and caspase-1 activity were assayed with western blotting. Results: Treatment with TBI significantly (p < 0.05) reduced OVA-mediated increases in nasal rub scores, and decreased serum levels of IgE, TNF-α, thymic stromal lymphopoietin (TSLP), IL-1β and histamine in mice. It also significantly regulated spleen weight and IL-4 secretion (p < 0.05) in OVAadministered mice. TBI significantly downregulated the expressions of IL-5, IL-13, TNFα, TSLP, IL-1β and IL-6 (p < 0.05). Administration of TBI caused a marked reduction in OVA-mediated increase in caspase-1 activity in mice intranasal tissues, and also significantly reduced OVA-induced excessive production of MIP-2 and ICAM-1 (p < 0.05). Moreover, TBI prevented OVA-induced infiltration of eosinophils and mast cells into intranasal tissues (p < 0.05). Conclusion: TBI reduces levels of IgE and various pro-inflammatory cytokines in OVA-administered mice. It also regulates Th1:Th2 ratio, inhibited activity of caspase-1, suppressed mast cell/eosinophil infiltration and reduced ICAM-1 and MIP-2 levels. Therefore, TBI possesses inhibitory potential against rhinitis allergy, and thus can potentially be developed as a new treatment strategy for asthma. Keywords: Trifluorobenzamidine, Anti-inflammation, Allergic rhinitis, Cytokines, Caspase-1, Itchin

Late Holocene forcing of the Asian winter and summer monsoon as evidenced by proxy records from the northern Qinghai-Tibetan Plateau

Little is known about decadal- to centennial-scale climate variability and its associated forcing mechanisms on the Qinghai-Tibetan Plateau. A decadal-resolution record of total organic carbon (TOC) and grainsize retrieved from a composite piston core from Kusai Lake, NW China, provides solid evidence for decadal- to centennial-scale Asian monsoon variability for the Northern Qinghai-Tibetan Plateau during the last 3770 yr. Intensified winter and summer monsoons are well correlated with respective reductions and increases in solar irradiance. A number of intensified Asian winter monsoon phases are potentially correlated with North Atlantic climatic variations including Bond events 0 to 2 and more recent subtle climate changes from the Medieval Warm Period to the Little Ice Age. Our findings indicate that Asian monsoon changes during the late Holocene are forced by changes in both solar output and oceanic-atmospheric circulation patterns. Our results demonstrate that these forcing mechanisms operate not only in low latitudes but also in mid-latitude regions (the Northern Qinghai-Tibetan Plateau)

The differential spectrum of a ternary power mapping

Postponed access: the file will be available after 2022-03-06A function f(x)from the finite field GF(pn)to itself is said to be differentially δ-uniform when the maximum number of solutions x ∈GF(pn)of f(x +a) −f(x) =bfor any a ∈GF(pn)∗and b ∈GF(pn)is equal to δ. Let p =3and d =3n−3. When n >1is odd, the power mapping f(x) =xdover GF(3n)was proved to be differentially 2-uniform by Helleseth, Rong and Sandberg in 1999. Fo r even n, they showed that the differential uniformity Δfof f(x)satisfies 1 ≤Δf≤5. In this paper, we present more precise results on the differential property of this power mapping. Fo r d =3n−3with even n >2, we show that the power mapping xdover GF(3n)is differentially 4-uniform when n ≡2 (mod 4) and is differentially 5-uniform when n ≡0 (mod 4). Furthermore, we determine the differential spectrum of xdfor any integer n >1.acceptedVersio

Reliability based optimization for semi-actively controlled seismic structures

A stochastic semi-active control strategy for the MR damping controlled structure is provided in this paper. The integrated optimization of the weighting matrices pertaining to the active optimal control and the MR parameters pertaining to the semi-active optimal control is implemented. In order to reveal the advantages of this strategy, comparative studies on two aspects are involved, i.e. optimization schemes and probabilistic criteria. The comparison between the integrated and the separated schemes based on the probabilistic criteria in terms of statistical moments shows that the integrated scheme exhibits a better control effectiveness. While the comparison between the probabilistic criteria in terms of statistical moments and the reliability used for the integrated scheme shows that the probabilistic criteria in terms of reliability attains a more safe structure

Dynamic distribution of contact stress of friction lining in the process of friction transmission

The dynamic distribution of contact stress of friction lining in the process of deep coal mine friction transmission was investigated in this study. Rope tensions during lifting and lowering were obtained using Simulink simulation models first. Then, correlation model of contact stress of friction lining was established. Subsequently, effects of the friction coefficient, lifting load, terminal mass ratio, maximum speed, maximum acceleration and acceleration rate on the dynamic distribution of contact stress were explored. The results show that the wrap angle of the friction pulley is divided into three, i.e. static, mixed, and friction angles, respectively. Furthermore, the friction angle decreases with the increasing coefficient of friction, and the increases of the terminal mass ratio induce expanding trends of overall ranges of the friction angle, which could result in rope skid accidents and unpredictable failure of friction lining