57 research outputs found

    Information Support Technology of Ship Survey Based on Case-based Reasoning

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    Recently, the significance of ship inspections hasbeen increasingly recognized because sea pollution andsafety problems are occurring more and more frequently. However, current ship inspections rely on the experience ofthe workers. Therefore, it is difficult to understand, and hence to improve, the state of ship inspections. The present problemsare that the ship inspection technical support level in China is not balanced, especially as to the current situation with low level, poor technologyin under-developed areas. In this paper, the case technology about the case-based reasoning to the ship inspection is proposed. The methods of normative inspection case representation are discussed.This is considered to be the basis of case-based reasoning. Then the tertiary case structure with the index is defined, in which the K-nearest neighbor method to calculate the similarity between caseswas used so that the ship’s inspection information can be searched effectively. In addition, animproved retrievalstrategy of the nearest neighbor method is introduced. Therefore, in the inspection site,the inspectors can acquire support information by the case bases, and then the new cases are calculated automatically. Further, a ship inspection case managementwereintroduced to improve the stability of the system. By carrying the case-based reasoning into an inspection, an inspector can generate fault information and inspection information simply and easily. Some examples of the organization and retrieval are shown at the end of the paper

    A New Restriction on Low-Redundancy Restricted Array and Its Good Solutions

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    In array signal processing, a fundamental problem is to design a sensor array with low-redundancy and reduced mutual coupling, which are the main features to improve the performance of direction-of-arrival (DOA) estimation. For a NN-sensor array with aperture LL, it is called low-redundancy (LR) if the ratio R=N(N−1)/(2L)R=N(N-1)/(2L) is approaching the Leech's bound 1.217≤Ropt≤1.6741.217\leq R_{opt}\leq 1.674 for N→∞N\rightarrow\infty; and the mutual coupling is often reduced by decreasing the numbers of sensor pairs with the first three smallest inter-spacings, denoted as ω(a)\omega(a) with a∈{1,2,3}a\in\{1,2,3\}. Many works have been done to construct large LRAs, whose spacing structures all coincide with a common pattern D={a1,a2,…,as1,cℓ,b1,b2,…,bs2}{\mathbb D}=\{a_1,a_2,\ldots,a_{s_1},c^\ell,b_1,b_2,\ldots,b_{s_2}\} with the restriction s1+s2=c−1s_1+s_2=c-1. Here ai,bj,ca_i,b_j,c denote the spacing between adjacent sensors, and cc is the largest one. The objective of this paper is to find some new arrays with lower redundancy ratio or lower mutual coupling compared with known arrays. In order to do this, we give a new restriction for D{\mathbb D} to be s1+s2=cs_1+s_2=c , and obtain 2 classes of (4r+3)(4r+3)-type arrays, 2 classes of (4r+1)(4r+1)-type arrays, and 1 class of (4r)(4r)-type arrays for any N≥18N\geq18. Here the (4r+i)(4r+i)-Type means that c≡i(mod4)c\equiv i\pmod4. Notably, compared with known arrays with the same type, one of our new (4r+1)(4r+1)-type array and the new (4r)(4r)-type array all achieves the lowest mutual coupling, and their uDOFs are at most 4 less for any N≥18N\geq18; compared with SNA and MISC arrays, the new (4r)(4r)-type array has a significant reduction in both redundancy ratio and mutual coupling. We should emphasize that the new (4r)(4r)-type array in this paper is the first class of arrays achieving R<1.5R<1.5 and ω(1)=1\omega(1)=1 for any N≥18N\geq18

    Testing System Optimization and Design for Slurry Pipeline Transportation

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    Abstract: This study aims to introduce the design and optimization of a testing system for the on the slurry pipeline transportation in dredging projects. Due to characteristics of slurries such as high concentration, irregular particles and complex ingredients, slurry transportation often subjects to huge pipe resistance, high energy consumption, pipe blockage and short transportation distance. Literature review indicates that the gas injection to pipeline can effectively improve slurry flow state and reduce pipeline resistance. However, the research on design and optimization of slurry pipeline transportation in dredging projects is scarce. Hence, this study has designed a new air-injected pipeline system for dredging projects. The general structure of the new system and new features of subsystems have been introduced in details. In the design process, key parameters have been monitored, including the inner pressure, quantity of flow and flow state. These parameters have been used in measurement and control subsystems, which are suitable for the dredging projects. The optimization and design results demonstrate that the designed air-injected pipeline system are reasonable in design, inclusive in functions and reliable in accuracy and can be applied to simulation of real conditions in slurry translation in dredging projects

    Induction of the mesenchymal to epithelial transition by demethylation-activated microRNA-125b is involved in the anti-migration/invasion effects of arsenic trioxide on human chondrosarcoma

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    Background: In addition to treating acute promyelocytic leukemia, arsenic trioxide (ATO) suppresses other solid tumors, including chondrosarcoma. However, the effects of ATO on metastasis in chondrosarcoma cells, and the underlying molecular mechanisms remain unclear. Methods: The effects of ATO on the migratory and invasive capacities of chondrosarcoma cells were investigated by Wound healing, Transwell and EMT assays. The expression of miR-125b in human chondrosarcoma tissues and cell lines was detected by real-time PCR analysis. Bisulfite sequencing analysis (BSP) was used to detect the effects of ATO on the expression of miR-125b. The gain-of-function and loss-of-function experiments were performed on chondrosarcoma cell lines to investigate the effects of miR-125b on chondrosarcoma invasion, and to determine whether signal transducer and activator of transcription 3(Stat3) mediates these effects. Dual-luciferase reporter assay was used to identify whether Stat3 is a direct target of miR-125b. Results: MiR-125b was significantly downregulated in human metastatic chondrosarcoma tissues and cell lines but not in non-metastatic chondrosarcoma tissues. ATO up-regulates the expression of miR-125b by the demethylation of DNA. ATO induces MET and attenuates the invasive capacities of chondrosarcoma cells through miR-125b. Stat3 was verified as a direct target of miR-125b, which is involved in ATO regulating EMT-associated traits. Conclusions: These findings, for the first time, provides evidence that the miR-125b-mediated inhibition of Stat3 is involved in the ATO-induced attenuation of metastasis in chondrosarcoma cells.National Natural Science Foundation of China [81572633]; Research Fund for the Doctoral Program of Higher Education of China [20130001110076]SCI(E)[email protected]

    Influence of heat stress on leaf morphology and nitrogen–carbohydrate metabolisms in two wucai (Brassica campestris L.) genotypes

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    Heat stress is a major environmental stress that limits plant growth and yield worldwide. The present study was carried out to explore the physiological mechanism of heat tolerant to provide the theoretical basis for heat-tolerant breeding. The changes of leaf morphology, anatomy, nitrogen assimilation, and carbohydrate metabolism in two wucai genotypes (WS-1, heat tolerant; WS-6, heat sensitive) grown under heat stress (40°C/30°C) for 7 days were investigated. Our results showed that heat stress hampered the plant growth and biomass accumulation in certain extent in WS-1 and WS-6. However, the inhibition extent of WS-1 was significantly smaller than WS-6. Thickness of leaf lamina, upper epidermis, and palisade mesophyll were increased by heat in WS-1, which might be contributed to the higher assimilation of photosynthates. During nitrogen assimilation, WS-1 possessed the higher nitrogen-related metabolic enzyme activities, including nitrate reductase (NR), glutamine synthetase (GS), glutamate synthase (GOGAT), and glutamate dehydrogenase (GDH), which were reflected by higher photosynthetic nitrogen-use efficiency (PNUE) with respect to WS-6. The total amino acids level had no influence in WS-1, whereas it was reduced in WS-6 by heat. And the proline contents of both wucai genotypes were all increased to respond the heat stress. Additionally, among all treatments, the total soluble sugar content of WS-1 by heat got the highest level, including higher contents of sucrose, fructose, and starch than those of WS-6. Moreover, the metabolism efficiency of sucrose to starch in WS-1 was greater than WS-6 under heat stress, proved by higher activities of sucrose phosphate synthase (SPS), sucrose synthase (SuSy), acid invertase (AI), and amylase. These results demonstrated that leaf anatomical alterations resulted in higher nitrogen and carbon assimilation in heat-tolerant genotype WS-1, which exhibited a greater performance to resist heat stress

    Response of Carex breviculmis to phosphorus deficiency and drought stress

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    IntroductionThe drought and phosphorus deficiency have inevitably become environmental issues globally in the future. The analysis of plants functional trait variation and response strategies under the stress of phosphorus deficiency and drought is important to explore their ability to respond to potential ecological stress.MethodsIn this study, Carex breviculmis was selected as the research object, and a 14-week pot experiment was conducted in a greenhouse, with two phosphorus treatment (add 0.5mmol/L or 0.05μmol/L phosphorus) and four drought treatment (add 0-5%PEG6000), totaling eight treatments. Biomass allocation characteristics, leaf anatomical characteristics, biochemical parameters, root morphology, chemical element content, and photosynthetic parameters were measured.ResultsThe results showed that the anatomical characteristics, chemical elements, and photosynthetic parameters of Carex breviculmis responded more significantly to main effect of phosphorus deficiency. Stomatal width, leaf phosphorus content and maximum net photosynthetic rate decreased by 11.38%, 59.39%, 38.18% significantly (p&lt;0.05), while the change in biomass was not significant (p&gt;0.05). Biomass allocation characteristics and root morphology responded more significantly to main effect of drought. Severe drought significantly decreased leaf fresh weight by 61% and increased root shoot ratio by 223.3% compared to the control group (p&lt;0.05). The combined effect of severe drought and phosphorus deficiency produced the highest leaf N/P ratio (291.1% of the control) and MDA concentration (243.6% of the control). Correlation analysis and redundancy analysis showed that the contributions of phosphorus and drought to functional trait variation were similar. Lower epidermal cell thickness was positively correlated with maximum net photosynthetic rate, leaf phosphorus, chlorophyll ab, and leaf fresh weight (p&lt;0.05).DiscussionIn terms of response strategy, Carex breviculmis was affected at the microscopic level under phosphorus deficiency stress, but could maintain the aboveground and underground biomass well through a series of mechanisms. When affected by drought, it adopted the strategy of reducing leaf yield and improving root efficiency to maintain life activities. Carex breviculmis could maintain its traits well under low phosphorus and moderate drought, or better conditions. So it may have good ecological service potential in corresponding areas if promoted. This study also provided a reference for plant response to combined drought and phosphorus deficiency stresses
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