Wyniki wyszukiwania - BazTech

1

An expert elicitation analysis for vessel allision risk near the offshore wind farm by using fuzzy rule-based bayesian network

Yu Q., Liu K.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2019

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Vol. 13. no. 4

831--837

EN

This paper develops an expert based framework for analysing and synthesising the ship allision risk near the offshore wind farm (OWF) on the basis of a generic Fuzzy Bayesian network and FMEA analysis. This framework is specifically intended to overcome the difficulty of using traditional risk assessment methods in OWF allision. Under the introduced framework, subjective belief degrees are assigned to model the incompleteness encountered in establishing the knowledge base. The fuzzy transformation technology is then used to introduce all judgements results under various situations. Fully, a Bayesian network is established to aggregate all relevant attributes to the conclusion and to prioritise potential allision risk level of each ship categories. A series of case studies of different ship categories are studied to illustrate the application of the proposed framework. Results show that the fishing vessel and the service vessel have a higher allision risk than the merchant vessel due to insufficient risk detection. The collision consequence of the tanker is significantly higher than other types of vessel. The framework facilitates subjective risk assessment when historical failure data is not available in their practice, which provides support to OWF-safeguarding and decision-making.

2

Permeability of P and K-nutrient through polystyrene membrane from aqueous solutions of urea + KH2PO4

Deng X., Liu K., Han X., Hu X., Zheng S.

Polish Journal of Chemical Technology

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2018

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Vol. 20, nr 4

113--122

EN

With the polymer-coated fertilizer as background, the permeability of P- and K-nutrient through a representative polymer membrane-polystyrene membrane were investigated by measuring their permeability in the solutions of KH2 PO4 -water and urea-KH2 PO4 water at nominal temperature of 298 K using the Ussing chamber method. To analyze and interpret the variation of permeability with solute concentration, the solubility of permeate in polymer membrane were determined experimentally and the permeate diffusion coefficient were assessed by the measurements of density and apparent molar volume of the aqueous fertilizer solutions. An interesting “increase-decrease” trend for the permeability of both phosphorous (P)-nutrient, and potassium (K)-nutrient fertilizer with permeate concentration was observed, in which the increases in permeability at low concentrations of permeate could be attributed to the increase in solubility of KH2 PO4 in polymer while the decreases in permeability at high concentrations was due to the decrease in diffusion coefficient of permeate in polymer membrane. Finally, the release kinetics of these nutrients from a PS-coated urea-KH2 PO4 compound fertilizer granule was predicted using the Shaviv’s model along with the permeability data of P- and K-nutrient generated.

3

Microscale laser shock imprinting of micro-molds with different sizes and shapes

Yang H., Liu K., Liu H.

Optica Applicata

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2018

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Vol. 48, nr 4

671--686

EN

There are higher requirements for microstructures and high-precision components in microelectronics, photonics, sensors, optoelectronics and medical devices. For changing the traditional manufacturing methods with cumbersome process and complex equipment, researchers put forward a laser shock forming technique which can contribute to the metal forming with high precision and efficiency in recent years. So far, the laser shock forming needed high pulse energy and high energy. In this paper, nanosecond laser with high frequency and low pulse energy was adopted to make possible the aluminum foil forming on the copper micro-molds with different sizes and shapes. The deformations of aluminum foil were measured by SEM, optical profiler and AFM. Also, the deformation laws were analyzed by comparing imprinting results under different micro-molds. Lastly, stress distribution and deformation process of aluminum foil was investigated by numerical simulations.

4

Visual-Simulation-Based Personalized Garment Block Design Method for Physically Disabled People with Scoliosis (PDPS)

Hong Y., Bruniaux P., Zeng X., Liu K., Curteza A., Chen Y.

Autex Research Journal

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2018

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Vol. 18, no. 1

35--45

EN

This research presented a novel method using 3D simulation methods to design customized garments for physically disabled people with scoliosis (PDPS). The proposed method is based on the virtual human model created from 3D scanning, permitting to simulate the consumer’s morphological shape with atypical physical deformations. Next, customized 2D and 3D virtual garment prototyping tools will be used to create products through interactions. The proposed 3D garment design method is based on the concept of knowledge-based design, using the design knowledge and process already applied to normal body shapes successfully. The characters of the PDPS and the relationship between human body and garment are considered in the prototyping process. As a visualized collaborative design process, the communication between designer and consumer is ensured, permitting to adapt the finished product to disabled people afflicted with severe scoliosis.

5

A Novel Through Capacity Model for One-way Channel Based on Characteristics of the Vessel Traffic Flow

Nie Y., Liu K., Xin X., Yu Q.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2017

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Vol. 11, no. 3

495--502

EN

Vessel traffic flow is a key parameter for channel-through capacity and is of great significance to vessel traffic management, channel and port design and navigational risk evaluation. Based on the study of parameters of characteristics of vessel traffic flow related to channel-through capacity, this paper puts forward a brand-new mathematical model for one-way channel-through capacity in which parameters of channel length, vessel arrival rate and velocity difference in different vessels are involved and a theoretical calculating mechanism for the channel-through capacity is provided. In order to verify availability and reliability of the model, extensive simulation studies have been carried out and based on the historical AIS data, an analytical case study on the Xiazhimen Channel validating the proposed model is presented. Both simulation studies and the case study show that the proposed model is valid and all relative parameters can be readjusted and optimized to further improve the channel-through capacity. Thus, all studies demonstrate that the model is valuable for channel design and vessel management.

6

Nutrient Uptake and Allocation by Plants in Recent Mounds Created by Subterranean Rodent, Plateau Zokor Eospalax baileyi

Wu R., Wei X., Liu K., Zhong M., Liu Y., Pan D., Shao X.

Polish Journal of Ecology

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2017

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Vol. 65, nr 1

132--143

EN

To understand the nutrient absorption and adaptability of plant species that initially colonize mounds and the influences of the plateau zokor on the diversity of the plant community after 4 years' period, a series of experiments was conducted in an alpine meadow on the Qinghai-Tibetan Plateau. The contents of C and N and the flow of N in pioneer species were measured and tracked using the 15N isotope tracer method, and the species diversity on 4-year-old mounds was investigated. The results showed that (1) plateau zokors could influence the plant species on the mounds by creating gaps in the grassland; (2) Elymus nutans and Elsholtzia feddei, with high rates and efficiencies of nutrient absorption and transportation, were more competitive on the newly formed mounds than other species; (3) Elymus nutans played a dominant role in the plant community of the mounds; and (4) plateau zokors did not change the plant diversity after 4 years' period. These findings indicated that species colonizing the mounds experienced a process of competition when gaps were created by the rodents, that species with greater capabilities for resource acquisition and utilization had stronger competitiveness and vice versa, and that after a few years, the plant diversity on the mounds was almost similar to that of the undisturbed grassland.

7

Collaborative 3D-To-2D Tight-Fitting Garment Pattern Design Process for Scoliotic People

Hong Y., Zeng X., Bruniaux P., Liu K., Chen Y., Zhang X.

Fibres & Textiles in Eastern Europe

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2017

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Vol. 25, no. 5 (125)

113--118

EN

This paper presents a virtual design process for a tight-fitting garment pattern for adapter consumer garments, aimed at consumers with scoliosis. The design process proposed is based on a virtual human model created using a 3D scanner, allowing simulation of the morphological shape of an individual with atypical physical deformations. Customized 2D and 3D virtual garment prototyping tools are used in combination to create products through interactions between the consumer, designer and pattern maker. After following an interactive sequence: Scanning – Design – Display – Evaluation – Adjustment, a final design solution acceptable to both the designer and consumer can be obtained. Through this process, traditional 2D garment design knowledge, especially design rules influenced by the fabric information, is fully utilized to support the design process proposed. Using the knowledge based collaborative design process, design satisfaction can be largely improved.

PL

W artykule przedstawiono wirtualny proces projektowania wzoru odzieży dla osób ze skoliozą. Zaproponowany projekt jest oparty na wirtualnym modelu ciała człowieka stworzonym przy użyciu skanera 3D, umożliwiającego symulację morfologicznego kształtu ciała osoby o nietypowych deformacjach fizycznych. Po wykonaniu sekwencji interaktywnej: skanowanie – projekt – wyświetlacz – ocena – dostosowanie, można uzyskać ostateczne rozwiązanie projektowe akceptowalne zarówno dla projektanta, jak i dla konsumentów. W tym procesie tradycyjna wiedza z zakresu zasad projektowania odzieży 2D jest w pełni wykorzystywana w celu wspierania zaproponowanego procesu projektowania. Korzystając z kombinacji obu systemów 2D i 3D można w znacznym stopniu poprawić jakość otrzymanego projektu. Udane rozwiązania projektowe można zintegrować z bazą wiedzy o projektowaniu mody, aby tworzyć nowe zasady projektowania i rozszerzać profesjonalną wiedzę dotyczącą projektowania.

8

Safety problem of cavity under open pit bench

Liu X., Li X., Gong F., Liu K.

Archives of Mining Sciences

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2015

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Vol. 60, no. 2

565--580

EN

Some open pits in China are severely threatened by hidden cavities under benches which are always inaccessible and unmapped. The first thing to be well considered is safe and precise cavity detection, as the conventional detection methods cannot output a clear cavity vision, a three-dimensional laser measurement system is employed to perform detection, which is deployed from the surface through boreholes. The results from the scanner demonstrated very well the detailed level of information that can be collected In a cavity using this method, with the cavities’ layout under various benches being fully mapped. As detected cavities are always in horizontal and vaulted roof shape, two different theoretical calculation methods are proposed to analyze the cap rock stability for different roof shape. And also, the three-dimensional solid model generated through scanned laser data is used for stability numerical simulation by converting the data format into the one that recognized in corresponding software. Furthermore, acoustic emission technique is adopted to carry out long term real time rupture monitoring in cap rock, and four kinds of typical monitoring results are discussed which represent the rupture behavior in cap rock of unstable cavity, stable cavity, cavity with large working drill above and cavity beside explosion site. Thus, a complete safety evaluation system for such cavity will be established to ensure safe operation above.

PL

W wielu kopalniach odkrywkowych na terenie Chin powstało zagrożenie wskutek istnienia ukrytych pustek pod warstwami wybierania (ławami), część z nich jest trudno dostępna, a niektóre nie są nawet naniesione na mapach. Najważniejszą kwestią jest więc bezpieczna i dokładna lokalizacja pustek. Ponieważ konwencjonalne metody wykrywania nie są w stanie ujawnić dokładnego obrazu pustek, zastosowano trójwymiarowy laserowy system detekcji pustek, zakładany z powierzchni poprzez wywiercone otwory. Odczyty ze skanera ujawniły dokładne zarysy pustek. Z pomocą tej metody można dokładnie obrazować układy pustek pod warstwami wybierania (ławami). Ponieważ stropy w wykrywanych pustkach są zawsze poziome lub sklepione, zaproponowano dwie teoretyczne metody obliczania stabilność stropu dla różnych jego kształtów. Ponadto, na podstawie danych ze skanera wygenerowano model bryły trójwymiarowej, który wykorzystany został do numerycznych badań stabilności stropu poprzez przekształcenie formatu danych na format rozpoznawalny w zastosowanym oprogramowaniu. Zastosowano także techniki pomiary emisji akustycznej w długofalowym monitorowaniu spękań stropu w czasie rzeczywistym, przeanalizowano cztery rodzaje uzyskanych wyników opisujących zachowanie stropu w przypadku pustek niestabilnych, stabilnych, pustek ponad którymi wykonano otwory znacznych rozmiarów oraz pustek w pobliżu miejsc prowadzenia prac strzałowych. Opracowano w ten sposób pełny system oceny stabilności pustek zapewniający bezpieczne prowadzenie prac ponad nimi.

9

Leaf morphology shift of three dominant species along altitudinal gradient in an alpine meadow of the Quinghai â Tibetan Plateau

Zhong M., Wang J., Liu K., Wu R., Liu Y., Wei X., Pan D., Shao X.

Polish Journal of Ecology

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2014

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Vol. 62, nr 4

639--648

EN

It has been observed that leaf morphology shift within species is linked to climate change, but there are few studies on the effects of altitude change on leaf morphology of species. We hypothesized that similar to climate change, a morphological shift within species would occur over time under different growing altitudes. In this study, we evaluated three dominant grass species: Elymus nutans Griseb., Kobresia capillifolia Clarke., Carex moorcroftii Boott., taking advantage of the altitudinal variations (3000-4000 a.s.l.) on the Qinghai-Tibetan Plateau. Our study showed that almost all leaf traits of these three species had significant differences (P <0.05) across an altitudinal gradient. Different species responded differently to altitude change. Leaf thickness (LT) of the three species increased with increase in altitude. Leaf area (LA) of E. nutans and C. moorcroftii decreased with increasing altitude, but that of K. capillifolia increased. There was no obvious linear effect on leaf dry matter content (LDMC) and specific leaf area (SLA) of these three species. LDMC of E. nutans and C. moorcroftii showed a trend of increase, while that of K. capillifolia decreased. SLA of E. nutans and K. capillifolia showed a trend of increase, but that of C. moorcroftii decreased with increase in altitude. In addition, soil pH (pH) and air temperature (AT) decreased with increase in altitude. However, other soil and climate factors increased as altitude increased. The finding of this work is that leaf morphology shift within species happens under altitude change to adapt to specific environment.

10

Design for reliability: delay faults modeling and simulation for CMOS flip-flops

Cai H., Liu K., An T, Naviner L

International Journal of Microelectronics and Computer Science

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2014

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Vol. 5, nr 3

98--104

EN

Continuously scaling down of CMOS technology brings on low power but also reliability problems such as aggravated aging effects and process variations. They can inﬂuence and degrade the performance of integrated circuits. In recent years, reliability issues of 65nm CMOS node has been intensively studied. In this work, a reliability assessment approach considering aging mechanisms and parametric process variation induced delay fault is proposed in design loop. Negative bias temperature instability (NBTI) and hot carrier injection (HCI) induced degradation are simulated in 65nm ﬂip-ﬂops with different architectures. An example with simple combinational logic (65nm full adder) illustrates this approach for fault probability. It is concluded that process variations are more important comparing to aging effects induced degradation when designing low power digital ﬂip-ﬂops.

11

On a system of rational difference equations ...[wzór]

Liu K., Li P., Zhong W

Fasciculi Mathematici

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2013

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Nr 51

105--114

EN

In this paper, we are concerned with a three- dimensional system of rational difference equations. We present solutions of the system in an explicit way and obtain the asymptotical behavior of solutions according to initial values. We also give sufficient conditions of existing four-period solutions.

12

Udoskonalenia wprowadzane do zabezpieczenia różnicowego transformatorów - doświadczenie płynące z projektowania testów

Yip H. T., Moscoso M., Lloyd G., Liu K., Wang Z.

Wiadomości Elektrotechniczne

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2012

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R. 80, nr 5

62-66

PL

Przedstawiono nowe algorytmy działania zabezpieczenia różnicowego transformatorów wykorzystujące prądy stabilizacji stanu nieustalonego.

EN

The paper presents new algorithms of operation of differential protection of transformers taking advantage of stabilizing currents in transient state.

13

Carbon dioxide detection using NIR diode laser based wavelength modulation photoacoustic spectroscopy

Li J., Liu K., Zhang W., Chen W., Gao X.

Optica Applicata

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2008

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Vol. 38, nr 2

341-352

EN

A photoacoustic sensor using a laser diode emitting near 1573 nm in combination with a dual-microphone resonant photoacoustic cell has been developed for carbon dioxide trace gas analysis at atmospheric pressure. Wavelength-modulation scheme and 1f detection for CO2 concentration measurements in Ar are demonstrated. The noise equivalent absorption sensitivity of NEAS(1? ) = 1.01×10-8 Wcm-1/Hz1/2, corresponding to a detection limit of 30 parts in 106 by volume (ppmv) for a 100 s integration time and 4.5 mW average laser power. The photoacoustic response of CO2 dependence on the buffer gases with different mixture ratio of Ar and N2 was investigated. Finally, the possibility to make use of the sensor for measurements of ambient CO2 is also presented.