A two-parameter multiple shooting method and its application to the natural vibrations of non-prismatic multi-segment beams

This paper presents an enhanced version of the standard shooting method that enables problems with two unknown parameters to be solved.A novel approach is applied to the analysis of the natural vibrations of Euler-Bernoulli beams.The proposed algorithm,named as two-parameter multiple shooting method,is a new powerful numerical tool for calculating the natural frequencies and modes of multi-segment prismatic and non-prismatic beams with different boundary conditions.The impact of the axial force and additional point masses is also taken into account.Due to the fact that the method is based directly on the fourth-order ordinary differential equation,the structures do not have to be divided into many small elements to obtain an accurate enough solution,even though the geometry is very complex.To verify the proposed method,three different examples are considered,i.e.,a three-segment non-prismatic beam,a prismatic column subject to non-uniformly distributed compressive loads,and a two-segment beam with an additional point mass.Numerical analyses are carried out with the software MATHEMATICA.The results are compared with the solutions computed by the commercial finite element program SOFiSTiK.Good agreement is achieved,which confirms the correctness and high effectiveness of the formulated algorithm.

Multiple Shoots Propagation with Bioreactor Culture of Labisia pumila(Bl.) F. Vill.

This study was to establish the micropropagation system of Labisia pumila （Bl.） F. Vill. and explore the feasibility of mass production of its multiple shoots by bioreactor culture. [Method] The effects of cytokinin or cytokinin/auxin mixture solution at different concentrations on its shoot growth and propagation by nodal segment culture were tested. In order to mass-proliferate its shoots, multiple shoots were suspension-cultured on Murashige and Skoog （MS） liquid medium in the bioreactor. [Results] Thidiazuron （TDZ） showed the highest cytokinin-like activity and the number of its shoots at the TDZ concentration of 0.1 mg/L was the maximum up to 21.5 shoots per explant, without the TDZ effect on shoot elongation, but zeatin signifcantly promoted the shoot elongation and each explant grew 6.8 relatively long shoots at 5.0 mg/L of zeatin. There was no signifcant effect on shoot propagation on induction medium supplemented with auxin. By inoculating 10 g/L （260 shoots） of multiple shoots into 3 L airlift bioreactor containing 2 L MS liquid medium supplemented with 0.1 mg/L TDZ for solution culture, 6 100 multiple shoots with a fresh weight of 183.13 g were harvested. After explant regeneration was conducted in MS solid medium, the regenerated plants were transplanted into flowerpot and the morphologically normal and healthy plants were obtained. [Conclusion] The development of bioreactor technology was conducive to the high efficiency propagation of L. pumila shoot.

Journal of Intelligent Agricultural Mechanization Visual navigation in orchard based on multiple images at different shooting angles

The orchards usually have rough terrain,dense tree canopy and weeds.It is hard to use GNSS for autonomous navigation in orchard due to signal occlusion,multipath effect,and radio frequency interference.To achieve autonomous navigation in orchard,a visual navigation method based on multiple images at different shooting angles is proposed in this paper.A dynamic image capturing device is designed for camera installation and multiple images can be shot at different angles.Firstly,the obtained orchard images are classified into sky and soil detection stage.Each image is transformed to HSV space and initially segmented into sky,canopy and soil regions by median filtering and morphological processing.Secondly,the sky and soil regions are extracted by the maximum connected region algorithm,and the region edges are detected and filtered by the Canny operator.Thirdly,the navigation line in the current frame is extracted by fitting the region coordinate points.Then the dynamic weighted filtering algorithm is used to extract the navigation line for the soil and sky detection stage,respectively,and the navigation line for the sky detection stage is mirrored to the soil region.Finally,the Kalman filter algorithm is used to fuse and extract the final navigation path.The test results on 200 images show that the accuracy of visual navigation path fitting is 95.5%,and single frame image processing costs 60 ms,which meets the real-time and robustness requirements of navigation.The visual navigation experiments in Camellia oleifera orchard show that when the driving speed is 0.6 m/s,the maximum tracking offset of visual navigation in weed-free and weedy environments is 0.14 m and 0.24 m,respectively,and the RMSE is 30 mm and 55 mm,respectively.

Shoot multiplication of Syringa reticulata var.mandshurica from in vitro cultured seedlings

We developed a shoot multiplication protocol for Syringa reticulata Blume vat. mandshurica Hara from in vitro cultured seedlings that derived from in vitro germinated seeds. The shoots could be induced on Murashige and Skoog （MS） medium with proper plant growth regulator combinations of 6-benzylaminopurine （BA） and indole-3-butyric acid （IBA）. The better medium for shoot multiplication and growth was MS ＋ 5 mg L-1 BA ＋ 0.5 mg L-1 IBA ＋ 20 g L-1 sucrose ＋ 7 g L-1 agar, and the corresponding shoot induction rate was 75 %. The plantlets grew well after rooting on I/2MS medium （macro-elements of MS medium are at half-strength） sup- plemented with 1 mg L-1 IBA, and the survival percentage was 〉80 % at 16 weeks after transplanting.

A computational model of the human glucose-insulin regulatory system

Objective：A computational model of insulin secretion and glucose metabolism for assisting the diagnosis of diabetes mellitus in clinical research is introduced.The proposed method for the estimation of parameters for a system of ordinary differential equations（ODEs）that represent the time course of plasma glucose and insulin concentrations during glucose tolerance test（GTT）in physiological studies is presented.The aim of this study was to explore how to interpret those laboratory glucose and insulin data as well as enhance the Ackerman mathematical model.Methods：Parameters estimation for a system of ODEs was performed by minimizing the sum of squared residuals（SSR）function,which quantifies the difference between theoretical model predictions and GTT＇s experimental observations.Our proposed perturbation search and multiple-shooting methods were applied during the estimating process.Results：Based on the Ackerman＇s published data,we estimated the key parameters by applying R-based iterative computer programs.As a result,the theoretically simulated curves perfectly matched the experimental data points.Our model showed that the estimated parameters,computed frequency and period values,were proven a good indicator of diabetes.Conclusion：The present paper introduces a computational algorithm to biomedical problems,particularly to endocrinology and metabolism fields,which involves two coupled differential equations with four parameters describing the glucose-insulin regulatory system that Ackerman proposed earlier.The enhanced approach may provide clinicians in endocrinology and metabolism field insight into the transition nature of human metabolic mechanism from normal to impaired glucose tolerance.

LONG-TERM RIGOROUS NUMERICAL INTEGRATION OF NAVIER-STOKES EQUATION BY NEWTON-GMRES ITERATION

The recent result of an orbit continuation algorithm has provided a rigorous method for long-term numerical integration of an orbit on the unstable manifold of a periodic solution.This algorithm is matrix-free and employs a combination of the Newton-Raphson method and the Krylov subspace method.Moreover,the algorithm adopts a multiple shooting method to address the problem of orbital instability due to long-term numerical integration.The algorithm is described through computing the extension of unstable manifold of a recomputed Nagata′s lowerbranch steady solution of plane Couette flow,which is an example of an exact coherent state that has recently been studied in subcritical transition to turbulence.

Launch Vehicle Reconfigurable Guidance Method Based on Online Trajectory Optimization

In order to improve the safety and reliability of a launch vehicle, we present a reconfigurable guidance method based on online trajectory optimization for thrust decrease at the ascending stage of the launch vehicle in this paper. We used a multiple shooting method to convert the optimal control problem into a nonlinear programming(NLP) problem. Finally, we used the interior point method to solve the NLP problem. The simulation results show that the method can effectively adapt to thrust decreases by 5% and 10%. This reconfigurable guidance method based on online planning is proposed to realize launch missions under the condition of power descent, thus verifying the feasibility of the method.

Efficient Micropropagation of Chestnut Hybrids(Castanea spp.)Using Modified Woody Plant Medium and Zeatin Riboside

The chestnuts genus(Castanea spp.)is comprised of economically important trees native to the Northern hemisphere that are used as food and hardwood timber.Here,a very efficient method for micropropagation of European×Japanese chestnut hybrids(Castanea sativa×C.crenata)is described.Woody Plant Medium was used as the basal medium.In vitro shoots of four rootstock cultivars were micropropagated without shoot-tip necrosis on multiplication medium containing 5.7 or 11.4μmol·L^(−1)zeatin riboside,and were rooted on rooting medium containing 2.46μmol·L^(−1)indolebutyric acid.Monthly shootmultiplication rates for each cultivarwere 2–5 folds.In vitro rooting percentages for four cultivars were 87%for‘Maraval’,67%for‘Marigoule’,93%for‘Marsol’,and 97%for‘Précoce Migoule’.Within a 5 week period,80%–95%of rooted shoots were successfully acclimated under high humidity conditions after they were planted in either soil or rockwool.

Micropropagation of Curcuma Sp., a Threatened Medicinal Plant

A rapid and improved micropropagation protocol was developed for Curcuma sp., a threatened and high value medicinal plant, using main bud sprout and top of rhizome sprout as explants. Stepwise optimization of different plant is to change the growth regulator, reduce the level of macro-nutrition and add humate. The present study has created multiple shoot and root induction and plantlet in vitro culture, transfers the plantlet to ex vitro. The M2 medium (MS’s macronutrition 1/4, MS’s micronutrition + Morel’s vitamine + coconut milk 10% + sucrose 25 g/l + humate 1.0 ml/l + agar 7.5 g/l + 2,4D 0.5 mg/l + BAP1.0 mg/l + TDZ 1.0 mg/l) is the highest ratio of callus induction. The TA3 medium (MS’s macronutrition 1/4 + MS’s micronutrition + Morel’s vitamin+ coconut milk 10% + sucrose 25g/l + humate 2.0 ml/l + 2,4 D 0.5 mg/l + Kinetin 2.0 mg/l + TDZ 1.0 mg/l + BAP 1.0 mg/l2 + NAA 2.0 mg/l + activated carbon 2.0 g/l) is able to create buds and regeneration multiple bud for Curcuma sp. TA3 medium adding IAA 2 mg/l and IBA 0.5 mg/l has resulted in the highest indices of quantity, healthy shoot and large diameter of roots. A large number of healthy plantlets are induced by the medium of MS’s macronutrients 1/2, MS’s micronutrients full, Morel’s vitamin, humate 3 g/l, coconut milk 150 ml/l, activated carbon 3 g/l, composition phytohormone: IAA 2 mg/l + BAP 2 mg/l + TDZ 0.5 mg/l. Further studies should focus on optimizing the humate concentration for these species of Zingiberaceae. The duration of the research is from 5/2015 to 4/2016 at Faculty of Agriculture and Forestry, Tay Nguyen University, Vietnam.

Effects of plant growth regulators on the rapid proliferation of shoots and root induction in the Chinese traditional medicinal plant Atractylodes macrocephala

We developed an efficient plant regeneration protocol for rapidly propagating Atractylodes macrocephala Koidz,an important traditional Chinese medicinal plant,via shoot organogenesis.Shoot multiplication was induced on Murashige-Skoog(MS)medium supplemented with various concentrations of N-phenyl-N-1,2,3-thidiazol-5-ylurea(TDZ),6-benzylaminopurine(BA)andα-naphthaleneacetic acid(NAA).Rooting was induced on half-strength MS medium supplemented with NAA and indolebutyric acid(IBA).The maximum mean number of shoots(5.61)was obtained from a single explant by the combined effect of 1.08μmol/L NAA and 2.25μmol/L TDZ.The longest roots and a minimum number of roots were produced when they were cultured in a medium without plant growth regulators.The shortest roots and the largest number of roots were observed in the medium supplemented with 2.7μmol/L NAA.

Systematic Direct Approach for Optimizing Continuous-thrust Earth-orbit Transfers

This article presents a systematic direct approach to carry out effective optimization of a wide range of continuous-thrust Earth-orbit transfers with intermediate-level thrust acceleration,including minimum-time (with a single burn arc) and mini-mum-fuel (with multiple burn arcs) transfers. With direct control parameterization,in which the control steering programs of burn arcs are interpolated through a finite number of nodes,the optimal control problem is converted into the parameter optimi-zation proble...