optimal value
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2023 ◽  
Vol 83 ◽  
R. Vega-Aguayo ◽  
C. Drake ◽  
V. Guzmán ◽  
A. Mardones ◽  
I. Valdebenito ◽  

Abstract Galaxias maculatus aquaculture objectives is to produce millions of eggs. Wild females are small (2 g), have quick sexual maturity and low mean fecundity (500 eggs/female), requiring larger fishes with higher fecundity. This study aim is to evaluate experimentally the effect of the levels of protein, lipid and dietary energy on weight increases in adults. Five independent experiments were performed at different sequential time periods at the UCT hatchery, Chile. Specimens were obtained from a) Crystalline sea return specimen catches in the Tolten estuary (4 -6 cm, 0.3-0.4 g.). b) Hatchery cultured fish. Fish were fed by hand ad libitum. In experiments 1 to 4, pelleted diets were prepared with 3 to 5 levels of protein (treatments 27 up to 57%), crumble size, three 100 L fibre ponds replicates. In experiment 5 the effect of two lipid levels (8 and 21%) was evaluated with commercial extruded Salmon Nutra Starter isoproteic crumble 1 diet at 63%, replicated in 4 ponds. The results show: A tendency to increased weight in all sizes with an increased protein level in the pelleted diet.A maximal adult growth is obtained with a diet containing a minimum of 37% crude protein, with 40% the optimal value. A higher % protein in the diet or growth in weight lower feed conversion ratio. The feed conversion ratio in the extruded diet reaches up to 0.5 and in the pelleted vary from 0.7 to 1.5. Fish 0.6 g fed with 63% protein, extruded commercial diet with two different lipid levels (8 and 21%, 20.40 and 23.84 MJ kg-1, PE/TE 0.62 and 0.71) increased weight the first month 67 and 105% each. It has been established that high-energy diets with optimal levels of protein and lipid are a good short-term solution to obtain G. maculatus of higher weight.

Mathematics ◽  
2022 ◽  
Vol 10 (2) ◽  
pp. 270
Chenyang Hu ◽  
Yuelin Gao ◽  
Fuping Tian ◽  
Suxia Ma

Quadratically constrained quadratic programs (QCQP), which often appear in engineering practice and management science, and other fields, are investigated in this paper. By introducing appropriate auxiliary variables, QCQP can be transformed into its equivalent problem (EP) with non-linear equality constraints. After these equality constraints are relaxed, a series of linear relaxation subproblems with auxiliary variables and bound constraints are generated, which can determine the effective lower bound of the global optimal value of QCQP. To enhance the compactness of sub-rectangles and improve the ability to remove sub-rectangles, two rectangle-reduction strategies are employed. Besides, two ϵ-subproblem deletion rules are introduced to improve the convergence speed of the algorithm. Therefore, a relaxation and bound algorithm based on auxiliary variables are proposed to solve QCQP. Numerical experiments show that this algorithm is effective and feasible.

2022 ◽  
Alexander Shapiro ◽  
Yi Cheng

A construction of the dual of a periodical formulation of infinite-horizon linear stochastic programs with a discount factor is discussed. The dual problem is used for computing a deterministic upper bound for the optimal value of the considered multistage stochastic program. Numerical experiments demonstrate behavior of that upper bound, especially when the discount factor is close to one.

2022 ◽  
monireh Ahmadimanesh ◽  
Alireza Pooya ◽  
Hamidreza Safabakhsh ◽  
Sedigheh Sadeghi

Abstract Inventory managers in the blood supply chain always seek timely and proper response to their customers, which is essential because of the perishability and uncertainty of blood demand and the direct relationship of its presence or non-presence with human life. On the other hand, timely and regular delivery of blood to consumers is vital, as the weakness in delivery and transportation policies results in increased shortages, returns, blood loss and significant decrease in the quality of blood required by patients. Given the significance of this for the blood transfusion network, the paper tried to design a comprehensive and integrated optimal model of blood transfusion network logistics management by blood group to reduce the cost of losses, returns and blood shortages. This model is divided into two parts: Inventory management and routing. A combination of simulation techniques and neural network with several recurrent layers was used to evaluate the optimal inventory management and a multi-objective planning model was designed to determine the delivery and distribution of blood to consumers. The model designed was implemented in Khorasan Razavi Blood Transfusion Network with a main base, six central bases and 54 hospitals. Solving the model led to estimating the f consumer demand, the optimal value of target inventory and re-ordering point of central bases and hospitals, and blood distribution from the supplier to its consumers that decreased the units of blood returned to bases, increased inventory availability, and reduced costs significantly.

2022 ◽  
Vol 51 (2) ◽  
pp. 345-364
Heni Nuraeni Zaenudin ◽  
Rika Sartika ◽  
Muhammad Endriski Agraenzopati Haryanegara

This study is aimed at measuring the effectiveness of policy communication in promoting #KangPisMan program among university students. #KangPisMan is a top priority program of Bandung Municipal Government to tackle waste management problem. In this sense, the problem of plastic waste has become a global concern about environment, therefore it is a hope that, by promoting #KangPisMan, a new lifestyle will make people more aware of environmental sustainability. The program was established in 2018, so it is necessary to measure the effectiveness of its communicating strategy. In terms of public communication, the realization of promoting the program should be measured based on its optimal value. The present study seeks to analyse the effectiveness of communication strategy by employing 7C concepts as introduced. The questionnaire was distributed to 300 respondents (based on purposive sampling) which were registered as students of Faculty of Social Sciences Education, Universitas Pendidikan Indonesia. Validity of the questionnaire is measured by corrected item-total correlation. The analysis shows that communication strategy in promoting #KangPisMan was relatively effective by considering the lowest scores of continuity and consistency. It shows that the aspect of consistency in promoting the program should be enhanced. Meanwhile, the aspect of credibility had the highest value. Therefore, it is a big capital to promote the program through the role model as reflected by the team. In general, all respondents were satisfied of the communication strategy in promoting the program. However, the effectiveness is still potential to be developed in the upcoming time.

2022 ◽  
Vol 1213 (1) ◽  
pp. 012007
E Demidova ◽  
P Pchelnikov ◽  
S Belyaev ◽  
N Resnina ◽  
A Shelyakov

Abstract Strain variation on holding under a constant stress was studied in the Ti40,7Hf9,5Ni41,8Cu8 alloy. It was found, that on holding under stress, the isothermal strain rose up to saturation, which value depended on holding temperature and stress. It was found that the dependencies of the isothermal strain on the holding temperature and stress were non-monotonic. This allowed to find the optimal value of stress and time at which the isothermal strain attained the maximum value of 3.2 %. It was found that the maximum isothermal strain in the Ti40,7Hf9,5Ni41,8Cu8 alloy was less than in the Ti40,7Hf9,5Ni44,8Cu5 alloy.

2022 ◽  
Vol 130 (2) ◽  
pp. 317
А.В. Цуканов

A theoretical model of a semiconductor nanostructure consisting of a single-mode microresonator containing two quantum dots is considered. It is shown that the Coulomb interaction between electrons localized in the quantum dots modifies a spectral response of the system to an external laser field. The possibility of its use for detecting an elementary charge in the third (optically inactive) quantum dot is discussed. The influence of both diagonal (Stark effect) and non-diagonal (Förster effect) Coulomb matrix elements of the Hamiltonian on the detection accuracy is studied. The dependences of a measuring contrast on the parameters of the resonator and the quantum dots are calculated. The existence of such structural configurations for which the contrast retains an optimal value even at large distances to the measured dot is established.

2021 ◽  
Vol 45 (6) ◽  
pp. 431-437
Ahmed Redha Latrous ◽  
Ramdane Mahamdi ◽  
Naima Touafek ◽  
Marcel Pasquinelli

Among the causes of the degradation of the performance of kesterite-based solar cells is the wrong choice of the n-type buffer layer which has direct repercussions on the unfavorable band alignment, the conduction band offset (CBO) at the interface of the absorber/buffer junction which is one of the major causes of lower VOC. In this work, the effect of CBO at the interface of the junction (CZTS/Cd(1-x)ZnxS) as a function of the x composition of Zn with respect to (Zn+Cd) is studied using the SCAPS-1D simulator package. The obtained results show that the performance of the solar cells reaches a maximum values (Jsc = 13.9 mA/cm2, Voc = 0.757 V, FF = 65.6%, ɳ = 6.9%) for an optimal value of CBO = -0.2 eV and Zn proportion of the buffer x = 0.4 (Cd0.6Zn0.4S). The CZTS solar cells parameters are affected by the thickness and the concentration of acceptor carriers. The best performances are obtained for CZTS absorber layer, thichness (d = 2.5 µm) and (ND = 1016 cm-3). The obtained results of optimizing the electron work function of the back metal contact exhibited an optimum value at 5.7 eV with power conversion efficiency of 13.1%, Voc of 0.961 mV, FF of 67.3% and Jsc of 20.2 mA/cm2.

2021 ◽  
pp. 73-81
Bing Xu ◽  
Decong Zheng ◽  
Jiaxin Wang ◽  
Youzhi Yang

In order to improve the seed filling performance of mechanical hole type seed metering device with high speed, a vertical disc metering device was designed with seed agitator to improve the seed filling probability. Discrete element simulation method and physical prototype bench tests were used to simulate and analyse the seed metering process. The structure parameters of the seed agitators were optimized by the quadratic orthogonal rotation central composite design test. The results showed that: 1) the addition of seed agitator had a significant influence on the MIS (miss index), among which the concave type had the lowest MIS, and it was the highest without agitator; 2) for concave type agitator, the optimal value of depth and angle were 3.1 mm and 60.5°, respectively; 3) the physical prototype tests showed that the QFI (quality of feed index) was more than 95% under the speed of 2-10 km/h, and the MIS was less than 1%, which meets the requirements of precision sowing.

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 215
Hongli Jia ◽  
Hongbing Xin

In contrast to the conventional forced wave generator which consists of cam and flexible bearing in harmonic drive, the novel forced wave generator retains cam but cancels flexible bearing. In this article, the lubrication characteristics of the novel forced wave generator in harmonic drive is studied. First, an elliptical sliding bearing (ESB) model of simplified structure between the novel forced wave generator and the flex spline is established. Further, the computational fluid dynamics (CFD) method is employed to study the effect of some factors on the lubrication characteristics of the ESB model including elliptical gap ratio, width, and rotational speed. According to the analysis, the elliptical gap ratio has a great impact and its optimal value is 3, which is used in the design of the novel forced wave generator. Last, the practical design of the novel forced wave generator in harmonic drive is given, which can provide a basis for design and optimization of a forced wave generator without flexible bearing of the harmonic drive.

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