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Economic and safe structural design of high-rise buildings is a high-dimensional optimization problem. Finding the globally optimal solution is challenging, and analysis, design and optimization are very time consuming. This article proposes a new approach, where the search space dimension is reduced through substructuring. The high-dimensional high-rise building optimization problem is converted to a set of low-rise building optimization subproblems of lower dimensions. The subproblems are iteratively solved instead of the original problem. The substructures are analysed and optimally designed, one after another, until convergence, taking into account the effects of other parts of the building to maintain the building's integrity. Thus, the analysis of a high-rise building is accomplished by analysing a set of low-rise building substructures. Concurrently, the high-dimensional optimization problem is solved through some low-dimensional subproblems. Therefore, building analysis, design and optimization are conducted simultaneously. To demonstrate the efficiency and robustness of the approach, examples from the literature aresolved. [ABSTRACT FROM AUTHOR]

The self-adaptive population Rao algorithms (SAP-Rao) are employed in this study to produce the optimal designs for steel grillage structures. The size variables in the optimization problem consist of the cross-sectional area of the discrete W-shapes of these beams. The LRFD-AISC design code was used to optimize the constrained size of this kind of structure. The solved problem's primary goal is to determine the grillage structure's minimum weight. As constraints, it is decided to use the maximum stress ratio and the maximum displacement at the inner point of the steel grillage structure. The finite element method (FEM) was employed to compute the moment and shear force of each member, as well as the joint displacement. A computer program for the study and design of grillage structures, as well as the optimization technique for SAP-Rao, was created in MATLAB. The outcomes of this study are compared to earlier efforts on grillage structures. The findings demonstrate that the optimal design of grillage structures can be successfully accomplished using the SAP-Rao method described in this paper. [ABSTRACT FROM AUTHOR]

In this paper, we study the codes Ck(n, q) arising from the incidence of points and k-spaces in PG(n, q) over the field Fp, with q = ph, p prime. We classify all codewords of minimum weight of the dual code Ck(n, q)⊥ in case q ∊ {4,8}. This is equivalent to classifying the smallest sets of even type in PG(n, q) for q ∊{4,8}. We also provide shorter proofs for some already known results, namely, of the best known lower bound on the minimum weight of Ck(n, q)\bot for general values of q, and of the classification of all codewords of Cn-1(n, q) of weight up to 2qn-1. [ABSTRACT FROM AUTHOR]

Abstract Background Parathyroidectomy (PTX), an effective treatment for refractory secondary hyperparathyroidism (SHPT) in chronic kidney disease (CKD) patients, still has a high persistent rate. This study aimed to analyze the predictive value of characteristics of resected parathyroid glands for postoperative persistent SHPT. Methods The clinical data of patients with persistent SHPT and successful PTX controls who had or underwent total parathyroidectomy with forearm autotransplantation (TPTX + AT) was retrospectively collected. The characteristics including the number, minimum weight, maximum weight and total weight of resected parathyroid glands from each patient were recorded. Characteristics and cutoff value of resected parathyroid glands for the prediction of persistent SHPT were analyzed. Results A total of 227 patients (62 persistent SHPT patients and 165 successful PTX controls) were enrolled in the study. Forty-one (66%) persistent SHPT cases related to supernumerary parathyroid and the remaining 21 (34%) cases related to residual undetected parathyroid. In addition, ectopic parathyroid was found in 8 patients (13%) before PTX. The average number of resected glands in the persistent SHPT group and successful PTX group was 3.53 ± 0.72 and 3.93 ± 0.25 respectively (p

The minimum weight of the code generated by the incidence matrix of points versus lines in a projective plane has been known for over 50 years. Surprisingly, finding the minimum weight of the dual code of projective planes of non-prime order is still an open problem, even in the Desarguesian case. In this paper, we focus on the case of projective planes of order p 2 , where p is prime, and we link the existence of small weight code words in the dual code to the existence of embedded subplanes and antipodal planes. In the Desarguesian case, we can exclude such code words by showing a more general result that no antipodal plane of order at least 3 can be embedded in a Desarguesian projective plane. Furthermore, we use combinatorial arguments to rule out the existence of code words in the dual code of points and lines of an arbitrary projective plane of order p 2 , p prime, of weight at most 2 p 2 - 2 p + 4 using more than two symbols. In particular, this leads to the result that the dual code of the Desarguesian projective plane PG (2 , p 2) , p ≥ 5 , has minimum weight at least 2 p 2 - 2 p + 5 . [ABSTRACT FROM AUTHOR]

Background: Parathyroidectomy (PTX), an effective treatment for refractory secondary hyperparathyroidism (SHPT) in chronic kidney disease (CKD) patients, still has a high persistent rate. This study aimed to analyze the predictive value of characteristics of resected parathyroid glands for postoperative persistent SHPT. Methods: The clinical data of patients with persistent SHPT and successful PTX controls who had or underwent total parathyroidectomy with forearm autotransplantation (TPTX + AT) was retrospectively collected. The characteristics including the number, minimum weight, maximum weight and total weight of resected parathyroid glands from each patient were recorded. Characteristics and cutoff value of resected parathyroid glands for the prediction of persistent SHPT were analyzed. Results: A total of 227 patients (62 persistent SHPT patients and 165 successful PTX controls) were enrolled in the study. Forty-one (66%) persistent SHPT cases related to supernumerary parathyroid and the remaining 21 (34%) cases related to residual undetected parathyroid. In addition, ectopic parathyroid was found in 8 patients (13%) before PTX. The average number of resected glands in the persistent SHPT group and successful PTX group was 3.53 ± 0.72 and 3.93 ± 0.25 respectively (p < 0.001). There was significance in the number of patients with different resected parathyroid glands between two groups (p < 0.001). When the resected gland number was 4, minimum weight of the parathyroid was noted to be heavier in the persistent SHPT group than that in the successful PTX group (0.52 ± 0.31 g vs. 0.38 ± 0.19 g, p < 0.001). For persistent SHPT prediction, cutoff value of minimum weight was 0.535 g, with sensitivity of 46% and specificity of 82% (AUC = 0.611; p = 0.029). Conclusions: Major reason for the persistent SHPT is the existence of supernumerary parathyroid glands or resection of less than 4 glands. When 4 glands were resected, a minimum total parathyroid gland weight heavier than 0.535 g implied the potential presence of a missed supernumerary parathyroid gland, which also contributed to the persistent SHPT. [ABSTRACT FROM AUTHOR]

The letter presents a modification on the block-wise operation of convolutional interleavers for the Parallel Concatenated Block (PCB) codes. Interleaving is conducted so that every block of the interleaved data includes one bit of a message block. This leads to determining the minimum weight of PCB codes from messages with weight 1. Due to the insertion of some stuff bits in the permutation process, multiplicities of the minimum weight of the PCB’s constituent code is less than that obtained from the previously proposed interleavers. This improves the performance of code in its error floor region. [ABSTRACT FROM AUTHOR]

We present methods for computing the distance from a Boolean polynomial on $m$ variables of degree $m-3$ (i.e., a member of the Reed–Muller code $RM(m-3, m)$) to the space of lower-degree polynomials ($RM(m-4, m)$). The methods give verifiable certificates for both the lower and upper bounds on this distance. By applying these methods to representative lists of polynomials, we show that the covering radius of $RM(4,8)$ in $RM(5,8)$ is 26 and the covering radius of $RM(5,9)$ in $RM(6,9)$ is between 28 and 32 inclusive, and we get improved lower bounds for higher $m$. We also apply our methods to various polynomials in the literature, thereby improving the known bounds on the distance from 2-resilient polynomials to $RM(m-4, m)$. [ABSTRACT FROM AUTHOR]

The aim of the research was to develop a new lightweight sandwich structure, which can be used for elements of air containers. The structure consists of aluminum foam core with fiber reinforced composite face-sheets. Nine different laminated glass or/and carbon fiber reinforced plastic face-sheet combinations were investigated. Finite element analysis of the sandwich structures was introduced. Single-objective optimization of the new sandwich structure was achieved for minimal weight. Five design constraints were considered: stiffness of the structure, face-sheet failure, core shear, face-sheet wrinkling, size constraints for design variables. The elaborated composite structure results significant weight savings due to low density. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the boneless yield of the carcass of 64 feedlot-finished young Nellore bulls fed diets containing coated or uncoated urea and slaughtered at five body weights (350, 455, 485, 555, and 580 kg). A completely randomized design with a 5 × 2 factorial arrangement was used. No significant effect was detected for the interaction between slaughter weight and diet; therefore, the variables were analyzed separately, compared by polynomial contrasts and the F test, respectively. The absolute weights of the primal cuts from the fore- and hind-quarter increased linearly as the slaughter weight of the animals increased. Increasing slaughter weights elevated the percentage of rump cap in the pistola hindquarter as well as its yield. The percentages of the rump cap and rump skirt increased linearly, whereas those of knuckle, tenderloin, flank steak, rump, and outside flat decreased and the sum of prime cuts had a quadratic effect in relation to the weight of the right 1/2 carcass. Increasing slaughter weights led to a higher percentage of fat from the trimming of the hindquarter cuts relative to the weight of the 1/2 carcass. The weight of meat cuts was similar between the groups of animals fed coated and uncoated urea. Higher slaughter weights generate heavier meat cuts but lower percentages of primal cuts from the pistola hindquarter relative to the carcass weight.

The paper presents the design and principle of operation of a new type of articulated connection of adjacent links of manipulation systems of mobile transport and technological machines – the drive swivel joints to provide a rotary rela-tive movement of the links. Their design allows to combine the function of ensuring the continuity of the kinematic chain and the function of providing rotary movement adjacent units and without the use of additional external devices. The design of the device is protected by a patent of the Russian Federation. Drive swivel joints are an alternative to tra-ditional designs of articulated joints with external power hydraulic drives. Developed a mathematical optimization model. The model is based on the minimization of the mass of the drive swivel joints when you complete the necessary design, installation, operating and strength constraints. Based on this mathematical model the proposed method of com-puter-aided design of the drive swivel joints, which is implemented in a computer program. A study was conducted of the influence of the main technical characteristics and magnitude of the operational load at the optimal weight and the optimal constructive dimensions of the drive swivel joints. It is shown that at equal freight-altitude characteristics of mobile crane-manipulator the drive swivel joint allows you to exclude a number of operational shortcomings of the tra-ditional swivel: 1) development over time of the additional dynamic load of metal due to the increased clearances in connection; 2) lowering the volume of the working area of the crane due to the presence of external power of hydraulic drives; 3) the appearance of cracks due to fatigue failure of the elements of the attachment point of the hydraulic drives to the links of manipulation system. It is possible that the transfer of the hydraulic system for lower operating pressure, which increases the efficiency of the crane and the efficiency of the hydraulic drive as a whole, as well as reduction in operating maintenance costs.

Optimization of sustainable seismic design (SSD) of building structures has been one of the most challenging and ongoing research subjects in the earthquake and structural engineering worldwide during the past ten years. The purpose of the current research article is to supplement recently developed concepts of sustainable seismic design of building structures through the limitation of damage, repairability, purpose-specific detailing, form optimization, material, and construction optimization, and development of practical technologies to achieve cost-efficient construction and post-earthquake realignment and repairs (PERR). Earthquake resisting moment frames of minimum-weight have been introduced as essential parts of SSD. Global stiffness reduction (GSR) and restoring force adjustment (RFA) concepts have been introduced to facilitate post-earthquake realignment and repairs. The rocking core-moment frame (RCMF) is the key part of the archetype in combination with other structural systems. SSD is a concept that requires a thorough appreciation of the mechanics of structural optimization, sequential failures, recentering, and earthquake-induced P-delta and residual effects. Article results show utilizing the proposed archetype can provide sustainability as well as weight and construction optimization. The archetype components are one of the conventional structural systems with no significant change in the construction procedure. Several cases have been discussed in detail to illustrate the applications of the proposed concepts. [ABSTRACT FROM AUTHOR]

Operating outside the spacecraft via remotely controlled structures is an important opportunity in different space applications. The research in this area is focused on designing robots that are sufficiently flexible to allow inspection in locations where access is difficult or impossible for astronauts, while minimizing weight and bulk. The purpose of the research is to design a borescope for space applications with no hinges or other mechanisms, exploiting biomimetic design concepts. This is pursued by giving to the borescope a backbone exoskeleton provided by a continuous structure made of fibre reinforced composite material and using NiTi wires as tendons, taking advantage of their low weight and dimensions, which allow them to be embedded between the composite layers during the lamination process. After a study of the state of the art of flexible structures, concentrated in the medical and robotic fields, the research work unfolded in two phases. In the first design phase, several composite layup solutions were considered and analysed using finite element models, leading to the definition of the borescope geometrical parameters and to an initial estimate of the displacements that can be achieved. In the second experimental phase, seven prototypes were produced and tested, with one or more wires, to validate the design and to search for a configuration that can be actuated in different directions. The borescope prototypes resulted flexible enough to achieve an extended degree of bending and at the same time sufficiently rigid to allow complete rearm of the NiTi wires. The numerical and experimental study led to the definition of the design parameters, the number of wires, and the manufacturing technique to integrate NiTi actuators., (Creative Commons Attribution license.)

We establish the existence of optimal entanglement-assisted quantum [ [ n , k , d ; n − k ] ] 2 codes for (n , k , d) = (1 4 , 6 , 7) , (1 5 , 7 , 7) , (1 7 , 6 , 9) , (1 7 , 7 , 8) , (1 9 , 7 , 9) and (2 0 , 7 , 1 0). These codes are obtained from quaternary Hermitian linear complementary dual codes. We also give some observations on the largest minimum weights. [ABSTRACT FROM AUTHOR]

In this paper, using equivalence, we classify the error correcting linear codes of length 5 and dimension 2 over GF(3). We are able to show that these codes can be partitioned into 3 mutually disjoint equivalence classes. In the final section, we compute the weight distributions of the of the codes belonging to various distinct classes. We did similar investigations for [5,2] codes over GF(4) in [1]. [ABSTRACT FROM AUTHOR]

Through applying an exemplary design study, the dependencies between current density, temperatures, and weight in an electrical drive system for a small range aircraft with conventional electrical fan or propeller drives are evaluated. This study applies a combined numerical (Finite Element Method FEM) and analytical approach to the machine design, calculation of temperatures, and cooling system design (cooler, pumps, piping). A design scenario was defined using start and climb flight in a warm tropical surrounding as the worst load case. The design has to move between two fixed temperature limits: The maximum allowable temperature in the machine insulation and the ambient temperature. The implemented method facilitates a comparatively fast-medium depth design of the drive system. The derived results show, in fact, a minimum of weight at a certain current density, which is one of the key interests for the designers of the electrical machine. The main influences on this minimum are the temperature drops in the machine, the heat transfer to the cooling fluid, the heat transfer to the cooler wall, and the remaining heat rejection to the ambient. Method and results are transferable to other types of airplanes with different ratings.

The aim of this study was to evaluate the boneless yield of the carcass of 64 feedlot-finished young Nellore bulls fed diets containing coated or uncoated urea and slaughtered at five body weights (350, 455, 485, 555, and 580 kg). A completely randomized design with a 5 × 2 factorial arrangement was used. No significant effect was detected for the interaction between slaughter weight and diet; therefore, the variables were analyzed separately, compared by polynomial contrasts and the F test, respectively. The absolute weights of the primal cuts from the fore- and hind-quarter increased linearly as the slaughter weight of the animals increased. Increasing slaughter weights elevated the percentage of rump cap in the pistola hindquarter as well as its yield. The percentages of the rump cap and rump skirt increased linearly, whereas those of knuckle, tenderloin, flank steak, rump, and outside flat decreased and the sum of prime cuts had a quadratic effect in relation to the weight of the right 1/2 carcass. Increasing slaughter weights led to a higher percentage of fat from the trimming of the hindquarter cuts relative to the weight of the 1/2 carcass. The weight of meat cuts was similar between the groups of animals fed coated and uncoated urea. Higher slaughter weights generate heavier meat cuts but lower percentages of primal cuts from the pistola hindquarter relative to the carcass weight. [ABSTRACT FROM AUTHOR]

In this paper, a practical optimization framework and enhanced strategy within an industrial setting are proposed for solving large-scale structural optimization problems in aerospace. The goal is to eliminate the difficulties associated with optimization problems, which are mostly nonlinear with numerous mixed continuous-discrete design variables. Particular emphasis is placed on generating good initial starting points for the search process and in finding a feasible optimum solution or improving the chances of finding a better optimum solution when traditional techniques and methods have failed. The efficiency and reliability of the proposed strategy were demonstrated through the weight optimization of different metallic and composite laminated wingbox structures. The results show the effectiveness of the proposed procedures in finding an optimized solution for high-dimensional search space cases with a given level of accuracy and reasonable computational resources and user efforts. Conclusions are also inferred with regards to the sensitivity of the optimization results obtained with respect to the choice of different starting values for the design variables, as well as different optimization algorithms in the optimization process. [ABSTRACT FROM AUTHOR]

An approach to reliability-based design (RBDO) of beam reinforced composite structures with non-linear geometric behavior is proposed. A unified approach following both buckling and first-ply failure (FPF) is used to verify the integrity of beam reinforced shallow shell laminated structures. A new RBDO methodology using a genetic algorithm and a hierarchical decomposition searches the global most probable failure point (MPP). For the reliability analysis, the random parameters are the mechanical properties of laminates. Simultaneously the optimal design based on weight minimization under prescribed reliability and buckling constraints is searched through this hierarchical genetic algorithm (HGA). The design variables are the ply angle, the ply thickness, the height and the width of the cross sections of the stiffeners. Numerical results show the capabilities of the proposed approach using the MPP search inner loop integrated in a HGA scheme. Based on a sensitivity methodology the uncertainty for the optimal solution obtained from HGA is analyzed. In the neighborhood of critical buckling values of the structural response the asymptotic behavior of uncertainty propagation is observed. The influence of uncertainties from random parameters and design variables are studied on critical load factor and critical displacement. The variability of these structural response functions are measured by their coefficients of variation and Sobol indices. The most important influences for uncertainty propagation are obtained from ply angle of shell laminates and from longitudinal elastic modulus group. [ABSTRACT FROM AUTHOR]