Modular Ones Research Articles

Last generation fluted modular titanium stem in revision hip arthroplasty: a narrative review of mid- and long-term outcomes.

Tapered fluted titanium stems (TFTS), were introduced to overcome proximal femur bone defects. They obtain stable fixation even in catastrophic proximal bone loss. Modular ones have the advantage to adjust length, rotation, off-set independently from the distal module. Short-term publications have been showing favorable outcomes burdened by an unacceptably high rate of stem failure. Still, there is a paucity of mid- and long-term reports. This narrative review aims at analyzing recent literature on modular TFTS with at least 5 years of minimum follow-up to gain a better understanding of implant survival, performance, and complications. A search of the PubMed database was performed with selected key terms. Results were screened after the application of strict inclusion and exclusion criteria. Extracted data were subsequently evaluated to obtain an up-to-date overview of the results and complications of TFTS. Modular TFTS showed a consistent increase in patient reported outcomes that persists at 10 years and above. Femoral fractures were the most common intraoperative complication. Despite modularity, dislocation still occurs at a variable rate (1.2-12%). With revision for any cause as an endpoint, overall survival approaches 83% after 10 years of follow-up. If femoral revision only is evaluated, excellent survival rates (>95%) have been published. Stem subsidence over 5 mm was reported in less than 5% of patients, only 1 requiring femoral revision. The mean incidence of stem mechanical failure was 3.39%, although most breakages occurred in stems eventually retired from the market. Satisfactory survival rates were observed, with an acceptable rate of complications. Stem mechanical failure, excluding those stems eventually retired from the market, remains a marginal event. Therefore, the use of modular TFTS in revision surgery is safe and effective even in the long term.

Substantiation of methods for calculation of traction forces redistribution indicators on modular front and rear wheels of the vehicle (4Х4)

An analysis of the existing study of the redistribution of traction forces on the wheels of four-wheel drive wheeled vehicles and the need to take them into account when assessing the stability and efficiency of vehicles have been vehicleried out. Proposed phenomenon of redistribution of traction forces of vehicle is considered on front and rear drive wheels separately as modular ones with reduction of all parameters to equation for each wheel separately. In such a statement, equations are justified for calculating indicators of redistribution of traction forces on modular front and rear wheels of a vehicle (4 × 4). Calculations of tangential traction forces on modular front and rear wheels of low-speed self-propelled wagon ВС5Э (4 × 4) have been vehicleried out according to the presented equations.

Study of loading of an improved container design during transportation by railway

The object of research. The object of research is the processes of occurrence, perception and redistribution of loads in the design of a container with a frame made of square pipes and lining made of smooth sheets.
 Investigated problem. Under operating conditions, damage to containers may occur due to the loads acting on them during transportation by various modes of transport. One of the most determining among such loads are dynamic loads, which are experienced not only by the container structure, but also by the cargo placed in it. As a result, there may be damage to the structure of the container, as well as to the cargo, which necessitates additional costs, both for the repair of containers and for reimbursement of expenses for damage to the transported cargo. In addition, this situation is unfavorable from an environmental point of view. In this regard, there is a need to conduct research to improve the design of a universal container in order to reduce its load, as well as increase operational efficiency.
 The main scientific results. A scientific substantiation of the use of square pipes as components of the frame of a universal container has been carried out.
 The area of practical use of research results. The sphere of practical use of the obtained results is the engineering industry, in particular railway transport.
 Innovative technological product. The concept of a universal container with a frame made of square pipes and a lining made of smooth sheets.
 Scope of the innovative technological product. The developments proposed as part of the study will be useful recommendations for creating innovative vehicle designs, including modular ones.

Comparing expert elicitation and model-based probabilistic technology cost forecasts for the energy transition

We conduct a systematic comparison of technology cost forecasts produced by expert elicitation methods and model-based methods. Our focus is on energy technologies due to their importance for energy and climate policy. We assess the performance of several forecasting methods by generating probabilistic technology cost forecasts rooted at various years in the past and then comparing these with observed costs in 2019. We do this for six technologies for which both observed and elicited data are available. The model-based methods use either deployment (Wright's law) or time (Moore's law) to forecast costs. We show that, overall, model-based forecasting methods outperformed elicitation methods. Their 2019 cost forecast ranges contained the observed values much more often than elicitations, and their forecast medians were closer to observed costs. However, all methods underestimated technological progress in almost all technologies, likely as a result of structural change across the energy sector due to widespread policies and social and market forces. We also produce forecasts of 2030 costs using the two types of methods for 10 energy technologies. We find that elicitations generally yield narrower uncertainty ranges than model-based methods. Model-based 2030 forecasts are lower for more modular technologies and higher for less modular ones. Future research should focus on further method development and validation to better reflect structural changes in the market and correlations across technologies.

Homotopy-coherent algebra via Segal conditions

Many homotopy-coherent algebraic structures can be described by Segal-type limit conditions determined by an “algebraic pattern”, by which we mean an ∞-category equipped with a factorization system and a collection of “elementary” objects. Examples of structures that occur as such “Segal O-spaces” for an algebraic pattern O include ∞-categories, (∞,n)-categories, ∞-operads (including symmetric, non-symmetric, cyclic, and modular ones), ∞-properads, and algebras for a (symmetric) ∞-operad in spaces.In the first part of this paper we set up a general framework for algebraic patterns and their associated Segal objects, including conditions under which the latter are preserved by left and right Kan extensions. In particular, we obtain necessary and sufficient conditions on a pattern O for free Segal O-spaces to be described by an explicit colimit formula, in which case we say that O is “extendable”.In the second part of the paper we explore the relationship between extendable algebraic patterns and polynomial monads, by which we mean cartesian monads on presheaf ∞-categories that are accessible and preserve weakly contractible limits. We first show that the free Segal O-space monad for an extendable pattern O is always polynomial. Next, we prove an ∞-categorical version of Weber's Nerve Theorem for polynomial monads, and use this to define a canonical extendable pattern from any polynomial monad, whose Segal spaces are equivalent to the algebras of the monad. These constructions yield functors between polynomial monads and extendable algebraic patterns, and we show that these exhibit full subcategories of “saturated” algebraic patterns and “complete” polynomial monads as localizations, and moreover restrict to an equivalence between the ∞-categories of saturated patterns and complete polynomial monads.

Reaktif Güç Kompanzasyonu için Gözetimli Kontrolör Tasarımı

The process of reducing the phase difference between current and voltage as much as possible by balancing the reactive power is known as reactive power compensation. With reactive power compensation, over currents and voltage drops in the transmission lines are prevented and higher quality, cheaper, and more efficient energy is provided. Reactive power compensation is done by switching capacitors with proper values. In a reactive power compensation system, capacitors are switched on and off by a controller. The switching behavior of this system can be characterized as a discrete event system (DES) that has discrete states and the state evolution depends on the occurrence of asynchronous events. In this paper, the control mechanism of a reactive power compensation system is considered in the sense of DES. The system is modeled by using automata and supervisory control structures are computed. The supervisors are obtained by using the supervisory control theory (SCT). Supervisors in the form of monolithic, reduced, and modular are synthesized to correct the power factor. The computed supervisors are also integrated with the system and simulated. The total size of supervisors, ie the total number of transitions and states of each, are compared. The computed supervisors in the form of modular ones have the smallest size. According to simulation results, it is demonstrated that the power factor is successfully corrected by all of the computed supervisors. The presented study shows how to calculate controllers for reactive power compensation systems by using the supervisory control theory. Since the supervisory control theory used in the study is a formal controller computation method, the presented approach enables the computation of formal controllers for reactive power compensation systems. The use of formal methods in the synthesis of controllers offers significant benefits in terms of realization and verification.

Using CAD – CAM Technology in The Design of Prosthetic Devices

During last years a lot of improvements have been put on in order to develop many products by the introduction of computer-aided tools, to reduce the cost and time of the Design and Manufacturing process, and to have a faster and cheaper evaluation for different variants of the same product. Also, a great interaction has been happened between the custom-fit of products character-rized with the human body or part of it. Innovative computer-aided tools could support to realize custom-fit products with a strict interaction with human body and definitely improve people’s life style, in particular of persons with disabilities. This research presented a specific-fit of the lower limb prosthesis, which can guide and support the user of prosthetic devices, it has been studied the history and improvement of prosthetics, the modular ones that mainly composed by commercial components, except for the socket that is highly customized and manufactured around the patient stump. All the product and process knowledge is strictly correlated to a specific set of parameters, which guides the whole prosthesis design process: the patient’s characteristics. In particular, these data are necessary to select the appropriate standard components, to model a functional socket according to the patient’s anatomy, and creates the 3D model of the socket. The proposed framework is centered on the digital model of the amputee and directly manages the experts’ knowledge in order to guarantee a product of high quality, commercial 3D CAD system has been adopted to create a library of 3D parametric models to represent standard components and for final prosthesis assembly.

A Control Perspective on the Evolution of Biological Modularity

Abstract Biological networks can be nearly decomposed into sets of components or subunits commonly referred as modules. Despite the ubiquity of modularity in biological networks, the understanding of its evolutionary origins remains an open problem in biology. Our previous work on sparsity-promoting control of complex networks has shown that the increased cost of feedback channels selects organized topological structures such as modular ones in networks with Laplacian dynamics as the cheapest option to control. Here we test the hypothesis that the minimization of total control cost promotes modularity in biological networks such as gene regulatory systems. We employ genetic algorithms of network populations using the total control cost as the fitness function for natural selection. Our results suggest that blind random mutations do not create modular networks, even though they offer the optimal fitness from a control perspective. However, mutation schemes combining up to 80% of random mutations and 20% of biased mutations to maximize the diffusion of biological information can increase the average modularity and organized structures of the population. We conclude that control efficiency is an important driver of modularity in biological networks, when the evolutionary process is not entirely random and gradual.

Modular junction may be more problematic than bearing wear in metal-on-metal total hip arthroplasty.

In total hip arthroplasty (THA), local adverse reaction to metal debris (ARMD) may be caused by abnormal metal ion release from a metal-on-metal (MoM) bearing, or by wear and corrosion of the implant's modular junction. The aim of this study was to compare ion levels and rate of ARMD between patients sharing the same MoM bearing but 1 group having monoblock stems versus another having modular stems. Whole blood cobalt (Co) and chromium (Cr) ion concentrations, ARMD rate, revision rate, and function measured by UCLA and WOMAC scores were compared between groups. ARMD rate was significantly higher in the modular group (46%) compared with the monoblock group (16%, p = 0.031). Revision for ARMD was performed at 52.8 ± 8.1 months in the modular group versus 98.2 ± 15.5 months after primary THA in the monoblock group. ARMD originated from wear and corrosion of the junction between stem and femoral head adapter sleeve in all monoblock cases, and the junction between stem and modular neck in all the modular ones. Cr and Co ions levels were significantly higher in the modular stem group ( p < 0.001 for both). Although both groups had MoM bearings, corrosion at stem/neck or neck/head junctions combining dissimilar metal (Ti and Cr-Co) was seen as the source of excess metal ions release leading to ARMD. Poor performance of the modular junction may be more deleterious than wear of the bearing. To avoid such complications, THA femoral stem modular junctions should be eliminated (return to a full monoblock implant) or have improved junction design.

Adverse reaction to local metal debris does not always come from metal on metal bearing wear

Introduction Abnormal metal ion release from wear of metal-on-metal (MoM) bearing in total hip arthroplasty (THA) is associated with adverse local reactions to metal debris (ARMD). Metal particles may also arise from wear and corrosion of the implant's modular junction. The aim of this study was to compare ion levels and rate of ARMD between patients with THA sharing the same MoM bearing but one group having monoblock stems versus another group having modular stems. Materiel et methodes This study included 45 patients who underwent primary MoM THA using the same acetabular component and large diameter metallic modular femoral head. 32 hips received a modular stem and 13 hips received a monoblock stem. Cobalt (Co) and chromium (Cr) ion concentrations, ARMD rate and function measured by UCLA and WOMAC scores were compared between groups. Resultats ARMD rate was significantly lower in the monoblock group (16%) compared to the modular group (46%, P = 0.031). Revision for ARMD was performed at 115 ± 5.9 months after primary THA in the monoblock group versus 63 ± 2.3 months in the modular group. ARMD cases had severe wear and corrosion of the junction between stem and femoral head trunnion in all monoblock cases and the junction between stem and modular neck in all the modular ones. Cr and Co ions levels were significantly lower in the monoblock stem group: 2.0 ± 1.0 μg/L vs. 7.2 ± 11.4 μg/L (P Discussion The rate of ARMD was significantly higher in the modular stem group and this group required revision earlier. Although both groups had MoM bearings, corrosion at stem/neck or neck/head junctions were seen as the source of excessive metal ions release lea. Conclusion In the presence of ARMD, MoM bearing wear may not be the main source of failure. Modular junction's poor performances may be more deleterious than the bearing. To avoid such complication, THA femoral stem modular junctions should be eliminated (return to a full monoblock implant) or have improved junction design.

On-line failure prediction in safety-critical systems

In safety-critical systems such as Air Traffic Control system, SCADA systems, Railways Control Systems, there has been a rapid transition from monolithic systems to highly modular ones, using off-the-shelf hardware and software applications possibly developed by different manufactures. This shift increased the probability that a fault occurring in an application propagates to others with the risk of a failure of the entire safety-critical system. This calls for new tools for the on-line detection of anomalous behaviors of the system, predicting thus a system failure before it happens, allowing the deployment of appropriate mitigation policies.The paper proposes a novel architecture, namely CASPER, for online failure prediction that has the distinctive features to be (i) black-box: no knowledge of applications internals and logic of the system is required (ii) non-intrusive: no status information of the components is used such as CPU or memory usage; The architecture has been implemented to predict failures in a real Air Traffic Control System. CASPER exhibits high degree of accuracy in predicting failures with low false positive rate. The experimental validation shows how operators are provided with predictions issued a few hundred of seconds before the occurrence of the failure.

Evaluation of plasticity and radiopacity of elastic separators by means of traction tests and radiography

INTRODUCTION: Elastic separators are widely used in the orthodontic clinic, in different sizes and thicknesses. Their function is to promote the separation between the teeth that will receive orthodontic bands, however, when subgingivally lost, they may cause periodontal problems and, ultimately, cause tooth extraction. OBJECTIVE: Concerned not only about their function but also about their properties, this experimental work was performed in order to evaluate, with a clinical perspective, the plasticity and radiopacity of the elastic separators, usually used in orthodontic clinic, through physical traction tests and radiographs. METHODS: Six different brands were analyzed and divided in two groups: extruded separators (American Orthodontics, GH, Morelli Blue and Morelli Green) and modular separators (Abzil, Dentaurum, GAC, Blue Modular Morelli and Green Modular Morelli). The plasticity was evaluated after physical traction tests, stretching the separators to 3 times their initial diameter. While the radiopacity was assessed using x-rays. RESULTS: When stretched to three times their inner diameter (ID), the extruded separators American Orthodontics, GH, Morelli Blue and Morelli Green and the modular ones Dentaurum, Morelli Blue Modular and Morelli Green Modular, presented elastic deformation, recovering their original inner diameter. The modular separators from Abzil and GAC showed permanent plastic deformation. With respect to radiopacity, the Abzil, American Orthodontics, Dentaurum, GAC and GH separators were radiopaque. CONCLUSION: Correlating the results concerning the plasticity and radiopacity, the separators which showed the most satisfactory results on both tests were, among the extruded separators, American Orthodontics and GH, and among the modular separators, GAC and Dentaurum.

Monoblock hemiarthroplasties for femoral neck fractures – A part of orthopaedic history? Analysis of national registration of hemiarthroplasties 2005–2009

This study from the Swedish Hip Arthroplasty Register (SHAR) compares cemented (Thompson®, Exeter Trauma Stem (ETS)®) and uncemented (Austin-Moore®) monoblock hemiarthroplasties (n=1116 and 616, respectively) with modular ones (n=18,659).Austin-Moore® prostheses lead to more re-operations (6.7%) compared to modular implants (3.5%) and Thompson®/ETS® (2.4%).A Cox regression analysis, adjusting for other risk factors, shows twice the risk of re-operation for Austin-Moore® implants (CI 1.5–2.8), in particular, due to periprosthetic fracture (5.4; CI 3.2–9.1) and dislocation (1.9; CI 1.3–3.0). The Thompson®/ETS® implants do not influence the overall risk of re-operation (0.7; CI 0.5–1.2) compared to modular implants and decrease the risk of re-operation due to infection (0.2;CI 0.04–0.7). An increased risk of re-operation is also seen in men, age groups 75–85 years and <75 years and after secondary fracture surgery.Both Swedish and Australian orthopaedic surgeons have decreased their use of Austin-Moore® implants after reports from their national arthroplasty registers identifying inferior outcome for this implant. Due to the increased risk of re-operations, it should not be used in modern orthopaedic care. Cemented Thompson® or ETS® implants could still be suitable for the oldest, low-activity patients. To finally decide if there is a place for them, patient-reported outcome must be analysed as well.

Optimization of modular structures using Particle Swarm Optimization

In most configurations of modular structures, products are assumed to have a unique modular structure. However, it is well known that alternatives for constructing modular structures may exist in any level of abstraction. Explicit considerations of alternative structures invoke changes in the number of module instances so that lower costs, more independency of structures and higher efficiency can be achieved. Relatively few research papers were found in the literature that deal with the optimization of modular structures problem with alternative assembly combinations aiming at minimization of module investments. First, this paper proposes an optimization model which helps users to change their dedicated systems gradually into modular ones. The optimization is achieved through appropriately selecting the subsets of module instances from given sets. The proposed optimization model is general in the sense that products can have any number of modules and alternatives of assemblies. Secondly, the paper presents an adapted Discrete Particle Swarm Optimization algorithm (DPSO), which is applied in the aforementioned problem. Comparisons with Genetic Algorithm, Simulated Annealing and total enumeration are presented. Finally performance comparisons using a set of large scale problems (for which the optimal solution is unknown) between the proposed algorithm (DPSO) and the other optimization techniques, are presented and discussed.

The use of taxonomic distinctness indices in assessing patterns of biodiversity in modular organisms

AbstractEstimating diversity of modular organisms may be problematic due to actual difficulties in discriminating between ‘individuals’ and quantifying their abundances. Quantitative data, when available, are collected through methods that could preclude the application of classical diversity indices, making comparisons among studies difficult. Taxonomic distinctness indices, such as the ‘Average Taxonomic Distinctness’ (Δ+) and the ‘Variation in Taxonomic Distinctness’ (Λ+) may represent suitable tools in investigating diversity beyond the simple species number. The potential usefulness of such indices has been explored almost exclusively on unitary organisms, neglecting modular ones. In this study, we employed Δ+ and Λ+ to analyse patterns of diversity of epiphytic hydroid assemblages living on Cystoseira seaweeds at a hierarchy of spatial scales, along 800 km of rocky coast (SE Italy). ANOVA on species richness and Λ+ showed no significant difference in sample diversity at the investigated spatial scales. In contrast, there were significant differences at the scale of 10s of km in Δ+. Analyses based on simulations detected significant variations at all spatial scales in Δ+. Such findings underline the potential of Δ+ in highlighting relevant spatial scales of variation in patterns of hydroid diversity. Our results also suggest that the interplay between natural environmental variations and the complex ecological traits of modular organisms might affect taxonomic distinctness indices. We stress the need for further investigations focusing on modular organisms before any generalizations on the use of taxonomic relatedness measures in examining marine biodiversity can be made.

Modularity concepts for the automotive industry: A critical review

Modularization has been used mostly in order for the management of complex systems to be simplified. In the present paper, the major evolutions of modularity concepts are reviewed in the case of the automotive industry. The current trend indicates that the next generation of vehicles will change from the integrated “unibody” with high production volume and low flexibility, to the modular ones of middle to high production volume and flexibility. Typical examples of different modular design approaches are presented and discussed. The paper includes the vehicle's body design requirements that have to be met in order for such a modular approach to be effective.

A CONSTRUCTIVE AND MODULAR APPROACH TO DECENTRALIZED SUPERVISORY CONTROL PROBLEMS

We plunge decentralized control problems into modular ones to benefit from the know-how of modular control theory: any decentralized control problem is associated to a natural modular control problem, which over-approximates it. Then, we discuss how a solution of the latter problem delivers a solution of the former.

Metaphor, Modularity, and the Evolution of Conceptual Integration

We integrate information from distinct domains, especially in metaphor. What sort of cognitive architecture underlies this kind of integration? Fodor (1983) argued that it involves nonmodular mechanisms. He also contended that the nonmodular mechanisms evolved from modular ones through a process of demodularization, a position elaborated by Mithen (1996). In this article, I defend Fodor and Mithen from criticisms offered by Sperber (1994). Sperber suggested that nonmodular mechanisms are unlikely to have evolved because an increasingly large database would incapacitate the cognitive system due to combinatorial explosion and the frame problem. Moreover, he argued that nonmodular mechanisms are not required to explain our ability to integrate information. I argue that proponents of demodularization can respond to Sperber's criticisms by assuming that either an expanding database co-evolved with increasingly sophisticated search mechanisms or the cognitive system evolved along connectionist lines. Moreover, I argue that Sperber's modular account of conceptual integration fails to satisfy the criteria for modularity-namely, information encapsulation.

Transcendance et indépendance algébrique: liens entre les points de vue elliptique et modulaire.

There exist, now, numerous transcendental and algebraic independence results about elliptic and modular functions i.e. E2, E4, E6 the standard Eisenstein series, j the modular invariant ... (works done by T. Schneider, D. Masser, G.V. Chudnovsky, Y. Nesterenko, P. Philippon ...). Transcendence properties of modular functions have been studied by using their relations with periods of elliptic integrals; and until 1996, all results about these modular functions were corollaries of “elliptic results” (i.e. results established by means of Weierstrass elliptic functions and elliptic curves). With the proof of Mahler-Manin conjecture (1995) and Nesterenko-Philippon works (1996), we can now get new elliptic and exponential results from modular ones (for example this corollary of Nesterenko's paper “π and exp(π) are algebraically independent”, striking result which owes nothing to the exponential function). My aim is twofold: (1) to recall classical links between elliptic and modular functions and to translate algebraic independence results from one setting to the other; (2) to show that this translation suggests a lot of conjectures.

Modular metazoans: gonochoric, hermaphroditic, or both at once?

Summary We introduce a classification system for the sexual modes of modular (clonal and colonial) animals which incorporates both spatial and temporal components of modular sexuality. After explaining and illustrating each potential sexual mode, we compare the prevalence patterns of sexual modes among modular animals, unitary animals, and flowering plants. Our conclusions are: (1) There are far more potential colonial modes of sex, and more clonal modes of sex, than there are unitary modes of sex. This is a function of the tri-level and bi-level organization, respectively, of colonial and clonal animals, in contrast to the single level of unitary ones. (2)Only five of ten potential colonial modes of sex have known examples, while only four of six potential clonal modes of sex have known examples. (3) The sexual mode of many modular metazoans is not known, in part because of a previous lack of terms by which to refer to modular sex at all its levels of expression. (4) Comparison of clonal and colonial animals reveals that genet gonochorism is nearly twice as common in clonal as in colonial animals. Genet hermaphroditism achieved by gonochoric modules of both sexes (monoecy) is about three times as common in colonial as in clonal animals. (5) Comparison of unitary and modular animals reveals that genet sequential hermaphroditism, while moderately common among unitary animals, has virtually no examples among modular ones. Genet gonochorism is also more prevalent among unitary animals than among modular ones (and conversely, genet simultaneous hermaphroditism is far more prevalent among modular than unitary animals). (6) Despite striking differences in the prevalence of different sexual modes at the genet level, clonal, colonial, and unitary animals display very similar patterns of sexual mode when examined at the modular level. (7) Comparison of seed plants and modular animals reveals that both genet gonochorism and monoecy are considerably rarer in plants than in modular animals. Sequentially hermaphroditic genets may be more common among plants than among modular animals. Some sexual modes in our classification may be represented among plants, but not among animals.