Complexity Research Articles

Clump interpolation error for the identification of damage using decentralized sensor networks

Recent developments in the field of smart sensing systems enable performing simple onboard operations which are increasingly used for the decentralization of complex procedures in the context of vibration-based structural health monitoring (SHM). Vibration data collected by multiple sensors are traditionally used to identify damage-sensitive features (DSFs) in a centralized topology. However, dealing with large infrastructures and wireless systems may be challenging due to their limited transmission range and to the energy consumption that increases with the complexity of the sensing network. Local DSFs based on data collected in the vicinity of inspection locations are the key to overcome geometric limits and easily design scalable wireless sensing systems. Furthermore, the onboard pre-processing of the raw data is necessary to reduce the transmission rate and improve the overall efficiency of the network. In this study, an effective method for real-time modal identification is used together with a local approximation of a damage feature, the interpolation error, to detect and localize damage due to a loss of stiffness. The DSF is evaluated using the responses recorded at small groups of sensors organized in a decentralized topology. This enables the onboard damage identification in real time thereby reducing computational effort and memory allocation requirements. Experimental tests conducted using real data confirm the robustness of the proposed method and the potential of its implementation onboard decentralized sensor networks.

Governing complexity: interview with David Tyfield

Governing complexity: interview with David Tyfield

Effects of forest gap disturbance on forest ecosystem.

Forest gap disturbance has important consequences on plant species assemblage, stand structure and ecosystem functions of forests via changing micro-scale heterogeneity and community succession. Here, we reviwed research progress in the effects of forest gap disturbance on forest ecosystem. The effects of forest gap disturbance on plant species assemblage was analyzed based on the intrinsic biological characteristics and external environmental factors. The effects of forest gap disturbance on stand structure was discussed from the perspectives of texture and architecture of plant community. Forest gap disturbance effect on forest ecosystem functions was reviewed. After analyzing the theoretical shortcomings and the key bottleneck of forest ecosystem management practices, the following research directions were proposed, including the methods of determining threshold of forest gap, the mechanism of canopy closure, the effect of forest gap disturbance on forest ecosystem processes, and the relationship between forest gap disturbance and forest productivity. The advantage of forest gap disturbance in accelerating plant species regeneration and structure complexities could provide scientific evidence for enhancing the quality of low yield and low function plantations in China.

New explicit formulas for optimum design of concrete gravity dams

Large dams are a part of the infrastructure of any society, and a huge amount of resources are consumed to build them. Among the various types of dams, the optimum design of concrete gravity dams requires special attention because these types of dams require a huge amount of concrete for their construction. On the other hand, concrete gravity dams are among the structures whose design, regarding the acting forces, geometric parameters, and resistance and stability criteria, has some complexities. In the present study, an optimization methodology is proposed based on Sequential Quadratic Programming (SQP), and a computer program is developed to perform optimization of concrete gravity dams. The optimum results for 45 concrete gravity dams are studied and regression analyses are performed to obtain some explicit formulas for optimization of the gravity dams. The optimization of concrete gravity dams can be provided easily using the developed formulas, without the need to perform any more optimization process.

Clinical application and research progress of digital complete denture.

Digital technologies use high-precision three-dimensional scanning, intelligence-aided design software, and multi-axis numerical control milling or 3D printing, which can produce restorations with reliable precision and suitable function. However, the development of digital technologies in the field of complete denture restoration has been slow due to the complexity of prosthesis. This review article introduces the current research status and clinical applications of digital complete dentures in prosthodontic clinics and dental laboratories to provide beneficial references to prosthodontists and dental technicians.

Inclusive education and migrant pupils: interpersonal effects of cooperative goal structures

The article discusses the interpersonal effects of cooperative goal structures in classrooms with a large number of immigration background students. A goal structure could be one of the relational patterns that supports the migrant pupils and their classmates to accomplish school-related goals. A cooperative goal structure emphasizes positive interdependence between classmates. The main purpose of the research-invention is to remove the interpersonal barriers and promote better peer relationships between migrant and non-migrant pupils. We measured the cooperative goal structures’ effects through two variables: a) collaborative interaction; b) relational structure. For the collaborative interaction, we observed a positive result. Upon the collaboration offered by migrant students, the analysis yielded a statistically significant effect: Wilks Lambda = .80, F (2, 68) = 4.43, p <.001. With regard to the received collaboration, the outcome was: Wilks Lambda = .73, F (2, 64) = 11.37, p <.0005. As to the second variable, the study showed the improvement of the mutual relationship between migrant and non-migrant students and the overall increase of social density index in the classrooms. The paper proposes a new direction of development: integrating different levels of schoolbooks linguistic complexity within cooperative goal structures . Two methods can facilitate the control of linguistic complexity: the computing of linguistic indexes and text-layering . Both methods can help educators to scaffold reading difficulty levels for diverse students.

Numerical and experimental investigation for monitoring and prediction of performance in the soft actuator

Due to various benefits such as unlimited degrees of freedom, environment adaptability, and safety for humans, engineers have used soft materials with hyperelastic behavior in various industrial, medical, rescue, and other sectors. One of the applications of these materials in the fabrication of bending soft actuators (SA) is that they have eliminated many problems in the actuators such as production cost, mechanical complexity, and design algorithm. However, SA has complexities, such as predicting and monitoring behavior despite the many benefits. The first part of this paper deals with the prediction of SA behavior through mathematical models such as Ogden and Darijani, and its comparison with the results of experiments. At first, by examining different geometric models, the cubic structure was selected as the optimal structure in the investigated models. This geometrical structure at the same pressure showed the most significant bending in the simulation. The simulation results were then compared with experimental, and the final gripper model was designed and manufactured using a 3D printer with silicone rubber as for the polymer part. This geometrical structure is capable of bending up to a 90-degree angle at 70 kPa in less than 2 seconds. The second section is dedicated to monitoring the bending behavior created by the strain sensors with different sensitivity and stretchability. In the fabrication of the sensors, silicon is used as a soft material with hyperelastic behavior and carbon fiber as a conductive material in the soft material substrate. The SA designed in this paper is capable of deforming up to 1000 cycles without changing its characteristics and capable of moving objects weigh up to 1200 g. This SA has the capability of being used in soft robots and artificial hand making for high-speed objects harvesting.

Dal plain language all'easy-to-read per lettori con disabilità intellettive: oltre la semplificazione

This paper deals with the topic of text simplification discussing two models of writing that make texts easier to read and understand. First, it briefly discusses plain language, which has been debated in Italy since the beginning of the 1990s as a tool to improve government communication. However, even though several initiatives tried to promote it, it is still little used, and it has not defeated bureaucratese. Second, this paper presents “Easy-to-Read”, a model of linguistic adaptation designed to write texts that are easy to read and understand for people with intellectual disabilities. Its features of conciseness and simplicity also make it suitable for other categories with reading difficulties due to psychological and neuropsychiatric conditions, social factors, and/or poor knowledge of a language. Plain language and Easy-to-Read share several traits, although Easy-to-Read is a more specific application designed for readers with special needs. Easy-to-Read is a relatively new concept: several guidelines have already been created for some languages, along with the European ones, designed during the Pathways project by the European association Inclusion Europe. Yet, the existing guidelines often lack extensive linguistic indications and can prove insufficient to write proper easy-to-read texts. After presenting Easy-to-Read, the paper will discuss some methodological issues, such as some problems regarding the existing guidelines for the Italian version of Easy-toRead; the complexity of the needs of its recipient; and the absence of proofs, as Easy-toRead currently lacks a more scientific approach and further studies are still needed. Finally, the paper briefly discusses the need to spread both plain language and Easy-toRead in order to foster the participation in social life of people with reading difficulties or intellectual disabilities and promote their right to information.

Labour, Trade Union and Tea Industry: Contextualizing Indian Plantation System

ABSTRACT The present study tries to examine the correlation between labour, trade union and tea industry in India with particular reference to Darjeeling Tea Industry. In order to understand, complexities between labour, trade union and tea industry in Darjeeling hills, it requires to be discussed the origin of tea industry. As far as the origin of tea industry in Darjeeling hills is concerned, during early 1850s the first experimental tea plantation started. By 1856, experimental tea plantation was transformed into full-fledged commercial industry in Darjeeling hills. Owing to increasing demand of tea, the planters require more labour forces. However, since the beginning of tea industry in Darjeeling, one can understand that the living conditions of workers are said to be poor. As we shall see, the origin of trade union in tea industry began during 1940s to mobilize the workers voice. Thus, this study tries to examine the existing socio-economic conditions of tea garden workers and how trade unions are active to mobilize the workers’ voice. Key words: Labour, Trade Union, Tea Industry, Plantation and Darjeeling.

Deindustrialization, economic complexity and exchange rate overvaluation: the case of Brazil (1998-2017)

We analyze the determinants of the deindustrialization of the Brazilian economy in the period between 1998 and 2017. This is a typical example of ‘premature deindustrialization’ in the sense that the major reason for the fall in the manufacturing share has not been the increase in per-capita income but rather real exchange rate overvaluation. In the Brazilian case, real exchange rate overvaluation results both from an appreciation of the real effective exchange rate, and an increase in the equilibrium value of the real exchange rate, the “industrial equilibrium exchange rate” of the new developmentalist literature. The elimination of the real exchange rate overvaluation requires not only the adoption of a macroeconomic policy regime in which some kind of real exchange rate targeting is adopted, but also industrial policies designed for increasing the economic complexity of the Brazilian economy and, hence, to reduce the equilibrium value of the real exchange rate. JEL codes : O11, O14, O24

DESCENTRALIZACIÓN EDUCATIVA EN EL MUNICIPIO CERTIFICADO DE TUNJA: UN PROCESO COMPLEJO EN TIEMPO DE POSTCONFLICTO

Este artículo plantea una reflexión sobre la complejidad de la descentralización educativa en el municipio Certificado de Tunja, enmarcada dentro de la investigación llevado a cabo en mi tesis doctoral titulada “Descentralización Educativa en el Municipio Certificado de Tunja, desde una visión del pensamiento complejo”, donde los elementos de calidad, cobertura y eficiencia, generan grandes expectativas e interrogantes sobre el verdadero impacto de las nuevas reglas de juego, que modificaron las relaciones de poder entre el Estado y las entidades territoriales, y, por ende estos últimos debían tener una mayor capacidad técnica y de gestión para manejar el sistema educativo y construir espacios reales de autonomía en la búsqueda de generar políticas educativas desde lo local, que respondan a la coyuntura actual frente al cumplimiento de los acuerdos de La Habana, en tiempos de transición donde el sector educativo tunjano no es ajeno a esta nueva realidad cambiante orientada a la inclusión y a la reconciliación.

Antimicrobial Resistance in Oral biofilm: Challenges and Alternatives

Bacterial biofilm has been a major contributor to severe bacterial infections in humans. Oral infections have also been associated with biofilm-forming microbes. Several antimicrobial strategies have been developed to combat bacterial biofilms. However, the complexity of the oral cavity has made it difficult to use common drug treatments. Most effective ways to control normal bacterial infections are rendered ineffective for bacterial biofilms. Due to limited drug concentration availability, drug neutralization or altered phenotype of bacterial cells, different drug have been ineffective to identify the target cells. This leads to the development of the multifaceted phenomenon of antimicrobial resistance (AMR). Biofilm research done so far has been focused on using antimicrobial drugs to target molecular mechanisms of cells. The severity and resistance mechanisms of extracellular matrix (ECM) have been underestimated. The present study describes different antimicrobial strategies with respect to their applications in dental or oral infections. A prospective strategy has been proposed targeting ECM which is expected to provide an insight on biofilm obstinacy and antimicrobial resistance.

Influence of soil model complexity on the seismic response of shallow foundations

The time-history finite element analysis is usually used to evaluate the seismic response of shallow foundations. However, the literature lacks studies on the influence of the soil constitutive model complexity on the seismic response of shallow foundations. This study, thus, aims to fill this gap by investigating the seismic response of shallow foundation resting on dry silica sand using the linear elastic (LE) model, elastic-perfectly-plastic (EPP) model, and hardening soil with small strain stiffness (HS small) model. These models have been used because it is intended to compare the results of a soil constitutive model that accurately captures the seismic response of the soil-structure interaction problems (which is the HS small model) with simpler models (the LE and EPP models) that are routinely used by practitioners in geotechnical designs. The results showed that the LE model produces a very small seismic settlement value which is approximately equal to zero. The EPP model predicts a seismic settlement higher than that produced using the HS small model for earthquakes with a peak ground acceleration (PGA) lower than 0.25 g for a relative density of 45% and 0.40 g for a relative density of 70%. However, the HS small model predicts a seismic settlement higher than the EPP model beyond the aforementioned PGA values with the difference between both models increases as the PGA rises. The results also showed that the LE and EPP models predict similar trend and magnitude of the acceleration-time relationship directly below the foundation, which was different than that predicted using the HS small model. The results reported in this paper provide a useful benchmark for future numerical studies on the response of shallow foundations subjected to seismic shake.

Reduce Complexity

Vereinfachte Einkaufs- und Bestellprozesse, eingesparte Lagerfläche und Minimierung des Kapitaleinsatzes. Für Oliver Heyne, Director Sales &amp; Business Development beim Rollen- und Räderproduzenten Tente, liegen die Vorteile einer reduzierten Komplexität auf der Hand. Gemeinsam mit seinen Kunden will er dieses Optimierungspotenzial heben.

Strategic Technologies Selection for Oil Production: An Application of Attractiveness-Capability Matrix of Technology

Rapid development of technologies, their increasing complexity and variety, together with limited organizational resources and efforts for survival in industrial competitions have made the task of appropriate technology selection a major challenge. The present research is aimed at the formulation of technology strategy related to oil production in one of the west Karoon oil fields in Iran. At the first, the processes and challenges of production in the studied oil field are recognized by the experts’ survey. Then, the priority of the challenges is evaluated and four key challenges of the considered field are recognized by using a paired comparison questionnaire and Chang Fuzzy AHP. In the next step, the existing and new technologies of oil production in the four recognized key challenges are determined. For each of the recognized technologies, the attractiveness assessment and capability assessment questionnaire are designed based on Jolly indexes and distribute in a sample composed of production engineering experts. Sampling is done by the non-random and purposive-judgmental method. Based on the results of the questionnaires, the attractiveness-capability matrix is designed by Morin’s model, and then based on the obtained technology portfolio, the strategies of each of the four areas are formulated and discussed.

Fuzzy-based multiple decision method for landslide susceptibility and hazard assessment: A case study of Tabriz, Iran

Due to the complexity of the causes of the sliding mass instabilities, landslide susceptibility and hazard evaluation are difficult, but they can be more carefully considered and regionally evaluated by using new programming technologies to minimize the hazard. This study aims to evaluate the landslide hazard zonation in the Tabriz region, Iran. A fuzzy logic-based multi-criteria decision-making method was proposed for susceptibility analysis and preparing the hazard zonation maps implemented in MATLAB programming language and Geographic Information System (GIS) environment. In this study, five main factors have been identified as triggering including climate (i.e., precipitation, temperature), geomorphology (i.e., slope gradient, slope aspect, land cover), tectonic and seismic parameters (i.e., tectonic lineament congestion, distribution of earthquakes, the unsafe radius of main faults, seismicity), geological and hydrological conditions (i.e., drainage patterns, hydraulic gradient, groundwater table depth, weathered geo-materials), and human activities (i.e., distance to roads, distance to the municipal areas) in the study area. The results of analyses are presented as a landslide hazard map which is classified into 5 different sensitive categories (i.e., insignificant to very high potential). Then, landslide susceptibility maps were prepared for the Tabriz region, which is categorized in a high-sensitive area located in the northern parts of the area. Based on these maps, the Bozgoosh-Sahand mountainous belt, Misho-Miro Mountains and western highlands of Jolfa have been delineated as risk-able zones.

From Commons to Urban Commons. Complexity and Contradiction in the Translation of a Concept

From Commons to Urban Commons. Complexity and Contradiction in the Translation of a Concept

Integration of MBSE and PLM: complexity and uncertainty

Integration of MBSE and PLM: complexity and uncertainty

Investigation of blasting impact on limestone of varying quality using FEA

Large deformation and rapid pressure propagation take place inside the rock mass under the dynamic loads caused by the explosives, on quarry faces in order to extract aggregate material. The complexity of the science of rock blasting is due to a number of factors that affect the phenomenon. However, blasting engineering computations could be facilitated by innovative software algorithms in order to determine the results of the violent explosion, since field experiments are particularly difficult to be conducted. The present research focuses on the design of a Finite Element Analysis (FEA) code, for investigating in detail the behavior of limestone under the blasting effect of Ammonium Nitrate & Fuel Oil (ANFO). Specifically, the manuscript presents the FEA models and the relevant transient analysis results, simulating the blasting process for three types of limestone, ranging from poor to very good quality. The Finite Element code was developed by applying the Jones-Wilkins-Lee (JWL) equation of state to describe the thermodynamic state of ANFO and the pressure dependent Drucker-Prager failure criterion to define the limestone plasticity behavior, under blasting induced, high rate stress. A progressive damage model was also used in order to define the stiffness degradation and destruction of the material. This paper performs a comparative analysis and quantifies the phenomena regarding pressure, stress distribution and energy balance, for three types of limestone. The ultimate goal of this research is to provide an answer for a number of scientific questions, considering various phenomena taking place during the explosion event, using advanced computational tools.

A ilustração do conto infantil: uma proposta para a educação literária imagética e paratextual na sala de aula

Frente ao desafio de se trabalhar com os paratextos e as ilustrações de livros infantis e juvenis na sala de aula, o presente estudo objetiva mostrar a importância e o significado desses elementos no processo formativo do professor de língua portuguesa, disciplina escolar em que a leitura literária deve ter espaço privilegiado. Para o efetivo trabalho com a literatura infantil e juvenil, é necessário apresentar os diversos sentidos das ilustrações, explorar os paratextos como elementos compositivos do objeto livro e criar um projeto de leitura literária na escola, que amplie e emancipe a experiência literária dos jovens leitores, conforme apontam Camargo (1998), Colomer (2007) e Lins (2003). Desse modo, por meio de um estudo bibliográfico e da aplicação da oficina “Ilustração do conto infantil: construção da imagem narrativa”, dirigida a graduandos em letras, foi possível identificar que a sensibilização dos futuros professores sobre a importância das ilustrações e dos paratextos provocou resultado satisfatórios, principalmente com a mudança de percepção da maioria dos licenciandos a respeito do significado que tais elementos possuem dentro das páginas do livro. O que permitiu concluir que, quando a escola se articula em torno de um projeto de leitura literária, unindo a parte imagética com a paratextual, é possível produzir muitos frutos, como a mudança de percepção dos alunos para os significados das ilustrações e os elementos paratextuais, desenvolvendo um olhar mais apurado e favorecendo uma experiência sinestésica com a complexidade do objeto livro.