Search results for "CONST"
showing 10 items of 7706 documents
Über die verzweigung des polyvinylacetats. I. Die bestimmung der übertragungskonstante des polymeren nach der methode der „α-polymeren”.
1962
Die Ubertragungskonstante (Cp) am Polymeren wird ermittelt, indem der Einflus relativ kurzkettiger „α-Polymerer” auf den Polymerisationsgrad des „α-Polymeren” gemessen und daraus Cp mit Hilfe der Reglergleichung berechnet wird. Der Polymerisationsgrad wird viskosimetrisch auf Grund der Eichmessungen von MATSUMOTO u.a. unter Berucksichtigung der Mittelwertbildung bestimmt. Aus den Messungen ergibt sich ein neuer Wert fur das Konstantenverhaltnis kab/Kw2; die Einzelwerte der Wachstums- und der Abbruchskonstante liegen danach erheblich hoher als bisher angenommen wurde. Fur Cp ergibt sich (2,5 ± 0,5)·10−4 in guter Ubereinstimmung mit entsprechenden Mesergebnissen an niedermolekularen Modellsub…
Limited Resistance Rigid Perfectly Plastic Hinges for Steel Frames
2017
The paper concerns the proposal of a new special device for steel frames that can be utilized as external constraint as well as internal one connecting the structure beam elements. The device is designed as a rigid perfectly plastic hinge characterized by suitably chosen stiffness and resistance. Its constituting material is steel. The elastic stiffness and the limit resistance, treated as independent of each other, are fixed with the aim of satisfying special features required to the structure. The proposed device is thought as a sandwich section with wing thickness appropriately variable. Its dimensions are designed so that it can exhibit the fixed independent stiffness and limit resistan…
Revista electrónica de investigación y evaluación educativa
2010
Este trabajo tiene el propósito de mostrar el uso de la metodología de Modelos de Ecuaciones Estructurales (SEM) para validar la estructura conceptual de cuestionarios de contexto que se utilizan en los estudios nacionales e internacionales para evaluar el logro educativo de los escolares. Desgraciadamente, los organismos evaluadores no destinan los mismos recursos técnicos a los cuestionarios de contexto que a las pruebas de aprendizaje, por lo que rara vez los primeros son sujetos a estudios de validez. Para mostrar el uso de la metodología SEM, se seleccionó el cuestionario dirigido a alumnos que utilizó el Instituto Nacional para la Evaluación de la Educación (INEE) para conocer los fac…
A tool for a first analysis of architectural façades
1997
Abstract This work presents a tool for analysing the figurative structure of architectural facades. The procedure begins by singling out the elementary shapes which make up the facade image; it detects and identifies them as “area objects”, even if present in combination in virtual or mental form and groups them into classes of equal objects. A second step is the analysis of the inner structure of the classes: equidistant, arithmetical and geometrical sequences, or alternate distances are distinguished. The procedure ends by singling out the symmetries which structure the facade image and displaying them, pointing out their implied hierarchy through a thickness differentiation.
Theoretical and Experimental Model for the Analysis of a Cardan Cross
2015
The work presents the aproach of initial moddeling and calculus in order to prepare an finite element investigation of the cardan transmission joint. For this, it is necessary to develop a flexible informational system that would connect the constructive design of cardan transmissions to the technological design within a unitary structure. Due to the typodimensional diversity of cardan transmissions, the design and manufacturing of the various components for a certain application domain (medical aparature, dental and agricultural machines, lifting and transportation machines etc.) has been typified. In order to study the problems that occur in the practice of using cardan transmissions, the…
Groups are not always the same
1993
The idea of supporting group meetings at the same time and at the same place by computer raises the problem of how salient features of group behaviors are understood in meetings. In this paper we take a critical look at several beliefs about group behaviors in research dealing with electronic meeting systems (EMS). The paper argues based on an empirical study that the concept of a small, cohesive business team, so widely held, in all EMS research is not necessarily a valid starting point in thinking of meeting support. In particular, the paper critically evaluates a number of beliefs of user aspects, group features such as composition, structure and protocols, and task characteristics such …
The integration of information technologies in the knowledge based organizations
2016
Relations between the users' expertise, complexity of tasks to be solved by knowledge-based organizations and mission of smart information systems, is a multi-dimensional structure that should provide the necessary conceptual framework of sustainable integrated smart development. The users of smart information systems face a variety of problems, such as: system access, data recovery, identifying and retrieving a specific document and its contents, and difficulties associated with understanding and interpreting of the used system on stages and methods following to be used, respectively problems on understanding the meaning of information provided. Using smart information systems and smart da…
Feeding, cooking, sharing : a brief social history of food
2020
This work addresses the food system as a complex structure connected to the environment, like a living organism. It uses the contributions from multiple fields (including anthropology, nutritional, medicine, and economics) to establish connections between analytically disparate fields in order to highlight their transformations over time and space. It also studies social organisation over millions of years to understand the synergy between the environment, extraction technologies, economic and political structures, and the resulting cooking environments (each with their own social construction of tastes) as conditioning factors for sickness and death. In short, it delves into the anthropolo…
Participación asociativa percibida en contextos socio-educativos: validación de contenido
2019
En las asociaciones del Tercer Sector de acción socioeducativa se han ido estableciendo lógicas, políticas y prácticas para acreditar la calidad de los servicios. Este tipo de orientaciones organizativas son similares a los procedimientos que se han llevado a cabo en los últimos años, en otros contextos educativos, y que han mermado considerablemente la participación real y eficaz de los principales agentes implicados. A ello se suma la falta de estándares para evaluar la participación asociativa percibida. Atendiendo a esta problemática, nos planteamos el objetivo de establecer unos indicadores válidos que permitan registrar la perspectiva de los socios y los profesionales acerca de su par…
Employing artificial neural networks to find reaction coordinates and pathways for self-assembly
2021
Capturing the autonomous self-assembly of molecular building blocks in computer simulations is a persistent challenge, requiring to model complex interactions and to access long time scales. Advanced sampling methods allow to bridge these time scales but typically require to construct accurate low-dimensional representations of the transition pathways. In this work, we demonstrate for the self-assembly of two single-stranded DNA fragments into a ring-like structure how autoencoder architectures based on unsupervised neural networks can be employed to reliably expose transition pathways and to provide a suitable low-dimensional representation. The assembly occurs as a two-step process throug…