• Title/Summary/Keyword: technical university

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Computational modeling of cracking of concrete in strong discontinuity settings

  • Oliver, J.;Huespe, A.;Pulido, M.D.G.;Blanco, S.
    • Computers and Concrete
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    • v.1 no.1
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    • pp.61-76
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    • 2004
  • The paper is devoted to present the Continuum Strong Discontinuity Approach (CSDA) and to examine its capabilities for modeling cracking of concrete. After introducing the main ingredients of the CSDA, an isotropic continuum damage model, which distinguishes tension and compression states, is used to implicitly induce a projected traction separation-law that rules the cracking phenomena. Criteria for onset and propagation of material failure and specific finite elements with embedded discontinuities are also briefly sketched. Finally, some representative numerical simulations of cracking, in plain and reinforced concrete specimens, using the CSDA are presented.

Dynamic analysis of helicoidal bars with non-circular cross-sections via mixed FEM

  • Eratli, Nihal;Yilmaz, Murat;Darilmaz, Kutlu;Omurtag, Mehmet H.
    • Structural Engineering and Mechanics
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    • v.57 no.2
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    • pp.221-238
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    • 2016
  • One of the objectives of this study is to implement the direct calculation of the torsional moment of inertia for non-circular cross-sections, which is based on the St. Venant torsion formulation and the finite element method. Recently the proposed method provides a unique calculation of the torsional rigidity of simply and multiply connected cross-sections. Next, free vibration analyses of cylindrical and non-cylindrical helices with non-circular cross-sections are solved by a curved two-nodded mixed finite element based on the Timoshenko beam theory. Some thin-thick closed or open sections are handled and the natural frequencies of cylindrical and non-cylindrical helices are compared with the literature and the commercial finite element program SAP2000.

Space Deformation of Parametric Surface Based on Extension Function

  • Wang, Xiaoping;Ye, Zhenglin;Meng, Yaqin;Li, Hongda
    • International Journal of CAD/CAM
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    • v.1 no.1
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    • pp.23-32
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    • 2002
  • In this paper, a new technique of space deformation for parametric surfaces with so-called extension function (EF) is presented. Firstly, a special extension function is introduced. Then an operator matrix is constructed on the basis of EF. Finally the deformation of a surface is achieved through multiplying the equation of the surface by an operator matrix or adding the multiplication of some vector and the operator matrix to the equation. Interactively modifying control parameters, ideal deformation effect can be got. The implementation shows that the method is simple, intuitive and easy to control. It can be used in such fields as geometric modeling and computer animation.

Flexible Service Composition Based on Bundle Communication in OSGi

  • Alcarria, Ramon;Robles, Tomas;Morales, Augusto;Gonzalez-Miranda, Sergio
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.6 no.1
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    • pp.116-130
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    • 2012
  • Service provision and consumption platforms are more and more used to enable communication between sensors, actuators and intelligent devices, since they provide mechanisms that make possible the combination of components to create composed services. However, these kinds of platforms have limitations to adapt themselves to new and unknown devices. In this work we analyze the challenge of component or bundle communication by using the Open Services Gateway Initiative (OSGi) technology and we propose three mechanisms with the aim of contributing to flexible component communication: Common Service, Specific Service and WSIF Web Service Invocation. We provide these solutions with some architectural models and validate them through different example services. Finally we compare them regarding performance, flexibility and application complexity.

Current Approaches in Development of Immunotherapeutic Vaccines for Breast Cancer

  • Allahverdiyev, Adil;Tari, Gamze;Bagirova, Melahat;Abamor, Emrah Sefik
    • Journal of Breast Cancer
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    • v.21 no.4
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    • pp.343-353
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    • 2018
  • Cancer is the leading cause of death worldwide. In developed as well as developing countries, breast cancer is the most common cancer found among women. Currently, treatment of breast cancer consists mainly of surgery, chemotherapy, hormone therapy, and radiotherapy. In recent years, because of increased understanding of the therapeutic potential of immunotherapy in cancer prevention, cancer vaccines have gained importance. Here, we review various immunotherapeutic breast cancer vaccines including peptide-based vaccines, whole tumor cell vaccines, gene-based vaccines, and dendritic cell vaccines. We also discuss novel nanotechnology-based approaches to improving breast cancer vaccine efficiency.

AN EXISTENCE OF THREE DIFFERENT NON-TRIVIAL SOLUTIONS FOR DISCRETE ANISOTROPIC EQUATIONS WITH TWO REAL PARAMETERS

  • Ahmed A.H., Alkhalidi;Haiffa Muhsan B., Alrikabi;Mujtaba Zuhair, Ali
    • Nonlinear Functional Analysis and Applications
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    • v.27 no.4
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    • pp.855-867
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    • 2022
  • This study finds three different solutions (3-Sol's) for the fourth order nonlinear discrete anisotropic equations (DAE) with real parameter. We use the variational method(VM) and 𝜙p-Laplacian operator (𝜙p-LO) to prove the main results. In the following paper, we take the parameters λ, 𝜇 such that λ > 0 and 𝜇 ≥ 0 into consideration.

The Problem Analysis and Improvement of Technical Guidance On Construction Accident Prevention (건설재해예방 기술지도의 문제점 분석 및 개선방안)

  • Oh, Heui-Keun;Kim, Yong-Su
    • Journal of the Korea Safety Management & Science
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    • v.18 no.2
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    • pp.19-27
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    • 2016
  • Safety accident rate of small-medium construction site is high. because of lack of safety management system, lack of safety management capacity, lack of investment for safety, Owner's insufficient awareness about safety. In order to improve this, Currently in Occupational Safety and Health Act, Construction site of amounts more than 300 million won less than 120 billion (architectural),150 billion won(civil) mandatory subject to the technical guidance on construction accident prevention. Context of construction accident causes with construction accident rate relationship analysis and case analysis of technical guidance, through a survey of stakeholders in the technical guidance drawn the problems of the construction accident prevention technical guidance system and ways to improve on this.

Technical efficiency of the coastal composite fishery in Korea: a comparison of data envelopment analysis and stochastic frontier analysis

  • Kim, Do-Hoon;Seo, Ju-Nam;Lee, Sang-Go
    • The Journal of Fisheries Business Administration
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    • v.41 no.3
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    • pp.45-58
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    • 2010
  • This study estimated the technical efficiency of coastal composite fishery in Korea by using the data envelopment analysis (DEA) and the stochastic frontier analysis (SFA) methods, and the results on the respective method were compared. In the DEA method, the constant returns to scale (CRS) and the variable returns to scale (VRS) output-oriented DEA models were separated and technical efficiencies were estimated, respectively. The average estimated value of technical efficiency by the SFA method (0.633) was found to be lower than that by the VRS-DEA method (0.738), while it was higher than that by the CRS-DEA method (0.479). It was found that strong correlation exists between the SFA method and the VRS-DEA method. The method which can utilize both methods in mutually complementing way for the estimation of technical efficiency was also considered.

Predicting Stock Prices Based on Online News Content and Technical Indicators by Combinatorial Analysis Using CNN and LSTM with Self-attention

  • Sang Hyung Jung;Gyo Jung Gu;Dongsung Kim;Jong Woo Kim
    • Asia pacific journal of information systems
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    • v.30 no.4
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    • pp.719-740
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    • 2020
  • The stock market changes continuously as new information emerges, affecting the judgments of investors. Online news articles are valued as a traditional window to inform investors about various information that affects the stock market. This paper proposed new ways to utilize online news articles with technical indicators. The suggested hybrid model consists of three models. First, a self-attention-based convolutional neural network (CNN) model, considered to be better in interpreting the semantics of long texts, uses news content as inputs. Second, a self-attention-based, bi-long short-term memory (bi-LSTM) neural network model for short texts utilizes news titles as inputs. Third, a bi-LSTM model, considered to be better in analyzing context information and time-series models, uses 19 technical indicators as inputs. We used news articles from the previous day and technical indicators from the past seven days to predict the share price of the next day. An experiment was performed with Korean stock market data and news articles from 33 top companies over three years. Through this experiment, our proposed model showed better performance than previous approaches, which have mainly focused on news titles. This paper demonstrated that news titles and content should be treated in different ways for superior stock price prediction.

Protective Effect of Melatonine Against Radiation Induced Nephrotoxicity in Rats

  • Kucuktulu, Eda;Yavuz, Aydin Ali;Cobanoglu, Umit;Yenilmez, Engin;Eminagaoglu, Selcuk;Karahan, Caner;Topbas, Murat;Kucuktulu, Uzer
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.8
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    • pp.4101-4105
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    • 2012
  • Purpose: The degree of radiation injury to kidneys which are located within the limits of radiotherapy area is determined by the volume and the dose of radiation to which the organ is exposed. When the tolerance dose of the kidney is exceeded after a latent period of 6 months acute nephritis develops and after 18 months chronic nephritis ensues. Melatonin is known to prevent the oxidative injury of toxins and radiotherapy with its free radical scavenging capacity. Methods and Materials: In this study 8 weeks old 24 Sprague -Dawley rats were allocated into 4 groups: Control group; Radiotherapy group (20 Gy bilaterally in 5 fractions); Melatonin group (10 mg/kg intraperitoneally), and Melatonin+radiotherapy group (20 Gy Radiotherapy in 5 fractions+ melatonin 10 mg/kg intraperitoneally). After a follow-up period of 6 months BUN was determined in all groups. After rats were euthanized the kidneys were removed for histopathological examination under both light and electron microscopes. Results: After 6 months follow-up, both at light and electron microscopy levels, the rats in radiotherapy+melatonin group were significantly protected against the radiation injury comparing to radiotherapy group (p<0.05). Conclusion: It was shown in this experimental model that melatonin has protective effects against radiation injury to kidneys.