화학발광에 의한 질소화합물의 측정

NAVAS, M. J.,GALAN, G.,JIMENEZ, A. M. 慶星大學校 環境問題硏究所 1997 環境硏報 Vol.7 No.1

화학발광에 대한 기술은 대기중에서 발견되는 질소화합물과 중요하게 언급이 되는 특정한 입자상 물질과 같은 대기오염물질의 측정에 사용되어 왔다. NO, NO₂, 질산염, 아질산염, 질산, 아질산 그리고 alkyl nitrates가 그와 같은 방법으로 측정되어 밝혀져 왔다. 변화가 많은 과정들에 대한 가능성과 한계들이 평가되어 왔다.

Wafer Level Packaging

Navas Khan 한국생산제조학회 2012 한국생산제조시스템학회 학술발표대회 논문집 Vol.2012 No.10

How Have Indian Banks Adjusted Their Capital Ratios to Meet the Regulatory Requirements? An Empirical Analysis

Jalaludeen NAVAS,Periyasamy DHANAVANTHAN,Daniel LAZAR 한국유통과학회 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.11

The purpose of this study is to examine how the Indian banks have adjusted their risk-based capital ratios during 2009–2018 to meet the regulatory requirements. Banks can, in principle, increase their risk-based regulatory capital ratio, either by increasing their levels of regulatory capital or by shrinking their risk-weighted assets by adjusting asset growth or risk in the portfolio. We investigate banks’ capital behavior by decomposing the change in the capital ratio into the contribution of its components and analyzing their variance across regulatory regimes and banks’ ownerships. We further investigate how each component of the capital ratio is adjusted by the banks by breaking down them into balance sheet items. We find that the banks’ capital behavior significantly differed between public and private sector banks and between the two regulatory regimes. During Basel II, banks, in general, followed a strategy of aggressive asset growth with increased risk-taking. The decline in the CRAR because of such an expansionary strategy was adjusted by augmenting additional capital. However, during Basel III, due to higher capital requirements, both in terms of quantity and quality, banks followed a strategy of cutting back their asset growth and reducing the risk in their portfolio to maintain their CRAR.

Study of TiCN Aditions to an 2xxx Series Aluminium Alloy

Ruiz-Navas E.M.,Delgado Tienda M.L.,Benito Gonzalez S.,Gordo E. 한국분말야금학회 2006 한국분말야금학회 학술대회논문집 Vol.2006 No.1

The increasing demand of PM parts for automobile and aerospace applications has caused a strong development of the aluminium based metal matrix composites (MMCs).Aluminium alloys are one of most widely used materials as matrix in MMCs, both in research and development as well as in industrial applications. In the present work, the influence of the ceramic reinforcement addition to a 2xxx series aluminium alloy is studied. Several percentages of TiCN have been added to the Al-Cu alloy using PM techniques, in order to analyze its influence on the liquid phase sintering process and on the final properties of the material.

Comparison of macrosynthetic and steel FRC shear-critical beams with similar residual flexure tensile strengths

Francisco Ortiz-Navas,Juan Navarro-Gregori,Gabriel Leiva,Pedro Serna 국제구조공학회 2020 Structural Engineering and Mechanics, An Int'l Jou Vol.76 No.4

This study extends previous experimental research on the shear behaviour of macrosynthetic fibre-reinforced concrete beams and compares them to steel fibre-reinforced concrete beams with similar mechanical and geometrical properties. This work employed two fibre types: 60/0.9 (long/diameter) double hooked-end steel fibre and 60/85 monofilament polypropylene fibre. Beams were tested by shear loading covering parameters, such as two different cross-section widths, two shear-span-to-effective-depth ratios, two fibre types and using repetitions with and without transverse reinforcement. For quantitative comparison purposes, crack pattern evolution was studied along increasing loads levels. Effects were studied by photogrammetry, including influence of fibres on crack propagation in uncracked and dowel zones, influence of fibres on stirrup behaviour, and shear deformation or kinematics of critical shear cracks. The results evidenced similar effectiveness for both fibre types in controlling shear crack propagation and horizontal dowel cracking. Both fibres provided similar shear ductility and shear deflections. Consequently, the authors confirm that residual flexural tensile strengths are a convenient parameter for characterising the shear behaviour of fibre-reinforced concrete beams.

Benign osteoblastoma of the mandible: a case report

María del Carmen Navas-Aparicio(María del Carmen Navas-Aparicio ) 대한구강악안면외과학회 2023 대한구강악안면외과학회지 Vol.49 No.1

Osteoblastoma is a rare benign neoplasm formed by osteoid tissue and well-vascularized bone that occurs mainly in children and adolescents. It appears primarily in the long bones, vertebral column, and small bones of the hands and feet, and not typically in the skull and maxillary bones. The purpose of this study is to present the case of an 8-year-old girl with a diagnosis of right mandibular osteoblastoma and a review of the relevant literature. The goals of treatment were to preserve dental occlusion, masticatory function and facial symmetry while minimizing the effects on patient body image and quality of life. Osteoblastoma, although it is benign, can be aggressive, and its treatment will depend on the timing of diagnosis, size and location. Early diagnosis is essential to avoid not only radical surgery as in the case presented, but also to help minimize the risk of possible relapse and potential malignancy of a benign osteoblastoma.

Parallel Multithreaded Processing for Data Set Summarization on Multicore CPUs

Ordonez, Carlos,Navas, Mario,Garcia-Alvarado, Carlos Korean Institute of Information Scientists and Eng 2011 Journal of Computing Science and Engineering Vol.5 No.2

Data mining algorithms should exploit new hardware technologies to accelerate computations. Such goal is difficult to achieve in database management system (DBMS) due to its complex internal subsystems and because data mining numeric computations of large data sets are difficult to optimize. This paper explores taking advantage of existing multithreaded capabilities of multicore CPUs as well as caching in RAM memory to efficiently compute summaries of a large data set, a fundamental data mining problem. We introduce parallel algorithms working on multiple threads, which overcome the row aggregation processing bottleneck of accessing secondary storage, while maintaining linear time complexity with respect to data set size. Our proposal is based on a combination of table scans and parallel multithreaded processing among multiple cores in the CPU. We introduce several database-style and hardware-level optimizations: caching row blocks of the input table, managing available RAM memory, interleaving I/O and CPU processing, as well as tuning the number of working threads. We experimentally benchmark our algorithms with large data sets on a DBMS running on a computer with a multicore CPU. We show that our algorithms outperform existing DBMS mechanisms in computing aggregations of multidimensional data summaries, especially as dimensionality grows. Furthermore, we show that local memory allocation (RAM block size) does not have a significant impact when the thread management algorithm distributes the workload among a fixed number of threads. Our proposal is unique in the sense that we do not modify or require access to the DBMS source code, but instead, we extend the DBMS with analytic functionality by developing User-Defined Functions.

Parallel Multithreaded Processing for Data Set Summarization on Multicore CPUs

Carlos Ordonez,Mario Navas,Carlos Garcia-Alvarado 한국정보과학회 2011 Journal of Computing Science and Engineering Vol.5 No.2

Data mining algorithms should exploit new hardware technologies to accelerate computations. Such goal is difficult to achieve in database management system (DBMS) due to its complex internal subsystems and because data mining numeric computations of large data sets are difficult to optimize. This paper explores taking advantage of existing multithreaded capabilities of multicore CPUs as well as caching in RAM memory to efficiently compute summaries of a large data set, a fundamental data mining problem. We introduce parallel algorithms working on multiple threads, which overcome the row aggregation processing bottleneck of accessing secondary storage, while maintaining linear time complexity with respect to data set size. Our proposal is based on a combination of table scans and parallel multithreaded processing among multiple cores in the CPU. We introduce several database-style and hardware-level optimizations: caching row blocks of the input table, managing available RAM memory, interleaving I/O and CPU processing, as well as tuning the number of working threads. We experimentally benchmark our algorithms with large data sets on a DBMS running on a computer with a multicore CPU. We show that our algorithms outperform existing DBMS mechanisms in computing aggregations of multidimensional data summaries, especially as dimensionality grows. Furthermore, we show that local memory allocation (RAM block size) does not have a significant impact when the thread management algorithm distributes the workload among a fixed number of threads. Our proposal is unique in the sense that we do not modify or require access to the DBMS source code, but instead, we extend the DBMS with analytic functionality by developing User-Defined Functions.

Influence of High-energy Milling and Sintering Cycle on Obtaining of TiAl from Elemental Ti and Al Powders

Esteban P.G.,Gordo E.,Ruiz-Navas E.M. 한국분말야금학회 2006 한국분말야금학회 학술대회논문집 Vol.2006 No.1

The present work studies the influence of high-energy milling (HEM) and sintering cycle of Ti and Al powders on the obtainment of TiAl. This study shows that HEM modifies the diffusion processes during the sintering stage. The samples were obtained by cold uniaxial and isostatic pressing, pre-sintered at different temperatures, and heated up to the sintering temperature. This study also shows the effect of powder additions processed by HEM on the sintering behavior of elemental Ti and Al powders.

Study for the Development of Fe-NbC Composites by Advanced PM Techniques

Gordo E.,Gomez B.,Gonzalez R.,Ruiz-Navas E.M. 한국분말야금학회 2006 한국분말야금학회 학술대회논문집 Vol.2006 No.1

The development of Fe-based metal matrix composites (MMCs) with high content of hard phase has been approached by combining the use of advanced powder metallurgy techniques like high-energy milling (HEM), cold isostatic pressing (CIP) and vacuum sinterings. A 30% vol. of NbC particles was mixed with Fe powder by HEM in a planetary mill during 10h, characteristing the powder by the observation of morphology and microstructure by scanning electron microscopy (SEM). After of sintering process the variation of density, hardness,carbon content and the microstructural changes observed, permits to find the optimal conditions of processing. Afterwards, a heat treatment study was performed to study the hardenability of the composite.