• Title/Summary/Keyword: Structural Transformations

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Exploring geometric and kinematic correspondences between gear-based crank mechanism and standard reciprocating crankshaft engines: An analytical study

  • Amir Sakhraoui;Fayza Ayari;Maroua Saggar;Rachid Nasri
    • Structural Engineering and Mechanics
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    • v.90 no.1
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    • pp.97-106
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    • 2024
  • This paper presents a significant contribution to aided design by conducting an analytical examination of geometric links with the aim of establishing criteria for assessing an analogy measure of the extrinsic geometric and kinematic characteristics of the Variable Compression Ratio (VCR) engine with a Geared Mechanism (GBCM) in comparison to the existing Fixed Compression Ratio (FCR) engine with a Standard-Reciprocating Crankshaft configuration. Employing a mechanical approach grounded in projective computational methods, a parametric study has been conducted to analyze the kinematic behavior and geometric transformations of the moving links. The findings indicate that in order to ensure equivalent extrinsic behavior and maintain consistent input-output performance between both engine types, precise adjustments of intrinsic geometric parameters are necessary. Specifically, for a VCR configuration compared to an FCR configuration, regardless of compression ratio and gearwheel radius, for the same crankshaft ratios and stroke lengths, it is imperative to halve lengths of connecting rods, and crank radius. These insights underscore the importance of meticulous parameter adjustment in achieving comparable performance across different engine configurations, offering valuable implications for design optimization.

A Study on Intention to Adopt Digital Payment Systems in India: Impact of COVID-19 Pandemic

  • Kavita Jain;Rupal Chowdhary
    • Asia pacific journal of information systems
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    • v.31 no.1
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    • pp.76-101
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    • 2021
  • Digitalization and digital transformations have metamorphized the face of Financial Inclusion globally, more so, in cash obsessed economies like India. The purpose of our study is to empirically analyze the users' intention to adopt digital payment systems, post Demonetisation, during the COVID-19 pandemic in India. The conceptual framework for the study is based on the Unified Theory of Acceptance and Use of Technology (UTAUT) adoption model with added operationalized constructs of Perceived Risk and Stickiness to use Cash. A total of 326 respondents were surveyed using a pre-tested questionnaire during the Nationwide Lockdown 3.0 in India. These responses were analyzed using Partial Least Squares - Structural Equation Modelling (PLS-SEM) technique. The findings of the study revealed that performance expectancy and facilitating conditions directly influence the intention of individuals to use digital payment systems, whereas the effect of perceived ease of use on digital payment systems is mediated through the attitude towards the digital payment systems during COVID-19 pandemic situation. Implications of the proposed adoption model are discussed. This will enable the other developing economies to formulate a digital ecosystem, that is here to stay even after the pandemic.

Preparation and Characterization of Multiferroic $0.7BiFeO_3-0.3BaTiO_3$ Thin Films by Pulsed Laser Deposition (펄스 레이저 증착법으로 제작된 다강체 $0.7BiFeO_3-0.3BaTiO_3$ 박막의 특성 연구)

  • Kim, Kyung-Man;Yang, Pan;Zhu, Jinsong;Joh, Young-Gull;Lee, Hee-Young
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.11a
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    • pp.88-88
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    • 2009
  • $BiFeO_3$(BFO), when forming a solid solution with $BaTiO_3$(BTO), shows structural transformations over the entire compositional range, which not only gives a way to increase structural stability and electrical resistivity but also applies a means to have better ferromagnetic ordering. In this respect, we have prepared and studied 0.7BFO-0.3BTO thin films on $Pt(111)/TiO_2/SiO_2/Si$ substrates by pulsed laser deposition. Various deposition parameters, such as deposition temperature and oxygen pressure, have been optimized to get better quality films. Based on the X-ray diffraction results, thin films were successfully deposited at the temperature of $600^{\circ}C$ and an oxygen partial pressure of 10mTorr. The dielectric, ferroelectric, and magnetic properties have then been characterized. It was found that the films deposited under lower oxygen pressure corresponded to lower leakage current. Magnetism measurement showed an induced ferromagnetism. The microstructures associated with. the magnetic and dielectric properties of this mixed-perovskite solid solutions were observed by transmission electron. microscopy, which revealed the existence of complicated ferroelectric domains, suggested that the weak spontaneous magnetization was closely associated with the decrease in the extent of rhombohedral distortion by a partial substitution of $BaTiO_3$ for $BiFeO_3$.

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PREPARATION AND CHARACTERIZATION OF MULTIFERROIC 0.8 $BiFeO_3$-0.2 $BaTiO_3$ THIN FIMLS BY PULSED LASER DEPOSITION

  • Kim, K.M.;Yang, P.;Zhu, J.S.;Lee, H.Y.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.06a
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    • pp.313-313
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    • 2010
  • $BiFeO_3$ (BFO), when forming a solid solution with $BaTiO_3$ (BTO), shows structural transformations over the entire compositional range, which not only gives a way to increase structural stability and electrical resistivity but also applies a means to have better ferromagnetic ordering. In this respect, we have prepared and studied 0.8 BFO-0.2 BTO thin films on Pt(111)/$TiO_2/SiO_2$/Si substrates by pulsed laser deposition. Various deposition parameters, such as deposition temperature and oxygen pressure, have been optimized to get better quality films. Based on the X-ray diffraction results, thin films were successfully deposited at the temperature of $700^{\circ}C$ and an oxygen partial pressure of 10mTorr and 330mTorr. The dielectric, ferroelectric, and magnetic properties have then been characterized. It was found that the films deposited under lower and higher oxygen pressure corresponded to lower leakage current. Magnetism measurement showed an induced ferromagnetism. The microstructures associated with the magnetic and dielectric properties of this mixed-perovskite solid solutions were observed by transmission electron microscopy, which revealed the existence of complicated ferroelectric domains, suggested that the weak spontaneous magnetization was closely associated with the decrease in the extent of rhombohedral distortion by a partial substitution of $BaTiO_3$ for $BiFeO_3$.

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A partially occluded object recognition technique using a probabilistic analysis in the feature space (특징 공간상에서 의 확률적 해석에 기반한 부분 인식 기법에 관한 연구)

  • 박보건;이경무;이상욱;이진학
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.26 no.11A
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    • pp.1946-1956
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    • 2001
  • In this paper, we propose a novel 2-D partial matching algorithm based on model-based stochastic analysis of feature correspondences in a relation vector space, which is quite robust to shape variations as well as invariant to geometric transformations. We represent an object using the ARG (Attributed Relational Graph) model with features of a set of relation vectors. In addition, we statistically model the partial occlusion or noise as the distortion of the relation vector distribution in the relation vector space. Our partial matching algorithm consists of two-phases. First, a finite number of candidate sets areselected by using logical constraint embedding local and structural consistency Second, the feature loss detection is done iteratively by error detection and voting scheme thorough the error analysis of relation vector space. Experimental results on real images demonstrate that the proposed algorithm is quite robust to noise and localize target objects correctly even inseverely noisy and occluded scenes.

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Multicomponent assessment and ginsenoside conversions of Panax quinquefolium L. roots before and after steaming by HPLC-MSn

  • Huang, Xin;Liu, Yan;Zhang, Yong;Li, Shuai-Ping;Yue, Hao;Chen, Chang-Bao;Liu, Shu-Ying
    • Journal of Ginseng Research
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    • v.43 no.1
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    • pp.27-37
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    • 2019
  • Background: The structural conversions in ginsenosides induced by steaming or heating or acidic condition could improve red ginseng bioactivities significantly. In this paper, the chemical transformations of red American ginseng from fresh Panax quinquefolium L. under steaming were investigated, and the possible mechanisms were discussed. Methods: A method with reversed-phase high-performance liquid chromatography coupled with linear ion trap mass spectrometry ($HPLC-MS^n$)-equipped electrospray ionization ion source was developed for structural analysis and quantitation of ginsenosides in dried and red American ginseng. Results: In total, 59 ginsenosides of protopanaxadiol, protopanaxatriol, oleanane, and ocotillol types were identified in American ginseng before and after steaming process by matching the molecular weight and/or comparing $MS^n$ fragmentation with that of standards and/or known published compounds, and some of them were determined to be disappeared or newly generated under different steaming time and temperature. The specific fragments of each aglycone-type ginsenosides were determined as well as aglycone hydrated and dehydrated ones. The mechanisms were deduced as hydrolysis, hydration, dehydration, and isomerization of neutral and acidic ginsenosides. Furthermore, the relative peak areas of detected compounds were calculated based on peak areas ratio. Conclusion: The multicomponent assessment of American ginseng was conducted by $HPLC-MS^n$. The result is expected to provide possibility for holistic evaluation of the processing procedures of red American ginseng and a scientific basis for the usage of American ginseng in prescription.

Re-Engineering of Educational Contexts in the Digital Transformation of Socio-Economic Interactions of Society

  • Tsekhmister Yaroslav;Tetiana Konovalova;Tsekhmister Bogdan
    • International Journal of Computer Science & Network Security
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    • v.24 no.3
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    • pp.135-141
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    • 2024
  • The article examines the key constants of reengineering the modern educational cluster, associated with the processes of digital transformation of all spheres of modern socio-cultural space. The first constant is the strategic rethinking of the educational process organization and awareness of the new roles of all participants (tutors, applicants, controlling elements, etc.). The other constant involves practical re-design of the system of educational services, which consists in the reorientation from the traditional model of education functioning for society to the implementation of the educational format in the form of new projects (structural, target, business). Consequently, the purpose of the study is to highlight the attitudes relevant to the modern realities of information and technological support of education in the context of socio-economic interactions of society. The criteria for the reengineering of educational concepts and the structural organization of the educational sphere are defined. The modern world is going through a period of complete digital transformation of all spheres of public activity. The scientific intelligence notes that education is no exception in these processes, as the dependence of educational realities on information and computer technologies is now noted. The COVID-19 pandemic, for all its tragedy, was also a kind of trigger, clearly marking the new components that have become defined in the organization of the educational process. The conclusion is made that the use of digital technologies in the organization of the educational institution or in the organization of the educational process has become not an auxiliary element, but a dominant factor. Mobility, dynamism, interdisciplinarity, synergy - all these aspects are relevant for socio-economic interactions of society and should be provided by educational programs. The results of the study can be used in the reorganization processes of educational institutions and institutions. Further research requires aspects of the analysis of the foreign experience of reengineering in education, carried out taking into account digital transformations of modern sociocultural space.

A Study on the Ornaments in Western Dress History (서양 복식사에 나타난 의상장식에 관한 연구)

  • 이순홍
    • The Research Journal of the Costume Culture
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    • v.11 no.1
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    • pp.20-46
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    • 2003
  • This study analyzes the garment decorations in the history of western costume based on their kinds and techniques, and consider the beginning and the development of costume decoration. The purpose is to promote a historical understanding of modern ornamentation. Based on the theoretical background concerning the origin and purpose of costume decoration, its symbolism and its relationship with images, this study classified the techniques and kinds of ornament and considered each costumes by their decoration. 1. The ornament was originated from the primitive custom of coloring the skin for the purpose of protecting the body, symbolizing the tribe, indicating the class, and threatening the enemies. As this custom changed into the decoration on the body as a form of tattoos or physical transformations, the practice of ornament seems to begin as a display of one's authority and wealth as well as a human instinct to decorate oneself beautifully. 2. The basic purpose of ornament is to look attractive by decorating oneself with ornaments. Addition of decorative design to the garment tends to complement the practical aspects of the whole clothing, and elevate its value and originality. 3. From the past, ornament has been used as a symbol of wealth and status. Originated from the desire to display one´s authority and power and to receive respect from others, the people's interest in ornament have rising. 4. The kinds and techniques of ornament can be classified into the structural and applied decorations. The former is decorating a part of a garment, such as the neckline, cellar, cuffs, or pockets. The latter includes braids, laces and embroideries. These ornament are diverse in their details and techniques, and should consider both functional aspects of clothing and its decorative functions emphasizing the aesthetic expressions. In the above considerations, we can see that costume ornament was most splendid in the premodern times and it was the simplest in the ancient times. And we also saw the possibility that decorative techniques could be created almost limitlessly.

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Stage transformation characteristice of Li, K and Na-graphite intercalation compounds (Li, K과 Na-흑연 층간화합물의 stage 전이특성)

  • 오원춘;임창성;오근호;고영신
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.8 no.1
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    • pp.83-90
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    • 1998
  • Stage transformation characteristics of Li, K and Na-graphite deintercalation compounds (GDICs) were studied under consideration of a deintercalation mechanism of the intercalants between carbon layers. Li-graphite intercalation compounds (GICs) synthesized by a controlling temperatures and pressures have been spontaneously decomposed in the atmosphere. By X-ray differaction analysis the $d_{001}$-values of stage 1 and 2 were identified to be 3.71 and 7.06 $\AA$, respectively. After 6 weeks, the deintercalation reaction of the Li-GICs ceased and only residual compounds could be observed. K-GICs were synthesized by the modified two-bulb method resulting in structural stabilities and stage transitions. By X-ray diffraction analysis the very stable K-graphite residue compounds were observed after 10 weeks. Na-GICs with stage 1 and 2 were synthesized using the high temperature and pressure technique. The temperature dependence of a deintercalation reaction and a thermal stability of Na-GICs were discussed. The structure changes of the Na-GDICs depending on heating rates were identified by X-ray diffraction. According to the deintercalation process, the stage transformations could be attributed to irregular deintercalations of the GDICs with disordered stage.

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Social Contexts and Media-Historical Meaning of the Early 'Noraebang' Culture in Busan Focusing on the Relationship between Noraebang and Karaoke Culture in 1980s (초기 부산 노래방 문화 형성의 사회적 맥락과 매체사적 의미 1980년대 가라오케 문화와의 관계를 중심으로)

  • YOON, Sangkil;CHANG, Il
    • Korean journal of communication and information
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    • v.77
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    • pp.164-199
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    • 2016
  • This study analyzes the socio-economical contexts of Japan's Karaoke inflow in Busan of the 1980s, and examines the relationship between Karaoke culture of the 1980s and 'Noraebang' culture of the early 1990s in Busan from the perspective of the SCOT(social construction of technology) theory. By the end of 1970s, Japan's Karaoke was introduced under the contexts of structural transformations of a geisha tourism in the East Asian regions. Karaoke culture in Busan of the 1970s and 1980s has formulated social recognitions of the novelty of Noraebang culture in the 1990s, although it has done so through the ways of misunderstandings and Nationalism.

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