• Journal of Electrical Engineering and Technology
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• 제2권1호
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• pp.19-28
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• 2007

The paper discussed various techniques for islanding detection and described in detail the working principles of ROCOF and vector shift relays. A simulator was used to investigate why the stability of both types of relays maybe affected by network and load switching, short-circuit faults and in the case of a ROCOF relay the loss of bulk generation or the tripping of a transmission feeder. Finally, to enhance the reliability of Loss of Mains protection, a new islanding detection technique based on a GPS synchronized phasor measurement system was proposed.

• 영어영문학
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• 제64권4호
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• pp.531-550
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• 2018

This paper contemplates egalitarian ethics and ecumenical consumerism suggesting expansive possibilities of Northern Ireland's sectarian limits towards unlimited spatialities in Robert McLiam Wilson's Belfast novel, Eureka Street. This paper argues that Northern Ireland's (Belfast's) (post)modernity and a social ethics promoting outwardly mediated relationships are a vision for nonidentity Eureka Street espouses against the identity politics of Protestant-Catholic schism. Eureka Street remarkably challenges Northern Irish sectarian politics propelling inwardly unmediated relationships by ethical possibilities of infinitively mediated relationships. In the argument for a postmodern view of the novel, commodity fetishism and consumerism are considered as key to a prospect of emancipation of Northern Ireland from the political fetters of total identity the partisan communities impose on themselves. This paper also demonstrates that a post-national cosmopolitanism Eureka Street envisages embraces a new social solidarity predicated upon socio-political pluralisms against Northern Irish sectarian identities.

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 2000년도 춘계수산관련학회 공동학술대회발표요지집
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• pp.383-384
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• 2000

Most of the photoperiodic responses result in a sharp contrast between development in long and short days, so that qualitative observations are quite sufficient to establish that development is under photoperiodic control, and qualitative information of this type is all that is available for many of the responses (Dring 1984). However, we need to devise some quantitative measurement of the response in order to study the physiological mechanism of photoperiodic control. We report here the quantification of photoperiodic control of erect thalli production of Sargassum muticum in different daylength regimes. (omitted)

• Animal Bioscience
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• 제37권2_spc호
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• pp.337-345
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• 2024

Ruminants possess a specialized four-compartment forestomach, consisting of the reticulum, rumen, omasum, and abomasum. The rumen, the primary fermentative chamber, harbours a dynamic ecosystem comprising bacteria, protozoa, fungi, archaea, and bacteriophages. These microorganisms engage in diverse ecological interactions within the rumen microbiome, primarily benefiting the host animal by deriving energy from plant material breakdown. These interactions encompass symbiosis, such as mutualism and commensalism, as well as parasitism, predation, and competition. These ecological interactions are dependent on many factors, including the production of diverse molecules, such as those involved in quorum sensing (QS). QS is a density-dependent signalling mechanism involving the release of autoinducer (AIs) compounds, when cell density increases AIs bind to receptors causing the altered expression of certain genes. These AIs are classified as mainly being N-acyl-homoserine lactones (AHL; commonly used by Gram-negative bacteria) or autoinducer-2 based systems (AI-2; used by Gram-positive and Gram-negative bacteria); although other less common AI systems exist. Most of our understanding of QS at a gene-level comes from pure culture in vitro studies using bacterial pathogens, with much being unknown on a commensal bacterial and ecosystem level, especially in the context of the rumen microbiome. A small number of studies have explored QS in the rumen using 'omic' technologies, revealing a prevalence of AI-2 QS systems among rumen bacteria. Nevertheless, the implications of these signalling systems on gene regulation, rumen ecology, and ruminant characteristics are largely uncharted territory. Metatranscriptome data tracking the colonization of perennial ryegrass by rumen microbes suggest that these chemicals may influence transitions in bacterial diversity during colonization. The likelihood of undiscovered chemicals within the rumen microbial arsenal is high, with the identified chemicals representing only the tip of the iceberg. A comprehensive grasp of rumen microbial chemical signalling is crucial for addressing the challenges of food security and climate targets.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.1730-1735
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• 2003

The plume-induced shock wave is a complex phenomenon, consisting of plume-induced boundary layer separation, separated shear layer, multiple shock waves, and their interactions. The knowledge base of plume interference effect on powered missiles and flight vehicles is not yet adequate to get an overall insight of the flow physics. Computational studies are performed to better understand the flow physics of the plume-induced shock and separation particularly at high plume to exit pressure ratio. Test model configurations are a simplified missile model and two rounded and porous afterbodies to simulate moderately and highly underexpanded exhaust plumes at the transonic/supersonic speeds. The result shows that the rounded afterbody and porous wall attached at the missile base can alleviate the plume-induced shock wave phenomenon, and improve the control of the missile body.

• 한국디자인학회:학술대회논문집
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• 한국디자인학회 2001년도 Bulletin of The 5th Asian Design Conference International Symposium on Design Science
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• pp.20.2-20
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• 2001

• Asian Pacific Journal of Cancer Prevention
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• 제16권15호
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• pp.6557-6559
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• 2015

Background: Cervical human papillomavirus (HPV) infection among young women (20-25 years of age) is common and normally transient. There are growing concerns that referral to a colposcopy clinic may lead to unnecessary treatment with an increased risk of obstetric complications. Therefore, the purpose of this study was to determine the level of intervention for cervical abnormalities in this age group of the Northern Ireland population. Materials and Methods: A review of all serial new patients under 25 years of age, who were referred to colposcopy clinics in Northern Ireland between January 1, 2009 to June 30, 2009 formed the basis of this study. Results: During the study period, a total of 4,767 women under 25 years of age were screened. Two-hundred-and-thirty-four (4.9%) cases were referred to the colposcopy clinics. The cervical cytology results were: high-grade abnormality in 35%, and low-grade abnormality in 31% of these cases. One-hundred-and-seventy-eight (76%) of the referred women received at least one treatment. One-hundred-and-twenty-one of 234 (51.5%) women underwent an excisional treatment with histology showing the presence of high-grade abnormalities (CIN2-3) in 52%, CIN1 in 28%, and Koilocytosis or normal tissue in 20% of this sub-group of cases. Conclusions: Screening women under the age of 25 years cause unnecessary referral for colposcopy. This may also result in considerable anxiety and psychosexual morbidity. It leads to an over-treatment with a potential of negative impact on the future pregnancy outcomes (including pre-term delivery, low birth weight, and pre-term premature rupture of membranes).

• BMB Reports
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• 제41권3호
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• pp.223-229
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• 2008

Reactive oxygen species (ROS) are implicated in vascular homeostasis. This study investigated whether ${O_2}^{\cdot^-}$, the foundation molecule of all ROS, regulates vasomotor function. Hence, vascular reactivity was measured using rat thoracic aortas exposed to an ${O_2}^{\cdot^-}$ generator (pyrogallol) which dose-dependently regulated both $\alpha$-adrenergic agonist-mediated contractility to phenylephrine and endothelium-dependent relaxations to acetylcholine. Pyrogallol improved and attenuated responses to acetylcholine at its lower (10 nM - 1 ${\mu}M$) and higher (10 - 100 ${\mu}M$) concentrations, respectively while producing the inverse effects with phenylephrine. The endothelial inactivation by L-NAME abolished acetylcholine-induced vasodilatations but increased phenylephrine and KCl-induced vasoconstrictions regardless of the pyrogallol dose used. Relaxant responses to sodium nitroprusside, a nitric oxide donor, were not affected by pyrogallol. Other ROS i.e. peroxynitrite and $H_2O_2$ that may be produced during experiments did not alter vascular functions. These findings suggest that the nature of ${O_2}^{\cdot^-}$-evoked vascular function is determined by its local concentration and the presence of a functional endothelium.

• Steel and Composite Structures
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• 제15권5호
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• pp.519-538
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• 2013

The design optimization of a cold-formed steel portal frame building is considered in this paper. The proposed genetic algorithm (GA) optimizer considers both topology (i.e., frame spacing and pitch) and cross-sectional sizes of the main structural members as the decision variables. Previous GAs in the literature were characterized by poor convergence, including slow progress, that usually results in excessive computation times and/or frequent failure to achieve an optimal or near-optimal solution. This is the main issue addressed in this paper. In an effort to improve the performance of the conventional GA, a niching strategy is presented that is shown to be an effective means of enhancing the dissimilarity of the solutions in each generation of the GA. Thus, population diversity is maintained and premature convergence is reduced significantly. Through benchmark examples, it is shown that the efficient GA proposed generates optimal solutions more consistently. A parametric study was carried out, and the results included. They show significant variation in the optimal topology in terms of pitch and frame spacing for a range of typical column heights. They also show that the optimized design achieved large savings based on the cost of the main structural elements; the inclusion of knee braces at the eaves yield further savings in cost, that are significant.

• Steel and Composite Structures
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• 제28권6호
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• pp.709-718
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• 2018

Masonry walls are sometimes removed in buildings to either make new passages or increase the usable space. This may change the loading paths in the structure, and require new beams to transfer the loads which are carried by the masonry walls that are to be removed. One possible method of creating such new beams is to attach steel plates onto part of the existing walls to form a steel plate-masonry composite (SPMC) beam, leading to a new structure with part of the masonry wall supported by a new SPMC beam. This paper presents an experimental investigation into the interaction between the SPMC beam and the masonry wall above. Five SPMC beams supporting a masonry wall were tested to study the influence of parameters including the height-to-span ratio of the masonry wall, height of the beam and thickness of the steel plates. The test results, including failure mode, load-carrying capacity, load-deflection curves and strain distribution, are presented and discussed. It is found that for developing better arching effect in the masonry wall the ratio of the in-plane flexural stiffness of the masonry wall to the flexural stiffness of the SPMC beam must be between 2.8 and 7.1.