• International Journal of Fluid Machinery and Systems
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• v.4 no.1
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• pp.179-190
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• 2011

The swirling flow developing in Francis turbine draft tube under part load operation leads to pressure fluctuations usually in the range of 0.2 to 0.4 times the runner rotational frequency resulting from the so-called vortex breakdown. For low cavitation number, the flow features a cavitation vortex rope animated with precession motion. Under given conditions, these pressure fluctuations may lead to undesirable pressure fluctuations in the entire hydraulic system and also produce active power oscillations. For the upper part load range, between 0.7 and 0.85 times the best efficiency discharge, pressure fluctuations may appear in a higher frequency range of 2 to 4 times the runner rotational speed and feature modulations with vortex rope precession. It has been pointed out that for this particular operating point, the vortex rope features elliptical cross section and is animated of a self-rotation. This paper presents an experimental investigation focusing on this peculiar phenomenon, defined as the upper part load vortex rope. The experimental investigation is carried out on a high specific speed Francis turbine scale model installed on a test rig of the EPFL Laboratory for Hydraulic Machines. The selected operating point corresponds to a discharge of 0.83 times the best efficiency discharge. Observations of the cavitation vortex carried out with high speed camera have been recorded and synchronized with pressure fluctuations measurements at the draft tube cone. First, the vortex rope self rotation frequency is evidenced and the related frequency is deduced. Then, the influence of the sigma cavitation number on vortex rope shape and pressure fluctuations is presented. The waterfall diagram of the pressure fluctuations evidences resonance effects with the hydraulic circuit. The influence of outlet bubble cavitation and air injection is also investigated for low cavitation number. The time evolution of the vortex rope volume is compared with pressure fluctuations time evolution using image processing. Finally, the influence of the Froude number on the vortex rope shape and the associated pressure fluctuations is analyzed by varying the rotational speed.

• Journal of The Korean Association For Science Education
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• v.23 no.5
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• pp.484-493
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• 2003

This case study exemplifies science classroom observation and analysis. Data from two-day classroom observation, pre- and post-instruction interviews with the teacher and instructional materials were used to analyse the features of a science classroom. A teacher's classroom practices were examined in terms of the following six categories: (1)curriculum and science content, (2)teaching and learning methods, (3) teacher' s knowledge about learners, (4)classroom environment, (5)assessment, and (6)teacher's efforts for professional development. The teacher in this case study not only improved his own classroom practices, but also took an active role in teachers' in-service education to share his practical knowledge with others. Implications that valid evaluation(or observation) frameworks of classroom practices have on teacher education and teachers' inservice education are also discussed. These evaluation frameworks should provide teachers with a vision of highly accomplished practices.

• Journal of Sensor Science and Technology
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• v.10 no.1
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• pp.52-61
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• 2001

We propose a new saccadic eye movement system with visual selective attention. Saliency map models generate the scan pathways in a natural scene, of which the output makes an attended location. Saccadic eye movement model is used for producing the target trajectories to move the attended locations very rapidly. To categorize human saccadic eye movement, saccadic eye movement model was divided into three parts, each of which was then individually modeled using different neural networks to reflect a principal functionality of brain structures related with the saccadic eye movement in our brain. Based on the proposed saliency map models and the saccadic eye movement model, an active vision system using a CCD type camera and BLDC motor was developed and demonstrated with experimental results.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.2
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• pp.477-483
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• 2004

This paper describes preliminary results we have obtained in developing a computer vision system based on active IR illumination for real time gaze tracking for interactive graphic display. Unlike most of the existing gaze tracking techniques, which often require assuming a static head to work well and require a cumbersome calibration process for each person our gaze tracker can perform robust and accurate gaze estimation without calibration and under rather significant head movement. This is made possible by a new gaze calibration procedure that identifies the mapping from pupil parameters to screen coordinates using the Generalized Regression Neural Networks(GRNN). With GRNN, the mapping does not have to be an analytical function and head movement is explicitly accounted for by the gaze mapping function. Futhermore, the mapping function can generalize to other individuals not used in the training. The effectiveness of our gaze tracker is demonstrated by preliminary experiments that involve gaze-contingent interactive graphic display.

• Archives of Plastic Surgery
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• v.37 no.6
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• pp.795-800
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• 2010

Purpose: According to various medical publications, it is believed that epinephrine should not be injected in fingers. However numerous articles show the successful use of local anesthetic with epinephrine in the digits. Epinephrine-mixed lidocaine solution enables to maintain a bloodless field for operation and provides long duration of local anesthesia when patient was wide awake. Methods: From May 2009 to December 2009, ten patients underwent flexor tendon reconstruction with local anesthesia using epinephrine. No tourniquet was necessary. Before operation, all patients were injected with local anesthetics using 1% lidocaine 20 mL and 0.1% epinephrine 0.1 mL. Results: There was no case of digital necrosis nor gangrene in the epinephrine injection. All 10 patients actively could move the finger through a full range of motion. All procedures were performed without sedation nor tourniquet and we could obtain a good vision of operative field and patients were comfortable. The patient make his or her fingers move through a full range of active motion before the skin is closed. Phentolamine was not required to reverse the vasoconstriction in any patients. Conclusion: The assertation that epinephrine should not be injected into the fingers is clearly no longer valid. The epinephrine injection allowed the authors to adjust flexor tendon surgery without risks associated with general anesthesia. It also enables to ensure longer anesthetic duration and bloodless operative field, and prevent post operative complications. In case of flexor tendon surgery, the use of epinephrine injection is recommended because of the advantages of local anesthesia.

• English & American cultural studies
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• v.18 no.2
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• pp.27-50
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• 2018

Old age is often compared as climbing mountains which requires walking out of breath, yet with wider vision. And it is also likened to the estuary where the river flows slowly and broadly into the open sea. Socially, old age has been regarded as a symbol of wisdom and reflection, and elderly people often take the role of sage who leads the community. On the other hand, the dementia, gray hair and wrinkles of old age were sometimes perceived as the decline of intellect and vitality. Especially, in the digital age in which technology makes people more sensitive to physical artificiality, the evaluation of the old age becomes more complex and obscure. In other words, some elderly people can not escape from Confucious convention of the elders first, which causes the denouncement by younger generations. On the other hand, some elderly people are becoming more adaptable to the trend of young people, emerging as the new elderly people. The anti-aging movement, early adaptation of IT, bioengineering regimen also strong for the advanced age. However, as the new elderly people are active in many fields of society, they also face intergenerational conflicts in some areas where remains the overlap between young people and them due to the limited openings in economy and culture. This study is a transdisciplinary research which can be called old age humanities. First of all, this paper looks at the aspects of lifestyles and intergeneration conflicts in old age in four Korean and Western literary works about the old people, and also searches how to improve the quality of the later life of old people, Overall, this paper aims to explore the way the old people can achieve the full life with the help of intergenerational dependency through building aging humanities and new communities for old people.

• English & American cultural studies
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• v.14 no.1
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• pp.73-94
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• 2014

Accounts from therapeutic culture seem often to associate the selfish, or at least self-centered quest for self-fulfillment with individual choice or satisfaction, self-expression, expressive individualism, and emotionalism. These associations point to the downside of therapy as they present it as constituting a culture of narcissism, selfishness, or irresponsibility. While some of these characterizations contain useful insights, they overlook what are maybe some of the most important features of a therapeutic outlook. This paper aims to reveal that the therapeutic imperative is not so much geared towards the realization of self-fulfillment, as it is the promotion of self-limitation. Therapeutic culture tends to posit the self in a fragile and feeble form and insist that the management of life requires the continuous intervention of therapeutic expertise. Because of this, the elevated concern with the self is underpinned by anxiety, pain, suffering, and survival, rather than seen as a positive vision of realizing the human potential. Therapeutic culture has in this way helped to construct a diminished sense of self by which one is seen as suffering from an emotional deficit and vulnerability. This paper demonstrates this downside of therapeutic culture concerning self-limitation and the sense of a diminished self by examining popular "misery memoirs." Misery memoirs are widely consumed by the general public, therefore tend to be treated by contemporary therapeutic culture as a gospel on the therapeutic ideal for self-fulfillment and self-discovery. This is, despite the existence of hidden evidence to the contrary, because of their redemptive, happy endings that show individuals overcoming difficult trials such as child abuse, incestuous rape, and domestic violence. Individual self-fulfillment and self-discovery in such stories are not achieved through the active agency of the subject but through the passive endurance of pathological symptoms and with the aid of expertise and outside support. Therefore, such stories put victims in the limited position.

• The Journal of the Convergence on Culture Technology
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• v.7 no.2
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• pp.359-366
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• 2021

It's been more than 30 years since global warming by the increase in CO2 became a cause celebre worldwide. Recently the government promulgated Framework Act on on Low-Carbon Green Growth and has been continuously putting much effort into saving energy and reducing carbon dioxide emissions such as an international climate change conference to prevent the increase in CO2. However, because most cities are not planned for energy saving, new cities should be planned as the active energy-efficient urban structure for 'sustainable urban development' from a long-term perspective. This study aims to design a new prototype for the sustainable energy-independent and environment-friendly housing estates which is the nation's new vision in the era of the Fourth Industrial Revolution. A study on the energy-independent site planning and the quantitative standardization of its factor will be conducted.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.4
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• pp.81-87
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• 2021

Artificial intelligence technology is developing as it enters the fourth industrial revolution. Active researches are going on; visual-based models using CNNs. U-net is one of the visual-based models. It has shown strong performance for semantic segmentation. Although various U-net studies have been conducted, studies on tracking objects with unclear outlines such as gases and smokes are still insufficient. We conducted a U-net study to tackle this limitation. In this paper, we describe how 3D cameras are used to collect data. The data are organized into learning and test sets. This paper also describes how U-net is applied and how the results is validated.

• Journal of The Korean Association For Science Education
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• v.42 no.2
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• pp.177-184
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• 2022

This article aims to explain the concept and characteristics of the 'Intelligent Science Lab', which is being promoted nationwide in Korea since 2021. The Korean Ministry of Education creates a master plan containing a vision for science education every five years. The most recently announced '4th Master plan for science education (2020-2024)' emphasizes the policy of setting up an 'intelligent science lab' in all elementary and secondary schools as an online and offline space for scientific inquiry using advanced technologies, such as Internet of Things and Augmented and Virtual Reality. The 'Intelligent Science Lab' project is being pursued in two main directions: (1) developing an online platform named 'Intelligent Science Lab-ON' that supports science inquiry classes, and (2) building a science lab space in schools that encourages active student participation while utilizing the online platform. This article presents the key features of the 'Intelligent Science Lab-ON' and the characteristics of intelligent science lab spaces newly built in schools. Furthermore, it introduces inquiry-based science learning programs developed for intelligent science labs. These programs include scientific inquiry activities in which students generate and collect data ('data generation' type), utilize datasets provided by the online platform ('data utilization' type), or utilize open and public data sources ('open data source' type). The Intelligent Science Lab project is expected to not only encourage students to engage in scientific inquiry that solves individual and social problems based on real data, but also contribute to presenting a model of online and offline linked scientific inquiry lessons required in the post-COVID-19 era.