• Journal of the Korean Institute of Intelligent Systems
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• v.3 no.2
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• pp.18-35
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• 1993

The water level control system of the steam generator in a pressurized water reactor and its control problems are analysed. In this work the stable control strategy during the low power operation and transient states is studied. To solve the problem, a fuzzy logic control method is applied as a basic algorithm of the controller. The control algorithm is based on the operator's knowledges and the experiences of manual operation for water level control at the compact nuclear simulator set up in Korea Atomic Energy Research Institute. From a viewpoint of the system realization, the control variables and rules are established considering simpler tuning and the input-output relation. The control strategy includes the dynamic tuning method and employs a substitutional information using the bypass valve opening instead of incorrectly measured signal at the low flow rate as the fuzzy variable of the flow rate during the pressure control mode of the steam generator. It also involves the switching algorithm between the control valves to suppress the perturbation of water level. The simulation results show that both of the fine control action at the small level error and the quick response at the large level error can be obtained and that the performance of the controller is improved.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.12 no.3
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• pp.221-229
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• 1992

A series of experiments on the resuspension of deposited fine-grained sediments were carried out in a recirculating straight flume to investigate the influence of the sediment type, water content and bed shear stress (${\tau}_b$) on the resuspension characteristics of the sediments. The sediments were sampled from Youngkwang coast and Youngdo coast which are located in the western sea and southeastern sea of Korea, respectively. Critical bed shear stress (${\tau}_c$) for resuspension was deduced for each experimental series. For the same sediment, critical bed shear stress for resuspension decreased but suspension mass or rate increased with increasing water content. The resuspension of deposited fine-grained sediments depended strongly on the water content, and the sediment type characterizing the inter-particle bond strength. It has been found that critical bed shear stress for resuspension in the unidirection flow is about 4 times higher than that in the combined wave-current flow, In case of lower bed shear stress, after an initially high suspension, suspension mass approaches a constant value due to the bed hardening with increasing time, but in case of higher bed shear stress, suspension mass increased successively due to the bed softening with time. Initial suspension rate, $E={\alpha}_3({\tau}_b/{\tau}_c-1)^{\beta}$ (where ${\alpha}_3$ and ${\beta}$=empirical constants), was estimated for each experimental series, ${\alpha}_3$ and ${\beta}$ values for the same sediment increased with water content.

• Cartoon and Animation Studies
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• s.20
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• pp.47-61
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• 2010

The Uncanny Valley is a hypothesis introduced by a roboticist, Masahiro Mori. The theory holds that as robots and other facsimiles of humans look and act more human-like, the emotional response from a human spectator to them will become increasingly empathic, until they approach realistic similarity to humans but not quite exactly like them, when those images stop being likable and instead become repulsive and "uncanny." Although the scientific validity of this hypothesis is still debatable, it is true that many spectators has tendency to reject hyper-realistic animation. For that reason, the great success of the recent movie Avatar is remarkable. Computer animations that try to represent humans in hyper-realistic way fall into a paradox: successful result images would look too mundane and unsuccessful ones look "wrong". On top of that, audience would expect from hyper-realistic animation to see same level of acting of live-action films, which is usually not the case. The subtle differences between digital characters and real actors irritate spectators and hinder them in absorbtion. The biggest difference between Avatar and other hyper-realistic animation is the referent of their representation. While Avatar pursues a similar hyper-realistic visual style, the referents of the representation shown in this movie are totally alien to us thus impossible to compare with the real counterparts. Unlike characters in other hyper-realistic animations who had to fight an uphill battle with great actors in real life, those in Avatar have criteria of their own. That is why this movie can be free from the dreadful valley and let the audience absorb into the spectacle.

• Cartoon and Animation Studies
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• s.45
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• pp.367-396
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• 2016

As an animation educator at Mahidol University International College, Bangkok, for eight years I have been in a privileged position to be educating a small section of a new generation of Thai animators. Thailand has had little animation experimentation of their own and pre-internet had limited access to such diversity so I have attempted to bring some of the wealth of animation history, in particular British and European, as this is my background, into the classroom. In particular my teaching aim has been to introduce various possibilities to the choices of medium, styles and textual narratives that early (and current) experimental and independent animators have explored. Since the release of the first commercial feature film, Khun Kluay 2006, the Thai animation industry has gone through various highs and lows in the commercial sector, building a skilled workforce, many of whom trained and worked abroad then returned. Now there is strong evidence of an independent animation starting to emerge. In a continuation to my research on Thai Animation this paper will analyze selected independent works in more detail, exploring the themes, style and technology used. Whilst also acknowledging the possible mis- interpretation as that this is coming from the perspective of an outsider whose cultural language and interpretation may transcend the creators' given experiences and add alternative interpretation. The aim will be to contextualize the content, ideas and cultural perspective and bring more Thai works into the gaze of animation studies academics

• The Journal of the Korea Contents Association
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• v.19 no.11
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• pp.111-121
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• 2019

Recently, through the services that use drones at fire sites to deliver on-site and road conditions into the situation room and life-saving activities or the deliveries of first aid outfits at the accident scenes that are inaccessible to humans, there are more and more cases of dealing with emergency situations. Therefore, by studying the service design using drones in the initial stage of response to fires in dense residential areas, this study was intended to reify the service design area of the response stage, including the dispatch of fire sites and the fire suppression. To do this, through literature researches, research directions were explored by examining the concept and process review of service design, and by analyzing the application cases using service design. In order examine the validity of this study, a one-on-one interview was conducted to identify the use and problems of drones among incumbent firefighters, and identified the applicability of drones to fire sites by targeting drone experts. Field research was conducted to identify the location and distance of road conditions, site conditions, and 119 safety centers, by making Yongsan-gu, the most vulnerable area to fire in Seoul, as a research sample. And, among the methodologies of service design, Persona and Customer Journey Map were prepared and Insight was derived, by using virtual scenarios for the experience values and behavior analyses of the interested parties. Through these processes, this researcher intended to present the fire-response service design and help establish the direction of service design in the initial stages of fire in Korea.

• The Journal of Korean Orthopaedic Ultrasound Society
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• v.4 no.2
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• pp.101-110
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• 2011

To describe the background, mechanism, clinical results and complications of prolotheapy based on the literature review. Prolotherapy is a minimally invasive injection-based treatment of chronic musculoskeletal pain, including ligament and joint laxity. The mechanism of this injection-based technique is to initiate a local inflammatory response with resultant tissue healing. The used proliferants are classified by bio-mechanism to act in three different ways as osmotic, irritants, and chemotatics. The most commonly used proliferant is hyperosmolar (10~25%) dextrose to act by osmotic rupture of cells. High resolution ultrasound imaging of musculoskeletal structure provide a more accurate diagnosis. Also ultrasound-guided intervention provides a more high efficacy and low rate of complications. The most common complication is local pain at the injected site, that is self-limited and good responsive to anti-inflammatory agents. Other complications are rare. It is reported that prolotherapy appears safe when performed by an experienced clinician. Prolotherapy has grown in popularity and has received significant recent attention. However there are limited evidence-based data supporting the indication and efficacy of prolotherapy in the treatment of chronic musculoskeletal pain or soft tissue injuries. Future studies are necessary to determine whether prolotherapy can play an independent and definitive role in a treatment for chronic musculoskeletal pain.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 2008.03a
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• pp.79-88
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• 2008

Since the hydraulic fracturing field testing method was introduced first to Korean geotechnical engineers in 1994, there have been lots of progresses in a hardware system as well as an interpretation tool. The hydrofracturing system of first generation was the pipe-line type, so it was not easy to handle. It had been modified to a wire-line system at their second generation. It was more compact one but it also needed an additional air-compressor. Our current system is much more compact and operated by all-in-one system, so it doesn't need an additional air-compressor. With a progress in a hardware system, the software for analyzing the in-situ stress regime has also been progressed. For example, the shut-in pressure, which is the most ambiguous parameter to be obtained from hydrofracturing pressure curves, can now be acquired automatically from the various methods. While the hardware and software for hydrofracturing tests are being developed during the last decade, the author could accumulate the field test results which can cover the almost whole area of South Korea. Currently these field data are used widely in a feasibility study or a preliminary design step for tunnel construction in Korea. Regarding the difficulties in a site selection and a test performance for the in-situ stress measurement at an off-shore area, the in-situ stress regime obtained from the field experiences in the land area can be used indirectly for the design of a sub-sea tunnel. From the hydrofracturing stress measurements, the trend of magnitude and direction of in-situ stress field was shown identically with the geological information in Korea.

• Ecology and Resilient Infrastructure
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• v.3 no.4
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• pp.272-278
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• 2016

Porous pavements are recommended as a Low-Impact Development (LID) method which is a strategy to develop a water cycle as close to a natural state as possible, and to solve the urban impervious surface problems. Porous pavements can yield a solution if it provides a more permeable surface with extra space to contain extra water from building roofs. But there are few applications in Korea because of a lack of recognition and experience. Highway engineers are mainly concerned about the infiltration of water into pavement structures. They worry about the weakening of the asphalt mixture and subgrade, and freezing during the winter season due to the infiltration of water. Meanwhile, hydrological experts doubt the effects of the amount of water to control during the flooding season, and environmental experts prefer a non-point pollution treatment system established beside highway. In this study, from reviewing the history and the body of literature about porous pavements, conclusions regarding the most advanced technologies were made. First, traditional thickness designs can be used for porous pavement, no extra distresses was found by weakening and freezing during the winter season. Second, hydrological design can be made by controlling the thickness of the pavement and the outlet of water. Third, the treatment efficiency of non-point pollution of porous pavements is not worse than any other method. Importantly, it's a more eco-friendly solution because of its lower requirement for de-icing agents.

• Journal of the Korean School Mathematics Society
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• v.22 no.3
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• pp.329-350
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• 2019

Productive struggle is a student's persevering effort to understand mathematical concepts and solve challenging problems that are not easily solved, but the problem can lead to curiosity. Productive struggle is a key component of students' learning mathematics with a conceptual understanding, and supporting it in learning mathematics is one of the most effective mathematics teaching practices. In comparison to research on students' productive struggles, there is little research on preservice mathematics teachers' productive struggles. Thus, this study focused on the productive struggles that preservice mathematics teachers face in solving a non-routine mathematics problem. Polya's four-step problem-solving process was used to analyze the collected data. Examples of preservice teachers' productive struggles were analyzed in terms of each stage of the problem-solving process. The analysis showed that limited prior knowledge of the preservice teachers caused productive struggle in the stages of understanding, planning, and carrying out, and it had a significant influence on the problem-solving process overall. Moreover, preservice teachers' experiences of the pleasure of learning by going through productive struggle in solving problems encouraged them to support the use of productive struggle for effective mathematics learning for students, in the future. Therefore, the study's results are expected to help preservice teachers develop their professional expertise by taking the opportunity to engage in learning mathematics through productive struggle.

• Journal of Chest Surgery
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• v.30 no.12
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• pp.1184-1189
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• 1997

Tetralogy of Falloff is the most common cyanotic congenital cardiac malformation. Between April 1984 and December 1993, we experinced with 39 cases of total correction for the tetralogy of Falloff at the department of Thoracic and Cardiovascular Surgery, Masan Samsung General Hospital. The results were as follows; There were 14 males and 25 females, and their ages ranged from 2 to 36 years, with an average age of 13.33 $\pm$7.40 years. There was type I VSD in 10 cases(25.6%), type II VSD in 19 cases(48.8%) and type 1+ II VSD in 10 cases(25.6%) Types of right ventricular outflow tract obstruction were valvar + infundibular stenosis in 19 cases(48.7%), valvar + infundibular + annular stenosis in 10 cases(25.6%), infundibular stenosis in 9 cases(23.1%)and pure valvar stenosis in 1 case(2.6%). Right ventricular outflow tract patch widening was necessary in 33 cases(84.6%) and a Iransannular patch including 2 cases of Monocusp-bearing outflow patch was used in 10 cases. n 36 hospital survivors, 23 patients were evaluated by 2 dimensional and doppler echocardiography. The most common complication was arrthymia, especially complete right bundle branch block, in 30 cases (76.9%). The operative mortality was 7.7%, and the cause of death was low cardiac output syndrome.