• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2001.05a
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• pp.45-52
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• 2001

The study on the heat exchanger with catalytic combustion was performed as the development of the catalytic combustion applications. This study tried to achieve the both goals-the mixture preheating and the heat transfer to working fluid simultaneously by using the steady state catalytic combustion. The combustion characteristics were investigated with the quantitative, qualitative experimental variants of the mixture. In addition, the temperature distribution of catalytic layer was investigated to investigate the correlation between the combustion characteristics and the heat balance of the catalytic layer. As a result, the steady state reaction within the appropriate range of temperature is the critical factor in catalytic applications. To get this, the sensible control of both the mixture flow and the heat balance of catalytic layer were required.

• Particle and aerosol research
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• v.5 no.3
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• pp.123-131
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• 2009

This paper presents simulation results of particle transport in low-pressure, low-temperature plasma environment. The size dependent transport of particles in the plasma is investigated with a two-dimensional simulation tool developed in-house for plasma chamber analysis and design. The plasma model consists of the first two and three moments of the Boltzmann equation for ion and electron fluids respectively, coupled to Poisson's equation for the self-consistent electric field. The particle transport model takes into account all important factors, such as gravitational, electrostatic, ion drag, neutral drag and Brownian forces, affecting the motion of particles in the plasma environment. The particle transport model coupled with both neutral fluid and plasma models is simulated through a Lagrangian approach tracking the individual trajectory of each particle by taking a force balance on the particle. The size dependant trap locations of particles ranging from a few nm to a few ${\mu}m$ are identified in both electropositive and electronegative plasmas. The simulation results show that particles are trapped at locations where the forces acting on them balance. While fine particles tend to be trapped in the bulk, large particles accumulate near bottom sheath boundaries and around material interfaces, such as wafer and electrode edges where a sudden change in electric field occurs. Overall, small particles form a "dome" shape around the center of the plasma reactor and are also trapped in a "ring" near the radial sheath boundaries, while larger particles accumulate only in the "ring". These simulation results are qualitatively in good agreement with experimental observation.

• Perspectives in Nursing Science
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• v.9 no.1
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• pp.1-8
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• 2012

Purpose: The purpose of this study was to compare variables related to weight control between normal weight and overweight/obese female adolescents. Methods: This study is a supplementary analysis using a total of 293 female adolescents in Seoul. Data were collected through self-report questionnaires on the topics of stages of change, processes of change, and the decisional balance pertaining to weight control. Body weight and height were also measured. Results: There was a significant difference in the stages of change between the normal weight and overweight/obese groups. Of 12 processes of change, 9 processes were significantly higher in the overweight/obese group than in the normal weight groups. Also, female adolescents who were overweight or obese had significantly higher pros and eating efficacy scores comparing to those in the normal weight group. Conclusion: The findings of this study suggest that overweight/obese female adolescents, especially those in the action stage need supports to continue their weight control behaviors. In addition, a weight control program for female adolescents should emphasize their participation in physical activities in addition to their dietary control efforts.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.25 no.1
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• pp.50-63
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• 2016

Successful treatment in the anterior esthetic prosthetic can be a balance between aesthetics in the facial, tooth, and periodontal tissue in the oral. In the case of facial symmetry of patients with normal occlusal plane, If you establish criteria of finding balance of aesthetics such as a several books and articles and manufacture a prostheses by the established-criteria, you can manufacture a harmonious and aesthetic prostheses without any trouble. However, in the case of patients with facial asymmetry, if you manufacture a tooth as patient's facial aesthetic symmetry by force even facial asymmetry case, you can't get a result not only aesthetic but also functional prostheses. Also, to produce the prosthetic of harmonious and aesthetic with periodontal tissue, and excellent self-cleansing function, you must apply to the form of the prosthetic changed dental environment.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.59-62
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• 2005

Small force measurements ranging from 1 pN to $100{\mu}N$, we call it Nano Force, become the questions of common interests of biomechanics, nanomechanics, material researches, and so on. However, unfortunately, quantitative and accurate force measurements have not been taken so far. This is because there ,are no traceable force standards and a calibration scheme. This paper introduces a quantitative force metrology, which provides traceable link to SI (International Systems of Units). We realize SI traceable force ranging from 1 nN to $100{\mu}N$ using an electrostatic balance and disseminate it through transfer standards, which are self-sensing cantilevers that have integrated piezoresistive strain gages. We have been built a prototype electrostatic balance and Nano Force Calibrator (NFC), which is an AFM cantilever calibration system. As a first experiment, we calibrated normal spring constants of commercial AFM cantilevers using NFC. Calibration results show that the spring constants of them are quite differ from each other and nominal values provided by a manufacturer (up to 240% deviation).

• Nuclear Engineering and Technology
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• v.40 no.1
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• pp.87-92
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• 2008

Tokamak reactor system analysis code was developed at KAERI (Korea Atomic Energy Research Institute) and is used here for the conceptual development of a DEMO reactor. In the system analysis code, prospects of the development of plasma physics and the relevant technology are included in a simple mathematical model, i.e., the overall plant power balance equation and the plasma power balance equation. This system analysis code provides satisfactory results for developing the concept of a DEMO reactor and for identifying the necessary R&D areas, both in the physics and technology areas for the realization of the concept. With this system analysis code, the performance of a DEMO reactor with a limited extension of the plasma physics and technology adopted in the ITER design. The main requirements for the DEMO reactor were selected as: 1) demonstrate tritium self-sufficiency, 2) generate net electricity, and 3) achieve a steady-state operation. It was shown that to access an operational region for higher performance, the main restrictions are presented by the divertor heat load and the steady-state operation requirements.

• Journal of Power Electronics
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• v.19 no.1
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• pp.68-78
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• 2019

The emergence of high voltage conversion applications has resulted in a trend of using semiconductor device series associations. Series associations allow for operation at blocking voltages, which are higher than the nominal voltage for each of the semiconductor devices. The main challenge with these topologies is finding a way to guarantee the voltage balance between devices in both blocking and switching transients. Most of the methods that have been proposed to mitigate static and dynamic voltage unbalances result in increased losses within the device. This paper introduces a new series stack topology, where the voltage unbalances are reduced. This in turn, mitigates the switching losses. The proposed topology consists of a circuit that ensures the soft switching of each device, and one auxiliary circuit that allows for switching energy recovery. The principle for the topology operation is presented and experimental tests are performed for two modules. The topology performs excellently for switching transients on each of the devices. The voltage static unbalances were limited to 10%, while the activation/deactivation delay introduced by the lower module IGBT driver takes place in the dynamic unbalances. Thus, the switching losses are reduced by 40%, when compared to hard switching configurations.

• Journal of Fashion Business
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• v.28 no.1
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• pp.83-97
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• 2024

A plantar pressure mat with visual notifications was developed to confirm whether individuals can effectively balance themselves and correct imbalances. The sensor-embedded mat was made with a commercial yoga mat, and was tested on seven working women in their 30s to determine plantar pressure distribution when standing and squatting, and if they could recognize and correct imbalances with visual feedback. The study found that visual notifications significantly changed the plantar pressure ratio of the forefoot and hindfoot, as well as the left and right foot plantar pressure ratio. Without notifications, the center of gravity was more concentrated in the rear foot than the forefoot in both standing and squatting positions. Visual notifications showed that the center of gravity, which was largely focused on the rear foot, was distributed to the forefoot, resulting in a more evenly distributed center of gravity throughout the sole. For the change in left and right plantar pressure, the weight that was largely loaded on the left side was distributed to the right foot through the visual notification mat, confirming a more balanced plantar pressure.

• Journal of Society of Preventive Korean Medicine
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• v.24 no.1
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• pp.15-25
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• 2020

Objective : The purpose of this study was to analyze the frequency and contents of each 'Yangseng(養生)' category appeared in 『The Annals of Joseon Dynasty』, based on the Yangseng-related terms used in the records. Method : We selected 11 terms with the same meaning as 'Yangseng(養生)' and searched each of them on the website of the Annals of Joseon Dynasty online search service. Among the total of 679 records, 343 were classified into five categories: 'Mind Yangseng(精神養生)', 'Food Yangseng(飮食養生)', 'Doin-angyo(導引按蹻)', 'Lifestyle Yangseng(生活養生)', and 'Herb Yangseng(藥草養生)'. The contents and characteristics of each Yangseng category appeared in the 『The Annals of Joseon Dynasty』 were studied. Results : The term 'Jo-seop(調攝)' was most frequently used in the same meaning as Yangseng(養生), followed by 'Jo-ri(調理)', 'Jo-ho(調護)', 'Jo-yang(調養)', and 'Seop-yang(攝養)'. The frequency of records categorized into specific Yangseng methods(養生法) was in the order of 'Lifestyle Yangseng', 'Mind Yangseng', 'Food Yangseng', 'Herb Yangseng' and 'Doin-angyo(導引按蹻)'. The contents of 'Mind Yangseng' included 'control of emotions and thoughts', 'control of self-interest', 'emphasis on the cultivation of mind', and 'avoidance of stress'. The contents of 'Food Yangseng' were related to the amount of food intake and types of food. The contents of 'Lifestyle Yangseng' were related to 'work-rest balance(勞逸)', 'seasons(季節)', 'residence(居處)', 'bath(沐浴)', 'sexual life', 'sleep', and 'clothing'. The frequency of 'work-rest balance(勞逸)' was among the highest. Conclusion : Emphasis on mental health and work-rest balance appeared in 『The Annals of the Joseon Dynasty』 can have significant implications on people of today.

• Journal of the Korean Society of Physical Medicine
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• v.12 no.4
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• pp.73-82
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• 2017

PURPOSE: Proprioceptive Neuromuscular Facilitation (PNF) has been shown to improve body function and activity/participation in people with functional dysfunctions. This study evaluates if active exercise using theraband in PNF pattern may induce similar benefits as exercise using manual PNF pattern performed by physiotherapists on promoting mobility, balance and fear of fall in community-dwelling elderly. METHODS: Twenty-three community-dwelling elderly with independent activities of daily living were recruited and randomly allocated into either PNF group - exercise in PNF pattern by trained physiotherapists or Theraband-PNF (T-PNF) group - exercise using theraband in PNF pattern, for an hour, twice weekly for 4 weeks. Functional outcomes such as Timed Up and Go test, Elderly Mobility Scale, Berg balance scale, functional reach and subjective measures including fear of fall (FOF) scale, bodily pain in visual analogue scale were measured pre and post-program. RESULTS: Twenty-one participants completed the program. PNF group demonstrated significant within-group improvements in all subjective measures and objective measures. Similar within-group improvements were demonstrated in all outcome measures except FOFS in T-PNF group. However, no between-group differences were found in any of the outcome measures. CONCLUSION: Comparable improvements in functional outcomes in community dwelling elderly were demonstrated in both groups. As manual PNF exercise traditionally need clinicians' contact and feedback on patient which limit the training to be carried out extensively in community setting. The current findings suggest that exercise using theraband in PNF pattern is feasible to be adopted as self-practice exercise for community-dwelling elderly to induce beneficial effects on functional outcomes.