• Nuclear Engineering and Technology
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• v.49 no.4
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• pp.787-791
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• 2017

Americium-beryllium (Am-Be; n, ${\gamma}$) is a neutron emitting source used in various research fields such as chemistry, physics, geology, archaeology, medicine, and environmental monitoring, as well as in the forensic sciences. It is a mobile source of neutron activity (20 Ci), yielding a small thermal neutron flux that is water moderated. The aim of this study is to develop a model to increase the neutron thermal flux of a source such as Am-Be. This study achieved multiple advantageous results: primarily, it will help us perform neutron activation analysis. Next, it will give us the opportunity to produce radio-elements with short half-lives. Am-Be single and multisource (5 sources) experiments were performed within an irradiation facility with a paraffin moderator. The resulting models mainly increase the thermal neutron flux compared to the traditional method with water moderator.

• Journal of the Korea Society for Simulation
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• v.20 no.3
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• pp.29-39
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• 2011

The appointment system is widely used to facilitate customer access to service in many industries including healthcare and others. Because of its importance, much research has investigated how to build an effective appointment policy under various environments. However, most research has considered a single-server service system. The objective of this work is to evaluate several appointment policies in a two-stage service system in which multiple servers are available and build separate appointments at the second-stage. In such a system, we propose and evaluate the staggering appointment policy. Simulation experiments indicate that the proposed staggering appointment policy outperforms other traditional appointment policies in terms of customer waiting time, server idle time, and the number of customers who are later to scheduled appointments.

• Archives of Pharmacal Research
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• v.25 no.2
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• pp.158-164
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• 2002

In the course of searching immunomodulators from natural sources, the protein-bound polysaccharide, CM-Ala, has been isolated from the water extract of Chelidonium majus L. (Papaveraceae). The immunostimulatory characteristics have been investigated in several experiments such as generation of activated killer (AK) cells, proliferation of splenocytes, activation of macrophages and granulocyte macrophage-colony forming cell (GM-CFC) assay. Of the fractions obtained using Sephacryl S200 column chromatography, CM-Ala was the most effective fraction that augmented the cytotoxicity against Yac-1 tumor cells from 0.88% to 34.18% by culturing with splenocytes for 5 days. CM-Ala also enhanced nitric oxide production by two fold in peritoneal macrophages and exhibited antitumor activity. It showed mitogenic activity on both spleen cells and bone marrow cells. CM-Ala induced proliferation of splenocytes by 84 fold and increased GM-CFC numbers by 1.48 fold over than the non-treated. On the contrary, CM-Ala had cytotoxic activity to a diverse group of tumor cells. From the above results, we proposed that CM-Ala has a possibility of an effective antitumor immunostimulator.

• KSBB Journal
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• v.30 no.1
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• pp.33-37
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• 2015

Recently, several health benefits of rice wine, makgeolli, were known due to the interest on the traditional Korean liquor and the researches on the rice wine are increasing. Organic acids produced during the process of rice wine fermentation play important roles in the taste and flavor. In this study, we have examined the optimal conditions for lactic acid production in rice koji as a carbon source. Skim milk was also used as a supplementary ingredient for the optimization of lactic acid fermentation. Bacterial growth of Lactobacillus sakei was monitored under this condition. The pH, acidity of the culture and the ethanol tolerance of this bacterium were also tested. Through these experiments, we were able to optimize the growth condition of lactic acid bacteria by the addition of skim milk. This was also able to affect the change of pH, acidity, sugar concentration and alcohol tolerance, which might contribute to the improvement of the quality of rice wine. The optimal condition for the growth was 2 days with 10% (w/v) of skim milk concentration. With these results, it was confirmed that rice koji was an effective carbon source for the growth of lactic acid bacteria.

• Proceedings of the KIEE Conference
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• 2001.10a
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• pp.196-199
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• 2001

This paper deals with current harmonics and unbalanced source voltages compensation using combined filter system. Filter system consists of a series active filter and parallel passive filters. Passive filters were a traditional method to compensate current harmonics, so those were installed in power system widely. The active filter can be a substitution to improve filtering characteristics and complement drawbacks of the passive filter. The combined system of the active power filter and passive filter can has a better compensation performances and economical goods. The series type active power filter injects compensation voltage into power system by transformers. It's compensation principle is able to applicate for voltage compensation. A new control algorithm for series active filter to compensate current harmonics and unbalanced source voltages is proposed. In the proposed algorithm, a compensation voltage for harmonic reduction is calculated directly by instantaneous reactive power theory, and a compensation voltage for unbalanced source voltage is calculated in based on a synchronous reference frame. By experiments, we show validity of proposed compensation method.

• Journal of The Korea Institute of Healthcare Architecture
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• v.15 no.2
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• pp.59-66
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• 2009

The purpose of this study is to define the concept of sustainability, to understand the traditional belief system, to comprehend user-focused healing environment, to understand the current status of Korean Hospitals, to analyze the selected case studies, and to point the way toward enhanced architectural solutions for healing environment in hospitals. The research results indicate that the design of healthcare facilities with healing effects depend on the considerations of 5 senses of patients. In other words, the sustainable design approach to create a healthy healing environment is very important, and architects must be aware of diverse sensory needs of the patients. In addition, the following factors affection healthcare facilities must be considered to create healing environment for users: - "Emphasis on sustainable Design" for harmony among nature, man, and building. - Creation of user Focused Healing Environment reflecting the suers' senses. - Search for New Hospital Forms through various design experiments to create the most suitable healing environment. - "Perception of Paradigm Shift" form a focus on sickness-oriented to wellness-oriented healthcare facility design. - "Awareness of Creating User-Friendly Environment" covering the entire age group form youth to elderly.

• Korean Institute of Interior Design Journal
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• no.29
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• pp.77-85
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• 2001

The change of society causes the change of art necessarily. The experiments of plastic art which as been done by avant-garde movements at early 20th century have pursued ″Object drama″ consistently as trials of more or less abstract drama. As these plastic arts have used genre or media like circuses, sports, variate, films, screen play, newspapers and a quick method which had not been considered suitable for conventional aesthetic plastic arts, these arts looked provocative and, these provocative plastic arts have ignored universality shown in conventional arts and have caused extreme ″sensation″ accordingly. As a result, abstract art based on style which is against aestheticism and naturalism has been generalized. This style does not deny customary laws of art wholly but it requires new concept. Having ignored traditional styles, a new compositive and responsive way of composition which does not deviate from tradition has been pursued. A new and general understanding of arts which do not deny all conventionally-effective standards extremely has been developed. In this regard, this study analyzes characteristics of Bauhaus Theater which has tried to apply new technology engineering to plastic art as an integrated concept of art and technology amongst the directions of development of provocation, innovation and revolution in case of the plastic art of stage painting, and analyzes how this influences on modern painting in terms of avant-garde arts reviewing the meaning of this theory.

• Journal of Electrical Engineering and Technology
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• v.7 no.6
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• pp.905-910
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• 2012

This paper reports an investigation of pulse width modulation (PWM) techniques for twophase brushless DC (BLDC) motors fed by a two-phase eight-switch inverter in a fan application. The three-phase BLDC motor is widely applied in industry; however, a lower-cost two-phase BLDC motor and drive circuit has been greatly in demand in recent years. In this paper, we introduce a mathematical model of the two-phase BLDC motor with sinusoidal back electromotive forces (EMFs) based on traditional three-phase BLDC motors. To simplify the drive algorithm and speed up its application, we analyze the principle of block commutation for a two-phase BLDC motor drive in the 180-electricaldegree conduction mode, and we further propose five PWM schemes to improve the commutation performance of the two-phase BLDC drive. The effectiveness of the proposed PWM methods is verified through experiments.

• Journal of the Korean Society of Safety
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• v.8 no.1
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• pp.29-34
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• 1993

Two major hazardous gases. SOx and NOx. are emissioned from fossile fuels. SOx has been removed when oil is refined but NOx hasn't. So NOx is very serious problem in air pollution now There are several technologies to remove NOx. e.g. cooling method. scrubbers method. combustion method, polymer membrane method and adsorbent methods. Polymer membrane and adsorbent methods have good economic merit in removal systems of low content hazard gases. Traditional absorbents are porous silicas, aluminas. active carbon and zeolites. But these absorbents act only physisorption which has less removal performance than chemisorption. In this study. polymeric absorbent which has chemisorption as well as physisorption was analyzed about chemical structure and experimented about optimum operation conditions. The results showed that the chemical structure of the polymeric absorbent was expected as polystyrene having -N-CH$_2$COOH absorbent was revealed about 310$m^2$/g. The molar ratio of absored NO to charged NO in absorption experiments was shown 60% of the polymeric absorbent and 45% of zeolite absorbent at 3$0^{\circ}C$.

• Journal of the Institute of Convergence Signal Processing
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• v.5 no.3
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• pp.173-180
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• 2004

In this paper we provide a new image restoration method based on the multiscale regularization in the redundant wavelet transform domain. The proposed method uses the redundant wavelet transform to decompose the single-scale image restoration problem to multiscale ones and applies scale dependent regularization to the decomposed restoration problems. The proposed method recovers sharp edges by applying rather less regularization to wavelet related restorations, while suppressing the resulting noise magnification by the wavelet shrinkage algorithm. The improved performance of the proposed method over more traditional Wiener filtering is shown through numerical experiments.