• Journal of Microbiology and Biotechnology
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• v.18 no.11
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• pp.1826-1835
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• 2008

An autotrophic denitrification reactor (ADR-l) and a heterotrophic denitrification reactor (HDR-2) were operated to remove nitrate and nitrite in an anoxic environment in raw sewage. The $NO_3$-N removal rate of ADR-l was shown to range from 52.8% to 78.7%, which was higher than the $NO_3$-N removal rate of HDR-2. Specific denitrification rates (SDNR) of ADR-l and HDR-2 were 3.0 to 4.0 and 1.1 to $1.2\;mgNO_3$-N/gVSS/h, respectively. From results of restriction fragment length polymorphism (RFLP) of the 16S rRNA gene, Aquaspirillum metamorphum, Alcaligenes defragrans, and Azoarcus sp. were $\beta$-Proteobacteria that are affiliated with denitritying bacteria in the ADR-l. Specifically, Thiobacillus denitrificans was detected as an autotrophic denitrification bacteria. In HDR-2, the $\beta$-Proteobacteria such as Denitritying-Fe-oxidizing bacteria, Alcaligenes defragrans, Acidovorax sp., Azoarcus denitrificans, and Aquaspirillum metamorphum were the main bacteria related to denitrifying bacteria. The $\beta$-and $\alpha$-Proteobacteria were the important bacterial groups in ADR-l, whereas the $\beta$-Proteobacteria were the main bacterial group in HDR-2 based on results of fluorescent in situ hybridization (FISH). The number of Thiobacillus denitrificans increased in ADR-l during the operation period but not in HRD-2. Overall, the data presented here demonstrate that many heterotrophic denitritying bacteria coexisted with autotrophic denitrifying bacteria such as Thiobacillus denitrificans for nitrate removal in ADR-l. On the other hand, only heterotrophic denitritying bacteria were identified as dominant bacterial groups in HDR-2. Our research may provide a foundation for the complete nitrate removal in raw sewage of low-COD concentration under anoxic condition without any external organic carbon or the requirement of post-treatment.

• Journal of Microbiology and Biotechnology
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• v.24 no.11
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• pp.1566-1573
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• 2014

Although most algae cultivation systems are operated in suspended culture, an attached growth system can offer several advantages over suspended systems. Algal cultivation becomes light-limited as the microalgal concentration increases in the suspended system; on the other hand, sunlight penetrates deeper and stronger in attached systems owing to the more transparent water. Such higher availability of sunlight makes it possible to operate a raceway pond deeper than usual, resulting in a higher areal productivity. The attached system achieved 2.8-times higher biomass productivity and total lipid productivity of $9.1g\;m^{-2}day^{-1}$ and $1.9g\;m^{-2}day^{-1}$, respectively, than the suspended system. Biomass productivity can be further increased by optimization of the culture conditions. Moreover, algal biomass harvesting and dewatering were made simpler and cheaper in attached systems, because mesh-type substrates with attached microalgae were easily removed from the culture and the remaining treated wastewater could be discharged directly. When the algal biomass was dewatered using natural sunlight, the palmitic acid (C16:0) content increased by 16% compared with the freeze-drying method. There was no great difference in other fatty acid composition. Therefore, the attached system for algal cultivation is a promising cultivation system for mass biodiesel production.

• IEIE Transactions on Smart Processing and Computing
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• v.2 no.4
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• pp.240-247
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• 2013

The main aim of this study was to suppress the angular velocity against strong winds during storms and analyze the stability and performance of the phase plane method. The utilization of small-scale wind turbine system has become common in agriculture, houses, etc. Therefore, it is considered to be a scheme for preserving the natural energy or avoiding the use of fossil fuels. Moreover, settling small-scaled wind turbines is simpler and more acceptable compared to ordinary huge wind turbines. In addition, after converting the energy there is no requirement for distribution. Therefore, a much lower cost can be expected for small-scaled wind turbines. On the other hand, this system cannot be operated continuously because the small-scaled wind turbine consists of a small blade that has low inertia momentum. Therefore, it may exceed the boundary of angular velocity, which may cause a fault in the system due to the centrifugal force. The aim of this study was to reduce the angular velocity by controlling the stall factor. Stall factor control consists of two control methods. One is a shock absorber that is loaded in the junction of the axis of the blade of the wind turbine gear wheel and the other is pitch angle control. Basically, the stall factor itself exhibits nonlinear behavior. Therefore, this paper confirmed the feasibility of stall factor control in producing desirable performance whilst maintaining stability.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.9
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• pp.1042-1047
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• 2012

In order to obtain balanced ports matching and isolation between balanced ports of a Marchand balun, a compact isolation network is proposed. The proposed compact isolation network is designed using composite right/left-hand (CRLH) transmission line and compact phase inverter using CRLH transmission line unit cell. Also, design method and analysis of proposed isolation network are presented. The sizes of the proposed isolation networks are significantly reduced to $0.11{\lambda}_g$ and $0.07{\lambda}_g$ compared with the conventional isolation network of $0.5{\lambda}_g$. The Marchand balun is operated at 2.45 GHz and is demonstrated through excellent experimental results.

• Journal of Radiation Protection and Research
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• v.41 no.4
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• pp.368-372
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• 2016

Background: Methodologies for a series of radiological consequence assessments show a distinctive difference according to the design principles of the original nuclear suppliers and their technical standards to be imposed. This is due to the uncertainties of the accidental source term, radionuclide behavior in the environment, and subsequent radiological dose. Both types of PWR and PHWR are operated in Korea. However, technical standards for evaluating atmospheric dispersion have been enacted based on the U.S. NRC's positions regardless of the reactor types. For this reason, it might cause a controversy between the licensor and licensee of a nuclear power plant. Materials and Methods: It was modelled under the framework of the NRC Regulatory Guide 1.145 for light-water reactors, reflecting the features of heavy-water reactors as specified in the Canadian National Standard and the modelling features in MACCS2, such as atmospheric diffusion coefficient, ground deposition, surface roughness, radioactive plume depletion, and exposure from ground deposition. Results and Discussion: An integrated accident consequence assessment code, ACCESS (Accident Consequence Assessment Code for Evaluating Site Suitability), was developed by taking into account the unique regulatory positions for reactor types under the framework of the current Korean technical standards. Field tracer experiments and hand calculations have been carried out for validation and verification of the models. Conclusion: The modelling approaches of ACCESS and its features are introduced, and its applicative results for a hypothetical accidental scenario are comprehensively discussed. In an applicative study, the predicted results by the light-water reactor assessment model were higher than those by other models in terms of total doses.

• Journal of Haehwa Medicine
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• v.19 no.1
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• pp.25-34
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• 2010

Background : The human being and the bacteria have accomplished a balance and have coexisted each other during long time. Probiotics have evolved with the human host to exist and the result they have operated profitably to human host. So it requires that the functions of probiotics are expounded in view of Traditional Korean Medicine. Aim : Suggest the functions of probiotics in view of Traditional Korean Medicine. Method : The author's research has been performed to review the related references. Results : Probiotics assist the absorption of the lactose, proteins and minerals and product several kinds of vitamins, organic acids. Probiotics suppresses the growth of noxious bacteria and the production of harmful substances or gases. They absorbed and discharge the bile acid, and thus help us maintain the optimal level of blood cholesterol concentration. They can reinforce the immune response of the mucous membrane and control the hypersensitivity immune reaction such as asthma, atopy on the other hand. Probiotics have right functions as above and so can be applied widely in treatment of various disease and symptom. Conclusion : Considering the functions of probiotics in view of Traditional Korean Medicine, they participate in our spleen-earth-system (digestion and synthesis) and liver-wood-system (regulation of digestion, metabolism, internal secretion etc.), assist the function of lung-metal system(respiration and regulation of water metabolism) and regulate wi-chi (reinforce/control immune system). Consequently, hereafter there would be a necessity of control a circumstance in treatment of various diseases under these categories that probiotics should be able to do their right functions inside the human body.

• Journal of architectural history
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• v.19 no.6
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• pp.209-232
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• 2010

This thesis is to analyze the origin and transformation of the official building registers of Korean traditional temples, and also to suggest the amendment of their wrong archives. Especially, this study is to examine these subjects focused on Beomeo-sa which has maintained fine registers. The results are as follow; 1. In Chosun Dynasty, the Ip-an had been used, and in the period of Daehan-Empire, the Ga-gei had been used as each official registers for the common buildings. The other hand, the lists of properties and the legal registers had been used as official registers for the temple buildings between 1911 and 1962. 2. The current official building registers have been firstly recorded under in 1962. At that time, the current official registers have been also recorded for the Buddhist temple buildings. 3. Most of the official building registers of Buddhist temples are incomplete. Especially, these have usually the indistinct building names and wrong building areas. These were mainly caused by direct copying of the old registers recorded in 1956, the period of Buddhist confusion. Furthermore, the registers have been poorly operated by monks and offices. 4. Therefore, the registers has to be corrected as follow; The omitted buildings have to be added and the duplicated buildings have to be removed in the summary heading registers. The indistinct building names recorded in 1956 have to be correct into actual proper building names. The wrong building areas recorded in 1956 have to be correct into actual measurement building areas.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.3
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• pp.292-300
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• 2010

In this paper, we propose a RF front-end architecture based on hybrid conversion which is available to receive both broadband and multiband DVB-H receiver, and a multi-function circuit for implementing the RF front-end is fabricated. A multi-function circuit is operated as a sub-harmonic mixer mode in the case of receiving a broadband VHF/UHF band, which show a conversion loss of -10.0 dB, noise figure of 7.0 dB and IIP3 of 2.0 dBm. On the other hand, it is performed as a attenuation mode with a insertion loss of -10.0 dB in receiving a multiband, L-band.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.3
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• pp.533-539
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• 2017

ERTMS/ETCS Level 2 is currently planning, making contract, constructing and operating at several lines in European well-developed railway countries different from past ten years ago, and applying extensively for purpose of its intercompatibility and operational efficiency, and economic feasibility. On the other hand, ATP system correspond to ETCS Level 1, which was domestically introduced in early 2000, has introduced, operated, and planned or constructed in national railwaynetwork, but the lines, which its improvement period is come, are being occurred starting Gyeongbu Line. Therefore, we study the consideration and construction plan by stages if LTE-R Korean Radio-based Train Control System for conventional & high-speed railway under domestic development is extensively applied as the third National Railway Network Construction Plan was announced.

• Journal of Embryo Transfer
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• v.12 no.1
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• pp.111-116
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• 1997

The present study was carried out to produce in vitro fertilized embryos with immature follicular oocytes collected by transvaginal aspiration from Holstein cows. A simple aspiration apparatus consists of two stainless steel tubes, an inner tube (needle holder; 1.2cmdiameter, 55cm long) and an outer tube (1.5cm diameter, 4Scm long), and a hand-operated vacuum pump was used. Under epidural anesthesia, the needle guide was passed into the vagina of the cow to a point next to the cervix. An ovary was placed against the wall of the vagina over the end of the aspiration needle by rectal manipulation. As the needlepassed into the ovary, an assistant was asked to apply vacuum(l00mrnHg) and the ovary was manipulated back and forth in all directions over the needle. When all sites of the ovary was aspirated, the needle was withdrawn and the needle guide was moved to the other side of ovary and the procedure was repeated. When the oocyte aspiration procedure was finished, collected fluid was transported to laboratory. Oocytes surrounded with at least 1 layer of cumulus cells were matured, fertilized and cultured in vitro. The results were as follows; Ninety seven oocytes were collected by transvaginal aspiration from seventeen Holstein cows(5.7 /head). The number of oocytes surrounded with at least 1 layer of cumulus cells were 60(61.9%). Following in vitro maturation, fertilization and culture, the cleavage and development rate to morula+blastocyst were 83.3% and 30.0%, respectively. From this study, transferable in vitro fertilized embryos could be produced with imma- ture follicular oocytes collected by transvaginal aspiration from Holstein cows using a simple aspiration apparatus.