• 한국물환경학회지
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• 제20권6호
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• pp.547-554
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• 2004

We found that the Bacterium Burkholderia cepacia in livestock wastewater treatment plant was predominant species. We investigated the growth rate of this and treatment characteristics for organic matter and nitrogen removal in livestock wastewater using this microorganism. First, we cultured B. cepacia. And then, to conducted treatment for livestock wastewater by using B. cepacia., we changed C/N from 0.2~4.4. When we operated A and B process, changing F/M ratio from 1.2 to 4.4. In experiment of C/N variations, when C/N was 1.8, we found that the optimal condition for organic matter and nutrient removal effect was higher and the removal efficiency of $SCOD_{cr}$, $SBOD_5$,$NH_4-N$ was 78.4%, 95% and 74.8%. So, It is possible to treat the wastewater having the lower C/N contents such as livestock wastewater using this microorganism. In experiment of A and B process for livestock wastewater, we found that the removal efficiency of organic matter and nitrogen in operating mode of A process was higher than that of B process. Also, the optimal F/M operating A process was 0.013 and the removal efficiency of $SBOD_5$, $SCOD_{cr}$, TN and TP were 97%, 60%, 95% and 91%.

• 한국통신학회논문지
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• 제17권9호
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• pp.972-981
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• 1992

본 논문에서는 전력선 채널에서 DS/SSMA BPSK 통신 시스템의 전형 및 하드리미팅 상관 수신기의 성능을 분석하였다. Chan의 잡음 모델을 이용하여 전력전에서 발생하는 강한 임펄스성 잡음을 배경 잡음에 대한 임펄스성 잡음의 전력 스펙트럼 밀도비 $(N_1/N_b)$, 데이터 폭에 대한 임펄스성 잡음 폭의 비(f). 임펄스성 잡음의 발생주기에 대한 임펄스 잡음 폭 (DF)등의 파라미터로 모델링하여, 각 파라미터 변화에 따른 시스템의 성능을 분석하고, 다중접속 간섭 잡음을 가우시안 근사화하여 각 수신기의 다중접속 능력을 평가하였다. 분석 결과 $N_1/N_b$가 작고 f가 1에 가까운 경우 전형 상관 수신기의 성능이 더 우수했으나, $N_1/N_b$가 증가함에 따라 하드리미팅 상관 수신기가 비트 오율 및 다중 접속 능력면에서 전형 상관 수신기보다 더 우수한 성능을 나타냈다.

• Journal of electromagnetic engineering and science
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• 제13권1호
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• pp.28-33
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• 2013

This paper proposes a miniaturized high-isolation diversity antenna for wearable wireless body area network (WBAN) applications. An inverted-F type radiating element is used to reduce the overall dimension of the proposed antenna to $30mm{\times}30mm{\times}2.5mm$. The antenna performance on the human body phantom is analyzed through simulation and the performance of the fabricated antenna is verified by comparing the measured data with that of the simulation when the antenna is placed on a semi-solid flat phantom with equivalent electrical properties of a human body. The fabricated antenna has a 10 dB return loss bandwidth over the Industrial Scientific Medical (ISM) band from 2.35 GHz to 2.71 GHz and isolation is higher than 28 dB at 2.45 GHz. The measured peak gain of antenna elements # 1 and # 2 is -0.43 dBi and -0.54 dBi, respectively. Performance parameters are analyzed, including envelope correlation coefficient (ECC), mean effective gain (MEG), and the MEG ratio. In addition, the specific absorption ratio (SAR) distributions of the proposed antenna are measured for consideration in use.

• Journal of Microbiology and Biotechnology
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• 제18권6호
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• pp.1141-1145
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• 2008

Isomaltooligosaccharide (IMO) is a promising dietary component with prebiotic effect, and the long-chain IMOs are preferred to short chain ones owing to the longer persistence in the colon. To establish the optimal process for synthesis of long-chain IMOs, we systematically examined the reaction condition of dextransucrase of Leuconostoc mesenteroides B-512F by changing the ratio of sucrose to maltose (varying as 1:4, 1:2, 1:1, and 2:1) and amount of each sugar (from 2% to 20%). As a result, a ratio of 2:1 (sucrose to maltose, 10:5% or 20:10%, w/v) was determined as an optimal condition for long-chain IMO synthesis (DP3-DP9) with relatively higher yields (70-90%, respectively).

• Progress in Superconductivity
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• 제6권1호
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• pp.19-23
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• 2004

YBCO do superconducting quantum interference device (SQUID) magnetometers based on bicrystal Josephson junctions on 10 mm ${\times}$ 10 mm $SrTiO_3$ substrates have been fabricated. The pickup coil of the device was designed to have 16 parallel loops with 50-fm-wide lines. We could obtain optimised direct coupled YBCO SQUID magnetometer design with field sensitivity $B_{N}$ $\Phi$/ of $4.5 nT/\Phi_{0}$ and magnetic field noise $B_{N}$ of about $22 fT/Hz^{1}$2/ with an I/f corner frequency of 2 Hz measured inside a magnetically shielded room. Preliminary results of magnetocardiograph measurement using the HTS SQUID magnetometers show signal to noise ratio of about 110, which is comparable to the quality of a commercial MCG system based on Nb-SQUIDs.

• 한국수정란이식학회지
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• 제31권1호
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• pp.19-25
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• 2016

This study was conducted to evaluate the effects of type of culture media (BM, G2, OS, TCM, and MEM) on B6D2F1 mice oogenesis. In the present study, B6D2F1/CrljOri $F_1$ mice were utilized in order to maximize oogenesis. Also we used TCM-199, Dulbecco's medified Eagle's medium (DMEM), embryo culture medium (Fertilization medium, Cleavage medium, Blastocyst medium), G series medium and One step medium. In vitro maturation was highest in BM followed by the order of OS, MEM, TCM and G2 ($90{\pm}2.8%>88{\pm}3.2%>85{\pm}4.9%>78{\pm}10.2%>64{\pm}7.7%$, respectively). To note, the G2 group was statistically different compared to other groups (p<0.05). On the other hand the fertilization rate was highest in the G2 group followed by BM, OS, TCM, and MEM ($87{\pm}7.2%>85{\pm}6.9%>74{\pm}14.0%>71{\pm}13.8%>2{\pm}1.4%$, respectively). The MEM group was significantly lower compared to other groups (p<0.05). The developmental rate was highest in the OS group followed by the G2 group and the BM group albeit no statistical significance was noted ($73{\pm}11.6%>71{\pm}9.2%>66{\pm}10.4%$). Of note, all cells of the TCM and MEM groups were died during embryonic development. The zona hatched rate ($51{\pm}9.8%$ vs. $50{\pm}9.1%$ vs. $47{\pm}7.2%$ for BM, G2, and OS respectively) and attached rate ($45{\pm}12.3%$ vs. $38{\pm}16.1%$ vs. $37{\pm}11.5%$ for BM, G2, and OS respectively) were not different amongst groups. No difference was found in total cell numbers ($74{\pm}13.9$ vs. $64{\pm}9.2$ vs. $76{\pm}6.7$ for BM, G2, and OS respectively), ICM cell numbers ($20{\pm}1.9$ vs. $14{\pm}1.8$ vs. $15{\pm}2.1$), TE cell numbers ($55{\pm}12.5$ vs. $49{\pm}10.7$ vs. $61{\pm}5.9$), % ICM ($30{\pm}2.8%$ vs. $24{\pm}7.0%$ vs. $22.8{\pm}2.2%$) and ICM:TE ratio ($1:2{\pm}0.5$ vs. $1:3.1{\pm}0.8$ vs. $1:3.1{\pm}0.5$) amongst groups. In summary, these results can provide fundamental data to maximize culture condition for in vitro fertilization on B6D2F1 mice.

• 한국수정란이식학회지
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• 제33권4호
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• pp.205-210
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• 2018

This study was performed to investigate the effect of types of oil (OVOIL vs. OIL) on B6D2F1 mice oogenesis. In this study, B6D2F1 F1 mice were used in order to maximize oogenesis. The expansion rate of cumulus cells ($82.0%{\pm}0.2$ vs. $78.0%{\pm}0.1$), in vitro fertilization rate ($92.0%{\pm}0.1$ vs. $88.0%{\pm}0.1$), developmental rate ($91.0%{\pm}0.1$ vs. $87.0%{\pm}0.2$), blastocysts formation rate ($56.0%{\pm}0.1$ vs. $57.0%{\pm}0.1$), and zona hatched rate($41.4%{\pm}0.2$ vs. $24.0%{\pm}0.1$) were not different between groups (NS; P>0.05). However, there was a significant difference in maturation rate; the OVOIL group showed higher maturation rate compared to that of the OIL group ($96.0%{\pm}0.1$ vs. $87.0%{\pm}0.1$; P<0.05). In the blastocysts cell numbers, the total cell numbers ($83.9{\pm}26.1$ vs. $56.9{\pm}23.9$), ICM cell numbers ($15.7{\pm}8.8$ vs. $6.3{\pm}3.5$), TE cell numbers ($68.3{\pm}25.7$ vs. $50.7{\pm}24.1$), % ICM ($21.6%{\pm}0.1$ vs. $12.7%{\pm}0.1$), and the ratio of ICM:TE ($1:6.2{\pm}6.5$ vs. $1:10.3{\pm}7.0$) were significantly higher in the OVOIL group than the OIL group (P<0.05). These results suggested that it is expected to achieve the more developmental ability of B6D2F1 mice depending on the type of oil (OVOIL vs. OIL). In addition, the results can provide essential information for culture condition on B6D2F1 mice. Henceforth, thus, it is expected that these results herein might be used for in vitro culture of human embryos.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 1991년도 춘계연구발표회 논문개요집
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• pp.73-74
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• 1991

The films with ferromagnetic fine particles dispersed in nonmagnetic matrix, such as $Fe-Al_2O_3$ and Fe-Cu have been studied for use of magnetic recording medium, optically device and sensor. Their magnetic properties depend strongly on structural parameter such as size and volume fraction of ferromagnetic particles. Fe-Cr-Ni alloy sputtered films also have microstructure with ferromagnetic -- b.c.c phase and nonmagnetic f.c.c phase grains. Magnetic properties of these films depend strongly on such a unique structure. These are depend on the ratio in volume of ferromagnetic particles to nonmagnetic ones $V_F/V_N$, the saturation magnetization Ms increased with increase of $V_F/V_N$. The coercivity Hc of the as-deposited films took maximum value of about 200 Oe at adequate $V_F/V_N$ and then Ms and Squareness S were 500 emu/cc and 0.5, respectively.(omitted)

• 한국생산제조학회지
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• 제21권2호
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• pp.276-282
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• 2012

This study looked for Mode status of each for fatigue crack growth behavior about the repeat load of mode I and the static load of mode II. The experiment was performed in the state of the repetition frequency of the sine wave 10Hz, the stress ratio 0.1, maximum load 300kg.f, a static load 0, 100, 200, 300kg.f, As the experimental results, in mode of static load, while the load value increases, the crack growth rate is slower as the energy of a crack mixing grows. Mode I and the power mode II get an influence each other in the direction of crack propagation path, but as they eventually get closer to the breaking point of the crack growth, it is dominated by the mode I.

• 태양에너지
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• 제20권4호
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• pp.61-67
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• 2000

The purpose of this study is to improve heat transfer by attaching rectangular fins to tube. Experiments were carried out under the following conditions - Aspect ratio$(W_f/R_f)$ is 0.7, 1.2 and 1.8. Temperature conversion between high and low positions of water in the thermal storage appeared because maximum density point of water is about $4^{\circ}C$ and inlet direction of working fluid influenced conductive heat transfer Compared with the unfinned tube(bare tube), the rectangular tube increased the ice thermal storage energy and the ice thermal storage energy was increased as aspect ratio was increased.