• Journal of Food Hygiene and Safety
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• v.38 no.2
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• pp.69-78
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• 2023

This study aimed to investigate the protective effect of enzymatically modified stevia (EMS) on C2C12 cell-based model of dexamethasone (DEX)-induced muscle atrophy to provide baseline data for utilizing EMS in functional health products. C2C12 cells with DEX-induced muscle atrophy were treated with EMS (10, 50, and 100 ㎍/mL) for 24 h. C2C12 cells were treated with EMS and DEX to test their effects on cell viability and myotube formation (myotube diameter and fusion index), and analyze the expression of muscle strengthening or degrading protein markers. Schisandra chinensis Extract, a common functional ingredient, was used as a positive control. EMS did not show any cytotoxic effect at all treatment concentrations. Moreover, it exerted protective effects on C2C12 cell-based model of DEX-induced muscle atrophy at all concentrations. In addition, the positive effect of EMS on myotube formation was confirmed based on the measurement and comparison of the fusion index and myotube diameter when compared with myotubes treated with DEX alone. EMS treatment reduced the expression of muscle cell degradation-related proteins Fbx32 and MuRF1, and increased the expression of muscle strengthening and synthesis related proteins SIRT1 and pAkt/Akt. Thus, EMS is a potential ingredient for developing functional health foods and should be further evaluated in preclinical models.

• Korean Journal of Animal Reproduction
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• v.23 no.4
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• pp.281-291
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• 1999

The objective of this study was to optimize the freezing/thawing method of in vitro produced Hanwoo blastocysts. Day 7 blastocysts after IVF were vitrified using EFS40 (40% ethylene glycol, 18% ficoll, 0.3 M sucrose and 10% FBS added m-DPBS) as a freezing solution and electron microscope (EM) grid (V-G) or straw (V-S) as an embryo container. In both method, freezing/thawing were treated by 2-step, treatment time was required in V-G method and V-S method, for 2 min / 3 min and 3.5 min / 10 min, respectively. Embryo survival was assessed as re-expanded and hatched rates at 24 h and 48 h after warming, respectively. The results obtained in these experiments were summarized as follows: when the effect of exposure in vitrification solution and chilling injury from freezing procedure on in vitro produced expanded blastocysts were examined, at 24 h after warming, embryo survival in exposure group (100.0%) was not different compared to that in control group (100.0%), although those results were significantly different with two vitrified groups (V-G: 87.8, V-S: 77.8%) (P＜0.001). However, at 48 h after warming, hatched rates of V-G group (67.8%) were significantly higher than those of V-S group (53.3%) (P＜0.05). In addition, this hatched rate in V-G group was not different with that in exposure group (73.3%). When the effects of embryo developmental stage (early, expanded and early hatching blastocysts) and embryo container (EM grid and straw) to the in vitro survival of vitrified-warmed day 7 Hanwoo blastocysts were simultaneously examined, fast developed embryos were indicated the better resistance to freezing than delayed developed one, irrespective of embryo containers (early; 57.1 ＆ 24.4%, expanded; 84.7 ＆ 60.6%, early hatching; 91.7 ＆ 80.0%) (P＜0.001). Especially, in expanded and early hatching blastocysts, embryo survival of V-G group (67.8, 95.0%) was significantly higher than those of V-S group (53.0, 65.0%) at 48 h post warming, respectively (P＜0.05, P＜0.001). Therefore, this study indicates that Hanwoo blastocysts can be cryopreserved more simple, efficient and successful by vitrification method using EM grid.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.2
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• pp.189-195
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• 2015

There are many research works on the SAR image generation using EM(Electro Magnetic) simulation. Particularly, there are several dedicated S/Ws for SAR image generation and analysis. But, most of them are not available to the public due to the reason for defense and security. In this paper, we describe the generation of ISAR images for a realistic target model using the general purpose EM simulator like FEKO. This method can benefit us many advantages like building the database of many targets for target recognition with cost-and-time effective way.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.135-135
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• 2020

우리나라의 기후 자료는 일반적으로 기상청에서 발표하는 종관기상관측(ASOS)과 방재기상관측(AWS), 그리고 북한이 세계기상기구(WMO, World Meteorogical Organization)의 기상통신망(GTS)을 통해 보낸 북한기상관측(NKO)을 사용 할 수 있다. 그러나 이 중 40년 이상의 완전한 관측 자료를 얻을 수 있는 건 ASOS가 유일하지만 공간적인 표현에 한계를 갖고 있다. AWS는 관측소가 많다는 장점이 있지만 관측 기간이 길지 않고 이용 가능한 기간에도 관측이 연속적이지 못한 경우가 많다. NKO는 비록 27개의 관측소가 있지만 많은 데이터가 누락되어 일별 기후자료의 사용에 한계를 갖고 있다. 이러한 미관측 기간이나 관측 자료의 누락은 연속적인 시계열 자료분석을 기반으로 하는 수자원 모델링에 있어서 문제를 야기한다. 본 연구는 1973년부터 2019년까지 47년의 신뢰도 높은 한반도 일일 기후 자료를 구축하기 위해 다양한 방법론을 비교하였다. 추정에 사용한 방법은 총 7개로 EM algorithm for probabilistic principal components (PPCA-EM), Inverse distance weight method (IDWM), Nearest neighbor method (NNM), Multivariate normal copulas (Copula), Elastic net model (Elastic), Ordinary kriging (OK), Regularized principal components with EM algorithm (RPCA-EM)를 살펴보았다. 다양한 형태의 결측치를 가정하여 그 결과값을 비교하였고 이는 Root mean squared error(RMSE), Kling-Gupta efficiency(KGE), Nash-Sutcliffe efficiency(NSE)를 통해 평가하였다. 최종 선택된 방법론을 통하여 한반도 전역을 그리드 기반의 강수 및 최저온도/최고온도의 일별자료로 생성하였다.

• Bulletin of the Korean Chemical Society
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• v.33 no.2
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• pp.443-448
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• 2012

Ferrocenyl chalcones (Fc-C(O)CH=CH-Ar: Fc-Ar) with mono- and di-1-naphthalenyl moieties (Fc-1Naph and Fc-d1Naph) were prepared and spectroscopically characterized. The enone bridge was in the s-cis conformation and the $\pi$-electrons on the C=C bond were further delocalized on the bridge. The naphthalenyl moiety deviates greatly from the enone-Cp plane by $26.9(1)^{\circ}$. Cyclic voltammetry measurements for Fc-1Naph exhibit one reversible cycle for the redox of the ferrocenyl moiety at a lower potential, and one irreversible oxidation peak at the higher potential region. For Fc-d1Naph, the cyclic voltammogram is more featureless. Fluorescence properties for both compounds are active in polar solvents with $\lambda_{em}$ = 500 nm (EtOH) and $\lambda_{em}$ = 512 nm (MeOH) for Fc-1Naph and $\lambda_{em}$ = 496 nm (EtOH) and $\lambda_{em}$ = 508 nm (MeOH) for Fc-d1Naph. The intensity of Fc-d1Naph is more than twice than that of Fc-1Naph. The fluorescence properties for both compounds are inactive in the less polar solvents such as $CH_3CN$, $CH_2Cl_2$ and $CHCl_3$.

• Korean Journal of Medicinal Crop Science
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• v.7 no.3
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• pp.162-166
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• 1999

In 1998, there was heavy precipitation of 60 days with amount of 1,042mm from June to September in Andong. Upland crop was severely injured by excessive moisture(EM) on poor drainage field. In this trial, effects of EM on the growth characteristics and yield in Peucedanum japonicum Thunberct and Rehmannia glutinosa Liboschitz was investigated. In Peucedanum japonicum Thunberct, growth of root was decreased more severely than that of aerial part by EM injury, and fresh weight of root per ha was decreased by $21{\sim}80%$ at different degree of EM injury compared to that of normal growth. In Rehmannia glutinosa Liboschitz, percent of withered plant was $10{\sim}52%$ at different degree of EM injury. and rhizome's number per plant and diameter was extremely decreased by EM injury. Fresh weight of rhizomes per ha was decreased by $19{\sim}83%$ at different degree of EM injury compared to that of normal growth.

• Journal of Navigation and Port Research
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• v.31 no.8
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• pp.671-674
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• 2007

In this paper, the EM wave absorber was designed and fabricated for ETC system, because ETC system has some problems including signal error and system-to-system interference. We fabricated some samples in different composition ratio of MnZn-ferrite, Carbon and CPE, confirmed that optimum composition ratio of Mn2n-ferrite, Carbon, CPE was 40 : 15 : 45 wt%. Complex relative permittivity and complex relative permeability was calculated by the measured data. And absorption abilities were simulated according to different thickness of the EM wave absorbers using complex relative permittivity and permeability. The EM wave absorber was fabricated based on simulated data Simulated and measured values agree well. As a result, the developed EM wave absorber has a thickness of 3.38 mm and absorption ability over 20 dB at 5.8 GHz.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.117-120
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• 2008

In this paper, we developed the EM wave absorber for eliminating false images in collision-avoidance radar. First of all, we fabricated some samples in different composition ratio of $TiO_2$ and CPE. And the relative permittivities of samples are calculated from S-parameter of samples by using 1-port method. We designed and fabricated the EM wave absorber by using the calculated relative permittivity. As a result, the EM wave absorber with composition of $TiO_2$:CPE=70:30 wt% has thickness of 1.85 mm and absorption ability higher than 20 dB in the frequency range 76-77 GHz.

• Journal of Navigation and Port Research
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• v.30 no.9
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• pp.763-766
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• 2006

In this paper, the EM wave absorbers were designed and fabricated for X -band sensors using Carbon of dielectric material with CPE. The complex relative permittivity of samples is calculated by using measurement results of S-parameter. We simulated the double-layered type EM wave absorber with broad bandwidth using the measured complex relative permittivity by changing the thickness and layer, which was fabricated based on the simulated design The fabricated EM wave absorber consists of 1 mm first layer sheet facing metal with Carbon composition ratio 70 vol. % and 1.5 mm second layer sheet with Carbon composition ratio 60 vol. %. The measured results showed a good agreement to the simulated ones. It is found toot the optimized absorption ability of double-layered type EM wave absorber with thickness of 2.5 mm is higher than 10 dB from 7.8 GHz to 13.3 GHz.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.12
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• pp.1716-1721
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• 2014

In this paper, a study on automation method for the circuit/EM (Electro-Magnetic) simulation is carried out to analyze effectively the SI/PI (Signal Integrity/Power Integrity) issues which occur on circuits and/or PCBs (Printed Circuit Boards). For the automation of the circuit/EM simulation, algorithms performing each process of the SI/PI analysis automatically (such as ports setup, circuit definition and SI/PI evaluation) are developed; thereby automation system for the SI/PI analysis is constructed with the algorithms. The automation of the circuit/EM simulation is accomplished in the environment of the C/S (Client/Server) architecture in order to reduce resources such as high cost computers demanded for the SI/PI analysis. The automation method for the SI/PI analyses proposed in this paper reduces effort, time, and cost spent on the environment setup for simulation and the SI/PI analysis process. In addition, the proposed method includes automation of the documenting process, which organizes, records and displays the SI/PI analysis results automatically for users.