• Journal of Electrical Engineering and Technology
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• v.13 no.2
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• pp.781-789
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• 2018

This paper proposes a new approach utilizing empirical mode decomposition (EMD) reconstruction to process vibration signals of a transformer under DC bias caused by high voltage direction transmission (HVDC), which is the potential cause of additional vibration and noise from transformer. Firstly, the Calculation Method is presented and a 3D model of transformer is simulated to analyze transformer deformation characteristic and the result indicate the main vibration is produced along axial direction of three core limbs. Vibration test system has been built and test points on the core and shell of transformer have been measured. Then, the signal reconstruction method for transformer vibration based on EMD is proposed. Through the EMD decomposition, the corrupted noise can be selectively reconstructed by the certain frequency IMFs and better vibration signals of transformer have been obtained. After EMD reconstruction, the vibrations are compared between transformer in normal work and with DC bias. When DC bias occurs, odd harmonics, vibration of core and shell, behave as a nonlinear increase and the even harmonics keep unchanged with DC current. Experiment results are provided to collaborate our theoretical analysis and to illustrate the effectiveness of the proposed EMD method.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.136-136
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• 2022

This study investigates the possibility of coupling empirical mode decomposition (EMD) for runoff prediction from machine learning (ML) models. Here, support vector regression (SVR) and convolutional neural network (CNN) were considered for ML algorithms. Precipitation (P), minimum temperature (Tmin), maximum temperature (Tmax) and their intrinsic mode functions (IMF) values were used for input variables at a monthly scale from Jan. 1973 to Dec. 2020 in the Grand river basin, Canada. The support vector machine-recursive feature elimination (SVM-RFE) technique was applied for finding the best combination of predictors among input variables. The results show that the proposed method outperformed the individual performance of SVR and CNN during the training and testing periods in the study area. According to the correlation coefficient (R), the EMD-SVR model outperformed the EMD-CNN model in both training and testing even though the CNN indicated a better performance than the SVR before using IMF values. The EMD-SVR model showed higher improvement in R value (38.7%) than that from the EMD-CNN model (7.1%). It should be noted that the coupled models of EMD-SVR and EMD-CNN represented much higher accuracy in runoff prediction with respect to the considered evaluation indicators, including root mean square error (RMSE) and R values.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.5
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• pp.736-745
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• 2016

Cheonggukjang, a traditional Korean fermented soy food, was prepared by inoculation of Bacillus subtilis EMD4 or Bacillus amyloliquefaciens EMD17 with anti-bacterial or anti-fungal activities into soybeans. Cheonggukjang was also prepared by co-inoculation of EMD4 and EMD17 (1:1, v/v). Control cheonggukjang was prepared by using B. subtilis KACC16450 (Natto strain). Growth of B. cereus cells spiked with starter organisms was completely inhibited by B. amyloliquefaciens EMD17 after 12 h of fermentation at $37^{\circ}C$. Growth of B. cereus was also inhibited by B. subtilis EMD4, but the degree of inhibition was weaker. After 48 h of fermentation, cheonggukjang samples were stored for 10 days at $4^{\circ}C$. B. cereus cells were not detected from cheonggukjang inoculated with EMD4, whereas significant numbers still present in control. The pH values of cheonggukjang samples were not significantly different. During fermentation, cheonggukjang fermented with EMD17 showed the highest fibrinolytic activity and during storage, cheonggukjang fermented with a Natto strain was the highest. Cheonggukjang fermented with a Natto strain also showed the highest amount of total phenolic compounds. The results show that control of B. cereus in cheonggukjang is possible by using starters such as B. amyloliquefaciens EMD17.

• Journal of Periodontal and Implant Science
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• v.34 no.2
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• pp.333-344
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• 2004

The enamel matrix derivative (EMD) has been recently used in the periodontal regenerative techniques. The present study was established to investigate the influence of EMD on human periodontal ligament cells using expression of mRNA of periodontal ligament specific gene (PDLs)17, PDLs22, type I collagen when EMD applied to periodontal ligament cells. Periodontal ligament cells were obtained from a healthy periodontium and cultured in Dulbecco's modified Eagle's medium (DMEM) plus 10% fetal bovine serum and ${\beta}-glycerophosphate$ with ascorbic acid. Test groups were two; One adds EMD in culture media and another added EMD and Dexamethasone (DEX) in culture media. Positive control group added DEX in culture media, and negative control group adds niether of EMD nor DEX. $Emdogain^{(R)}$ (Biora, Sweden, 30 mg/ml) was diluted by 75 ${\mu}g/ml$ concentration to culture media. For reverse transcription-polymerase chain reaction (RT-PCR), total RNA isolated on days 0, 7, 14 and 21. mRNA of PDLs17 was expressed on days 14 and 21 in EMD or DEX group, and expressed on days 7, 14 and 21 in EMD plus DEX group, the other side, expressed on days 21 in negative control group. mRNA of PDLs22 expressed on days 7, 14 and 21 in EMD group, and expressed on days 14 and 21 in DEX group, and expressed on days 7, 14 and 21 in EMD plus DEX group. Negative control group expressed on days 14 and 21. Type I collagen was expressed on all days and all groups. These results indicate that EMD promotes differentiation of periodontal ligament cells, and this is considered to offer basis that can apply EMD to periodontal tissue regeneration technique.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.46 no.6
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• pp.27-34
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• 2009

Block truncation coding (BTC) is a simple and efficient image compression technique. However, it yields images of unacceptable quality and significant blocking effects are seen when the block size is increasing. Ordered dither block truncation coding (ODBTC) was proposed to solve above problem maintaining the same compression capability. In this paper, we propose a data hiding method which can be applied to halftone images. EMD was developed by Zhang and Wang [6] for data hiding in the grayscale image. Therefore, EMD is not proper for bitmap images. In this paper, we show that EMD can be used to apply bitmap halftone image. In our experiments, we prove that our method is efficient in a halftone image.

• The Journal of the Korean dental association
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• v.53 no.12
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• pp.935-948
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• 2015

목적: 법랑기질 유도체(EMD)가 사람 치주인대 줄기세포(hPDLSC)의 조직 형성능에 미치는 영향을 in vitro와 in vivo 분석 모델을 이용해 평가한다. 재료 및 방법: hPDLSC를 배양하여 운반체와 함께 면역 억제된 쥐 등에 이식하였다; (1)대조군: EMD 처치하지 않은 운반체에 심어진 hPDLSC군 ($EMD^-/hPDLSC^+$), (2)실험군: EMD 처치한 운반체에 심어진 hPDLSC군 ($EMD^+/hPDLSC^+$). 각 군당 5마리씩 시행하고 8주 후 희생하였다. 조직학적, 조직계측학적 분석을 통해 형성된 백악질의 면적과 백악세포의 수 그리고 샤피 섬유의 수를 계측하였으며 면역조직화학적 분석을 통해 백악질과 교원질 형성을 평가하였다. 또한 in vitro에서 hPDLSC의 수용성 교원질과 glycosaminoglycan 형성에 대한 EMD의 효과를 분석하였다. 결과: 조직학적 분석에서 교원질성 치주 인대 조직이 실험군에서 현저하게 많이 생성된 것을 관찰할 수 있었다. 형성된 백악질의 면적과 백악세포의 수는 군 간 차이가 없었으나, 새롭게 형성된 샤피 섬유의 수는 실험군에서 대조군보다 유의하게 많았다(p<0.05). 교원질 형성에 대한 면역조직 화학적 분석 결과, 실험군에서 I, III형 교원질과 hydroxyproline의 발현이 높았다. 또한 in vitro에서 hPDLSC에 의한 수용성 교원질과 glycosaminoglycan 형성이 EMD의 농도에 비례하여 증가하였다 (p<0.05). 결론: EMD는 hPDLSC에 의한 샤피 섬유 및 교원질 생성을 증가시키고, 이는 새로운 백악질의 기능적 부착과 치주조직 재생에 중요한 역할을 한다.

• The Journal of the Korean dental association
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• v.48 no.1
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• pp.56-62
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• 2010

In recent years, a number of special treatment procedures have been introduced to reestablish new tooth supporting tissues with varying degrees of success including guided tissue regeneration(GTR), bone grafting(BG) and the use of enamel matrix derivative(EMD). EMD is an extract of enamel matrix and contains amelogenins of various molecular weights. Emdogain(EMD) might have some advantages over other methods of regenerating the tissue supporting teeth lost by gum disease, such as less postoperative complications. Emdogain contains proteins(derived from developing pig teeth) believed to regenerate tooth attachment. The decrease in probing depth after EMD treatment is achieved primarily by clinical attachment gain and bone regeneration and only to a minor extent by gingival recession. In conclsion, EMD seems to be safe, was able to regenerate lost periodontal tissues in previously diseased sites based on clinical parameters.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.9
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• pp.1750-1756
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• 2009

In this paper, 5 kWh class Superconductor Flywheel Energy Storage System (SFES) was constructed including motor/generator, superconductor magnetic bearing(SMB), composite rotor and electromagnetic damper(EMD) system. High speed rotation test was performed after levitating flywheel rotor only using EMD without SMB. the PD controller of EMD was designed. the control system is constructed using xPC which is real time digital control system. the results of high speed rotation test showed that proposed EMD system have sufficient damping in cylindrical mode and conical mode, and vibration of wheel was suppressed below 10 ${\mu}m$.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.5
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• pp.532-536
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• 2008

Purpose: This study was designed to evaluate effect of EMD on proliferation of HPDLCs and MC3T3-E1 cells in high glucose condition in vitro. Material and method: The Human PDL fibroblasts(HPDLCs) were obtained through typical way and the cells used in this experiment were divided in 4 groups. $1{\times}10^4/ml$ HPDLCs suspension was cultured in typical DMEM and assigned to group 1. The cells cultured in DMEM which included 400mg/dl glucose are allocated to group 3. Group 2 and 4 are established by adding EMD to group 1 and 3 respectively. These control and experimental groups had been cultured for 24 and 48 hours, and MTT assay was conducted. The differences of each group in cellular proliferation was evaluated. The same experiment was conducted for preosteoblast (MC3T3-E1) with adding $25\;{\mu}g/ml$ EMD. Results: EMD had the same effect on both PDL cells and MCT3T3-E1 cells. The experimental group had more meaningful differences and active cellular proliferation than the control group did. The EMD accelerated cellular proliferation not only in normal glucose condition but also in high glucose condition. The same results were observed via MTT assay; EMD-added experimental group had more meaningful differences and showed higher cellular activity than control group did. Each experimental and control group was inspected for statistical significance through Kruskal-Wallis Test. Statistical significances were observed among these groups. (SPSS 12.0 Chicago, IL, USA, p=0.008, p=0.011) Conclusion: EMD is considered to accelerate proliferation of PDL cells and MC3T3-E1 cells in high glucose condition as well as normal glucose condition.

• Journal of Periodontal and Implant Science
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• v.38 no.4
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• pp.679-690
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• 2008

Purpose: The aim of this study was to investigate the effects of EMD on demineralized root surface using human periodontal ligament cells and compare the effects of root conditioning materials(tetracycline(TCN), EDTA). Material and Methods: Dentin slices were prepared from the extracted teeth and demineralized with TCN and EDTA. Demineralized dentin slices were incubated at culture plate with 25, 50 and $100{\mu}g/ml$ concentration of EMD. Cell attachment, alkaline phosphatase activity test, protein synthesis assay and scanning electronic microscopic examination were done. Results: Cells were attached significantly higher in EMD treated group at 7 and 14 days. Cell numbers were significantly higher in EMD treated group. Alkaline phosphatase activity was significantly higher in EMD treated group at 7 and 14 days. Protein synthesis was significantly higher in EMD treated group at 7 and 14 days. Conclusion: Enamel matrix derivatives enhance the biologic activities of human periodontal ligament cells on demineralized root surface and its effects are dependent on the concentration of EMD.