빔 구조물의 손상평가를 위한 임피던스 기술의 응용

홍동표,홍용,왕고평,김병진,김영문,이재정,김재열 한국공작기계학회 2006 한국공작기계학회 추계학술대회논문집 Vol.2006 No.-

This paper presents a primary study for a new method of enhancing measurement using impedance analysis method, which is widely used for structure health monitoring. Many of skyscrapers, bridges, tunnels, which have been built up several years, and nearly reached their operating life due to aging crack, material deterioration, and so on. therefore, the health monitoring technique has obtained considerable attention. The goal of this research is to show basic information to evaluate structural health condition using piezoelectric sensors. The piezoelectric materials have various merits. It is easy to shape various forms and can be embedded on the materials more conveniently. Moreover, the excitation frequency can be changed and the piezoelectric sensors cost less. All these features make the piezoelectric-based system applicable to structural healthy monitoring. This work presents a study for the development of a practical and quantitative technique for assessment of the structural health condition by piezoelectric impedance-based technique associated with longitudinal wave propagation. To estimate the damage condition numerically, we suggest the evaluation method Cov (Covariance) and CC (Correlation Coefficient) in this paper.

Development of Solar Array Regulator for Satellite Power System

Young Gao Jin,Se Jin Seong,Jae Dong Choi 대한전자공학회 1998 ICEIC:International Conference on Electronics, Inf Vol.1 No.1

Research on the Power Sharing Control and Stability of VSGs

Dong Xie,Da-Jin Zang,Peng Gao,Jun-Jia Wang 전력전자학회 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.2

Aiming at the deficiencies of power sharing control performances when a traditional droop control is adopted for microgrid inverters, this paper proposes a microgrid inverter power sharing control strategy based on a virtual synchronous generator. This control method simulates the electromechanical transient characteristics of a synchronous generator in a power system by an ontology algorithm and the control laws of a synchronous generator by control over the speed governor and excitation regulator. As a result, that the microgrid system is able to effectively retain the stability of the voltage and frequency, and the power sharing precision of the microgrid inverter is improved. Based on an analysis of stability of a microgrid system controlled by a virtual synchronous generator, design thoughts are provided for further improvement of the power sharing precision of inverters. The simulation results shows that when the virtual synchronous generator based control strategy was adopted, the power sharing performances of microgrid inverters are improved more obviously than those using the droop control strategy.

Surface third and fifth harmonic generation at crystalline Si for non-invasive inspection of Si wafer’s inter-layer defects

Gao, Yi,Lee, Hyub,Jiao, Jiannan,Chun, Byung Jae,Kim, Seungchul,Kim, Dong-Hwan,Kim, Young-Jin The Optical Society 2018 Optics express Vol.26 No.25

Generation, purification and engineering of extracellular vesicles and their biomedical applications

Gao, Jin,Dong, Xinyue,Wang, Zhenjia Elsevier 2020 Methods Vol.177 No.-

<P><B>Abstract</B></P> <P>Extracellular vesicles (EVs), derived from cell membranes, demonstrate the potential to be excellent therapeutics and drug carriers. Although EVs are promising, the process to develop high-quality and scalable EVs for their translation is demanding. Within this research, we analyzed the production of EVs, their purification and their post-bioengineering, and we also discussed the biomedical applications of EVs. We focus on the developments of methods in producing EVs including biological, physical, and chemical approaches. Furthermore, we discuss the challenges and the opportunities that arose when we translated EVs in clinic. With the advancements in nanotechnology and immunology, genetically engineering EVs is a new frontier in developing new therapeutics in order to tailor to individuals and different disease stages in treatments of cancer and inflammatory diseases.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Scalability and high-quality of production of EVs is critical to their translation. </LI> <LI> The biomedical applications of EVs will be discussed. </LI> <LI> The challenges and opportunities of EVs in translation will be discussed. </LI> <LI> Genetically engineering EVs is a new direction to develop personalized medicine. </LI> </UL> </P>

중국의 통신가격에 대한 법규제

Dong-gao Wu,Xiang-lan Jin 서울대학교 법학연구소 2011 경제규제와 법 Vol.4 No.1

2000년에 중국 국무원(중앙정부)은 <통신조례>를 제정반포하였다. 본 조례는 비록 전국인민대표대회 및 그 상무위원회에서 제정한 법률은 아니지만 현재 중국 통신영역에서의 유일한 종합성적인 법규범이다. 본 조례는 특히 한개 장절의 편폭으로 통신가격에 관하여 규정하고 있으며 통신가격의 유형, 정부가 통신가격을 결정하는 기본원칙, 통신가격결책기관 및 그 절차 등을 명확히 하고 있다. 그후 2002년에 중국 중앙정부의 통신산업 주요 담당기관인 국가계획발전위원회(현재의 국가발전과 개혁위원회)와 정보산업부(현재의 공업과 정보화부)가 공동으로 <통신가격 비준등록 절차규정>을 제정하였다. 본 규정은 상술한 <통신조례> 중의 통신가격에 관한 규정의 내용을 세밀화하였으며 통신가격 공개,통신업계의 自主定價에 관한 감독 등의 제도를 확립하였다. 상술한 두개의 법규범을 바탕으로 중국은 초보적으로 통신가격에 관한 법제도를 설립하게 되었다. 통신가격의 결정방식에 관하여 상술한 법규범은 비록 政府定價, 政府指導價, 市場調節價등 방식을 규정하고 있지만政府定價방식을 아주 작은 범위에 한정하고 그 밖의 방식의적용범위를 확대하고 있는바 이는 사실상 통신가격 결정에 있어서의 경영업자의 자율적 공간의 확충으로 이해할 수 있다. 政府定價, 政府指導價방식의 통신가격 결정주체에 관하여 상술한 법규정에 의하면 <공업과 정보화부>는 응당 통신가격심의위원회를 설립하여야 한다. 당해 위원회는 통신가격제정 또는 조정에 관한 결책권을 행사한다. 문제는 상술한<규정>이 통신가격방안의 구체설계자로서의 통신가격심의위원회를 명확히 하고 있지만 당해 기구의 구성상황을 규정하지 않고 있으며 또한 비록 당해 기구의 운영방식을 규정하고 있다 하더라도 그 운영절차에 대해서는 구체적으로 규정하고 있지 않다. 따라서 구체적인 가격방안의 제출절차는 역시 불투명하다. 중국의 법규범은 상술한 두가지 유형의 통신가격에 관하여 중국정부가 주동적으로 가격을 결정하는 제도를 확립하였을 뿐만아니라 정부의 규제대상인 통신업자에게 가격조정신청권한을 부여하였으며 해당 권리의 실현 경로를 명확히하였다. 문제는 비록 대체적인 가격조정신청절차와 신청서의내용을 규정하고 있으나 관련된 많은 구체절차가 불명확하다는 것이다. 상술한 법규정에 의하면 정부는 등록, 처벌 및 가격조정명령 등 수단으로 통신업자의 자주적 가격결정행위에 대하여 감독권을 행사한다. 문제는 상술한 규정이 등록제도만 규정하였을뿐 통신업자가 어떠한 절차로 등록하는가에 대해서는 규정하지 않고 있다. Chinese State Council formulated ‘Telecommunications Regulations’ in 2000. Though this regulation was not the law which the National People’s Congress and the Standing Committee of the National People’s Congress made, it is the only comprehensive legal norms right now. Its publication terminated the state which Chinese telecommunication didn’t have own law. SDPC and MII formulated ‘Examining and keeping Records Procedure Regulation of Telecommunication Fees’ in 2002. This regulation got into detail a bit and established telecommunication fees’ open system, supervision system for independent pricing of telecommunication business operators. Therefore, China has established a preliminary law system of telecommunication fees. The above regulations set three certain kinds of government pricing, government guidance pricing and market regulation pricing. Government pricing is limited to small range, but government guidance pricing and market regulation pricing’ applicable scope are enlarged. This actually enlarged independent space of communication business operators. According to the regulations, MIIT should found Review Committee of Communication Fees which decides whether to set or adjust fees. The problem is that the regulations although explicit the Review Committee of Communication Fees as designer of two kinds of communication fees scheme, its composition and operate procedure are not regulated. Consequently, proposing procedure of specific price scheme is very opaque. As for above two kinds of communication fees, Chinese government not only established government active pricing system, but also gave the application rights of adjusting pricing to communication business operators who are supervised by government and answered how to realize the rights. The problem is that application procedure and application content of adjusting pricing of communication business operators are regulated by and large, but a lot of specific procedures are not clear. In addition, according to the regulations, government supervises the independent pricing behavior of communication business operators by keeping records, punishing and requiring adjusting pricing, etc. The problem is that the regulations only stipulated keeping records system, and the communication business operators how to keep records is unknown.

The Model of Full Scale Converter Wind Turbine with PMSG

Gao Hongchao(고홍초),Seon-Ju Ahn(안선주),Joon-Ho Choi(최준호),Dong-Hyun Yoo(유동현),Seok-il Go(고석일),Yu-Jin Jung(정유진) 한국조명·전기설비학회 2014 한국조명·전기설비학회 학술대회논문집 Vol.2014 No.11

Detection of Powdery Mildew of Bitter Gourd Based on NIR/Fluorescence Spectra

Gao Jia Yu,Wei Dong Zheng,Wang Xiang,Tang Jin Cheng,Xu Ji Tong,Zhao Ping,Ning Xiao Feng 한국농업기계학회 2023 바이오시스템공학 Vol.48 No.3

Purpose Powdery mildew as one of the common vegetable diseases has very rapid infection. Its outbreak will bring about disastrous consequences to vegetable output; thus, it is of key importance to do rapid identifi cation and prevention of powdery mildew. Methods In this test, 100 bitter gourd leaves were collected as research samples, and the data of near-infrared spectra, fl uorescence spectra, and chromatic values L*a*b* , and the classic K-S algorithm was adopted to divide the sample sets; then, the quantitative forecasting and qualitative discrimination models were established. First, Pearson’s correlation analysis was carried out to fi nd the feasibility of taking a * as the modeling parameter, through cross-validation; the quantitative forecasting model was optimized by the PLSR (partial least squares regression) method. The model is also optimized by extracting the spectral feature bands using the continuous projection SPA method. Results The optimization results showed that the MSC + SPA + PLSR quantitative forecasting model of near-infrared spectra could eff ectively improve model precision, which was signifi cantly higher than that of fl uorescence spectra. Classifi cation Leaner was used to establish the quantitative forecasting model. Compared with the model of near-infrared spectra, the SPA + SVM qualitative discrimination model of fl uorescence spectra could improve the identifi cation precision of powdery mildew of bitter gourd as high as 98% through training. Conclusion This study proposed diff erent combination methods based on quantitative forecasting and qualitative discrimination and could provide a method and reference to the identifi cation of powdery mildew of bitter gourd.

Asiatic Acid Protects Dopaminergic Neurons from Neuroinflammation by Suppressing Mitochondrial ROS Production

( Dong Chen ),( Xiao-ya Zhang ),( Jing Sun ),( Qi-jie Cong ),( Wei-xiong Chen ),( Hafiz Muhammad Ahsan ),( Jing Gao ),( Jin-jun Qian ) 한국응용약물학회 2019 Biomolecules & Therapeutics(구 응용약물학회지) Vol.27 No.5

This study sought to evaluate the effects of Asiatic acid in LPS-induced BV2 microglia cells and 1-methyl-4-phenyl-pyridine (MPP+)-induced SH-SY5Y cells, to investigate the potential anti-inflammatory mechanisms of Asiatic acid in Parkinson’s disease (PD). SH-SY5Y cells were induced using MPP+ to establish as an in vitro model of PD, so that the effects of Asiatic acid on dopaminergic neurons could be examined. The NLRP3 inflammasome was activated in BV2 microglia cells to explore potential mechanisms for the neuroprotective effects of Asiatic acid. We showed that Asiatic acid reduced intracellular production of mitochondrial reactive oxygen species and altered the mitochondrial membrane potential to regulate mitochondrial dysfunction, and suppressed the NLRP3 inflammasome in microglia cells. We additionally found that treatment with Asiatic acid directly improved SH-SY5Y cell viability and mitochondrial dysfunction induced by MPP+. These data demonstrate that Asiatic acid both inhibits the activation of the NLRP3 inflammasome by downregulating mitochondrial reactive oxygen species directly to protect dopaminergic neurons from, and improves mitochondrial dysfunction in SH-SY5Y cells, which were established as a model of Parkinson’s disease. Our finding reveals that Asiatic acid protects dopaminergic neurons from neuroinflammation by suppressing NLRP3 inflammasome activation in microglia cells as well as protecting dopaminergic neurons directly. This suggests a promising clinical use of Asiatic acid for PD therapy.

Expression and Clinical Significance of Osteopontin in Calcified Breast Tissue

Huan, Jin-Liang,Xing, Li,Qin, Xian-Ju,Gao, Zhi-Guang,Pan, Xiao-Feng,Zhao, Zhi-Dong Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.10

Osteopontin (OPN) is an integrin-binding protein, believed to be involved in a variety of physiological cellular functions. The physiology of OPN is best documented in the bone where this secreted adhesive glycoprotein appears to be involved in osteoblast differentiation and bone formation. In our study, we used semi-quantitative RT-PCR of osteopontin in calcification tissue of breast to detect breast cancer metastasis. The obtained data indicate that the expression of osteopontin is related to calcification tissue of breast, and possibly with the incidence of breast cancer. The expression strength of OPN by RT-PCR detection was related to the degree of malignancy of breast lesions, suggesting a close relationship between OPN and breast calcification tissue. The results revealed that expression of OPN mRNA is related to calcification of breast cancer tissue and to the development of breast cancer. Determination of OPN mRNA expression can be expected to be a guide to clinical therapy and prediction of the prognosis of breast cancer patients.