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.

Prediction of Remaining Useful Life of Lithium-ion Battery based on Multi-kernel Support Vector Machine with Particle Swarm Optimization

Gao, Dong,Huang, Miaohua The Korean Institute of Power Electronics 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.5

The estimation of the remaining useful life (RUL) of lithium-ion (Li-ion) batteries is important for intelligent battery management system (BMS). Data mining technology is becoming increasingly mature, and the RUL estimation of Li-ion batteries based on data-driven prognostics is more accurate with the arrival of the era of big data. However, the support vector machine (SVM), which is applied to predict the RUL of Li-ion batteries, uses the traditional single-radial basis kernel function. This type of classifier has weak generalization ability, and it easily shows the problem of data migration, which results in inaccurate prediction of the RUL of Li-ion batteries. In this study, a novel multi-kernel SVM (MSVM) based on polynomial kernel and radial basis kernel function is proposed. Moreover, the particle swarm optimization algorithm is used to search the kernel parameters, penalty factor, and weight coefficient of the MSVM model. Finally, this paper utilizes the NASA battery dataset to form the observed data sequence for regression prediction. Results show that the improved algorithm not only has better prediction accuracy and stronger generalization ability but also decreases training time and computational complexity.

Studies on Genetic Diversity of Buckwheat Germplasms

Gao, Xiu-Dong,Kim, Jae-Hak,Park, Cheol-Ho,Hong, Soon-Kwan The Plant Resources Society of Korea 2010 한국자원식물학회지 Vol.23 No.3

Many research results have indicated that many kinds of useful ingredients are rich in buckwheat, which have high nutritional values and medicinal properties, so, buckwheat has been cultivated around Asia and Europe. In this paper, genetic diversity of common and tartary buckwheat germplasms were studied based on morphological and molecular markers in order to provide useful information for conservation and utilization of buckwheat genetic resources. The length, width, thick, value and weight of the seed of the common and tartary buckwheat were measured and analyzed by the statistics methods. The result has shown that there are morphological variation both in common buckwheat and tartary buckwheat seeds collected from different regions. It also has shown that the morphological variation of tartary seeds was significantly correlated to geographical regions. The nuclear ribosomal internal transcribed spacers (ITS) of the tartary buckwheat collected from different countries were cloned, sequenced and statistically analyzed. The data showed that ITS sequences were informative to analyze the phylogeny of the tartary buckwheat and the data also showed that the genetic distances varied among different tartary buckwheat seeds collected from different countries.

Nonionic Amphiphilic Surfactant Conjuncted Polyethyleneimine as a New and Highly Efficient Non-viral Gene Carrier

Dong Feng Yin,Cang Chu,Xue Ying Ding,Jing Gao,Hao Zou,Shen Gao 한국고분자학회 2009 Macromolecular Research Vol.17 No.1

Bioavailability of Salvianolic Acid B and Effect on Blood Viscosities after Oral Administration of Salvianolic Acids in Beagle Dogs

Dong-Yan Gao,Li-Mei Han,Li-Hong Zhang,Xiao-Ling Fang,Jian-Xin Wang 대한약학회 2009 Archives of Pharmacal Research Vol.32 No.5

Salvianolic acid B (SalB) is an active component isolated from Chinese herbal medicine Salvia miltiorrhiza. The aim of this study was to investigate the extent of absolute oral bioavailability (F) of SalB in beagle dogs and the effect on blood viscosity after intravenous and oral administration of Salvianolic acids (SAs). A gradient elution HPLC method was developed and validated to determine the concentration of SalB and its three possible metabolites in plasma. After SAs (180 mg/kg, p.o.; 9 mg/kg, i.v.) were given, the AUCs of SalB were 1680 ± 670 and 7840 ± 1140 ng/mL·h, respectively. The F of SalB in dogs was calculated to be only 1.07 ± 0.43%. The blood viscosity was remarkably decreased after a single intravenous injection of SAs (9 mg/kg). However, no significant change of blood viscosity was observed after a single oral administration of SAs (180 mg/kg). The results suggested that the F of SalB was extremely low and single oral administrated SAs had no effect on ameliorating blood viscosity in beagle dogs.

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.

Prediction of Remaining Useful Life of Lithium-ion Battery based on Multi-kernel Support Vector Machine with Particle Swarm Optimization

Dong Gao,Miaohua Huang 전력전자학회 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.5

The estimation of the remaining useful life (RUL) of lithium-ion (Li-ion) batteries is important for intelligent battery management system (BMS). Data mining technology is becoming increasingly mature, and the RUL estimation of Li-ion batteries based on data-driven prognostics is more accurate with the arrival of the era of big data. However, the support vector machine (SVM), which is applied to predict the RUL of Li-ion batteries, uses the traditional single-radial basis kernel function. This type of classifier has weak generalization ability, and it easily shows the problem of data migration, which results in inaccurate prediction of the RUL of Li-ion batteries. In this study, a novel multi-kernel SVM (MSVM) based on polynomial kernel and radial basis kernel function is proposed. Moreover, the particle swarm optimization algorithm is used to search the kernel parameters, penalty factor, and weight coefficient of the MSVM model. Finally, this paper utilizes the NASA battery dataset to form the observed data sequence for regression prediction. Results show that the improved algorithm not only has better prediction accuracy and stronger generalization ability but also decreases training time and computational complexity.

Sterically hindered amine-functionalized MCM-41 composite for efficient carbon dioxide capture

Fei Gao,Cailin Ji,Shougui Wang,Weiwen Wang,Jipeng Dong,Changqing Guo,Yuwen Gao,Guanghui Chen 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.8

A new adsorbent based on sterically hindered amine for efficient CO2 capture was prepared. Mesoporoussilicon MCM-41 was modified by sterically hindered amine AMPD (2-amino-2-methyl-1,3-propanediol) in differentAMPD loadings by a facile solid-state self-assembly approach. The physicochemical properties of the MCM-41@AMPDcomposites were analyzed using XRD, BET, FT-IR and SEM, and the composites were investigated for the CO2 captureperformance, including CO2 capture capacity, adsorption selectivity and cycling stability. Characterization analysesshowed that the AMPD active components were successfully incorporated and well dispersed into the mesoporous siliconMCM-41 surfaces. Adsorption results suggest that the modification by the active ingredient AMPD can significantlyimprove the CO2 capture performance. The MCM-41@AMPD material with an AMPD loading of 7mmol∙g1MCM-41 support exhibits a good CO2 adsorption capacity and CO2 adsorption selectivity, and shows excellent cyclingstability. Furthermore, the isosteric heat of CO2 adsorption on the MCM-41@AMPD-7 material was evaluated by theClausius-Clapeyron equation, and the value was 34-78 kJ∙mol1.

중·한 국가배상제도의 비교연구 -국가배상책임의 성립요건에 대한 고찰-

오동호 ( Dong Gao Wu ) 연세대학교 법학연구원 2007 法學硏究 Vol.17 No.2

Prediction Model of Weld Width during High-Power Disk Laser Welding of 304 Austenitic Stainless Steel

Xiang-Dong Gao,Yan-Xi Zhang 한국정밀공학회 2014 International Journal of Precision Engineering and Vol. No.

Morphology of molten pool is significantly associated with welding quality. In this study, an active vision system was designed to form the shadow of a molten pool to get its morphology information during high-power disk laser welding of Type 304 austenitic stainless steel. The shadow was segmented from the recorded images, and four features of the shadow were defined to describe the morphology of a molten pool. The BP (Back propagation) and RBF (Radial based function) neural networks were established to model the relation between the four features and the solid weld width which is the foremost characteristic of weld quality. The effectiveness of two models were compared and analyzed at different welding speeds, and it was found that the BP model had the better results than RBF. The study focuses on predicting the solid weld width by observing the morphology of a molten pool, and provides a necessary foundation for online monitoring and control of weld width during laser welding.