An FPGA-Based Modified Adaptive PID Controller for DC/DC Buck Converters

Lv, Ling,Chang, Changyuan,Zhou, Zhiqi,Yuan, Yubo The Korean Institute of Power Electronics 2015 JOURNAL OF POWER ELECTRONICS Vol.15 No.2

On the basis of the conventional PID control algorithm, a modified adaptive PID (MA-PID) control algorithm is presented to improve the steady-state and dynamic performance of closed-loop systems. The proposed method has a straightforward structure without excessively increasing the complexity and cost. It can adaptively adjust the values of the control parameters ($K_p$, $K_i$ and $K_d$) by following a new control law. Simulation results show that the line transient response of the MA-PID is better than that of the adaptive digital PID because the differential coefficient $K_d$ is introduced to changes. In addition, experimental results based on a FPGA indicate that the MA-PID control algorithm reduces the recovery time by 62.5% in response to a 1V line transient, 50% in response to a 500mA load transient, and 23.6% in response to a steady-state deviation, when compared with the conventional PID control algorithm.

An FPGA-Based Modified Adaptive PID Controller for DC/DC Buck Converters

Ling Lv,Changyuan Chang,Zhiqi Zhou,Yubo Yuan 전력전자학회 2015 JOURNAL OF POWER ELECTRONICS Vol.15 No.2

On the basis of the conventional PID control algorithm, a modified adaptive PID (MA-PID) control algorithm is presented to improve the steady-state and dynamic performance of closed-loop systems. The proposed method has a straightforward structure without excessively increasing the complexity and cost. It can adaptively adjust the values of the control parameters (Kp, Ki and Kd) by following a new control law. Simulation results show that the line transient response of the MA-PID is better than that of the adaptive digital PID because the differential coefficient Kd is introduced to changes. In addition, experimental results based on a FPGA indicate that the MA-PID control algorithm reduces the recovery time by 62.5% in response to a 1V line transient, 50% in response to a 500mA load transient, and 23.6% in response to a steady-state deviation, when compared with the conventional PID control algorithm.

The changes in the proteolysis activity and the accumulation of free amino acids during chinese traditional dry-cured loins processing

Chang-Yu Zhou,Ying Wang,Dao-Dong Pan,Jin-Xuan Cao,Yin-Ji Chen,Yuan Liu,Yang-Ying Sun,Chang-Rong Ou 한국식품과학회 2017 Food Science and Biotechnology Vol.26 No.3

Twelve pieces of longissimus dorsi were processed into Chinese traditional dry-cured loins. The changes in the proteolylic enzymes activities, myofibrillar proteins degradation, and free amino acids content were investigated during processing. Compared with fresh piece (0 day), the cathepsin B ? L and calpains activities decreased after dry-curing and maintained potential activities values of 23.25 and 15.04% in the final products, respectively. The myosin heavy chain (MHC) and C protein were intensely degraded at the dry-ripened stage; the 50 kDa desmin increased at day 2 and then disappeared at day 11. The total free amino acids content increased from 333.18 mg/100 g in the raw to 1096.54 mg/100 g at the end of the dry-ripening. This work provided a mechanism for the accumulation of free amino acids and predicted the proteolysis extent of myofibrillar proteins by monitoring the changes of three marker proteins (MHC, C protein and 50 kDa desmin) during Chinese traditional dry-cured loins processing. Keywords

The influence of bone graft procedures on primary stability and bone change of implants placed in fresh extraction sockets

Jun, Sang Ho,Park, Chang-Joo,Hwang, Suk-Hyun,Lee, Youn Ki,Zhou, Cong,Jang, Hyon-Seok,Ryu, Jae-Jun Korean Association of Maxillofacial Plastic and Re 2018 Maxillofacial Plastic Reconstructive Surgery Vol.40 No.-

Background: This study was to evaluate the effect of bone graft procedure on the primary stability of implants installed in fresh sockets and assess the vertical alteration of peri-implant bone radiographically. Methods: Twenty-three implants were inserted in 18 patients immediately after tooth extraction. The horizontal gap between the implant and bony walls of the extraction socket was grafted with xenografts. The implant stability before and after graft procedure was measured by Osstell Mentor as implant stability quotient before bone graft (ISQ bbg) and implant stability quotient after bone graft (ISQ abg). Peri-apical radiographs were taken to measure peri-implant bone change immediately after implant surgery and 12 months after implant placement. Data were analyzed by independent t test; the relationships between stability parameters (insertion torque value (ITV), ISQ abg, and ISQ bbg) and peri-implant bone changes were analyzed according to Pearson correlation coefficients. Results: The increase of ISQ in low primary stability group (LPSG) was 6.87 ± 3.62, which was significantly higher than the increase in high primary stability group (HPSG). A significant correlation between ITV and ISQ bbg (R = 0.606, P = 0.002) was found; however, age and peri-implant bone change were not found significantly related to implant stability parameters. It was presented that there were no significant peri-implant bone changes at 1 year after bone graft surgery. Conclusions: Bone graft procedure is beneficial for increasing the primary stability of immediately placed implants, especially when the ISQ of implants is below 65 and that bone grafts have some effects on peri-implant bone maintenance.

A Study on the Effect of Corporate Social Responsibility (CSR) on Earning Management of Chinese Companies

Zhou Bo,Kim, Jung-Ho,Im, Chae-Chang 한국경영컨설팅학회 2021 경영컨설팅연구 Vol.21 No.2

본 연구는 기업이 사회적 책임 활동이 이익조정에 미치는 영향을 중국의 상장기업을 중심으로 분석하고자 한다. 중국 상하이증권거래소에 상 장된 기업을 중심으로 2011년부터 2016년까지의 표본을 설정하였다. 기업의 사회적 책임활동(CSR)은 중국의 사회적 책임 평가기관인 RKS(Rankings CSR의 CSR 평가 점수를 활용하였으며, 기업의 재무정보 자료는 CSMAR (China StockMarket &Accounting Research Database) 에서 활용하였다. 그리고 기업의 이익조정은 수정 존스 모형의 재량적 발생액의 측정치를 사용하여 실증 분석하였다. 중국의 경우도 한국의 결과와 유사하게 CSR활동은 이익조정에 유의한 음(-)의 영향을 미치는 것으로 나타났다. 즉, 사회적 책임 활동의 대용 치인 RKS지수가 높을수록 이익조정이 감소(-)하는 것으로 나타나 기업의 회계투명성이 높을 것이다. 따라서 회계투명성이 높은 기업일수록 그 기업이 제공하는 회계정보에 대한 유용성과 신뢰도는 높아지므로 그 어느 때보다도 기업의 사회적 책임 활동의 중요성이 커지고 있다. The purpose of this study is to analyze the effect of corporate social responsibility (CSR) contribution activities on the earnings management of Chinese listed companies.We set up a sample of companies listed on the Shanghai Stock Exchange in China from2011 to 2016. The CSR Index is based on the CSR scores evaluated by RKS (Rankings CSR Ratings), a social responsibility assessment agency, and financial data from the CSMAR (China Stock Market & Accounting Research Database) in China. The level of earnings management of the companies was analyzed using the discretionary amount based on a revised Jonesmodel. The results of the study showed that Chinese companies with CSR performance had lower levels of earnings management similar to those of a reported Korean study. As accounting transparencies are higher than corporate’s provided usefulness and credibility of accounting information, CSR activities are becomingmore important nowthan they have ever been.

Comparison of the effect of lithium bentonite and sodium bentonite on the engineering properties of bentonite-cement-sodium silicate grout

Zhou, Yao,Wang, Gui H.,Chang, Yong H. Techno-Press 2020 Advances in concrete construction Vol.9 No.3

This paper focuses on the engineering properties of Bentonite-Cement-Sodium silicate (BCS) grout, which was prepared by partially replacing the ordinary Portland cement in Cement-Sodium silicate grout with lithium bentonite (Li-bent) and sodium bentonite (Na-bent), respectively. The effect of different Water-to-Solid ratio (W/S) and various replacement percentages of bentonite on the apparent viscosity, bleeding, setting time, and early compressive strength of BCS grout were investigated. The XRD method was used to detect its hydration products. The results showed that both bentonites played a positive role in the stability of BCS grout, increased its apparent viscosity. Na-bent prolonged the setting time of BCS, while 5% of Li-bent shortened the setting time of BCS. The XRD analysis indicated that the hydration products between the mixture containing Na-bent and Li-bent did not differ much. Using bentonite as supplementary cementitious material (SCM) to replace partial cement is a promising way to cut down on carbon dioxide emissions and to produce low-cost, eco-friendly, non-toxic, and water-resistant grout. In addition, Li-bent was superior to Na-bent in improving the strength and the thickening of BCS grouts.

Assessment of the crest cracks of the Pubugou rockfill dam based on parameters back analysis

Zhou, Wei,Li, Shao-Lin,Ma, Gang,Chang, Xiao-Lin,Cheng, Yong-Gang,Ma, Xing Techno-Press 2016 Geomechanics & engineering Vol.11 No.4

The crest of the Pubugou central core rockfill dam (CCRD) cracked in the first and second impounding periods. To evaluate the safety of the Pubugou CCRD, an inversion analysis of the constitutive model parameters for rockfill materials is performed based on the in situ deformation monitoring data. The aim of this work is to truly reflect the deformation state of the Pubugou CCRD and determine the causes of the dam crest cracks. A novel real-coded genetic algorithm based upon the differences in gene fragments (DGFX) is proposed. It is used in combination with the radial based function neural network (RBFNN) to perform the parameters back analysis. The simulated settlements show good agreements with the monitoring data, illustrating that the back analysis is reasonable and accurate. Furthermore, the deformation gradient of the dam crest has been analysed. The dam crest has a great possibility of cracking due to the uncoordinated deformation, which agrees well with the field investigation. The deformation gradient decreases to the value lower than the critical one and reaches a stable state after the second full reservoir.

Fin-Width Effects on Characteristics of InGaAs-Based Independent Double-Gate FinFETs

Chang, Sung-Jae,Zhou, Hong,Gong, Nanbo,Kang, Dong-Min,Lim, Jong-Won,Si, Mengwei,Ye, Peide D.,Ma, T. P. IEEE 2017 IEEE electron device letters Vol.38 No.4

<P>We report the characteristics of InGaAs-based independent double-gate FinFETs with Al2O3/LaAlO3 as gate dielectric. The device can be operated in three different modes ( i. e., single-, double-, and independent double-gate) made possible by the physically separated two sidewall gates. When the device is operated in the double-gatemode, it exhibits better performance in terms of the On/Off current ratio, subthreshold swing, Off current, and channel mobility than in the single-gate mode. In addition, independent double-gate operation makes it possible to modulate channel properties by applying a bias at the opposite gate via gate coupling effects. Our systematicmeasurements reveal that gate control and coupling effects are enhanced with reduced fin width.</P>

Analytical Solution of Transient Dynamic Response of Spherical Cavity in Viscoelastic and Saturated Soils

Chang-Jie Xu,Qizhi Chen,Jian Zhou,Yuanqiang Cai 대한토목학회 2015 KSCE Journal of Civil Engineering Vol.19 No.7

Based on the Biot’s theory of wave propagation in porous media, this paper studies the transient dynamic response of spherical cavity in viscoelastic and saturated soils. The analytical solution in transformed domain is obtained by the method of Laplace transformation, and numerical results are solved through inversed Laplace transformation. The displacements, stresses and pore water pressure developed in the viscoelastic soils are analyzed and compared with those from elastic model, and some new observations are discussed and interpreted from the perspective of material's properties. The findings resulting from the current study are helpful to analyzing the transient dynamic responses of underground structures in the engineering practice.

Improved resolution in single-molecule localization microscopy using QD-PAINT

Chang Yeonho,Kim Do-Hyeon,Zhou Kai,Jeong Min Gyu,Park Soyeon,Kwon Yonghoon,Hong Triet Minh,Noh Jungeun,Ryu Sung Ho 생화학분자생물학회 2021 Experimental and molecular medicine Vol.53 No.-

Single-molecule localization microscopy (SMLM) has allowed the observation of various molecular structures in cells beyond the diffraction limit using organic dyes. In principle, the SMLM resolution depends on the precision of photoswitching fluorophore localization, which is inversely correlated with the square root of the number of photons released from the individual fluorophores. Thus, increasing the photon number by using highly bright fluorophores, such as quantum dots (QDs), can theoretically fundamentally overcome the current resolution limit of SMLM. However, the use of QDs in SMLM has been challenging because QDs have no photoswitching property, which is essential for SMLM, and they exhibit nonspecificity and multivalency, which complicate their use in fluorescence imaging. Here, we present a method to utilize QDs in SMLM to surpass the resolution limit of the current SMLM utilizing organic dyes. We confer monovalency, specificity, and photoswitchability on QDs by steric exclusion via passivation and ligand exchange with ptDNA, PEG, and casein as well as by DNA point accumulation for imaging in nanoscale topography (DNA-PAINT) via automatic thermally driven hybridization between target-bound docking and dye-bound complementary imager strands. QDs are made monovalent and photoswitchable to enable SMLM and show substantially better photophysical properties than Cy3, with higher fluorescence intensity and an improved resolution factor. QD-PAINT displays improved spatial resolution with a narrower full width at half maximum (FWHM) than DNA-PAINT with Cy3. In summary, QD-PAINT shows great promise as a next-generation SMLM method for overcoming the limited resolution of the current SMLM.