Secure and Fine-grained Electricity Consumption Aggregation Scheme for Smart Grid

( Gang Shen ),( Yixin Su ),( Danhong Zhang ),( Huajun Zhang ),( Binyu Xiong ),( Mingwu Zhang ) 한국인터넷정보학회 2018 KSII Transactions on Internet and Information Syst Vol.12 No.4

Currently, many of schemes for smart grid data aggregation are based on a one-level gateway (GW) topology. Since the data aggregation granularity in this topology is too single, the control center (CC) is unable to obtain more fine-grained data aggregation results for better monitoring smart grid. To improve this issue, Shen et al. propose an efficient privacy-preserving cube-data aggregation scheme in which the system model consists of two-level GW. However, a risk exists in their scheme that attacker could forge the signature by using leaked signing keys. In this paper, we propose a secure and fine-grained electricity consumption aggregation scheme for smart grid, which employs the homomorphic encryption to implement privacy-preserving aggregation of users’ electricity consumption in the two-level GW smart grid. In our scheme, CC can achieve a flexible electricity regulation by obtaining data aggregation results of various granularities. In addition, our scheme uses the forward-secure signature with backward-secure detection (FSBD) technique to ensure the forward-backward secrecy of the signing keys. Security analysis and experimental results demonstrate that the proposed scheme can achieve forward-backward security of user’s electricity consumption signature. Compared with related schemes, our scheme is more secure and efficient.

Generalized Stability Criterion for Multi-module Distributed DC System

Liu, Fangcheng,Liu, Jinjun,Zhang, Haodong,Xue, Danhong The Korean Institute of Power Electronics 2014 JOURNAL OF POWER ELECTRONICS Vol.14 No.1

The stability issues of a multi-module distributed DC power system without current-sharing loop are analyzed in this study. The physical understanding of the terminal characteristics of each sub-module is focused on. All the modules are divided into two groups based on the different terminal property types, namely, impedance (Z) and admittance (Y) types. The equivalent circuits of each group are established to analyze the stability issues, and the mathematical equations of the equivalent circuits are derived. A generalized criterion for multi-module distributed systems is proposed based on the stability criterion in a cascade system. The proposed criterion is independent of the power flow direction.

Is there chiral correlation between graphitic layers in double-wall carbon nanotubes?

He, Maoshuai,Xu, Ziwei,Shang, Danhong,Zhang, Xiuyun,Zhang, Hao,Li, Dong,Jiang, Hua,Kauppinen, Esko,Ding, Feng Elsevier 2019 Carbon Vol.144 No.-

<P><B>Abstract</B></P> <P>Because of the unique concentric structure, double-wall carbon nanotubes (DWNTs) possess fascinating properties which depend on the respective chirality of both the outer and the inner tubes. In this work, we study the chiral correlations of DWNTs synthesized by chemical vapor deposition on Fe nanoparticles. Contrary to some recent report, the distribution of chiral angle difference between inner and outer tubes in our work agrees with that calculated for all possible configurations. Remarkably, DWNTs with commensurate structures, <I>i.e</I>. outer and inner tubes have same chiral angles, are observed. The mechanism for the formation of DWNTs with approximately commensurate structures is discussed on the basis of layer by layer model. Furthermore, the interactional energies between the inner and outer walls are calculated to address the stability of different DWNT configurations. This work helps understand the growth mechanism of DWNTs and comprehend their structure stabilities with different configurations.</P> <P><B>Graphical abstract</B></P> <P>Double-wall carbon nanotubes (DWNTs) synthesized by chemical vapor deposition show randomly distributed chiral angle differences between inner and outer tubes. The mechanism for the formation of DWNTs with approximately commensurate structures is discussed based on layer by layer model. The interactional energies between the inner and outer walls are calculated to address the stability of different DWNT configurations.</P> <P>[DISPLAY OMISSION]</P>

Generalized Stability Criterion for Multi-module Distributed DC System

Fangcheng Liu,Jinjun Liu,Haodong Zhang,Danhong Xue 전력전자학회 2014 JOURNAL OF POWER ELECTRONICS Vol.14 No.1

The stability issues of a multi-module distributed DC power system without current-sharing loop are analyzed in this study. The physical understanding of the terminal characteristics of each sub-module is focused on. All the modules are divided into two groups based on the different terminal property types, namely, impedance (Z) and admittance (Y) types. The equivalent circuits of each group are established to analyze the stability issues, and the mathematical equations of the equivalent circuits are derived. A generalized criterion for multi-module distributed systems is proposed based on the stability criterion in a cascade system. The proposed criterion is independent of the power flow direction.

Effects of model resolution and parameterizations on the simulations of clouds, precipitation, and their interactions with aerosols

Lee, Seoung Soo,Li, Zhanqing,Zhang, Yuwei,Yoo, Hyelim,Kim, Seungbum,Kim, Byung-Gon,Choi, Yong-Sang,Mok, Jungbin,Um, Junshik,Choi, Kyoung Ock,Dong, Danhong Copernicus GmbH 2018 Atmospheric Chemistry and Physics Vol.18 No.1

<P>Abstract. This study investigates the roles played by model resolution and microphysics parameterizations in the well-known uncertainties or errors in simulations of clouds, precipitation, and their interactions with aerosols by the numerical weather prediction (NWP) models. For this investigation, we used cloud-system-resolving model (CSRM) simulations as benchmark simulations that adopt high-resolution and full-fledged microphysical processes. These simulations were evaluated against observations, and this evaluation demonstrated that the CSRM simulations can function as benchmark simulations. Comparisons between the CSRM simulations and the simulations at the coarse resolutions that are generally adopted by current NWP models indicate that the use of coarse resolutions as in the NWP models can lower not only updrafts and other cloud variables (e.g., cloud mass, condensation, deposition, and evaporation) but also their sensitivity to increasing aerosol concentration. The parameterization of the saturation process plays an important role in the sensitivity of cloud variables to aerosol concentrations. while the parameterization of the sedimentation process has a substantial impact on how cloud variables are distributed vertically. The variation in cloud variables with resolution is much greater than what happens with varying microphysics parameterizations, which suggests that the uncertainties in the NWP simulations are associated with resolution much more than microphysics parameterizations. </P>

LDL Coating pVEGF/polyethylenimine Complex Enhances Vascular Endothelial Growth Factor Expression

Jian Li,Guang Yang,Min Feng,Hailong Liang,Jun Zhang,Danhong Huang,Siyun Deng,Yuan Shen 한국생물공학회 2012 Biotechnology and Bioprocess Engineering Vol.17 No.6

The major limitations to non-viral gene delivery are relatively low efficiency and cytotoxicity, which need to be addressed in the design of new vectors. In this study,negatively charged low density lipoproteins (LDL) were coated onto positively charged pVEGF/PEI complexes to form pVEGF/PEI/LDL terplexes by a two-step procedure. The biocompatible LDL was introduced to reduce the cytotoxicity of the gene delivery system and increase its affinity to cells. The successful formation of pVEGF/PEI/LDL terplexes was confirmed by their near-neutral and slightly negative surface charges. The pVEGF/PEI/LDL terplexes were well-defined sub-micron spherical particles. On the cell viability assay, both of the PEI/LDL combined vector and pVEGF/PEI/LDL terplexes exhibited much lower cytotoxicity to HeLa cells and HUVE cells than those of PEI and pVEGF/PEI complexes, attributed to the shielding effect of the LDL. pEGFP/PEI/LDL terplexes showed significantly higher transfection efficiency in comparison to pEGFP/PEI complexes in serum-containing medium. pVEGF/PEI/LDL terplexes at their optimal N/P ratio and LDL/PEI weigh ratio induced higher expression levels of VEGF protein in HUVE cells than those of pVEGF/PEI complexes. Therefore, the pVEGF/PEI/LDL terplexes could be used as a promising gene delivery system to enhance VEGF protein expression.

20(S)-ginsenoside Rh2 induces caspase-dependent promyelocytic leukemia-retinoic acid receptor A degradation in NB4 cells via Akt/Bax/caspase9 and TNF-α/caspase8 signaling cascades

Sirui Zhu,Xiaoli Liu,Mei Xue,Yu Li,Danhong Cai,Shijun Wang,Liang Zhang 고려인삼학회 2021 Journal of Ginseng Research Vol.45 No.2

Background: Acute promyelocytic leukemia (APL) is a hematopoietic malignancy driven by promyelocytic leukemia―retinoic acid receptor A (PML-RARA) fusion gene. The therapeutic drugs currently used to treat APL have adverse effects. 20(S)-ginsenoside Rh2 (GRh2) is an anticancer medicine with high effectiveness and low toxicity. However, the underlying anticancer mechanisms of GRh2-induced PML-RARA degradation and apoptosis in human APL cell line (NB4 cells) remain unclear. Methods: Apoptosis-related indicators and PML-RARA expression were determined to investigate the effect of GRh2 on NB4 cells. Z-VAD-FMK, LY294002, and C 87, as inhibitors of caspase, and the phosphatidylinositol 3-kinase (PI3K) and tumor necrosis factor-α (TNF-α ) pathways were used to clarify the relationship between GRh2-induced apoptosis and PML-RARA degradation. Results: GRh2 dose- and time-dependently decreased NB4 cell viability. GRh2-induced apoptosis, cell cycle arrest, and caspase3, caspase8, and caspase9 activation in NB4 cells after a 12-hour treatment. GRh2-induced apoptosis in NB4 cells was accompanied by massive production of reactive oxygen species, mitochondrial damage and upregulated Bax/Bcl-2 expression. GRh2 also induced PML/PML-RARA degradation, PML nuclear bodies formation, and activation of the downstream p53 pathway in NB4 cells. Z-VAD-FMK inhibited caspase activation and significantly reversed GRh2-induced apoptosis and PML-RARA degradation. GRh2 also upregulated TNF-a expression and inhibited Akt phosphorylation. LY294002, an inhibitor of the PI3K pathway, enhanced the antitumor effects of GRh2, and C 87, an inhibitor of the TNF-α pathway, reversed NB4 cell viability, and GRh2-mediated apoptosis in a caspase-8-dependent manner. Conclusion: GRh2 induced caspase-dependent PML-RARA degradation and apoptosis in NB4 cells via the Akt/Bax/caspase9 and TNF-α/caspase8 pathways.