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.

Which Indicator Among Lumbar Vertebral Hounsfield Unit, Vertebral Bone Quality, or Dual-Energy X-Ray Absorptiometry-Measured Bone Mineral Density Is More Efficacious in Predicting Thoracolumbar Fragility Fractures?

Bo Zhang,Lu-Ping Zhou,Xian-Liang Zhang,Dui Li,Jia-Qi Wang,Chong-Yu Jia,Hua-Qing Zhang,Liang Kang,Ren-Jie Zhang,Cai-Liang Shen 대한척추신경외과학회 2023 Neurospine Vol.20 No.4

Objective: Hounsfield units (HU), vertebral bone quality (VBQ), and bone mineral density (BMD) can all serve as predictive indicators for thoracolumbar fragility fractures. This study aims to explore which indicator provides better risk prediction for thoracolumbar fragility fractures. Methods: Patients who have received medical attention from The First Affiliated Hospital of Anhui Medical University for thoracolumbar fragility fractures were selected. A total of 78 patients with thoracolumbar fragility fractures were included in the study. To establish a control group, 78 patients with degenerative spinal diseases were matched to the fracture group on the basis of gender, age, and body mass index. The lumbar vertebral HU, the VBQ, and the BMD were obtained for all the 156 patients through computed tomography, magnetic resonance imaging, and dual-energy x-ray absorptiometry (DEXA). The correlations among these parameters were analyzed. The area under curve (AUC) analysis was employed to assess the predictive efficacy and thresholds of lumbar vertebral HU, VBQ, and BMD in relation to the risk of thoracolumbar fragility fractures. Results: Among the cohort of 156 patients, lumbar vertebral HU exhibited a positive correlation with BMD (p < 0.01). Conversely, VBQ showed a negative correlation with HU, BMD (p < 0.05). HU and BMD displayed a favorable predictive efficacy for thoracolumbar fragility fractures (p < 0.01), with HU (AUC = 0.863) showcasing the highest predictive efficacy, followed by the DEXA-measured BMD (AUC = 0.813). VBQ (AUC = 0.602) ranked lowest among the 3 indicators. The thresholds for predicting thoracolumbar fragility fractures were as follows: HU (88),VBQ (3.37), and BMD (0.81). Conclusion: All 3 of these indicators, HU, VBQ, and BMD, can predict thoracolumbar fragility fractures. Notably, lumbar vertebral HU exhibits the highest predictive efficacy, followed by the BMD obtained through DEXA scanning, with VBQ demonstrating the lowest predictive efficacy.

A Single Chord Localization Algorithm for Wireless Sensor Networks

Yong-Luo Shen,Yuan Zhang,Yu-Ping Hu,Jun Zhang 보안공학연구지원센터 2015 International Journal of Grid and Distributed Comp Vol.8 No.1

This paper presents a novel range-free single chord localization algorithm with low energy consumption and high accuracy for wireless sensor networks. A mobile anchor node and a mobile reference node are employed to periodically broadcast beacon messages and reference messages, respectively. Each sensor node is equipped with a received signal strength indicator for comparing the signal strength. By using the edge function and the result of comparing signal strength, each sensor node only needs one chord on the communication circle for localization. Compared with previous approaches that require multiple chords, less beacon messages are required by the sensor nodes. In the proposed algorithm, the localization error mainly depends on the move distance interval. However, for the other approaches, large localization errors can be observed according to the angle between chords which may descend the localization accuracy dramatically. Analysis results indicate that the proposed algorithm is superior to other approaches in energy consumption and localization accuracy.

Comparative Study of Field-Oriented Control in Different Coordinate Systems for DTP-PMSM

Zhang, Ping,Zhang, Wei,Shen, Xiaofeng Journal of International Conference on Electrical 2013 Journal of international Conference on Electrical Vol.2 No.3

This paper performs two kinds of Field-Oriented Control (FOC) for dual three phase permanent magnet synchronous motor (DTP-PMSM).The first is based on vector space decomposition to study the effect of current harmonics on electromechanical energy conversion. And the second presents the coupling relations between two sets of windings using two d-q transformation. And then this paper has deeply studied the differences between these two strategies, the different effect on the control of harmonic current and the reason for these differences. MATLAB-based Simulation studies of a 3KW DTP-PMSM are carried out to verify the analysis of differences between the two FOC strategies.

Vascular bundle xylem water transport repression and cell anatomical structure differences may lead to berry cracking near the proximal end

Zhang Chuan,Cui Liwen,Shen Meng,Yadav Vivek,Zhong Haixia,Zhang Fuchun,Zhou Xiaoming,Wu Xinyu 한국원예학회 2024 Horticulture, Environment, and Biotechnology Vol.65 No.2

Grape berries often crack near the proximal end, which may be related to water absorption and their cellular anatomical structure. To study the relationship between water absorption, cell anatomical structures, and berry cracking near the proxi mal end, 49 varieties were selected. Eighteen were prone to cracking near the proximal end, while 31 were resistant. An in vitro soaking experiment on ripe berries measured the diff erence in berry-cracking degrees among diff erent varieties. In vitro staining was used to trace water absorption and paraffi n sections were prepared to observe and analyze the struc tural parameters of diff erent tissues. Results showed that the cracking rate and water uptake of the crack-prone berries were signifi cantly higher than those of the crack-resistant berries. Fruit prone to cracking was characterized by a thinner cuticle, epidermis, and sub-epidermis. After staining, it was found that dye absorption was limited to the berry near the proximal end. Other cell size parameters may also lead to cracking near the proximal end. By tracing water transport and analyzing diff erences in cell structure characteristics among varieties, we speculated that the vascular bundle xylem water transport repression and diff erences in cell anatomical structures may have led to berry cracking near the proximal end. The reasons for berry cracking near the proximal end were preliminarily explained, providing theoretical support for further screening of crack-resistant varieties.

Numerical study of flow of Oldroyd-3-Constant fluids in a straight duct with square cross-section

Zhang, Mingkan,Shen, Xinrong,Ma, Jianfeng,Zhang, Benzhao The Korean Society of Rheology 2007 Korea-Australia rheology journal Vol.19 No.2

A finite volume method (FVM) base on the SIMPLE algorithm as the pressure correction strategy and the traditional staggered mesh is used to investigate steady, fully developed flow of Oldroyd-3-constant fluids through a duct with square cross-section. Both effects of the two viscoelastic material parameters, We and ${\mu}$, on pattern and strength of the secondary flow are investigated. An amusing sixteen vortices pattern of the secondary flow, which has never been reported, is shown in the present work. The reason for the changes of the pattern and strength of the secondary flow is discussed carefully. We found that it is variation of second normal stress difference that causes the changes of the pattern and strength of the secondary flow.

Possible Epithelial Ovarian Cancer Association with HPV18 or HPV33 Infection

Zhang, Pei-Pei,Zhou, Lei,Cao, Jia-Shi,Li, Yi-Ping,Zeng, Zhi,Sun, Ni,Shen, Li,Zhu, Hao-Yue,Ruan, Yang,Zha, Wen-Ting,Wang, Xin-Yu,Zhang, Ke-Qiang,Zhang, Ran Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.6

The present study was conducted to investigate the prevalence of HPV infection in epithelial ovarian cancer (EOC) in Hunan province. DNA samples were collected from paraffin embedded ovarian tissue from 322 patients with EOC, 99 with ovarian benign tumors and 199 normal persons. The polymerase chain reaction and direct sequencing were used to identify the HPV types in the samples. The relationship between the infection of human papillomavirus (HPV) and the epithelial ovarian carcinoma (EOC) was investigated combined with clinical data. The prevalence of HPV18 and HPV33 in EOC group and benign group was higher than in the normal group. HPV18 and HPV33 may play a role in the development of both EOC and ovarian benign tumor and may participate in the development of EOC with traditional risk factors, family history and abortion, possibly exerting synergistic effects.

FINITE NON-NILPOTENT GENERALIZATIONS OF HAMILTONIAN GROUPS

Shen, Zhencai,Shi, Wujie,Zhang, Jinshan Korean Mathematical Society 2011 대한수학회보 Vol.48 No.6

In J. Korean Math. Soc, Zhang, Xu and other authors investigated the following problem: what is the structure of finite groups which have many normal subgroups? In this paper, we shall study this question in a more general way. For a finite group G, we define the subgroup $\mathcal{A}(G)$ to be intersection of the normalizers of all non-cyclic subgroups of G. Set $\mathcal{A}_0=1$. Define $\mathcal{A}_{i+1}(G)/\mathcal{A}_i(G)=\mathcal{A}(G/\mathcal{A}_i(G))$ for $i{\geq}1$. By $\mathcal{A}_{\infty}(G)$ denote the terminal term of the ascending series. It is proved that if $G=\mathcal{A}_{\infty}(G)$, then the derived subgroup G' is nilpotent. Furthermore, if all elements of prime order or order 4 of G are in $\mathcal{A}(G)$, then G' is also nilpotent.

Semiparametric ARCH-X Model for Leverage Effect and Long Memory in Stock Return Volatility

Shen Zhang,한희준 한국계량경제학회 2014 계량경제학보 Vol.25 No.3

This paper investigates a new semiparametric ARCH-X model to account for both leverage effect and long memory property in volatility. It is a partial linear model combining a nonparametric ARCH component and an exogenous covariate that is persistent in memory. This model can allow for a flexible functional form of the asymmetric relationship between stock return and volatility and generate the long memory property in volatility. We adopt a realized volatility measure as the covariate in our model. For the daily FTSE 100 Index return series, the nonparametric component of our model captures the leverage effect and is estimated to be a complex nonlinear function. It is shown that our model outperforms other parametric or nonparametric volatility models both in within-sample and out-of-sample forecasts.

Spatial analysis of tuberculosis treatment outcomes in Shanghai: implications for tuberculosis control

Zhang Jing,Shen Xin,Yang Chongguang,Chen Yue,Guo Juntao,Wang Decheng,Zhang Jun,Lynn Henry,Hu Yi,Pan Qichao,Zhang Zhijie 한국역학회 2022 Epidemiology and Health Vol.44 No.-

OBJECTIVES: Tuberculosis (TB) treatment outcomes are a key indicator in the assessment of TB control programs. We aimed to identify spatial factors associated with TB treatment outcomes, and to provide additional insights into TB control from a geographical perspective.METHODS: We collected data from the electronic TB surveillance system in Shanghai, China and included pulmonary TB patients registered from January 1, 2009 to December 31, 2016. We examined the associations of physical accessibility to hospitals, an autoregression term, and random hospital effects with treatment outcomes in logistic regression models after adjusting for demographic, clinical, and treatment factors.RESULTS: Of the 53,475 pulmonary TB patients, 49,002 (91.6%) had successful treatment outcomes. The success rate increased from 89.3% in 2009 to 94.4% in 2016. The successful treatment outcome rate varied among hospitals from 78.6% to 97.8%, and there were 12 spatial clusters of poor treatment outcomes during the 8-year study period. The best-fit model incorporated spatial factors. Both the random hospital effects and autoregression terms had significant impacts on TB treatment outcomes, ranking 6th and 10th, respectively, in terms of statistical importance among 14 factors. The number of bus stations around the home was the least important variable in the model.CONCLUSIONS: Spatial autocorrelation and hospital effects were associated with TB treatment outcomes in Shanghai. In highly-integrated cities like Shanghai, physical accessibility was not related to treatment outcomes. Governments need to pay more attention to the mobility of patients and different success rates of treatment among hospitals.