Quantum Cryptanalysis of Multivariate Permutation Problem

Guodong Sun,Shenghui Su,Maozhi Xu 보안공학연구지원센터 2014 International Journal of Security and Its Applicat Vol.8 No.6

Quantum computation is a new computational model based on quantum mechanical principle. Shor invented the polynomial time algorithms for the prime factorization and discrete logarithm problem, which indicated that the cryptosystems based on them are totally unsafe in the quantum world. Grover constructed an algorithm that finds a solution in only O(2n)steps whereas the exhaustive search algorithm needs O(2n) steps on average. In this paper we investigate the cryptanalysis of a new cryptography problem----multivariate permutation problem (MPP), which could be used to design public-key cryptosystem, with the help of the two quantum algorithms. Specially, we discuss the strength of a private key of the REESSE1+ public-key cryptosystem, whose security is based on the hardness of MPP. Besides, some suggestions are also given about the implementation of the REESSE1+.

Cross‑domain health status assessment of three‑phase inverters using improved DANN

Quan Sun,Fei Peng,Hongsheng Li,Jiacai Huang,Guodong Sun 전력전자학회 2023 JOURNAL OF POWER ELECTRONICS Vol.23 No.9

Information and large number of fault labels are required to achieve intelligent health status assessment of three-phase inverters. However, the current signals of inverters cannot be sufficiently collected since open-circuit faults (OCFs) occur briefly, which makes it difficult to determine the OCF mode of the various power switches. A transfer learning model that effectively uses a small amount of sample data to achieve domain adaptation is proposed to address this problem. First, collected fault-sensitive signals are subjected to a continuous wavelet transform (CWT) to obtain two-dimensional image data with more abundant fault feature information. Second, the source domain and target domain features are projected into the same feature space through a domain adversarial neural network (DANN) to achieve multi-domain feature extraction and adaptation. Then, in the feature extraction module of the DANN, the deep residual network (Resnet) structure is used to replace the typical convolutional neural network (CNN) structure. Finally, an intelligent diagnosis network is used to identify the health status of the inverter samples under variable conditions. Experimental results show that the proposed model can accurately and effectively realize the cross-domain health assessment of three-phase inverters in the case of small samples. The accuracy of the proposed model is better than that of other classical transfer learning models.

Prognostics of capacitors for power converters based on data augmentation and IPSO‑GRU

Quan Sun,Lichen Yang,Hongsheng Li,Guodong Sun 전력전자학회 2022 JOURNAL OF POWER ELECTRONICS Vol.22 No.12

Aluminum electrolytic capacitors (AECs) play a crucial role in traction power electronic converters, which are also the most likely to be responsible for breakdowns. Fault prediction for AECs is helpful to realize preventive maintenance and to reduce the cost of the entire system. However, it is restricted by the collected data scale and the period of the deteriorative process of AECs. Thus, this paper takes the advantages of the synthetic minority oversampling technique (SMOTE) that is used to augment the degradation data information and the gate recurrent unit (GRU) that can be suitable for degradation samples to establish a prediction model. An improved particle swarm optimization (IPSO) algorithm is utilized to optimize the hyper parameters of the GRU to promote the feature learning and prediction performance. Thereupon, a prognostics model based on data augmentation and a GRU optimized by IPSO is simulated on a degradation dataset of AECs under an aging test. The results show that the integrated prediction model achieves better accuracy and reliability when compared to some traditional models. Furthermore, the relative error of each prediction point is less than 2.5% for single step and 3.0% for multi-step, respectively.

Cystoscopic Extraction Technique and External Drainage Rescue of a Failed Attempt to Traverse a Severe Transplanted Ureteral Obstruction

Guodong Zhang,Yang Xu,Peng Jin,Zhiyong Xie,Gang Sun 대한비뇨의학회 2013 Investigative and Clinical Urology Vol.54 No.12

Purpose: The aim of this research was to evaluate the efficacy of the cystoscopic extraction and external drainage techniques for unsuccessful antegrade stenting in transplanted severe ureteral obstruction. Materials and Methods: A total of 26 patients with severe transplanted ureteral obstruction in whom the cystoscopic extraction technique and/or external drainage technique was performed were retrospectively evaluated. After the severe obstruction was successfully traversed, balloon dilatation followed by double-J stent insertion was performed. Results: Of the 26 patients (male:female, 9:4; mean age, 38.1 years) who underwent failed ureteral stenting with the conventional procedure, 16 patients underwent successful stenting with the cystoscopic extraction technique, and 10 patients underwent successful stenting following external drainage. The mean serum creatinine of the 26 patients before stenting was 42.9 mg/dL (range, 32.7 to 54.1 mg/dL), which decreased to 10.3 mg/dL (range, 8.7 to 11.8 mg/dL) after stenting. The complications of the procedure were lower abdominal pain in 22 patients and gross hematuria in 9 patients. All complications were relieved with medical care within 3 to 5 days after the procedure. No major complications occurred. Conclusions: The cystoscopic extraction technique and external drainage technique are safe and useful for traversing a severe transplanted ureteral obstruction after a failed conventional procedure.

Erector Spinae Atrophy Correlates with Global Sagittal Imbalance and Postoperative Proximal Junctional Kyphosis Incidence in Lumbar Degenerative Kyphosis

Wang Guodong,Li Yang,Zhang Chenggui,Liu Ping,Sun Jianmin 대한척추외과학회 2024 Asian Spine Journal Vol.18 No.1

Study Design: Retrospective cohort study. Purpose: This study aimed to investigate the relationship between lumbar erector muscle atrophy and global sagittal imbalance in lumbar degenerative kyphosis (LDK) and with postoperative proximal junctional kyphosis. Overview of Literature: Lumbar erector muscle atrophy has been studied in LDK. However, its role in the compensatory mechanism is still under intense discussion, and the role of erector spinae (ES) muscle is always overlooked. Methods: This study enrolled 51 patients with LDK out of 382 patients with adult degenerative spinal deformity. Baseline information was reviewed including demographic data and complications. Sagittal spinopelvic alignments and global imbalance parameters were assessed on full-length X-ray images of the spine. Muscularity and the fatty infiltration area of the ES and multifidus (MF) were measured at the L4/5 level on preoperative magnetic resonance image to evaluate the lumbar erector muscle atrophy. Stratification by sagittal vertical axis (SVA) was performed: group 1 with SVA <100 mm and group 2 with SVA >100 mm, and these groups were compared. Spearman correlation and multivariable logistic regression analyses were performed to analyze and define risk factors of postoperative proximal junctional kyphosis (PJK). Results: Group 2 had lower ES and MF muscularity than group 1. ES muscularity correlated with SVA (r=−0.510, p=0.003), lumbar lordosis (r=−0.415, p=0.018), and postoperative PJK (r=−0.508, p=0.022). MF muscularity did not correlate with the above parameters. Multivariable logistic regression analysis verified ES muscularity (odds ratio [OR], 0.001; p=0.039) and SVA (OR, 1.034; p=0.048) as the risk factors for postoperative PJK. Conclusions: ES atrophy, besides the MF, is an important predictor in distinguishing decompensated LDK from well-compensated ones. It plays an important role in compensatory mechanism, not only correlates with global sagittal imbalance but also ties to PJK after deformity corrective surgery.

Sandwich Structure Electrode as Advanced Performance Anode for Lithium-Ion Batteries

Wei Chengcheng,Sun Xiaogang,Liang Guodong,Huang Yapan,Hu Hao,Xu Yuhao 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.10

In this work, a sandwich structure electrode was prepared by a simple vacuum filtration and rolling process. The SEM showed that the active materials were uniformly embedded in the pores of the three-dimensional conductive network of the carbon nanotube (CNTs) conductive paper. The contact interface area of active material and the conductive network significantly increased and the interface resistance was greatly reduced. The porous anode can accommodate the volume expansion of the silicon and effectively alleviated pressed during cycle. The electrode also exhibited good stability in cycles. Electrochemical tests showed that the first discharge specific capacity of the sandwich electrode reached 2330 mAh/g with a coulombic efficiency of 86%. After 500 cycles, the specific capacity was still maintained at 1512 mAh/g. At a large current density of 2 A/g, the specific capacity hold was 840 mAh/g compared with the copper foil electrode of 100 mAh/g.

Circulating MiRNA-21-enriched extracellular vesicles promote bone remodeling in traumatic brain injury patients

Lin Ze,Xiong Yuan,Sun Yun,Zeng Ruiyin,Xue Hang,Hu Yiqiang,Chen Lang,Liu Guodong,Panayi Adriana C.,Zhou Wu,Cao Faqi,Gao Fei,Mi Bobin,Liu Guohui 생화학분자생물학회 2023 Experimental and molecular medicine Vol.55 No.-

Fracture combined with traumatic brain injury (TBI) is one of the most common and serious types of compound trauma in the clinic and is characterized by dysfunction of cellular communication in injured organs. Our prior studies found that TBI was capable of enhancing fracture healing in a paracrine manner. Exosomes (Exos), as small extracellular vesicles, are important paracrine vehicles for noncell therapy. However, whether circulating Exos derived from TBI patients (TBI-Exos) regulate the prohealing effects of fractures remains unclear. Thus, the present study aimed to explore the biological effects of TBI-Exos on fracture healing and reveal the potential molecular mechanism. TBI-Exos were isolated by ultracentrifugation, and the enriched miR-21-5 p was identified by qRT‒PCR analysis. The beneficial effects of TBI-Exos on osteoblastic differentiation and bone remodeling were determined by a series of in vitro assays. Bioinformatics analyses were conducted to identify the potential downstream mechanisms of the regulatory effect of TBI-Exos on osteoblasts. Furthermore, the role of the potential signaling pathway of TBI-Exos in mediating the osteoblastic activity of osteoblasts was assessed. Subsequently, a murine fracture model was established, and the effect of TBI-Exos on bone modeling was demonstrated in vivo. TBI-Exos can be internalized by osteoblasts, and in vitro, suppression of SMAD7 promoted osteogenic differentiation, whereas knockdown of miR-21-5 p in TBI-Exos strongly inhibited this bone-beneficial effect. Similarly, our results confirmed that preinjection of TBI-Exos led to enhanced bone formation, whereas knockdown of exosomal miR-21-5 p substantially impaired this bone-beneficial effect in vivo.

Electrochemical Properties of Supercapacitors Using Boron Nitrogen Double-Doped Carbon Nanotubes as Conductive Additive

Hao Hu,Xiaogang Sun,Wei Chen,Jie Wang,Xu Li,Yapan Huang,Chengcheng Wei,Guodong Liang 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.7

Carbon nanotubes (CNTs) were doped by ammonium borate as the sources of nitrogen and boron. Under the protection of Ar gas, boron-nitrogen doped CNTs were prepared through nitriding and boronization at high temperature. It is a conductive additive. Then, the obtained CNTs were mixed with activated carbon (AC), SP, sodium dodecyl sulfate (SDS), and cellulose fiber to prepare electrodes. With all the materials, a symmetric electric double-layer supercapacitor (EDLC) was assembled. Next, the materials and electrodes were also characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The factors, chemical connections, and specific surface area of the CNTs were analyzed by X-ray energy spectrum analysis (EDS), X-ray photoelectron spectroscopy (XPS), as well as a specific surface area and porosimetry analyzer (BET). In addition, the electrochemical performances of electric double-layer capacitors were tested with the help of cyclic voltammetry, constant-current charging and discharging, and so on. From the results, we can make a conclusion, that is, both B and N atoms were added into the CNTs and formed bonds successfully with carbon atoms mutually. Besides, the specific surface area is about 1.5 times than that of the CNT. When the charge/discharge current density reaches 50 mA/g, we can find that the mass specific capacitance of the capacitor can run up to 32.19 F/g. Also, we observe that the maximum power density is close to 220 W/kg (700 mA/g), and the energy density can arrive 9.31 Wh/kg (50 mA/g). Based on the impedance test, the electrodes are characterized with low impedance. After 2000 cycles, the boron-nitrogen doped double-layer capacitors maintain a capacitance retention ratio of above 95%. Its power density can still achieve 220 W/kg when the energy density keeps at 3.46 Wh/kg. In other words, the electrochemical performance functions of the electric double-layer capacitors are enhanced while the CNTs serve as the electrodes.

A comparative study on antioxidant, anti-inflammatory, antimicrobial activities and chemical composition of Pyrus ussuriensis cultivars from northeastern China

Xiaoqian Wang,Chunyan Liu,Qiang Wang,Chang Liu,Huili Sun,Maojun Zhang,Deguo Lyu,Guodong Du 한국원예학회 2021 Horticulture, Environment, and Biotechnology Vol.62 No.3

Pyrus ussuriensis is the most important cultivated pear in the northeastern, cold areas of China. However, studies on thebiological activity of Pyrus ussuriensis fruit are rare in the public domain. The present study compared antioxidant, antiinflammatory, and antimicrobial activities and chemical composition in tissues from the peel and fl esh of nine Pyrus ussuriensiscultivars. The chemical composition diff ered among cultivars and tissue sources. Phenolics were predominant in peelsamples, whereas sugars were predominant in fl esh samples. Twenty-one phenolic compounds were identifi ed and quantifi ed,including hydroxycinnamic acids, hydroquinones, fl avanols, fl avonols, fl avones, and anthocyanins (only in peel samples). The total phenolic content ranged between 363.0 and 1734.0 mg kg − 1 FW in the peel and from 28.5 to 182.3 mg kg − 1 FWin the fl esh. In addition, cultivars with high total phenolic and fl avonoid contents had signifi cantly higher antioxidant activities. The in vitro anti-infl ammatory study, performed using an egg albumin denaturation assay, demonstrated that both peeland fl esh samples had strong activity, which was comparable with that of the standard anti-infl ammatory drug diclofenacsodium. The antimicrobial results showed that ‘Jianba’ and ‘Balixiang’ cultivars exhibited strong activity against bacteriastrains in the peel and fl esh, respectively. The present study provided information for selecting promising Pyrus ussuriensiscultivars with improved health benefi ts.

Efficient Constitutive Expression of Cellulolytic Enzymes in Penicillium oxalicum for Improved Efficiency of Lignocellulose Degradation

( Pankajkumar Ramdas Waghmare ),( Pratima Pankajkumar Waghmare ),( Liwei Gao ),( Wan Sun ),( Yuqi Qin ),( Guodong Liu ),( Yinbo Qu ) 한국미생물생명공학회(구 한국산업미생물학회) 2021 Journal of microbiology and biotechnology Vol.31 No.5

Efficient cellulolytic enzyme production is important for the development of lignocellulose-degrading enzyme mixtures. However, purification of cellulases from their native hosts is time- and labor-consuming. In this study, a constitutive expression system was developed in Penicillium oxalicum for the secreted production of proteins. Using a constitutive polyubiquitin gene promoter and cultivating with glucose as the sole carbon source, nine cellulolytic enzymes of different origins with relatively high purity were produced within 48 h. When supplemented to a commercial cellulase preparation, cellobiohydrolase I from P. funiculosum and cellobiohydrolase II from Talaromyces verruculosus showed remarkable enhancing effects on the hydrolysis of steam-exploded corn stover. Additionally, a synergistic effect was observed for these two cellobiohydrolases during the hydrolysis. Taken together, the constitutive expression system provides a convenient tool for the production of cellulolytic enzymes, which is expected to be useful in the development of highly efficient lignocellulose-degrading enzyme mixtures.