Cross-Layer Resource Allocation in Multi-interface Multi-channel Wireless Multi-hop Networks

Wei Feng,Suili Feng,Yongzhong Zhang3,Xiaowei Xia 한국전자통신연구원 2014 ETRI Journal Vol.36 No.6

In this paper, an analytical framework is proposed forthe optimization of network performance through jointcongestion control, channel allocation, rate allocation,power control, scheduling, and routing with theconsideration of fairness in multi-channel wireless multihopnetworks. More specifically, the framework modelsthe network by a generalized network utilitymaximization (NUM) problem under an elastic link datarate and power constraints. Using the dual decompositiontechnique, the NUM problem is decomposed into foursubproblems — flow control; next-hop routing; rateallocation and scheduling; power control; and channelallocation — and finally solved by a low-complexitydistributed method. Simulation results show that theproposed distributed algorithm significantly improves thenetwork throughput and energy efficiency compared withprevious algorithms.

Identification and Evaluation of Cytotoxicity of Peptide Liposome Incorporated Citron Extracts in an in Vitro System

Zhang, Xiaowei,Yoon, Hee Jeong,Kang, Min Gyeong,Kim, Gyeong Jin,Shin, Sun Young,Baek, Sang Hong,Lee, Jung Gyu,Bai, Jingjing,Lee, Sang Yoon,Choi, Mi Jung,Hong, Kwonho,Bae, Hojae MDPI 2018 INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES Vol.19 No.2

<P>Citrons have been widely used for medicinal purposes for a long time, but the application of citron in the food industry is still restricted. The extensive advantages of nanotechnology in the food industry have greatly broadened the application of foods. In this study, by employing nanotechnology, we prepared citron-extract nanoparticle with an average size of 174.11 ± 3.89 nm, containing protein peptide and/or liposome. In order to evaluate the toxicity of nanoparticles and to ensure food safety, biological cytotoxicity at the cell and genomic levels was also identified to examine the toxicity of citron extracts by using an in vitro system. Our results demonstrated that the cytotoxicity of citron<SUB>liposome</SUB> was dependent on cell type in high concentrations (1 and 5 mg/mL), selectively against primary human cardiac progenitor cells (hCPCs), and human endothelial progenitor cells (hEPCs) in MTT and lactate dehydrogenase (LDH) assays. Interestingly, for the NIH-3T3 and H9C2 cell lines, cell cytotoxicity was observed with slight genotoxicity, especially from citron<SUB>peptide</SUB> extract for both cell lines. Taken together, our study provides cytotoxicity data on nanoengineered citron extracts according to different cell type as is crucial for further applications.</P>

Experimental study on shear, tensile, and compression behaviors of composite insulated concrete sandwich wall

Zhang, Xiaomeng,Zhang, Xueyong,Liu, Wenting,Li, Zheng,Zhang, Xiaowei,Zhou, Yilun Techno-Press 2021 Advances in concrete construction Vol.11 No.1

A new type of composite insulated concrete sandwich wall (ICS-wall), which is composed of a triangle truss steel wire network, an insulating layer, and internal and external concrete layers, is proposed. To study the mechanical properties of this new ICS-wall, tensile, compression, and shearing tests were performed on 22 specimens and tensile strength and corrosion resistance tests on 6 triangle truss joints. The variables in these tests mainly include the insulating plate material, the thickness of the insulating plate, the vertical distance of the triangle truss framework, the triangle truss layout, and the connecting mode between the triangle truss and wall and the material of the triangle truss. Moreover, the failure mode, mechanical properties, and bearing capacity of the wall under tensile, shearing, and compression conditions were analyzed. Research results demonstrate that the concrete and insulating layer of the ICS-wall are pulling out, which is the main failure mode under tensile conditions. The ICS-wall, which uses a graphite polystyrene plate as the insulating layer, shows better tensile properties than the wall with an ordinary polystyrene plate. The tensile strength and bearing capacity of the wall can be improved effectively by strengthening the triangle truss connection and shortening the vertical distances of the triangle truss. The compression capacity of the wall is mainly determined by the compression capacity of concrete, and the bonding strength between the wall and the insulating plate is the main influencing factor of the shearing capacity of the wall. According to the tensile strength and corrosion resistance tests of Austenitic stainless steel, the bearing capacity of the triangle truss does not decrease after corrosion, indicating good corrosion resistance.

Temperature-Dependent Photovoltaic Characterization of a CdTe/CdSe Nanocrystal’s Solar Cell

Huichao Zhang,Zhengyang Li,Jun Qian,Qiumei Guan,Xiaowei Du,Yiping Cui,Jiayu Zhang 대한금속·재료학회 2014 ELECTRONIC MATERIALS LETTERS Vol.10 No.2

An all-inorganic thin film solar cell was fabricated with colloidal CdTe and CdSe nanocrystals. Its temperaturedependent photovoltaic characterization was measured, and an open circuit voltage decay technique was used to determine the electron lifetime. The photovoltaic parameters, such as the exact carrier lifetime, were remarkably different between under low-temperature region and under temperature above 267 K. It is suggested that the temperature-dependent carrier conductivity results from a thermally-activated hopping process and this nanocrystals device is a kind of donor-acceptor solar cell.

Intraparenchymal Atypical Meningioma in Basal Ganglia Region in a Child : Case Report and Literature Review

Liu, Xiaowei,Zhang, Yuekang,Zhang, Si,Tao, Chuanyuan,Ju, Yan The Korean Neurosurgical Society 2018 Journal of Korean neurosurgical society Vol.61 No.1

Intraparenchymal meningiomas without dural attachment are extremely rare, especially when they occur in basal ganglia region in child. An 8-year-old boy was admitted at our hospital, complaining of recurrent headache and vomiting for 3 months. Neurological examination showed impaired vision and mild paresis of the left extremities. Magnetic resonance imaging demonstrated a lesion located in the right basal ganglia region extending to superasellar cistern with solid, multiple cystic and necrotic components. Computed tomography revealed calcification within the mass. Due to the anterior cerebral artery involvement, a subtotal resection was achieved and postoperative radiotherapy was recommended. Histopathological examination indicated that the lesion was an atypical meningioma. The postoperative rehabilitation was uneventful. Mildly impaired vision and motor weakness of left extremities improved significantly and the patient returned to normal life after surgery. To our knowledge, intraparenchymal atypical meningioma in basal ganglia extending to superasellar cistern was never reported. The significance in differential diagnosis of lesions in basal ganglia should be emphasized.

A Co-design Study of Filters and Oscillator for Low Phase Noise and High Harmonic Rejection

Bing Zhang,Wenmei Zhang,Runbo Ma,Xiaowei Zhang,Junfa Mao 한국전자통신연구원 2008 ETRI Journal Vol.30 No.2

In this paper, we present a novel oscillator (OSC) design. Bandpass filters, which can suppress harmonics, are incorporated into a co-design with an OSC to improve the OSC phase noise and harmonic rejection. The proposed OSC/bandpass filter co-design achieves a phase noise of - 130.1 dBc/Hz/600 kHz and harmonic rejection of 37.94 dB and 40.85 dB for the second and third harmonics, respectively, as compared to results achieved by the OSC before co-design of - 101.6 dBc/Hz/600 kHz and 21.28 dB and 19.68 dB. Good agreement between the measured and simulated results is achieved.

De novo transcriptome assembly and characterization of the 10-hydroxycamptothecin-producing Xylaria sp. M71 following salicylic acid treatment

Xiaowei Ding,Kaihui Liu,Yonggui Zhang,Feihu Liu 한국미생물학회 2017 The journal of microbiology Vol.55 No.11

In the present study, we identified genes that are putatively involved in the production of fungal 10-hydroxycamptothecin via transcriptome sequencing and characterization of the Xylaria sp. M71 treated with salicylic acid (SA). A total of 60,664,200 raw reads were assembled into 26,044 unigenes. BLAST assigned 8,767 (33.7%) and 10,840 (41.6%) unigenes to 40 Gene Ontology (GO) annotations and 108 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, respectively. A total of 3,713 unigenes comprising 1,504 upregulated and 2,209 downregulated unigenes were found to be differentially expressed between SA-induced and control fungi. Based on the camptothecin biosynthesis pathway in plants, 13 functional genes of Xylaria sp. M71 were mapped to the mevalonate (MVA) pathway, suggesting that the fungal 10-hydroxycamptothecin is produced via the MVA pathway. In summary, analysis of the Xylaria sp. M71 transcriptome allowed the identification of unigenes that are putatively involved in 10-hydroxycamptothecin biosynthesis in fungi.

Double 2-dimensional H₂-evoluting catalyst tipped photocatalyst nanowires: A new avenue for high-efficiency solar to H₂ generation

Zhang, Kan,Qian, Shifeng,Kim, Wanjung,Kim, Jung Kyu,Sheng, Xiaowei,Lee, Jun Young,Park, Jong Hyeok Elsevier 2017 Nano energy Vol.34 No.-

<P><B>Abstract</B></P> <P>Asymmetric or symmetric metal-tipped one-dimensional (1D) semiconductors are promising systems for efficient photocatalytic reactions such as solar-to-fuel conversion because of ultrafast exciton dynamics that arise at the specific heterostructure interface. However, synthesizing such unique nanostructures experiencing colloid growth on noble metal that has faced a formidable challenge in practical application because these synthesis conditions are not suitable to deploy in mass production. Here, we report the gram-scale mass production of symmetric MoS<SUB>2</SUB>-tipped CdS nanowires (S-MtC NWs) via edge-terminated attachment in a binary solvent. The factors influencing the formation of symmetric heterostructures are investigated by varying the types of precursors, initial concentration, and solvent composition. Under visible-light irradiation (λ≥420nm), the S-MtC NWs exhibit superior photocatalytic H<SUB>2</SUB> evolution activity (12.6mmol/g/h) compared to common Pt/CdS NWs (2.6mmol/g/h), corresponding to an apparent quantum yield of 37.6% at 420nm. This impressive photocatalytic ability is ascribed to spatially separated redox-active sites in the S-MtC NWs, in which the reduction and oxidation sites are at the MoS<SUB>2</SUB> tip and the CdS stem, respectively. Additionally, it is found that the length of CdS NWs as higher aspect ratio as possible could get better photocatalyst H<SUB>2</SUB> performance. The symmetry of 2D MoS<SUB>2</SUB> tips and 1D CdS NWs may provide advanced avenues for specific co-catalyst decoration, enabling co-catalysts to be selectively located at reduction or oxidation sites for other targeted solar artificial syntheses.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Symmetric 2D tipped 1D heterostructured nanowires were synthesized. </LI> <LI> The tipped structure exhibited the spatially separated redox-active sites. </LI> <LI> Theoretical simulation demonstrated one order of magnitude decrease in energy barrier. </LI> <LI> The photocatalytic performance of symmetric heterostructure was superior to asymmetric counterpart. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Symmetric 2D tipped 1D heterostructured nanowires synthesized by edge-terminated attachment exhibit efficient spatial charge separation effect and the longer the better photocatalytic activity, resulting in photocatalytic H<SUB>2</SUB> activity of 12.6mmol/h·g with excellent long-term durability (>10h) without additional passivation under visible light (λ≥420nm).</P> <P>[DISPLAY OMISSION]</P>

A Lightweight Three-Party Privacy-preserving Authentication Key Exchange Protocol Using Smart Card

( Xiaowei Li ),( Yuqing Zhang ),( Xuefeng Liu ),( Jin Cao ) 한국인터넷정보학회 2013 KSII Transactions on Internet and Information Syst Vol.7 No.5

How to make people keep both the confidentiality of the sensitive data and the privacy of their real identity in communication networks has been a hot topic in recent years. Researchers proposed privacy-preserving authenticated key exchange protocols (PPAKE) to answer this question. However, lots of PPAKE protocols need users to remember long secrets which are inconvenient for them. In this paper we propose a lightweight three-party privacy-preserving authentication key exchange (3PPAKE) protocol using smart card to address the problem. The advantages of the new 3PPAKE protocol are: 1. The only secrets that the users need to remember in the authentication are their short passwords; 2. Both of the users can negotiate a common key and keep their identity privacy, i.e., providing anonymity for both users in the communication; 3. It enjoys better performance in terms of computation cost and security. The security of the scheme is given in the random oracle model. To the best of our knowledge, the new protocol is the first provably secure authentication protocol which provides anonymity for both users in the three-party setting.

NONADDITIVE STRONG COMMUTATIVITY PRESERVING DERIVATIONS AND ENDOMORPHISMS

Zhang, Wei,Xu, Xiaowei Korean Mathematical Society 2014 대한수학회보 Vol.51 No.4

Let S be a nonempty subset of a ring R. A map $f:R{\rightarrow}R$ is called strong commutativity preserving on S if [f(x), f(y)] = [x, y] for all $x,y{\in}S$, where the symbol [x, y] denotes xy - yx. Bell and Daif proved that if a derivation D of a semiprime ring R is strong commutativity preserving on a nonzero right ideal ${\rho}$ of R, then ${\rho}{\subseteq}Z$, the center of R. Also they proved that if an endomorphism T of a semiprime ring R is strong commutativity preserving on a nonzero two-sided ideal I of R and not identity on the ideal $I{\cup}T^{-1}(I)$, then R contains a nonzero central ideal. This short note shows that the conclusions of Bell and Daif are also true without the additivity of the derivation D and the endomorphism T.