A Lifetime-Preserving and Delay-Constrained Data Gathering Tree for Unreliable Sensor Networks

( Yanjun Li ),( Yueyun Shen ),( Kaikai Chi ) 한국인터넷정보학회 2012 KSII Transactions on Internet and Information Syst Vol.6 No.12

A tree routing structure is often adopted for many-to-one data gathering and aggregation in sensor networks. For real-time scenarios, considering lossy wireless links, it is an important issue how to construct a maximum-lifetime data gathering tree with delay constraint. In this work, we study the problem of lifetime-preserving and delay-constrained tree construction in unreliable sensor networks. We prove that the problem is NP-complete. A greedy approximation algorithm is proposed. We use expected transmissions count (ETX) as the link quality indicator, as well as a measure of delay. Our algorithm starts from an arbitrary least ETX tree, and iteratively adjusts the hierarchy of the tree to reduce the load on bottleneck nodes by pruning and grafting its sub-tree. The complexity of the proposed algorithm is O(N⁴). Finally, extensive simulations are carried out to verify our approach. Simulation results show that our algorithm provides longer lifetime in various situations compared to existing data gathering schemes.

Separation of 2,3-Butanediol from Fermentation Broth by Reactiveextraction Using Acetaldehyde-cyclohexane System

Yanjun Li,Yanyang Wu,Jiawen Zhu,Jiaxian Liu 한국생물공학회 2012 Biotechnology and Bioprocess Engineering Vol.17 No.2

Biochemical 2,3-butanediol is a renewable material with the potential to be used as an alternative fuel. However, in the lack of an effective separation process has limited its industrial application. In this paper, an effective process was achieved to separate 2,3-butanediol by reactive-extraction. Acetaldehyde and cyclohexane were chosen as the reactant and extractant, respectively. Ion-exchange resin HZ732 was used as the catalyst. Reaction equilibrium and a kinetic study on the reaction between 2,3-butanediol and acetaldehyde were investigated to provide basic data for process development. The reaction enthalpy and activation energy of reaction of 2,3-butanediol and acetaldehyde were −30.05 ± 1.62 KJ/mol and 45.29 ± 2.89 KJ/mol,respectively. Feasible conditions were obtained as follows:operating temperature = 20℃, acetaldehyde: 2,3-butanediol = 0.5:1 (w/w), cyclohexane: fermentation broth = 0.5:1 (w/w), catalyst amount = 100 g/L, stirring rate = 500 rpm and three-stage counter-current extraction method was used. Under these conditions, the total yield rate of 2,3-butanediol from fermentation broth was over 90% and the mass fraction of 2,3-butanediol in the final product reached 99%. Biochemical 2,3-butanediol is a renewable material with the potential to be used as an alternative fuel. However, in the lack of an effective separation process has limited its industrial application. In this paper, an effective process was achieved to separate 2,3-butanediol by reactive-extraction. Acetaldehyde and cyclohexane were chosen as the reactant and extractant, respectively. Ion-exchange resin HZ732 was used as the catalyst. Reaction equilibrium and a kinetic study on the reaction between 2,3-butanediol and acetaldehyde were investigated to provide basic data for process development. The reaction enthalpy and activation energy of reaction of 2,3-butanediol and acetaldehyde were −30.05 ± 1.62 KJ/mol and 45.29 ± 2.89 KJ/mol,respectively. Feasible conditions were obtained as follows:operating temperature = 20℃, acetaldehyde: 2,3-butanediol = 0.5:1 (w/w), cyclohexane: fermentation broth = 0.5:1 (w/w), catalyst amount = 100 g/L, stirring rate = 500 rpm and three-stage counter-current extraction method was used. Under these conditions, the total yield rate of 2,3-butanediol from fermentation broth was over 90% and the mass fraction of 2,3-butanediol in the final product reached 99%.

Optimized Resource Allocation for Utility-Based Routing in Ad Hoc and Sensor Networks

( Yanjun Li ),( Jianji Shao ) 한국인터넷정보학회 2015 KSII Transactions on Internet and Information Syst Vol.9 No.5

Utility-based routing is a special type of routing approach using a composite utility metric when making routing decisions in ad hoc and sensor networks. Previous studies on the utility-based routing all use fixed retry limit and a very simple distance related energy model, which makes the utility maximization less efficient and the implementation separated from practice. In this paper, we refine the basic utility model by capturing the correlation of the transmit power, the retry limit, the link reliability and the energy cost. A routing algorithm based on the refined utility model with adaptive transmit power and retry limit allocation is proposed. With this algorithm, packets with different priorities will automatically receive utility-optimal delivery. The design of this algorithm is based on the observation that for a given benefit, there exists a utility-maximum route with optimal transmit power and retry limit allocated to intermediate forwarding nodes. Delivery along the utility-optimal route makes a good balance between the energy cost and the reliability according to the value of the packets. Both centralized algorithm and distributed implementations are discussed. Simulations prove the satisfying performance of the proposed algorithm.

Identification of MicroRNAs as potential biomarkers for detecting ischemic stroke

Li Kexin,Shen Li,Zheng Pingping,Wang Yanjun,Wang Lijuan,Meng Xiaoli,Lv Yaogai,Xue Zhiqiang,Guo Xin,Zhang Anning,Pan Pan,Bi Chunli,Chen Yang,Feng Tianyu,Li Bo,Jin Lina,Yao Yan 한국유전학회 2022 Genes & Genomics Vol.44 No.1

Background: Increasing epidemic of ischemic stroke (IS) makes it urgent to understand the pathogenesis and regulatory mechanism, previous studies have described microRNAs (miRNAs) is part of the brain's response to ischemia. Objective: The aim of this study was to screen potential biomarkers for the prediction and novel treatment of IS. Methods: Differentially expressed miRNAs were screened from three newly diagnosed IS patients and three controls by RNA sequencing technology. Furthermore, target prediction databases were then used to analysis the target genes of different expressed miRNAs, and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway database were used to identify the functions and the main biochemical and signal pathways of differentially expressed target genes. Results: Our results revealed that 27 miRNAs were differentially expressed in IS, among which, hsa-miR-659-5p was the most highly increased and was first found to be associated with IS. In addition, KEGG pathway analyses showed that differentially expressed miRNAs were mainly significantly enriched in lysosome pathway, cytokine-cytokine receptor interaction pathway, spliceosome pathway, base excision repair pathway. Conclusions: miRNAs were involved in IS pathogenesis, and hsa-miR-659-5p, hsa-miR-151a-3p and hsa-miR-29c-5p as the three highest |log2FoldChange| regulation in this study, which may be the biomarkers of IS and need further study.

A Utility-Based and QoS-Aware Power Control Scheme for Wireless Body Area Networks

( Yanjun Li ),( Jian Pan ),( Xianzhong Tian ) 한국인터넷정보학회 2016 KSII Transactions on Internet and Information Syst Vol.10 No.9

Power control is widely used to reduce co-channel interference in wireless networks and guarantee the signal-to-interference plus noise ratio (SINR) of ongoing connections. This technique is also effective for wireless body area networks (WBANs). Although achieving satisfactory SINR is important for WBAN users, they may not be willing to achieve it at arbitrarily high power levels since power is a scarce resource in WBANs. Besides, for WBANs with different purposes, the QoS requirements and concern about the power consumption may be different. This motivates us to formulate the power control problem using the concepts from microeconomics and game theory. In this paper, the QoS objective is viewed as a utility function, which represents the degree of user satisfaction, while the power consumption is viewed as a cost function. The power control problem consequently becomes a non-cooperative multiplayer game, in which each player tries to maximize its net utility, i.e., the utility minus the cost. Within this framework, we investigate the Nash equilibrium existence and uniqueness in the game and derive the best response solution to reach the Nash equilibrium. To obtain the optimal transmission power in a distributed way, we further propose a utility-based and QoS-aware power control algorithm (UQoS-PCA). Tunable cost coefficient in UQoS-PCA enables this scheme to be flexible to satisfy diverse service requirements. Simulation results show the convergence and effectiveness of the proposed scheme as well as improvements over existing algorithm.

Numerical Simulation of Hydraulic Fracture Propagation within Fractured Shale Gas Reservoir Based on a Three-dimensional Fracture Network Model

( Yanyan Li ),( Yanjun Shang ),( Lihui Li ) 대한지질공학회 2019 대한지질공학회 학술발표회논문집 Vol.2019 No.2

This research presents coupled hydro-mechanical modeling of hydraulic fracturing processes within fractured reservoir based on a three-dimensional fracture network model. Field investigation was conducted to collect joint data from shale outcrops of the Yanchang Formation using the window sampling method. A three-dimensional joint network model was built using the Monte Carlo simulation method. Lamina data were collected from conventional logging, borehole TV and cores. The Monte Carlo method was also used to model artificial laminas. The fracture network model was built by adding the artificial laminas to the joint network model. The interactions between hydraulic fractures and natural fractures are analyzed, providing a better insight into the performance of hydraulic fracturing jobs in naturally fractured reservoir. Numerical results show that the hydraulic fracture may arrest, cross, or divert into natural fractures depending on the rock mechanical properties, direction of rock principal stresses, and fracture intersection angle. The propagation direction of hydraulic fractures is controlled the maximum horizontal stress. Laminas change the propagation direction of hydraulic fractures, suggesting that the heterogeneity of shale influences the propagation of hydraulic fractures. The influence of the injection rate of fracturing fluid on the propagation of hydraulic fractures was studied. The results show that there is only one major hydraulic fracture when the injection rate is 0.1 ㎥ per minute. With the increase of the injection rate, several major hydraulic fractures perpendicular to laminas were produced, improving the fracture complexity and expanding the reservoir drainage area.

Improving the efficacy and safety of concurrent chemoradiotherapy by neoadjuvant chemotherapy: a randomized controlled study of locally advanced cervical cancer with a large tumor

Fenghu Li,Fan Mei,Shuishui Yin,Yanjun Du,Lili Hu,Wei Hong,Jiehui Li 대한부인종양학회 2024 Journal of Gynecologic Oncology Vol.35 No.1

Objective: To compare the efficacy and safety of neoadjuvant chemotherapy combined withconcurrent chemoradiotherapy (NACT+CCRT) vs. concurrent chemoradiotherapy (CCRT) inlocally advanced cer vical cancer (LACC) patients with large tumor masses. Methods: LACC patients with localized tumor diameter >4 cm, were randomly allocated in anunblinded 1:1 ratio to NACT+CCRT or CCRT groups. Patients in the NACT+CCRT group weregiven paclitaxel combined with cisplatin (TP) NACT ever y 3 weeks for 2 cycles, followed byCCRT, with the chemotherapy regimen the same as for NACT. CCRT group were given CCRTwith the same as for NACT. Results: From March 1, 2019, to June 30, 2021, 146 patients were included in the finalanalysis. Sixty-eight (93.2%) patients in the NACT+CCRT group and 66 (90.4%) patientsin the CCRT group completed the expected treatment course. The complete response (CR)rate in the NACT+CCRT group was significantly higher than in the CCRT group (87.7% vs. 67.6%, χ2=54.540, p=0.000). In the NACT+CCRT group, the 1- and 2-year overall sur vival(OS) rates were significantly higher than those in the CCRT group (96% vs. 89% and 89%vs. 79%, χ2=5.737, p=0.017). Additionally, the rate of recurrences and distant metastaseswas significantly lower in the NACT+CCRT group than in the CCRT group (4.11% vs. 7.35%,χ 2=4.059, p=0.021). Most treatment-related adverse events in both groups were grade 3. Conclusion: Compared to CCRT, NACT+CCRT might improve the treatment completionrate, increase CR rate and 1- and 2-year OS rates, and reduce distant metastases rate for LACCpatients with large tumor masses.

《東方雜志》對小說《牧羊哀話》的影響研究

李艳军 ( Li Yanjun ) 중국어문학회 2020 中國語文學誌 Vol.0 No.73

Eve of the May Fourth Movement, as one of the most influential domestic publications at that time, the Eastern Miscellany was the important positions for the publication of literary works. Guo Moruo submitted his first novel Kulou to the Eastern Miscellany, but was rejected by the Eastern Miscellany. Guo Moruo began to create the second novel Muyang Aihua in accordance with the aesthetic standards of the Eastern Miscellany. In terms of themes, Muyang Aihua emphasized the sociality of inspiring and motivating the people. Muyang Aihua used North Korea, a neighboring country that is both familiar and unfamiliar to the Chinese, as the background of the story. The novel made extensive use of Buddhist and Christian cultural images, which was very preferred by Oriental Magazine when selecting manuscripts. The novel skillfully used the creative skills of Chinese traditional poetry and Chapter novel. The novel used creative means such as rhyme and drama dialogue. After Guo Moruo’s careful design, the standards of Muyang Aihua and the Eastern Miscellany were becoming more and more consistent. But when the novel was finished, the Eastern Miscellany was criticized by critics as “conservative” “restored” and “no social responsibility” publications, and its reputation plummeted. Because of the deterioration of the reputation of the Eastern Miscellany, Guo Moruo gave up his plan to vote Muyang Aihua to the Eastern Miscellany. Guo Moruo submitted his novel to the Magazine of New China, which was lower in reputation and status than the Eastern Miscellany, and was finally published. Muyang Aihua became Guo Moruo’s first publicly published novel, and it has a very important position in the Chinese literary world.

One-Step Hydrothermal Synthesis of Bi2S3-TiO2-RGO Composites with Enhanced Visible Light Photocatalytic Activities

Yanan Li,Zhongmin Liu,Yaru Li,Yongchuan Wu,Jitao Chen,Yanjun Liu,Ping Na 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2018 NANO Vol.13 No.5

The Bi2S3-TiO2-RGO composites were synthesized by a facile one-step hydrothermal method and applied for the photocatalytic degradation of Rhodamine B (Rh B) under the visible light. The Bi2S3-TiO2-RGO composites were characterized by transmission electron microscopy, X-ray diffraction, Raman and Fourier transform infrared spectrometer. The results indicated that the Bi2S3-TiO2-RGO composites were successfully prepared, and Ti-O-C and S-C bonds were existing among Bi2S3, TiO2 as well as RGO. Furthermore, the photocatalytic ability of Bi2S3-TiO2-RGO composites was excellent under visible light due to its responding to the whole visible light region, low recombination rate of photogenerated electron–hole pairs and relatively negative conduction band. Rh B photocatalytic degradation rate was 99.5% after 50 min and still could reach 98.4% after five cycles. Finally, a formation mechanism as well as a photocatalytic mechanism of Bi2S3-TiO2-RGO composites were proposed based on the experimental results.

Functional Evaluation of Transplanted Kidneys with Reduced Field-of-View Diffusion-Weighted Imaging at 3T

Yuan Xie,Yanjun Li,Jiqiu Wen,Xue Li,Zhe Zhang,Jianrui Li,Yan’e Zhao,Peng Wang,Jun Zhang,Ying Tian,Long Jiang Zhang,Guang Ming Lu 대한영상의학회 2018 Korean Journal of Radiology Vol.19 No.2

Objective: To determine the feasibility of reduced field-of-view diffusion-weighted imaging (rFOV DWI) with multi-b values to detect functional variability in transplanted kidneys. Materials and Methods: Using a 3T MRI scanner, multi-b rFOV DWI of transplanted kidney or native kidney was performed in 40 renal transplantation recipients and 18 healthy volunteers. The patients were stratified, according to an estimated glomerular filtration rate (eGFR): Group 1, eGFR ≥ 60 mL/min/1.73 m2; Group 2, eGFR ≥ 30 mL/min/1.73 m2 and < 60 mL/min/1.73 m2; Group 3, eGFR < 30 mL/min/1.73 m2. Total apparent diffusion coefficient (ADCT), perfusion-free ADC (ADCD) and perfusion fraction (FP) of kidneys were calculated and compared among the four groups. Correlations between the imaging results and eGFR were assessed. Results: All volunteers had eGFR ≥ 60 mL/min/1.73 m2, while 16, 16, and 8 patients were included in Groups 1, 2, and 3, respectively. In the renal cortex, ADCT was higher in Group 1 ([1.65 ± 0.13] x 10-3 mm2/s) than Group 3 ([1.44 ± 0.11] x 10-3 mm2/s) (p < 0.05), and the inter-group differences of FP values were significant (all p < 0.05) (0.330 ± 0.024, 0.309 ± 0.019, 0.278 ± 0.033, and 0.250 ± 0.028 for control group, Groups 1, 2, and 3, respectively). Renal cortical ADCT, ADCD, FP, and renal medullary ADCT and FP correlated positively with eGFR (r = 0.596, 0.403, 0.711, 0.341, and 0.323, respectively; all p < 0.05). When using 0.278 as the cutoff value, renal cortical FP had a sensitivity of 97.1% and a specificity of 66.7% for predicting decreased renal function. Conclusion: Multi-b rFOV DWI presents transplanted kidneys with high resolution, which is a promising functional tool for non-invasively monitoring function of transplanted kidneys.