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      • KCI등재

        Energy Efficient Air-to-Ground Communication Networks with Reconfigurable Intelligent Surface

        Yuanyuan Yao,Ke Lv,Nan Ma,Xinwei Yue,Xiaoqi Qin,Xiang Yun 한국통신학회 2022 Journal of communications and networks Vol.24 No.5

        Reconfigurable intelligent surface (RIS) assisted air- to-ground wireless powered communication networks (WPCNs) are constructed to promote the energy efficiency of the system, in which unmanned aerial vehicles (UAV) reflects energy towards the energy-constrained hybrid access points (HAP) through RIS. Subsequently, HAP uses the collected energy to communicate with users in blind areas through the RIS-UAV. By optimizing parameters such as charging time ratio, transmit power and phase shifts matrix, the energy efficiency for single and multi- user scenarios are maximized, respectively. The energy efficiency is modeled as a non-convex quadratic programming problem with inequality constraints in the single-user scenario. Then the problem is converted into an equivalent convex problem by using the Taylor expansion and convex approximation method. A joint optimization algorithm of power and phase shifts is proposed to obtain a feasible solution. The energy efficiency is modeled as a fractional programming problem with non-convex inequality constraints in the multi-user scenario, and the feasible solution is obtained by proposing an alternating algorithm. Finally, both two scenarios are compared with the system of traditional amplify- and-forward (AF) relay, respectively. Finally, the simulation results show that the proposed algorithms can provide up with 150% and 160% improvement of the energy efficiency in the single and multi-user scenarios, respectively, compared to the traditional AF relay.

      • KCI등재

        Increasing Throughput in Energy-Based Opportunistic Spectrum Access Energy Harvesting Cognitive Radio Networks

        Yuanyuan Yao,Chang-chuan Yin,Xiaoshi Song,Norman C. Beaulieu 한국통신학회 2016 Journal of communications and networks Vol.18 No.3

        The performance of large-scale cognitive radio (CR) networkswith secondary users sustained by opportunistically harvestingradio-frequency (RF) energy from nearby primary transmissionsis investigated. Using an advanced RF energy harvester, asecondary user is assumed to be able to collect ambient primary RFenergy as long as it lies inside the harvesting zone of an active primarytransmitter (PT). A variable power (VP) transmission modeis proposed, and an energy-based opportunistic spectrum access(OSA) strategy is considered, under which a secondary transmitter(ST) is allowed to transmit only if its harvested energy is largerthan a predefined transmission threshold and it is outside the guardzones of all active PTs. The transmission probability of the STs isderived. The outage probabilities and the throughputs of the primaryand the secondary networks, respectively, are characterized. Compared with prior work, the throughput can be increased byas much as 29%. The energy-based OSA strategy can be generallyapplied to a non-CR setup, where distributed power beacons(PBs) are deployed to power coexisting wireless signal transmitters(WSTs) in a wireless powered sensor network.

      • 해변도시의 양로원 공간디자인 색채 연구 - 부산지역 양로원을 중심으로 -

        요원이(YAO YUANYUAN),조정형(Joung hyung, Cho) 한국색채학회 2023 한국색채학회 학술대회 Vol.2023 No.4

        본문의 주요 내용은 양로원 실내 공간의 색채 디자인이다. 노인의 생리적, 심리적 특징을 분석하여 양로원의 기본적인 사용 기능을 보장하는 기초 위에서 특수 고령화층의 공간 색채 사용에 대한 수요를 만족시킨다. 본문에서는 3개의 양로원 공간 색채 디자인 방법을 제시하여 부산 양로원 공간 색채 디자인을 분석하면서 부산 양로원의 공간 색채를 거울로 삼고 양로원의 실내 공간 색채 디자인 품질을 향상시키며 양로원의 실내 공간 색채 디자인의 과학성과 실용성을 향상시킬 수 있기를 바란다.

      • KCI등재

        DHA-enriched phosphatidylcholine suppressed angiogenesis by activating PPARγ and modulating the VEGFR2/Ras/ERK pathway in human umbilical vein endothelial cells

        Yuanyuan Liu,Yingying Tian,Yao Guo,Ziyi Yan,Changhu Xue,Jingfeng Wang 한국식품과학회 2021 Food Science and Biotechnology Vol.30 No.12

        Docosahexaenoic acid-enriched phosphatidylcholine(DHA-PC) is a new generation of omega-3 lipids,which contains an ester bond linking DHA at the sn-2position of phospholipid. DHA-PC has become the interestrecently as its better bioavailability and anti-oxidationcapacity. In this study, the anti-angiogenic effect of DHAPCwas evaluated. The capacities of proliferation, migration,tube formation of human umbilical vein endothelialcells were significantly declined after DHA-PC treatment. Furthermore, DHA-PC inhibited the neovascularization ofthe chick chorioallantoic membrane in vivo. Mechanismresults indicated that DHA-PC enhances the expression ofperoxisome proliferator-activated receptor c (PPARc) attranscriptional and translational level, subsequently downregulatesthe VEGFR2 expression and VEGFR2-mediateddownstream Ras/ERK pathway, resulting in significantreduction in proliferation and differentiation. Additionally,PPARc-specific antagonist GW9662 partly reversed theinhibition effects of DHA-PC on tube formation and neovascularization,suggesting that DHA-PC exerts anti-angiogenesiseffect through activating PPARc. Thesefindings indicated that DHA-PC has a great prospect ofanti-tumor angiogenesis therapy.

      • KCI등재

        Study on the Mechanical Properties of Functional Graphene/Polyethylene Composites by Molecular Dynamics Simulation

        Yuanyuan Qin,Yifei Wang,Jin Liu,Fengfeng Chen,Aiying Yao,Zhanchun Chen,Fu Junyu 한국고분자학회 2022 Macromolecular Research Vol.30 No.12

        The mechanical properties of functionalized graphene/polyethylene (f- GRA/PE) composites and graphene/polyethylene (GRA/PE) composites were studied based on the crystallized models with the molecular dynamics simulation in this paper. The effects of GRA and f-GRA with different mass fractions on the mechanical properties of polyethylene were considered. The results showed that the adsorption capacity of polyethylene molecular chains of f-GRA is stronger, the compatibility of f-GRA/PE system is higher with decreasing the interface distance, and the dynamic property of molecular chain is weaker with reducing the radius of gyration of f-GRA/ PE. Furthermore, the reduction of mechanical energy consumption results in the increase of wear resistance of the system, which is more obvious when the mass fraction of f-GRA increases. Finally, the influence of different tensile rates on the composite system was studied. It was found that during the tensile process, the ability of the composite material to resist deformation in the stretching direction is enhanced, and the functionalized graphene inhibits the movement of the molecular chain due to the adsorption force, which improves the yield stress of the f-GRA/PE composite material, thereby increasing the tensile strength. Tensile rate has a certain effect on mechanical properties, and elastic modulus and yield stress increase with the increase of strain rate.

      • SCOPUSKCI등재

        Efficacy of Different Number of XELOX or SOX Chemotherapy Cycles After D<sub>2</sub> Resection for Stage III Gastric Cancer

        Yu, Yuanyuan,Zhang, Zicheng,Meng, Qianhao,Wang, Ke,Li, Qingwei,Ma, Yue,Yao, Yuanfei,Sun, Jie,Wang, Guangyu The Korean Gastric Cancer Association 2022 Journal of gastric cancer Vol.22 No.2

        Purpose: We aimed to explore whether the prognosis of patients treated with capecitabine and oxaliplatin (XELOX) or S-1 and oxaliplatin (SOX) regimens who received fewer cycles of chemotherapy after D2 radical resection for gastric cancer (GC) would be non-inferior to that of patients who received the standard number of cycles of chemotherapy. Materials and Methods: Data on patients who received XELOX or SOX chemotherapy after undergoing D2 radical resection at Harbin Medical University Cancer Hospital between January 2011 and May 2016 were collected. Results: In patients who received 4, 6, and 8 cycles of chemotherapy, the 5-year overall survival (OS) rates were 59.4%, 64.8%, and 62.7%, respectively. Compared to patients who received 4 cycles of chemotherapy, those who received 6 cycles (hazard ratio [HR], 0.882; 95% confidence interval [CI], 0.599-1.299; P=0.52) or 8 cycles (HR, 0.882; 95% CI, 0.533-1.458; P=0.62) of chemotherapy did not exhibit significantly prolonged OS. The 3-year disease-free survival (DFS) rate of patients who received 4, 6, and 8 cycles of chemotherapy was 62.1%, 67.2%, and 60.8%, respectively. Compared to patients who received 4 cycles of chemotherapy, those who received 6 cycles (HR, 0.835; 95% CI, 0.572-1.221; P=0.35) or 8 cycles (HR, 0.972; 95% CI, 0.606-1.558; P=0.91) of chemotherapy did not show significantly prolonged DFS. However, the 3-year DFS and 5-year OS rates of patients who received 6 cycles of chemotherapy appeared to be superior to those of patients who received 4 and 8 cycles of chemotherapy. Conclusions: For patients with stage III GC, 4 to 6 cycles of XELOX or SOX chemotherapy may be a favorable option. This study provides a rationale for further randomized clinical trials.

      • KCI등재

        Effect of light quality on regeneration and naphthoquinones accumulation of Arnebia euchroma

        Jia Hu,Yao Leng,Yuanyuan Jiang,Su Ni,Li Zhang 한국식물생명공학회 2019 Plant biotechnology reports Vol.13 No.4

        The influence of light quality on the regeneration (i.e., formation, proliferation, growth, development, and rooting) and naphthoquinones’ accumulation of Arnebia euchroma was investigated in vitro. The cotyledons of sterile seedings were placed on modified LS medium supplemented with 0.8 mg/L thidiazuron to obtain callus, which was incubated on the corresponding medium at different culture stages under varying light conditions, including dark, fluorescent lamp (Fl), white light-emitting diodes (LEDs), blue LEDs, red LEDs, and a combination of 25% red, 25% blue, and 50% white LEDs [RBW (1:1:2)]. During the establishment of the A. euchroma regeneration system, we obtained the maximum fresh weight, dry weight, germination rate, shoot number, and proliferation rate under RBW (1:1:2) LEDs in the formation and multiplication phases; the growth index, shoot height, leaf number, and photosynthetic pigment concentration were promoted under red LEDs in the growth and development phase; and the maximum rooting rate (89.29% ± 2.06%) was observed under red LEDs in the rooting phase. To study the effect of light quality on naphthoquinones’ accumulation of A. euchroma, we used the euphylla to achieve adventitious roots, and the highest shikonin (121.77 ± 6.68 μg/g DW) and β′β-dimethylacrylalkannin (619.18 ± 15.71 μg/g DW) contents were detected in the dark culture. The lowest naphthoquinone contents were recorded under Fl in the adventitious roots. Overall, RBW (1:1:2) LEDs enhanced A. enchroma formation and proliferation, while red LEDs promoted the plant’s growth, development, and rooting. The dark condition was beneficial to naphthoquinones’ accumulation, whereas the light condition inhibited the naphthoquinones production of A. enchroma adventitious roots. Determining the suitable light quality for the regeneration and accumulation of naphthoquinones that is conducive to the protection and promotes resource utilization is essential.

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