Primary side control method for constant voltage/current output of series‑none compensated inductive wireless transfer systems

Xin Ge,Yimin Lu 전력전자학회 2022 JOURNAL OF POWER ELECTRONICS Vol.22 No.9

In practical applications, inductive wireless power transfer (IWPT) systems are often required to output a constant voltage or current. However, a change of the load often leads to a change of the output. This paper presents a primary side control method for an IWPT system with the series-none (SN) compensation topology. By using this method, the load, output current, and voltage can be estimated in real time by detecting the output voltage and current of the primary inverter, along with the phase difference between them. This overcomes the disadvantage where the control for a IWPT system requires wireless or wired communication between the primary side and secondary side. Phase shift voltage regulation technology and a PI controller are used to regulate the output voltage or current based on the estimated data. In order to adjust the parameters of the PI controller, a small signal model is established by the generalized state-space averaging (GSSA) method. Finally, simulations and an experimental prototype were established to verify the performance of the primary side control method. The obtained results show that the secondary parameters and variables can be accurately estimated. Under the action of the primary controller, the system can output constant voltage and current values.

Identification and Mapping of a Thermo-Sensitive Genic Self-Incompatibility Gene in Maize

Xin Ge Lin,Hui Ling Xie,Zhang Ying Xi,Yan Min Hu,Guang Yuan Zhao,Liu Jing Duan,Zong You Hao,Zong Hua Liu,Ji Hua Tang 한국유전학회 2009 Genes & Genomics Vol.31 No.3

In this study, we describe a novel ecological self-incompatibility (SI) line HE97 in maize. The main environmental factors influencing the inbred line characteristics were identified through field sowing trials during a two-year study period (2001 and 2002). The results showed that daily minimum temperature had the greatest effect on floral morphology and breeding system of the SI line. In staminate floret differentiation, when the daily minimum temperature exceeded 24℃, the line exhibited complete self-compatibility; however SI was observed when the daily minimum temperature was below 20℃. Therefore, we characterized the line as exhibiting thermo-sensitive genic self-incompatibility (TGSI). A set of F2 and F2:3 populations, derived from the inbred lines HE97 and Z58, were evaluated for two years to elucidate the TGSI line patterns of inheritance. Classical genetic analyses and QTL mapping results revealed that HE97 self-incompatibility was governed by a single allele, named here as tgsi1. The tgsi1 gene was mapped to chromosome 2 between SSR markers nc131 and bnlg1633, with a distance of 2.40 cM from nc131 and 2.44 cM from bnlg1633.

SE-CAC: A Novel Call Admission Control Scheme for Multi-service IDMA Systems

( Xin Ge ),( Gongliang Liu ),( Xingpeng Mao ),( Naitong Zhang ) 한국인터넷정보학회 2011 KSII Transactions on Internet and Information Syst Vol.5 No.5

In this paper a simple and effective call admission control (CAC) scheme is proposed for the emerging interleave-division multiple-access (IDMA) systems, supporting a variety of traffic types and offering different quality of service (QoS) requirements and priority levels. The proposed scheme is signal-to-interference-plus-noise ratio (SINR) evolution based CAC (SE-CAC). The key idea behind the scheme is to take advantage of the SINR evolution technique in the process of making admission decisions, which is developed from the effective chip-by-chip (CBC) multi-user detection (MUD) process in IDMA systems. By virtue of this semi-analytical technique, the MUD efficiency can be estimated accurately. Additionally, the computational complexity can be considerably reduced. These features make the scheme highly suitable for IDMA systems, which can combat intra-cell interference efficiently with simple CBC MUD. Analysis and simulation results show that compared to the traditional CAC scheme considering MUD efficiency as a constant, the proposed SE-CAC scheme can guarantee high power efficiency and throughput for multimedia traffic even in heavy load conditions, illustrating the high efficiency of CBC MUD. Furthermore, based on the SINR evolution, the SE-CAC can make accurate estimation of available resource considering the effect of MUD, leading to low outage probability as well as low blocking and dropping probability.

Evaluation of Bentonite Swelling for Geosynthetic Clay Liners as Water Barrier Material

Ge Xin,Han-Yong Jeon,Bok Choon Kang 한국고분자학회 2006 한국고분자학회 학술대회 연구논문 초록집 Vol.2006 No.10

On Fair Resource Sharing in Downlink Coordinated Multi-Point Systems

Xin Ge,Hu Jin,Julian Cheng,Leung, Victor C. M. IEEE 2016 IEEE communications letters Vol.20 No.6

<P>An opportunistic scheduling scheme is proposed for the downlink of a coordinated multi-point (CoMP) system, which exploits both spatial multiplexing and multiuser diversity gains while maintaining fair resource sharing among users. The proposed scheduling scheme consists of two steps in each time slot: selecting a base station (BS) at each user, and then selecting a user at each BS. Although the proposed scheme selects users in a distributed manner, the channels among the selected users are proved to be orthogonal when the number of users approaches infinity. Simulation results demonstrate that the proposed scheme yields a better throughput than the existing scheduling schemes designed for fair resource sharing in CoMP systems.</P>

Multidisciplinary Collaborative Therapy for 30 Children with Orbital Rhabdomyosarcoma

Ge, Xin,Huang, Dong-Sheng,Shi, Ji-Tong,Ma, Jian-Min Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.8

Objective: To explore clinical experience and propose new ideas for treating children diagnosed with orbital rhabdomyosarcoma (RMS). Methods: We retrospectively analyzed the clinical data for30 patients (16 males and 14 females, with a median age of 6.2 years) with primary orbital RMS who were enrolled in the Department of Eye Oncology and Pediatrics of our hospital from November 2004 to December 2012. International Rhabdomyosarcoma Organization Staging Standards indicated that among the 30 patients, 4 cases were in phase II, 20 were in phase III, and 6 were in phase IV. All patients underwent a multidisciplinary collaborative model of comprehensive treatment (surgery, chemotherapy, external radiotherapy, $^{125}I$ radioactive particle implantation, and autologous peripheral blood stem-cell transplantation). Results: Follow-up was conducted until March 2013, with a median follow-up time of 47.2 months (5 to 95 months), and 7 deaths occurred. The 2-year estimated survival rate reached 86.1%, the ${\geq}3$-year estimated survival rate was 77%, and the 5-year estimated survival rate was 70.6%. Conclusions: The multidisciplinary collaborative model can be a safe and effective approach to the comprehensive treatment of children with orbital RMS. It has clinical significance in improving the tumor remission rate.

Joint User Association and User Scheduling for Load Balancing in Heterogeneous Networks

Ge, Xin,Li, Xiuhua,Jin, Hu,Cheng, Julian,Leung, Victor C. M. IEEE 2018 IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS Vol.17 No.5

<P>This paper investigates joint user association (UA) and user scheduling (US) for load balancing over the downlink of a wireless heterogeneous network by formulating a network-wide utility maximization problem. In order to efficiently solve the problem, we first approximate the nonconvex throughput achieved with US to a concave function, and demonstrate that the gap for such an approximation approaches zero when the number of users is sufficiently large. Then, by exploiting a distributed convex optimization technique known as <I>alternating direction method of multipliers</I>, a joint UA and US algorithm, which can be implemented on each user’s side and base station (BS)’s side separately, is proposed to obtain the single-BS association and resource allocation solutions. A remarkable feature of the proposed algorithm is that apart from load balancing, multiuser diversity is exploited in the association process to further improve system performance. We also extend the algorithm design to multi-BS association, whereby a user is associated with multiple BSs. The simulation results show the superior performance of the proposed algorithms and underscore the significant benefits of jointly exploiting multiuser diversity and load balancing.</P>

EPDM 고무/유기 벤토나이트 복합체의 제조

Xin Ge,Mei Chun Li,조을룡(Ur Ryoung Cho) 한국고분자학회 2014 폴리머 Vol.38 No.1

고무 매트릭스와 벤토나이트의 상용성을 향상시키기 위하여 유기개질 벤토나이트는 벤토나이트 현탁액에서실란커플링제인 [3-(2-aminoethylamino)propyl]trimethoxysilane(AEAPTMS)]를 사용하여 합성되었다. 유기개질 벤토나이트의 구조와 특성을 FTIR-spectroscopy, thermogravimetric analysis(TGA) and X-ray diffraction(XRD) 등을 사용하여 분석하였다. Ethylene-propylene-diene monomer(EPDM) 고무와 유기 벤토나이트를 two-roll mill에서 배합하였으며 가황을 하고 물성을 측정하였다. 벤토나이트 개질에 대하여 염산과 물의 농도가 복합체의 물성에 중요한 영향을 미치는 것으로 확인되었다. 벤토나이트의 함량이 20 phr 포함된 복합체의 경우 가장 좋은 물성을 나타내었고 인장강도는 1.95에서 4.8 MPa로 증가되었으며 신장률은 300에서 500%로 증가하는 경향을 보였다. To improve the compatibility of bentonite with rubber matrix, organo-modified bentonite was synthesized witha silane coupling agent, [3-(2-aminoethylamino)propyl]trimethoxysilane (AEAPTMS) in the suspension of bentonite. Thestructure and characteristics of organo-modified bentonite were investigated using FTIR-spectroscopy, thermogravimetricanalysis (TGA) and X-ray diffraction (XRD). Ethylene-propylene-diene monomer (EPDM) rubber/organo-bentonitecomposites were compounded by a two-roll mill. The vulcanization and mechanical properties were studied. Resultsshowed that the concentration of hydrochloric acid and H2O in the synthesis had significant influence on the modificationof bentonite, which further contributed to the properties of the composites. Filled with 20 phr modified bentonite, the tensilestrength and elongation at break of the rubber increased from 1.95 to 4.8 MPa and 300% to 500%, respectively.

Joint opportunistic user scheduling and power allocation: throughput optimisation and fair resource sharing

Ge, Xin,Jin, Hu,C. M. Leung, Victor Institution of Electrical Engineers 2018 IET communications Vol.12 No.5

<P>Despite extensive studies on optimal power allocation, how to design an efficient joint user scheduling and power allocation scheme for uplink multiuser networks remains largely unexplored. This study investigates joint opportunistic user scheduling and power allocation in uplink multiuser networks to maximise user throughput subject to the power and resource sharing constraints. By exploiting the cumulative distribution function-based scheduling method, the authors first characterise the optimal power allocation subject to both long-term and short-term power constraints. Instead of calculating the transmit power in an iterative and central manner, users can independently decide their instantaneous transmit power in the proposed scheme, which facilitates the algorithm implementation for each user in uplink networks. The closed-form throughput of the proposed scheme is also derived, which can provide an efficient way to estimate and evaluate user performance. Numerical results reveal that compared with several benchmark schemes, the proposed scheme improves throughput performance significantly.</P>

Exploiting Opportunistic Scheduling in Uplink Wiretap Networks

Ge, Xin,Jin, Hu,Zhu, Jun,Cheng, Julian,Leung, Victor C. M. IEEE 2017 IEEE Transactions on Vehicular Technology VT Vol.66 No.6

<P>Opportunistic scheduling schemes are investigated for uplink wiretap channels with multiple asymmetrically located legitimate users (LUs) and eavesdroppers. To exploit multiuser diversity, the cumulative distribution function-based scheduling method is leveraged to schedule the transmissions of the LUs. Under this scheduling framework, the closed-form expressions of the secrecy outage probability and ergodic secrecy rate are derived, illustrating the interplay among the system parameters, such as the channel statistics and the number of LUs and eavesdroppers. Through the secrecy outage analysis of the proposed scheduling schemes, we observe that the secrecy throughput is not always maximized with a larger channel access ratio (CAR), and consequently, we design a CAR adjustment scheme to maximize the secrecy throughput while satisfying the required secrecy level. We also prove that under our proposed scheduling schemes, the secrecy diversity order of each LU is equal to the reciprocal of the LU's CAR, implying that full diversity order is achieved, and the ergodic secrecy rate of each LU normalized by its CAR achieves the optimal double-logarithmic growth when the number of LUs increases to infinity.</P>