Synthesis of Dithiolopyrrolone Derivatives and Their Leukocyte-Increasing Activities

Chungang Li,Yiping Sun,Guoping Wang,Xiangduan Tan 대한화학회 2014 Bulletin of the Korean Chemical Society Vol.35 No.12

In search of new antileukopenia agents, twenty dithiolopyrrolone derivatives were synthesized and evaluated for their leukocyte-increasing activities in normal mice. Among the synthesized compounds 4-23, compounds 5 and 6 showed significant leukocyte-increasing activity ( p < 0.01), and compounds 4, 9 and 16 had a moderate effect ( p < 0.05). Compound 5 also displayed stronger leukocyte-increasing activity than that of the positive recombinant human granulocyte colony stimulating factor (rhG-CSF). Above all, compound 5 would be a potential antileukopenia agent which deserved further research.

Tradeoff between Energy-Efficiency and Spectral-Efficiency by Cooperative Rate Splitting

Chungang Yang,Jian Yue,Min Sheng,Jiandong Li 한국통신학회 2014 Journal of communications and networks Vol.16 No.2

The trend of an increasing demand for a high-quality userexperience, coupled with a shortage of radio resources, has necessitatedmore advanced wireless techniques to cooperatively achievethe required quality-of-experience enhancement. In this study, weinvestigate the critical problem of rate splitting in heterogeneouscellular networks, where concurrent transmission, for instance, thecoordinated multipoint transmission and reception of LTE-A systems,shows promise for improvement of network-wide capacityand the user experience. Unlike most current studies, which onlydeal with spectral efficiency enhancement, we implement an optimalrate splitting strategy to improve both spectral efficiency andenergy efficiency by exploring and exploiting cooperation diversity. First, we introduce the motivation for our proposed algorithm, andthen employ the typical cooperative bargaining game to formulatethe problem. Next, we derive the best response function byanalyzing the dual problem of the defined primal problem. Theexistence and uniqueness of the proposed cooperative bargainingequilibrium are proved, and more importantly, a distributed algorithmis designed to approach the optimal unique solution undermild conditions. Finally, numerical results show a performance improvementfor our proposed distributed cooperative rate splittingalgorithm.

Tradeoff between Energy-Efficiency and Spectral-Efficiency by Cooperative Rate Splitting

Yang, Chungang,Yue, Jian,Sheng, Min,Li, Jiandong The Korea Institute of Information and Commucation 2014 Journal of communications and networks Vol.16 No.2

The trend of an increasing demand for a high-quality user experience, coupled with a shortage of radio resources, has necessitated more advanced wireless techniques to cooperatively achieve the required quality-of-experience enhancement. In this study, we investigate the critical problem of rate splitting in heterogeneous cellular networks, where concurrent transmission, for instance, the coordinated multipoint transmission and reception of LTE-A systems, shows promise for improvement of network-wide capacity and the user experience. Unlike most current studies, which only deal with spectral efficiency enhancement, we implement an optimal rate splitting strategy to improve both spectral efficiency and energy efficiency by exploring and exploiting cooperation diversity. First, we introduce the motivation for our proposed algorithm, and then employ the typical cooperative bargaining game to formulate the problem. Next, we derive the best response function by analyzing the dual problem of the defined primal problem. The existence and uniqueness of the proposed cooperative bargaining equilibrium are proved, and more importantly, a distributed algorithm is designed to approach the optimal unique solution under mild conditions. Finally, numerical results show a performance improvement for our proposed distributed cooperative rate splitting algorithm.

Synthesis of Dithiolopyrrolone Derivatives and Their Leukocyte-Increasing Activities

Li, Chungang,Sun, Yiping,Wang, Guoping,Tan, Xiangduan Korean Chemical Society 2014 Bulletin of the Korean Chemical Society Vol.35 No.12

In search of new antileukopenia agents, twenty dithiolopyrrolone derivatives were synthesized and evaluated for their leukocyte-increasing activities in normal mice. Among the synthesized compounds 4-23, compounds 5 and 6 showed significant leukocyte-increasing activity ( p < 0.01), and compounds 4, 9 and 16 had a moderate effect ( p < 0.05). Compound 5 also displayed stronger leukocyte-increasing activity than that of the positive recombinant human granulocyte colony stimulating factor (rhG-CSF). Above all, compound 5 would be a potential antileukopenia agent which deserved further research.

Temperature-constrained topology optimization of nonlinear heat conduction problems

Zhuang Chungang,Xiong Zhenhua,Ding Han 한국CDE학회 2021 Journal of computational design and engineering Vol.8 No.4

This paper presents topology optimization of nonlinear heat conduction problems with multiple domains and multiple constraints, including regional temperature and material volume for reducing temperature. Maximum approximation temperatures in the constraint regions are accurately and dynamically calculated, though temperature and temperature-dependent thermal conductivity change with the update of material distribution. A temperature measure with constant error to approximate regional maximum temperature is adaptive to different temperature ranges. A strategy of hole nucleation generation combined with the regional temperature constraints is presented for the level set-based topology optimization. The solid isotropic material with penalization (SIMP) and parametrized level set methods are compared for the temperature-constrained topology optimization. Finally, several numerical examples are solved by the SIMP and parametrized level set methods. The results demonstrate that the proposed approach can obtain intricate topological details and reduce regional temperatures for the nonlinear heat conduction problems.

An improved three-point method for on-machine roundness measurement

Haifeng Ma,Chungang Zhuang,Zhenhua Xiong 한국생산제조학회 2014 한국생산제조시스템학회 학술발표대회 논문집 Vol.2014 No.9(2)

A Scalable Live Streaming Media Distribution Service for Peer-to-Peer Network

Jiujun Cheng,Chungang Yan,Kuifei Yu,Jian Ma 보안공학연구지원센터 2008 International Journal of Hybrid Information Techno Vol.1 No.4

Live streaming media distribution in a large scale P2P network and the impact on the real-time caused by the dynamicity of peers are still not well resolved. In order to address this problem, a scalable live streaming media distribution service in P2P network is presented. Our approach is that the P2P network combining tree with clusters is designed, and some super-peers are reserved in all clusters. In addition, we adopt the maximum accepted connection number of each super-peer and its average disposing delay to select the optimal father peer, and the limitation of packet discard between super-peers is given. The experiment results show that the distribution service assures the improvement of real-time and scalability in the large-scale P2P network.

A Mean Field Game-Theoretic Cross-Layer Optimization for Multi-Hop Swarm UAV Communications

Tong Li,Cong Li,Chungang Yang,Junqi Shao,Yue Zhang,Lei Pang,Lizhong Chang,Lingli Yang,Zhu Han 한국통신학회 2022 Journal of communications and networks Vol.24 No.1

Unmanned aerial vehicle (UAV) multi-hop communicationnetworks are foreseen to be widely employed inboth military and civilian scenarios. However, in ultra-densescenarios with swarm UAVs, nodes are highly dynamic mobile,ultra-dense deployment and non-centralized distribution. Thesecharacteristics make the centralized resource management policynot apply. Meanwhile, existing routing protocols can’t meetthe performance challenges of high dynamic, topology and linkfrequency changes of ultra-dense scenarios with swarm UAVs. Tosolve the above challenges of resource management and routingprotocol, a cross-layer optimization method is presented witha novel mean field game (MFG) in this paper. It is based onthe cross-layer design method of the MFG theory and jointlyconsiders the power resources in the physical layer, frequencyresources in the medium access control (MAC) layer, and routingresources in the network layer. By dividing into subproblems,the original problem is solved. Meanwhile, the optimal datatransmission path can be selected through the management andallocation of frequency resources and power resources. A crosslayerresource management dynamic source routing (CLRMDSR)protocol is designed based on that which adds link qualitymeasurement. The simulation results show that the presentedCLRM-DSR with the proposed resource management schemecan improve the data packet transmission rate, reduce end-toenddelay, and lower routing overhead for the multi-hop swarmUAV communication network.

Research on Cold-Formed Steel Stiffened-Web Built-up I-Section Columns with Complex Edge Stiffeners

Zhuangnan Zhang,Yudong Li,Chungang Wang,Yikai Hao,Jianqiao Song,Qinglin Guo 한국강구조학회 2022 International Journal of Steel Structures Vol.22 No.1

A series of double-limbs built-up I-section simply supported specimens subjected to compression were examined. The test columns contained 18 concentric compression columns and 12 eccentric compression columns with three section forms respectively. The infl uence of web stiff eners on buckling mode, ultimate bearing capacity and interaction between limbs were studied. It was shown that stiff eners in web eff ectively decreased the element width-to-thickness ratio and increased the bearing capacity of built-up I-section columns. But when larger eccentricity made the moment control the failure of eccentric compression specimens, the bearing capacity of the specimens was not improved obviously by web stiff eners. Distortional buckling could replace local buckling to control the failure modes of columns. Compared with double-limbs channel steel built-up open-sections with complex edge stiff eners under the same steel quantity and eccentricity, the load carrying capacity of double limb Σ-shaped channel built-up sections increased from 4.4% to 20.3%. While for double limb channel with V-type web stiff ener sections, the increment was from 2.2% to 17.4%. Furthermore, parametric study of 90 Σ-shaped built-up section members was investigated to obtain the optimization proportion of the web sub-element and relationship of carrying capacity between single Σ-shaped section and double limb Σ-shaped I-section. Finally, the ultimate load-carrying capacity of built-up columns subjected to axial compression were calculated by two kinds of direct strength method formulas, which were compared with the tests values. The results showed that the method considered the interaction between distortional buckling and fl exural buckling could obtain conservative results.

A fuzzy-based impedance control for force tracking in unknown environment

Yichao Shen,Yan Lu,Chungang Zhuang 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.10

Industrial manufacturing operations, such as grinding and polishing, are characterized by relatively constant contact force. In this article, a fuzzy-based adaptive impedance is proposed, which can grind or polish workpieces of different materials with constant contact force. The environmental parameters are estimated by iterative calculation with recursive least squares (RLS). The impedance parameters, such as damping and stiffness, are taken as the outputs of the fuzzy controller. The proposed force controller can track the desired force without the prior knowledge of the environment information. Experiments are conducted in finishing tasks using the self-developed industrial robot to verify the adaptive impedance control. The environmental parameters are instantly estimated for the following adjustment of the impedance parameters, and the real time contact force shows that the adaptive fuzzy logic impedance controller can achieve better performance with the oscillation below 2 N as the machining surface of the workpiece is not predefined.