Experimental study on wave motion of partial air cushion supported catamaran

Jinglei Yang,Hanbing Sun,Xiaowen Li,Defeng Wu 대한조선학회 2023 International Journal of Naval Architecture and Oc Vol.15 No.-

To study the performance of partial air cushion-supported catamaran (PACSCAT), which is sailing with a flexible air seal in waves, this paper uses the model tests, and research the motion characteristics of PACSCAT at different wavelengths, by monitoring the boundaries of heave, pitch, acceleration, air cushion pressure. Firstly this paper introduces the test situation of PACSCAT in the towing tank and introduces the test method, equipment, and test conditions. Second, this paper extracts the test data, analyzes the features of heave, pitch, acceleration, and air cushion pressure, and studies their linear and nonlinear changes in regular waves. Thirdly this paper analyzes the nonlinear air leakage flow of the bow of PACSCAT in detail under the test conditions and studies the internal and external free liquid surface under different conditions.

Experimental investigations on the resistance performance of a high-speed partial air cushion supported catamaran

Yang, Jinglei,Lin, Zhuang,Li, Ping,Guo, Zhiqun,Sun, Hanbing,Yang, Dongmei The Society of Naval Architects of Korea 2020 International Journal of Naval Architecture and Oc Vol.12 No.-

The partial air cushion supported catamaran (PACSCAT) is a novel Surface Effect Ship (SES) and possesses distinctive resistance performance due to the presence of planing bottom. In this paper, the design of PACSCAT and air cushion system are described in detail. Model tests were carried out for Froude numbers ranging from 0.1 to 1.11, the focus is on the influence of air cushion system on resistance characteristics. Drag-reducing effect of air cushion system was proved by means of contrast tests in cuhionborne and non-cushionborne mode. Wave-making characteristics reflect that the PACSCAT would eventually enter planing regime, in which the air could just escape under the seals and the hull body could operate in a steady state. To acquire different air cushion pressure, air flow rate and leakage height were adjusted during tests. Experimental results show that the resistance performance in planing regime would decrease evidently as the increased air flow rate, however, the scheme with medium leakage height presents the best resistance performance in the hump region.

Experimental investigations on the resistance performance of a high-speed partial air cushion supported catamaran

Yang, Jinglei,Lin, Zhuang,Li, Ping,Guo, Zhiqun,Sun, Hanbing,Yang, Dongmei The Society of Naval Architects of Korea 2020 International Journal of Naval Architecture and Oc Vol.12 No.1

The partial air cushion supported catamaran (PACSCAT) is a novel Surface Effect Ship (SES) and possesses distinctive resistance performance due to the presence of planing bottom. In this paper, the design of PACSCAT and air cushion system are described in detail. Model tests were carried out for Froude numbers ranging from 0.1 to 1.11, the focus is on the influence of air cushion system on resistance characteristics. Drag-reducing effect of air cushion system was proved by means of contrast tests in cuhionborne and non-cushionborne mode. Wave-making characteristics reflect that the PACSCAT would eventually enter planing regime, in which the air could just escape under the seals and the hull body could operate in a steady state. To acquire different air cushion pressure, air flow rate and leakage height were adjusted during tests. Experimental results show that the resistance performance in planing regime would decrease evidently as the increased air flow rate, however, the scheme with medium leakage height presents the best resistance performance in the hump region.

Neural-Network Based Optimal Dynamic Control of Delivering Packets in Selfish Wireless Networks

Jinglei Li,Qinghai Yang,Kyung Sup Kwak IEEE 2015 IEEE communications letters Vol.19 No.12

<P>In this letter, we investigate the dynamic packet delivery through a specific path in selfish wireless networks (SeWNs) with cascaded selfish relay nodes (RN). A dynamic node-selfishness model is designed to formulate the variation of the RN's degree of node-selfishness (DeNS) with both its own resource and the incentive controlled by the source. When the node-selfishness dynamics are unknown, using the neural network (NN), we further identify the node-selfishness model and then approximate the optimal incentives for maximizing the infinite-horizon utility, namely the tradeoff between the path reliability and the incentive cost in the long term. Simulation results demonstrate the effectiveness of the proposed scheme.</P>

End-to-End Multiservice Delivery in Selfish Wireless Networks Under Distributed Node-Selfishness Management

Jinglei Li,Qinghai Yang,Peng Gong,Kyung Sup Kwak IEEE 2016 IEEE TRANSACTIONS ON COMMUNICATIONS Vol.64 No.3

<P>In this paper, we investigate the multiservice delivery between the source-destination pairs in distributed selfish wireless networks (SeWN), where selfish relay nodes (RN) expose their selfish behaviors, i.e., forwarding or dropping multiservices. Owing to the effect of the RNs' node-selfishness on the multiservices, a distributed framework of the node-selfishness management is constructed to manage the RN's node-selfishness information (NSI) in terms of its available resources, the employed incentive mechanism and the quality-of-service (QoS) requirements, and the other RNs' NSI in terms of their historical behaviors. In this framework, the RNs' NSI includes the degree of node-selfishness (DeNS), the degree of intrinsic selfishness (DeIS) and the degree of extrinsic selfishness (DeES). Under the distributed node-selfishness management, a path selection criterion is designed to select the most reliable and shortest path in terms of RNs' DeISs affected by their available resources, and the optimal incentives are determined by the source to stimulate forwarding multiservices of the RNs in the selected path. Our simulation results demonstrate that this framework effectively manages the RNs' NSI, and the optimal strategies of both the path selection and the incentives are determined.</P>

Synthesis of P Doped EDTA-Co Structure and Synergistic Effect of ORR as Electrochemical Catalyst

김관우,Jinglei Yang,김주헌 한국고분자학회 2019 폴리머 Vol.43 No.6

In this study, we successfully developed an electrochemical cathodic catalyst with a previously unreported structure. In essence, a new material was fabricated by doping EDTA-Co with P. EDTA has six ligand sites and forms an octahedral structure through six coordination bonds with transition metals. In addition, by doping hetero atoms, the atomic and spin charge density of the catalyst surface are changed to lower the adsorption energy of oxygen, which leads to more favorable reactions and enhances the catalytic properties. Co and P were added to EDTA to synthesize a successful catalyst, and testing confirmed an increase in electrochemical performance due to the addition of Co and P. Moreover, this work demonstrates that the synergy effect exceeds that of simply adding Co and P.

Cross-Layer Resource Optimization for Wireless Relay Networks Under Dynamic Node Selfishness

Li, Jinglei,Yang, Qinghai,Kwak, Kyung Sup,Rao, Ramesh R. IEEE 2017 IEEE Transactions on Vehicular Technology VT Vol.66 No.8

<P>In this paper, we investigate the cross-layer resource optimization for wireless relay networks with dynamic node-selfishness information. The degree of intrinsic selfishness (DeIS) and the degree of extrinsic selfishness (DeES) of the relay node (RN) are defined as the effects of its own residual energy resource and the incentive in an incentive mechanism, respectively. A model of two-timescale node-selfishness dynamics is constructed to describe the time-varying characteristics of the RN's DeIS and DeES. Based on the two-timescale node-selfishness dynamics of the RNs, a two-timescale resource-optimization dynamical algorithm (TRODA) is employed to control the transmit powers of both RNs and end users (EU), as well as the flow rates of the data packets injected by all EUs. Meanwhile, the stability and the tracking error of the TRODA under the two-timescale node-selfishness dynamics are analyzed by Lyapunov theory. Our simulation results demonstrate that the two-timescale optimization algorithm is stable and has trivial tracking error.</P>

One-Pot Synthesis of Zincblende CuInSe2 Nanocrystals via a Green Solution Reaction Route

Dehui Li,Weichen Qi,Jinglei Xiao,Jing Yang,Yong Wu,Qiao Gao,Shengyong Zhai 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2017 NANO Vol.12 No.9

The facile and ecofriendly method for the synthesis of a suitable colloidal nanocrystal ink plays an important role in the field of solar cells. Here, we describe our recent efforts toward this direction by a simple one-pot colloidal method to engineer CuInSe2 (CISe) nanocrystals with cubic zinc-blende (ZB) structure. The suitable band gap value and obvious photoresponse of the as-synthesized CISe nanocrystals indicate their potential application in the field of thin film solar cells. In addition, a possible crystal growth mechanism has been suggested for the formation of ZB CISe.

The Study of Multi-walled Carbon Nanotube Surface and Matrix Structure for Thermal Conductive Composite Material

Kiho Kim(김기호),Jinglei Yang,Jooheon Kim(김주헌) 한국고분자학회 2018 폴리머 Vol.42 No.5

고방열 복합소재를 위하여 고분자 경화 유무에 따른 두 가지 종류의 표면처리된 탄소나노튜브/알루미나/ETDS(epoxy-terminated dimethylsiloxane)복합체를 제작하였다. 탄소나노튜브는 산처리 후 실란커플링제 및 dodecylamine을 이용하여 표면처리를 진행하였다. 실란커플링제와의 반응 메커니즘은 반응조건에 따라 조절되었다. 탄소나노튜브 표면처리에 따른 열전도도 특성 변화를 70 w% 알루미나/ETDS 복합체를 기반으로 확인하였다. 탄소나노튜브 표면처리의 효과는 복합소재의 종류에 따라 상이한 경향을 보이는데, 패드 형태의 복합소재에서는 아민기가 말단으로 위치할 때 가장 우수한 열전도도 특성을 보이는 반면 그리스 형태의 복합소재에서는 긴 탄소사슬이 말단에 위치한 구조가 가장 높은 열전도 특성을 보였다. 또한, 실란올기가 말단에 위치할 때 탄소나노튜브의 복합화 가능한 함량이 가장 높아져, 표면처리 방법에 따른 탄소나노튜브의 최대 함량 및 열전도도 차이가 나타나는 것을 확인하였다. Two kinds of surface-modified MWCNT/Al2O3/ETDS composites, cured pad and uncured grease, were fabricated for high-thermal-conductivity materials application. MWCNTs were modified using aminoproplytriethoxysilane (APTES) and dodecylamine after acid treatment. The reaction mechanism of APTES and the surface structure of MWCNT was controlled using different reaction conditions. The effect of surface modification on the thermal conductivity was confirmed based on a 70 wt% Al2O3/ETDS composite. The thermal conductivity was found to be dependent on the composite type and surface structure of the modified MWCNTs; the amine-terminated MWCNTs showed the highest thermal conductivity among the pad type composites, while long carbon chain-terminated MWCNTs showed outstanding performance among the grease type composites. Moreover, the maximum processable MWCNT content was also influenced by the surface modification; structurally similar silanol groups affected the molecular mobility of the ETDS resin and they had the highest MWCNT content under the same process conditions.