High-efficiency technique for five-axis side milling of niemann worm wheels

Haibing Wu,Zheng Zhang,Quanping Sun 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.6

Five-axis side milling technique for Niemann worm wheel teeth flank using a tapered flat-end mill is presented. Equations describing the worm wheel tooth flank were derived based on differential geometry and the working principle of gears. The tooth flank was modified by offsetting its point cloud computed using these equations along the normal direction. The maximum normal curvature of the worm wheel tooth flank was computed, and its minimum radius of curvature was obtained. The cutter path step length and spacing between cutter travels were computed to generate a uniform path for five-axis machining. Software simulations of the cutter path were performed for validation and for analysing errors in the worm wheel tooth flank machining; this technique was also verified by milling worm wheels. The results demonstrated that the technique not only improved machining efficiency by 5 times compared with point milling but also guaranteed precision machining of the tooth flank for five-axis machining of cylindrical worm drives.

A Concise Design for Irradiating U-10Zr Metallic Fuel at Very Low Burnup

Haibing Guo,Wei Zhou,Yong Sun,Dazhi Qian,Jimin Ma,Jun Leng,Heyong Huo,Shaohua Wang 한국원자력학회 2017 Nuclear Engineering and Technology Vol.49 No.4

In order to investigate the swelling behavior and fuelecladding interaction mechanism ofUe10Zr alloy metallic fuel at very low burnup, an irradiation experiment was conciselydesigned and conducted on the China Mianyang Research Reactor. Two types of irradiationsamples were designed for studying free swelling without restraint and the fuelecladdinginteraction mechanism. A new bonding material, namely, pure aluminum powder, wasused to fill the gap between the fuel slug and sample shell for reducing thermal resistanceand allowing the expansion of the fuel slug. In this paper, the concise irradiation rig designis introduced, and the neutronic and thermalehydraulic analyses, which were carried outmainly using MCNP (Monte Carlo N-Particle) and FLUENT codes, are presented. Out-of-piletests were conducted prior to irradiation to verify the manufacturing quality and hydraulicperformance of the rig. Nondestructive postirradiation examinations using cold neutronradiography technology were conducted to check fuel cladding integrity and swellingbehavior. The results of the preliminary examinations confirmed the safety and effectivenessof the design.

Preparation of Lovastatin Matrix Sustained-Release Pellets by Extrusion- Spheronization Combined with Microcrystal Dispersion Technique

Haibing He,Xing Tang,Bo Shi,Cuifang Cai 대한약학회 2011 Archives of Pharmacal Research Vol.34 No.11

The poorly water-soluble drug lovastatin (LVA) is an inhibitor of 3-hydroxy-3-methylglutarylcoenzyme A reductase and has a slow dissolution rate. In this study, a microcrystal dispersion (MCD) technique was used in the preparation of LVA to increase its dissolution rate and then combining with an extrusion-spheronization method, microcrystalline cellulose (MCC) matrix sustained-release pellets containing LVA-MCD were developed and characterized in vitro. Photomicrographs indicated that LVA-MCD existed as fine crystals, of which the mean particle size was reduced from 65.75 μm to 3.97 μm and the dried LVA-MCD powders released completely within 2 hours. SEM results during the release process showed that pellets possessed a matrix structure and after the dissolution test, this matrix structure became loose and porous. The release of LVA was fast and complete, and accumulated release by the optimal formulation was: 0.5 h (20.23 ± 3.40%), 2 h (56.87 ± 2.85%), 4 h (78.71 ± 3.42%), and 8 h (96.81 ± 3.30%). The 3 months accelerating test at 40^oC and 75% RH demonstrated that drug release of pellets was not changed and drug degradation was less than 1%. Thus, a novel MCD process with MCC matrix was feasible and effective to get complete release without a lag time for the poorly water soluble drug, LVA, with high stability.

Parametric Estimation for Semi-varying Coefficient Model via Penalized Spline

Guo Haibing,MingtaoZhao,Li Lianqing 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.12

A semi-varying coefficient model, a type of semi-parametric model between the linear model and the varying coefficient model offers a good flexibility and has become an important tool for exploring the dynamic patterns in many areas of research, including economics, finance and biomedical research. This paper proposes a new estimation method for semi-varying coefficient models based on the roughness penalized spline approach. Asymptotic properties of their estimators are also obtained. The penalized spline estimation method is applied to an economic example using a semi-varying coefficient model.

A High-security RFID Grouping Proof Protocol

Ping Huang,Haibing Mu 보안공학연구지원센터 2015 International Journal of Security and Its Applicat Vol.9 No.1

Several categories of RFID authentication protocols have been proposed recently, among which Jules [5] introduced a novel research direction, named yoking proof. It is used to solve the problem that two tags have to be scanned simultaneously for some reasons. Afterwards, the yoking proof was developed into the grouping proof protocol and many such protocols have been presented. However there are some flaws on security or computational overhead. Based on the existing grouping proof protocols, a new method on key distribution is developed in this paper by means of distributing the points on straight lines to the entities. With this method, the performance of the grouping proof protocol will be improved. In comparison with the previous protocols, it provides security enhancement and performance improvement, which balances security and computational overhead to some extent.

An Embedded Multifunctional Media System for Mobile Devices in Terrestrial DTV Relaying

( Jun Huang ),( Haibing Yin ) 한국정보처리학회 2018 Journal of information processing systems Vol.14 No.5

The paper presents a novel embedded multifunctional media sever (EMMS) for mobile devices to receive various media programs. Being different from other contemporary system research, the paper mainly studies how to design a reception solution for terrestrial digital television (DTV) on mobile devices and how to enable mobile devices can receive DTV program, enjoy video-on-demand (VOD), achieve video surveillance and relay Internet video program via local Wi-Fi simultaneously. In the system design, we integrate broadcasting-terrestrial DTV tuner, streaming media re-transmission system, VOD disk, video camera and access interface to the Internet into EMMS, which can either receive terrestrial DTV radio signals and demodulate out digital transport stream (TS), or can read streaming media bit-stream from VOD disk, surveillance camera or access interface to the Internet. The experimental results show the proposed system is stable and quality-efficient. Comparing with the other systems, the proposed system has the least packet loss rate and response time.

Study on the Mechanical Properties and Microstructure of Geogrid Under Different Materials and Temperatures

Junli Gao,Haibing Zhang,Xuelei Xie,Yapo Zhang 한국섬유공학회 2022 Fibers and polymers Vol.23 No.6

In response to the environmental problems caused by the difficulty of direct degradation of the raw materials usedin traditional geogrids and the impact of different temperatures on the mechanical properties of geogrids in practicalengineering applications, based on 3D printing technology, polylactic acid (PLA), carbon fiber reinforced polylactic acid(PLA/CF), and thermoplastic polyurethane (TPU) geogrids were fabricated. The 3D printed geogrids and the fiberglassgeogrids used in the actual project were tested in indoor tensile tests under different temperature conditions. The mechanicalproperties of the geogrids of the four kinds of materials and six kinds of temperature were analyzed. The microstructure of thegeogrids after tensile tests was investigated based on scanning electron microscopy technology to further analyze the effectsof different materials and temperatures on the mechanical properties of the geogrids. The results showed that the tensilestrength of PLA/CF geogrids and PLA geogrids decreased with increasing temperature. The tensile strength of fiberglassgeogrids increased with rising temperatures. The tensile strength of PLA/CF geogrids was significantly better than PLAgeogrids. Due to the addition of carbon fiber in PLA, PLA/CF can bear more tensile force at high temperatures. With theincrease of temperature, the elongation at break of PLA/CF geogrids and fiberglass geogrids increased, but the elongation atbreak of PLA geogrids decreased. The elongation at break of PLA/CF geogrids was significantly lower than that of PLAgeogrids. TPU geogrids had high tensile capacity in a high-temperature environment, and they also had high elasticity andmore significant elongation at break, which was not suitable to be used as geogrid material.

Sources and trace element geochemical characteristics of the coarse sediment in the Ningxia-Inner Mongolia reaches of the Yellow River

Xiaopeng Jia,Haibing Wang,Hongfang Wang 한국지질과학협의회 2014 Geosciences Journal Vol.18 No.2

Siltation of coarse sediment in the river channel isthe main cause of flooding and dike burst on China’s Yellow River,and the loess are thought as the coarse sediment sources of the lowerreach of the Yellow River. The Ningxia-Inner Mongolia reaches ofthe Yellow River flow through an extensive area of aeolian desert,with flood events occurring frequently in this region. In this paper,we investigate the trace element contents of the coarse sediment inthe Ningxia-Inner Mongolia reaches of the Yellow River. The mainchemical components of the coarse sediments consist of 28 traceelements. Correlation analysis and factor analysis of 21 of thesetrace elements indicates that Ti and Zr are stable indicators of thecoarse sediment sources. Comparing the spatial distribution of someof the main trace elements to major sources and riverbed sedimentof the main reaches of the Yellow River suggests that the coarsesediments deposited in the Ningxia-Inner Mongolia reaches aremostly controlled by the local sediment sources. The results of R-factoranalysis further proved that desert sand, riverbank material,and the Ten Tributaries are the primary sources of the coarse sedimentin the Ningxia-Inner Mongolia reaches of the Yellow River.

Synthesis of 4-arms hydroxy-functionalized PMMA-b-PE through combining free radical polymerization with coordination polymerization

Yaping Sheng,Qigu Huang,Haibing Huang,Mengshan Yu,Xinli Zhang,Lu Cheng,Zhi Liu,Wei Liu,Jianjun Yi,Wantai Yang 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.2

The copolymerization of MMA with ethylene was promoted by metallocene complex in the presence ofinitiator tetra(2,3-epoxy propoxy)silane (Is), reducing agent Zn and cocatalyst MAO, combining freeradical polymerization with coordination polymerization via sequential monomer addition strategy inone-pot to produce 4-arms hydroxy-functionalized PMMA-b-PE. The effects of polymerizationconditions such as temperature, time, ethylene pressure and Al/Ti molar ratio on the polymerizationperformance were investigated. 4-Arms hydroxy-functionalized PMMA-b-PE was obtained by solventextraction and determined by GPC, MALLS, DSC, FT-IR, WAXD and 1H(13C) NMR. The DSC result indicatedthat the 4-arms hydroxy-functionalized PMMA-b-PE had one Tg at 87.0 ℃ and one Tm at 117.0 ℃ whichattributed to Tg of PMMA segment and Tm of PE segment, respectively. The microstructure of 4-armshydroxy-functionalized PMMA-b-PE was further confirmed by WAXD, FT-IR, and 13C NMR analysis. These results demonstrated that the obtained 4-arms block copolymer consisted of PMMA segment andcrystalline PE segment.

Resonant Tank Design Considerations and Implementation of a LLC Resonant Converter with a Wide Battery Voltage Range

Wenjin Sun,Hongfei Wu,Haibing Hu,Yan Xing 전력전자학회 2015 JOURNAL OF POWER ELECTRONICS Vol.15 No.6

This paper illustrates resonant tank design considerations and the implementation of a LLC resonant converter with a wide battery voltage range based on the fundamental harmonic approximation (FHA) analysis. Unlike the conventional design at zero load, the parameter K (the ratio of the transformer magnetizing inductor Lm to the resonant inductor Lr) of the LLC converter in this paper is designed with two charging points, (Vo_min, Io_max1) and (Vo_max, Io_max2), according to the battery charging strategy. A 2.9kW prototype with an output voltage range of 36V to 72V dc is built to verify the design. It achieves a peak efficiency of 96%.