Fast Iterative Closest Point-Simultaneous Localization and Mapping(ICP-SLAM)with Rough Alignment and Narrowing-Scale Nearby Searching

Two deficiencies in traditional iterative closest pointsimultaneous localization and mapping( ICP-SLAM) usually result in poor real-time performance. On one hand, relative position between current scan frame and global map cannot be previously known. As a result, ICP algorithm will take much amount of iterations to reach convergence. On the other hand,establishment of correspondence is done by global searching, which requires enormous computational time. To overcome the two problems,a fast ICP-SLAM with rough alignment and narrowing-scale nearby searching is proposed. As for the decrease of iterative times,rough alignment based on initial pose matrix is proposed. In detail,initial pose matrix is obtained by micro-electro-mechanical system( MEMS) magnetometer and global landmarks. Then rough alignment will be applied between current scan frame and global map at the beginning of ICP algorithm with initial pose matrix. As for accelerating the establishment of correspondence, narrowingscale nearby searching with dynamic threshold is proposed,where match-points are found within a progressively constrictive range.Compared to traditional ICP-SLAM,the experimental results show that the amount of iteration for ICP algorithm to reach convergence reduces to 92. 34% and ICP algorithm runtime reduces to 98. 86% on average. In addition,computational cost is kept in a stable level due to the eliminating of the accumulation of computational consumption. Moreover,great improvement can also been achieved in SLAM quality and robustness.

An Analysis of the Turbulent Structure in the Unstable Surface Layer nearby a Shelter Belt

An analysis was performed of the turbulent data obtained from Yucheng experimental station in the Shandong Province in 1984. [t is shown that at variant wind speed, the spectra of streamwise velocity remain similar and the intensity of wind fluctuations is proportional to wind speed in the downwind area of shelter belt. Therefore, we may decide the similarity of wind fluctuations by a speed scale and a length scale which is not correlated with stability, σu /V0 = F(X / H). The -5/3 power range of temperature spectra extends to lower frequency. The variation of ratio σ0 /T. with stability becomes σ0 / T . = C(X / H)( - Z / L)-1/3 . There is not such an extension of -5 / 3 power range in the humidity spectra.

〔C II〕Continuum Intensity Ratio in the Far-Infrared Toward the Central Kiloparsec of the Nearby Spiral Galaxy M31

We observed the nearby galaxy M31 in the 〔C II〕158 μm emission line. An extended component was detected over the central 1 5 kpc region with a line-to-continuum ratio of 〔C II〕/〔40-120μm〕6×10 -3 . This ratio is 3 times larger than that of the Galactic counterpart and is comparable to that in the general Galactic Plane. We expect that the difference between the two central regions are due to different gas densities; the self-shielding of CO molecules decreases the C + abundance at the higher density in the Galactic case.

Ecological characteristics of the abundance and distribution of bacteria in the waters nearby the front of the Hangzhou Bay

Abundance of total bacteria, heterotrophic bacteria, coliform and oil degradable bacteria and their relations with salinity and suspended matter in the frontal waters in the Hangzhou Bay are described. The results obtained show that the highest abundances of total bacteria , heterotrophic bacteria are encountered around the front and near the northern shore of the Hangzhou Bay, where a positive correlation ( r =0. 70) between the total bacteria abundance and the total suspended matter (TSM) is persent. Moreover,the abundance of oil degradable bacteria being an indicator of oil pollution, is also high in that region.

Soft X-ray emission of nearby galaxy M81

The pointed observations of NGC3077 are analyzed by position sensitive proportional counter (PSPC) on board the ROSAT satellite on 1991-04-18, 1991, finding out that the X-ray emission range of M81 galaxy has, in the softer and more sensitive ROSAT PSPC band (0. 2-2. 4 keV), extended by 40% larger than ever observed by image proportional counter (IPC) on board the Einstein satellite, which shows that M81 galaxy has a larger X-ray corona. And by the aid of the timing analysis, it is concluded that M81 nucleus has no variabilities on time scale of a few minutes; hence the possibility of M81 nucleus having the marginal variability over time scale of about 2 min that Fabbiano (1988) found from the Einstein IPC observation is ruled out.

The Abundance of Strange Attractor in the Families of Nearby Singular Diffeomorphism

In this paper,we consider the families of nearby singular diffeomorphism and the measure of a set in the parameter space,such that for each point of the set the corresponding diffeomorphism possesses strange attractor.For some families of one-dimensional mapping satisfying certain transversality condition,we prove that there is a positive measure set in the parameter space, such that the system in the corresponding families of nearly singular diffeomorphism has strange attractor.Furthermore,we study the dynamics of this type of strange attractor.

A High-Quality Adaptive Video Reconstruction Optimization Method Based on Compressed Sensing

The video compression sensing method based onmulti hypothesis has attracted extensive attention in the research of video codec with limited resources.However,the formation of high-quality prediction blocks in the multi hypothesis prediction stage is a challenging task.To resolve this problem,this paper constructs a novel compressed sensing-based high-quality adaptive video reconstruction optimizationmethod.Itmainly includes the optimization of prediction blocks(OPBS),the selection of searchwindows and the use of neighborhood information.Specifically,the OPBS consists of two parts:the selection of blocks and the optimization of prediction blocks.We combine the high-quality optimization reconstruction of foreground block with the residual reconstruction of the background block to improve the overall reconstruction effect of the video sequence.In addition,most of the existing methods based on predictive residual reconstruction ignore the impact of search windows and reference frames on performance.Therefore,Block-level search window(BSW)is constructed to cover the position of the optimal hypothesis block as much as possible.To maximize the availability of reference frames,Nearby reference frame information(NRFI)is designed to reconstruct the current block.The proposed method effectively suppresses the influence of the fluctuation of the prediction block on reconstruction and improves the reconstruction performance.Experimental results showthat the proposed compressed sensing-based high-quality adaptive video reconstruction optimization method significantly improves the reconstruction performance in both objective and supervisor quality.

Effects of adjacent bubble on spatiotemporal evolutions of mechanical stresses surrounding bubbles oscillating in tissues

The cavitation dynamics and mechanical stress in viscoelastic tissues, as the primary mechanisms of some ultrasound therapies, are extremely complex due to the interactions of cavitation bubble with adjacent bubbles and surrounding tissues.Therefore, the cavitation dynamics and resultant mechanical stress of two-interacting bubbles in the viscoelastic tissues are numerically investigated, especially focusing on the effects of the adjacent bubble. The results demonstrate that the mechanical stress is highly dependent on the bubble dynamics. The compressive stress and tensile stress are generated at the stage of bubble expansion and collapse stage, respectively. Furthermore, within the initial parameters examined in this paper, the effects of the adjacent bubble will distinctly suppress the radial expansion of the small bubble and consequently lead its associated stresses to decrease. Owing to the superimposition of two stress fields, the mechanical stresses surrounding the small bubble in the direction of the neighboring bubble are smaller than those in other directions. For two interacting cavitation bubbles, the suppression effects of the nearby bubble on both the cavitation dynamics and the stresses surrounding the small bubble increase as the ultrasound amplitude and the initial radius of the large bubble increase, whereas they decrease with the inter-bubble distance increasing. Moreover, increasing the tissue viscoelasticity will reduce the suppression effects of the nearby bubble, except in instances where the compressive stress and tensile stress first increase and then decrease with the tissue elasticity and viscosity increasing respectively. This study can provide a further understanding of the mechanisms of cavitation-associated mechanical damage to the adjacent tissues or cells.

施工前模拟可减少压裂诱发地震

2015年11月26日,《加拿大岩土工程学报》（Canadian Geotechnical Journal）发表文章《针对流体注入诱发地震活动及激活断层的离散单元模型》（Discrete element modeling of fluid injection-induced seismicity and activation of nearby fault）,

CHANGE IN PROTEIN PATTERN ON TWO-DIMENSIONAL ELECTROPHORESIS GEL AFTER EXPOSURE OF DROSOPHILA MELANOGASTER TO MAGNETIC FIELDS.

To ascertain whether the gene expression is altered byexposure of living organisms to strong magnetic field,4-7 days old males of fruit fly Drosophila melanogasterwere exposed to 10,000 G static magnetic field

薛谭学讴

薜谭向秦青学唱歌,没有学到秦青的全部技巧,就自认为已把老师的本领都学到手了,于是,他向老师告辞回家。秦青并不挽留他,在郊外大道上为他饯行。 席间,秦青拨动琴弦,悲壮地唱着歌。歌声震荡着树林,树枝随着高亢的歌声轻轻摇摆,树叶簌簌,

Right Time to Upgrade the Cooperation Between Chinese & European Enterprises

"Wesincerely hope that not only Mercedes Benz can realize an increase in car sales volume in China for35 months in line,but also Geely will get popular in Europe;not only can we go to Carrefour after work,but also these Europeans can shop in a Wangfujing Department Store nearby,"said Jiang Zengwei,Chairman of China Council for the Promotion of International Trade(CCPIT),at the symposium

Four Minutes That Get You Hired

The 28-year-old had spent six years working at night whileshe attended university during the day.“I always wanted to be ateacher,”she says,“and I worked hard to earn my degree.When Ifinally graduated.I was very optimistic.”She had her eye on ateaching position at a nearby primary school.

Why He Was Unlucky in Love

During the war, a fighter pilot was injured. Fortunately, he wassaved by a group-of nuns from a nearby convent. He had beenvery weak, and lost his sense When he came to, he was astonished t^find a woman beside him. It was Sister Mary, the nun in charge. She said to the pilot,'This convent is a teaching hospital. We have many young girls here,learning to be nurses. We will hide you here as long as possible,

介词+hand的几个短语

hand作为名词时,常与不同的介词搭配.表示不同的意义。常见的有atband、in hand,on band,by hand,to bud等.如果不弄清楚它们各自的意义、用法,在使用时就很容易出现错误。现将它们的用法比较如下: (1)at hand表示“在时间、空间上临近”或”在手头”.包含有“即可使用”之意,相当于nearby;near;coming:ready for use ①The summer vacation is at hand.暑假马上就到了。②It is easy to find him.He lives close at hand. 要找到他很容易,他就住在附近. ③I didn’t buy the coat because I had no money at hand. 因为手里没钱,我没有买那件外套.

Art and Artists

If you found a painting by a famous artist in an old cupboard, you would be both cheerful and rich. The value of many works of art is very high. The world is now a small place, and people are no longer familiar only with art from their own country or from nearby countries. European artists have taken many ideas from African and Asian art; moder art is very experimental. Much of it may be difficult to understand or like. The important thing is that artists can paint what they want and how they want.

The Shiny Pocket-knife

The clock on the great dome of Nottingham Town Hall beganto strike the hour of seven.Always fearful of the noise,the pigeonsrose in their hundreds and fluttered over the enormous roof.A fewflew away,across the market p|ace.Two went on further,a hun-dred yards up the Derby Road,and came to rest on a nearby win-dow-still.

Star formation properties of galaxy cluster A1767

Abell 1767 is a dynamically relaxed, c D cluster of galaxies with a redshift of 0.0703. Among 250 spectroscopically confirmed member galaxies within a projected radius of 2.5r200, 243 galaxies（ Digital Sky Survey. Based on this ～97%） are spectroscopically covered by the Sloanhomogeneous spectral sample, the stellar evolutionary synthesis code STARLIGHT is applied to investigate the stellar populations and star formation histories of galaxies in this cluster. The star formation properties of galaxies, such as mean stellar ages, metallicities, stellar masses, and star formation rates, are presented as functions of local galaxy density. A strong environmental effect is found such that massive galaxies in the high-density core region of the cluster tend to have higher metallicities, older mean stellar ages, and lower specific star formation rates（SSFRs）, and their recent star formation activities have been remarkably suppressed. In addition, the correlations of the metallicity and SSFR with stellar mass are confirmed.

EXPERIMENTAL AND NUMERICAL STUDIES OF STEADY TURBULENT FLOW FIELD OF ARTIFICIAL BILEAFLET HEART VALVE WITH CAMBERED PROFILE

In this paper,the experimental and numerical studies of steady turbulent flowfield of bileaflet mechanical valve with cambered profie are presented.With LaserDoppler Anemometry,the author measured the flow of heart valve in vitro.Theworking fluid was water,the flow rates were 15,18,21,28 and 38 l/min respectively.The corresponding Reynolds numbers were 11789,14147,16505,22006 and 29866.