融合MacBERT和Talking⁃Heads Attention实体关系联合抽取模型

针对现有的医学文本关系抽取任务模型在训练过程中存在语义理解能力不足,可能导致关系抽取的效果不尽人意的问题,文中提出一种融合MacBERT和Talking⁃Heads Attention的实体关系联合抽取模型。该模型首先利用MacBERT语言模型来获取动态字向量表达,MacBERT作为改进的BERT模型,能够减少预训练和微调阶段之间的差异,从而提高模型的泛化能力;然后,将这些动态字向量表达输入到双向门控循环单元(BiGRU)中,以便提取文本的上下文特征。BiGRU是一种改进的循环神经网络(RNN),具有更好的长期依赖捕获能力。在获取文本上下文特征之后,使用Talking⁃Heads Attention来获取全局特征。Talking⁃Heads Attention是一种自注意力机制,可以捕获文本中不同位置之间的关系,从而提高关系抽取的准确性。实验结果表明,与实体关系联合抽取模型GRTE相比,该模型F1值提升1%,precision值提升0.4%,recall值提升1.5%。

A Cooperative Security Monitoring Mechanism Aided by Optimal Multiple Slave Cluster Heads for UASNs

As each cluster head(CH)sensor node is used to aggregate,fuse,and forward data from different sensor nodes in an underwater acoustic sensor network(UASN),guaranteeing the data security in a CH is very critical.In this paper,a cooperative security monitoring mechanism aided by multiple slave cluster heads(SCHs)is proposed to keep track of the data security of a CH.By designing a low complexity“equilateral triangle algorithm(ETA)”,the optimal SCHs(named as ETA-based multiple SCHs)are selected from the candidate SCHs so as to improve the dispersion and coverage of SCHs and achieve largescale data security monitoring.In addition,by analyzing the entire monitoring process,the close form expression of the probability of the failure attack identification for the SCHs with respect to the probability of attack launched by ordinary nodes is deduced.The simulation results show that the proposed optimal ETA-based multiple SCH cooperation scheme has lower probability of the failure attack identification than that of the existing schemes.In addition,the numerical simulation results are consistent with the theoretical analysis results,thus verifying the effectiveness of the proposed scheme.

Compacted graphite iron-A material solution for modern diesel engine cylinder blocks and heads

The demands for improved fuel economy,performance and emissions continue to pose challenges for engine designers and the materials they choose. This is particularly true for modern diesel engines,where the primary path to achieving improved engine performance and emissions is to increase the Peak Firing Pressure in the combustion chamber. The resulting increase in thermal and mechanical loading has required a change from conventional grey cast iron to Compacted Graphite Iron (CGI) in order to satisfy durability requirements without increasing the size or the weight of the engines. With at least 75% higher tensile strength,45% higher stiffness and approximately double the fatigue strength of conventional grey cast iron,CGI satisfies durability requirements and also provides the dimensional stability required to meet emissions legislation throughout the life of the engine. Currently,there are no CGI diesel engines running on the roads in North America. This is set to change considerably as new commercial vehicle and pick-up SUV diesel engines are launched with CGI cylinder blocks in 2008 and 2009. These initial programs will provide over 2 million CGI diesel engines when ramped to mature volume,potentially accounting for 10%-15% of the North American passenger vehicle fleet within the next four years.

Knowledge on breast cancer and its prevention among women household heads in Northern Ethiopia

Background: Breast cancer (BC) is one of the malignant diseases taking the lion’s share role in the devastating effects caused by cancer. BC related awareness and practice of females are known to have crucial contribution in the prevention and control efforts. The worst aspects of the disease in Ethiopia include absence of research and thus very limited information on any aspect. The study assessed knowledge and practice on BC among women household heads. Methods: A cross-sectional study was conducted on a sample of 845 women. The sample size was divided among five randomly selected kebeles (smallest government administrative units) proportional to the number of households. Samples were selected by systematic sampling technique. Data were collected by trained data collectors through a face-to-face interview using pre-tested, semi-structured questionnaire from female household heads. Pearson chi-square and logistic regression tests were used to assess the determinants of BC knowledge and breast cancer self examination (BSE) practice. Results: The respondents’ age ranged from 20 to 75 years with a mean age of 33.66 ± 10.8. Onefifth (19.8%) of the respondents were illiterate, while 257 (31.8%) had primary education. Majority of them were married 548 (67.7%), Orthodox Christians 649 (80.4%), and housewives 365 (45.1%). Only 675 (83.4%) of the respondents have ever heard/read about BC. Media 399 (59.1%) and colleagues/friends/neighbors 200 (29.6%) were the major information sources. Only 86 (12.7%) of the respondents had a high BC knowledge. Even though 304 (45%) of the BC informed participants had information on BSE, only 163 (53.6%) of them have ever done it. Both BC knowledge and BSE practice were significantly affected by educational level. Conclusion: Majority of women household heads in Mekelle town had low knowledge and insufficient BC related practices. The region’s health bureau and local mass-media need to work on breast cancer awareness and practice of the women in the town.

Development and application of d30mm and d32mm drill heads

ＤＥＶＥＬＯＰＭＥＮＴＡＮＤＡＰＰＬＩＣＡＴＩＯＮＯＦｄ３０ｍｍＡＮＤｄ３２ｍｍＤＲＩＬＬＨＥＡＤＳＬｉｕ，Ｒｏｎｇｘｉａｎｇ；Ｙｉ，Ｋａｉｈｕａ；Ｐｅｉ，ＸｉｔａｏＷａｎｇ，Ｗｅｎｚｈａｏ（ＰｏｗｄｏｒＭｅｔａｌｌｕｒｇｙＦａｃｔｏｒｙ，Ｃｅｎｔｒ...

Three Heads of Black Chinese Cabbage

It was early spring in 1985.I was watching a local opera on the village’s Willow Stage.Mom spotted me among the crowd and dragged me out.At that moment,the last thing I wanted to do was leave.While mom tugged at my black cotton-wadded coat,I struggled to resist,all the while trying to still catch a glimpse of the opera.

Report of a New Case of Interlocking Heads in a Breech-Vertex Twin Delivery: A Conversation with My Residents

“Locked twins” is a rare event occurring in about 1 in every 1000 twin births. A 21-year-old primigravida with a 31-week twin pregnancy was admitted for delivery. The head of the first twin was locked to the chin of the second twin at the top of the symphysis pubis. Caesarean section was performed allowing the delivery of both dead twins. Twins gestations with first twin in the breech presentation raise index of suspicion of potential locked twin. However, management of such situation is controversial with most authors and colleges recommending caesarean section to avoid interlocking heads. We report another rare case of interlocking heads and bring up the topic about management of breech-first twin deliveries.

Premier Wen Jiabao heads the newly set up National Energy Commission

On January 27, 2010, an overarching government agency, the National Energy Commission (NEC), which is responsible for drafting national energy

Comparative Analysis of Sonar Heads Drive Systems

This paper is dealing with a comparative analysis, from technical point of view of the solutions with the highest potentiality utilized in sonar heads drives. Even though the use of DC servomotors is a convenient solution for most customers, from some modem analysis criteria points of view, this type of drive system has a low reliability and a greater impact on the environment, compared to AC servomotors. From this class of AC servomotors, high behaviors, in such an application, have stepper motors and electronically commutated motor （brushless DC）. That is why, analysis in this paper, balances these two classes of AC servomotors. The systems performed are analyzed in Matlab/Simulink and PowerSim environments.

Huaneng Haimen heads the list of energy-based dispatching in Guangdong

Huaneng Haimen Thermal Power Plant, planned to install six 1 036-MW ultra-supercritical coal-fired generating units, is the first GW-class ultra-supercritical power plant in South China power grid,

Vessel density in OCT angiography permits differentiation between normal and glaucomatous optic nerve heads

AIM：To evaluate whether optical coherence tomography angiography（OCTA） can detect altered vessel density（VD） at the optic nerve head（ONH） in glaucoma patients.Special attention is paid to the accuracy of the OCTA technique for distinguishing healthy from glaucomatous eyes.METHODS：A total of 171 eyes were examined by the OCTA system Angio Vue^TM（Optovue）：97 eyes diagnosed with glaucoma and 74 healthy control eyes.The papillary and peripapillary VD was measured.Furthermore,the VD was correlated with different structural and functional measurements.In order to test the accuracy of differentiation between eyes with and without glaucoma,we calculated the receiver operating characteristic curve（ROC） and the area under the curve（AUC）.RESULTS：The papillary and peripapillary VD in glaucomatous eyes was significantly lower than in healthy eyes（P〈0.05）.The VD of the nasal peripapillary sector was significantly lower than in the other sectors.The further the disease had progressed [measured by determining the thickness of the ganglion cell complex（GCC） and the retinal nerve fiber layer（RNFL）] the greater the VD reduction.The AUC discriminated well between glaucomatous and normal eyes（consensus classifier 94.2%）.CONCLUSION：OCTA allows non-invasive quantification of the peripapillary and papillary VD,which is significantly reduced in glaucomatous eyes and accurately distinguishes between healthy and diseased eyes.OCTA expands the spectrum of procedures for detecting and monitoring glaucoma.

Microstructures and properties of cancellous bone of avascular necrosis of femoral heads

The aim of this study is to investigate microscopic structure and characterize cancellous bone of avascular necrosis of the femoral head （ANFH）. The rabbit model of the ANFH is established. The histopathologic features are studied successfully. The differences between the steroidinjection group （S.G.） and the controlled group （C.G.） are examined, including the weight of rabbits, the hematological examination and the three-dimensional stnactures. It is found that the plasma levels of cholesterol （CHO）, high-density lipoprotein （HDL） and low-density lipoprotein （LDL） in S.G. are lower than those in C.G. when the triglyceride （TG） increased in the S.G.; but the bone mineral content （BMC） and the structural model index （SMI） of the organ and tissue decreased significantly in S.G. Three-dimensional structures of the femoral head are obtained using micro-computed tomography （CT） scanning and the mechanical model is established to analyze the influences of these structural changes on the mechanical properties of the cancellous bone.

Flower heads in Asteraceae—recruitment of conserved developmental regulators to control the flower-like inflorescence architecture

Inflorescences in the Asteraceae plant family,flower heads,or capitula,mimic single flowers but are highly compressed structures composed of multiple flowers.This transference of a flower-like appearance into an inflorescence level is considered as the key innovation for the rapid tribal radiation of Asteraceae.Recent molecular data indicate that Asteraceae flower heads resemble single flowers not only morphologically but also at molecular level.We summarize this data giving examples of how rewiring of conserved floral regulators have led to evolution of morphological innovations in Asteraceae.Functional diversification of the highly conserved flower meristem identity regulator LEAFY has shown a major role in the evolution of the capitulum architecture.Furthermore,gene duplication and subsequent sub-and neofunctionalization of SEPALLATA-and CYCLOIDEA-like genes in Asteraceae have been shown to contribute to meristem determinacy,as well as flower type differentiation—key traits that specify this large family.Future challenge is to integrate genomic,as well as evolutionary developmental studies in a wider selection of Asteraceae species to understand the detailed gene regulatory networks behind the elaborate inflorescence architecture,and to promote our understanding of how changes in regulatory mechanisms shape development.

Quantitative Survivability Analysis Using Probability Model Checking: A Study of Cluster-Based Vehicle Networks with Dual Cluster Heads

As an important part of future 5G wireless networks,a vehicular network demands safety,reliability and connectivity.In this context,networking survivability is usually considered an important metric to evaluate network performance.In this paper,we propose a survivability model for vehicle communication networking based on dual cluster heads,wherein a backup cluster head(CH)will be activated if the primary CH fails,thereby effectively enhancing the network lifetime.Additionally,we introduce a software rejuvenation strategy for the prime CH to further improve the survivability of the entire network.Using the Probabilistic Symbolic Model Checker(PRISM),we verify and discuss the proposed survivability model via numerical simulations.The results show that network survivability can be effectively improved by introducing an additional CH and further enhanced by adopting the software rejuvenation technique.

Grain refinement of gravity die cast secondary AlSi7Cu3Mg alloys for automotive cylinder heads

The effects of AITi5B1 grain refinement and cooling rate on the microstructure and mechanical properties of a secondary AlSi7Cu3Mg alloy were reported. Metallographic and image analysis techniques have been used to quantitatively examine the macrostructural and microstructural changes occurring with the addition of grain-refining agent at different cooling rates by using a step casting die. The results indicate that the addition of AlTi5B1 produces a fine and uniform grain structure throughout the casting and this effect is more pronounced in the slowly solidified regions. Increasing the cooling rate, lower amount of grain refiner is necessary to produce a uniform grain size throughout the casting. On the other hand, the initial contents of Ti and B, present as impurity elements in the supplied secondary alloy, are not sufficient to produce an effective grain refinement. The results from the step casting geometry were applied to investigate a gasoline 16V cylinder head, which was produced by gravity semi-permanent mould technology. The grain refinement improves the plastic behaviour of the alloy and increases the reliability of the casting, as evidenced by the Weibull statistics.

Heuristic algorithms for scheduling on uniform parallel machines with heads and tails

This paper considers the uniform parallel machine scheduling problem with unequal release dates and delivery times to minimize the maximum completion time.For this NP-hard problem,the largest sum of release date,processing time and delivery time first rule is designed to determine a certain machine for each job,and the largest difference between delivery time and release date first rule is designed to sequence the jobs scheduled on the same machine,and then a novel algorithm for the scheduling problem is built.To evaluate the performance of the proposed algorithm,a lower bound for the problem is proposed.The accuracy of the proposed algorithm is tested based on the data with problem size varying from 200 jobs to 600 jobs.The computational results indicate that the average relative error between the proposed algorithm and the lower bound is only 0.667%,therefore the solutions obtained by the proposed algorithm are very accurate.

SUB-NANOMETER POLISHING OF MAGNETIC RIGID DISK HEADS TO AVOID POLE TIP RECESSION

For the purpose of solving the problem that too large pole tip recession （PTR） is produced in magnetic rigid disk heads by mechanical polishing, a chemical mechanical nano-grinding experiment is performed by using a float-piece polisher with a tin plate to achieve a more plane and smoother surface. A basal solution, addition agents and a range of pH value are suitably selected to find a kind of slurry, with which the PTR can be controlled on sub-nanometer scale and the giant magnetic resistance （GMR） corrosion and electrostatic damage （ESD） can be avoided. Moreover, the cause that TiC protrudes from the substrate surface of the heads is studied. The appropriate shape and size of diamond abrasive are selected according to the chemical activation of A1203 and TiC in the same slurry. In this way, the chemical and mechanical interactions are optimized and the optimal surface that has small PTR and TiC asperity is achieved. Ultimatily, the chemical mechanical nano-grinding in combination with mechanical nano-grinding is adopted. Sub-nanometer PTR is achieved and the TiC asperity is eliminated by the chemical mechanical nano-grinding with large size ofmonocrystalline followed by mechanical nano-grinding with smalle polycrystalline diamonds.