Efficient Processing of k Nearest Neighbor Joins using MapReduce

k nearest neighbor join (kNN join), designed to find k nearest neighbors from a dataset S for every object in another dataset R, is a primitive operation widely adopted by many data mining applications. As a combination of the k nearest neighbor query and the join operation, kNN join is an expensive operation. Given the increasing volume of data, it is difficult to perform a kNN join on a centralized machine efficiently. In this paper, we investigate how to perform kNN join using MapReduce which is a well-accepted framework for data-intensive applications over clusters of computers. In brief, the mappers cluster objects into groups; the reducers perform the kNN join on each group of objects separately. We design an effective mapping mechanism that exploits pruning rules for distance filtering, and hence reduces both the shuffling and computational costs. To reduce the shuffling cost, we propose two approximate algorithms to minimize the number of replicas. Extensive experiments on our in-house cluster demonstrate that our proposed methods are efficient, robust and scalable.Comment: VLDB201

Water Volume and Salinity Forecasts of the Small Aral Sea for the Years 2025

The Aral Sea is a saline endorheic basin in Central Asia. From 1960 onwards the lake started to shrink because of the utilization of rivers water for irrigation purposes. Since the irrigation began, massive amounts water has been used. Therefore, the lake divided into two parts in 1987: the Small Aral Sea in the north and the Large Aral Sea in the south. In the Small Aral Sea, the average water salinity increased from 25-130 g/l from 1987 to 2011. From 1999-2011, the water volume of the Small Aral Sea increased from 12.6 to 22.0 km3. Holt's linear trend forecast method was used to predict the water volume and salinity of the Small Aral Sea from 2010 to 2025. The prediction results indicate that the water volume of the Small Aral Sea will increase to around 22.8 km3, and salinity of the Small Aral Sea will rise to approximately 190 g/l by 2025

Betanodavirus non-structural protein B1: A novel anti-necrotic death factor that modulates cell death in early replication cycle in fish cells

AbstractThe functions of the Betanodavirus non-structural protein B1 is still unknown. We examined B1 expression patterns and investigated novel cell death regulatory functions for this viral protein following RGNNV infection in fish cells. The B1 gene (336 nt) was cloned from the redspotted grouper nervous necrosis virus (RGNNV) genome. B1 mRNA was rapidly expressed in the fish cells from viral RNA3 at 12 h post-infection (p.i.). At the protein level, expression was low at 12 h p.i., and then increased rapidly between 24 h and 72 h p.i. In RGNNV-infected, B1-containing fish cells, over expression of RGNNV B1 reduced Annexin-V positive cells by 50% and 65% at 48 h and 72 h p.i., respectively, and decreased loss of mitochondrial membrane potential (MMP) by 20% and 70% at 48 h and 72 h p.i., respectively. Finally, B1 knockdown during RGNNV infection using anti-sense RNA increased necrotic cell death and reduced cell viability during the early replication cycle (24 h p.i.). Our results suggest that B1 is an early expression protein that has an anti-necrotic cell death function which reduces the MMP loss and enhances viral host cell viability. This finding provides new insights into RNA viral pathogenesis and disease control

Using Adaptive Structuraction Theory to Study the Implementation of CIM Systems: A case study of TFT-LCD Companies

CIM (Computer Integrated Manufacturing) is like a strategic weapon that helps industries increase their capacity for competing. Case study by interviewing enterprise is the main technique applied in this research. Base on AST (Adaptive Structuraction Theory) introduced by multiple case analyses, in the process of implementing CIM the interaction between CIM and organization of two TFT-LCD industries whose business operation characteristics are different will be discussed. The research result can be treated as a reference for enterprises to perform their CIM system more effectively and promote their core competency. In the paper, some discoveries are found as follows: the enterprises that have higher degree of automation always pay more attention to the operation standard of manufacturing and system, and consider the correspondence between them for need of process automation. On the other hand, the enterprises that have lower degree of automation always pay more attention to the rationalization of production lines, the convenience of adjusting operation process after the system is implemented, division of labor among the related organizations and their responsibility as well. The reason why causes the difference is the former thinks both the system functions and information linking techniques are two most important key points in the CIM project, so the employee rate of the staff related with IT must be increased in the project organization

Kondo Signatures of a Quantum Magnetic Impurity in Topological Superconductors

We study the Kondo physics of a quantum magnetic impurity in two-dimensional topological superconductors (TSCs), either intrinsic or induced on the surface of a bulk topological insulator, using a numerical renormalization group technique. We show that, despite sharing the p+ip pairing symmetry, intrinsic and extrinsic TSCs host different physical processes that produce distinct Kondo signatures. Extrinsic TSCs harbor an unusual screening mechanism involving both electron and orbital degrees of freedom that produces rich and prominent Kondo phenomena, especially an intriguing pseudospin Kondo singlet state in the superconducting gap and a spatially anisotropic spin correlation. In sharp contrast, intrinsic TSCs support a robust impurity spin doublet ground state and an isotropic spin correlation. These findings advance fundamental knowledge of novel Kondo phenomena in TSCs and suggest experimental avenues for their detection and distinction

The restoration of sediment-related disasters and driftwood from national forest in Taiwan caused by Typhoon Morakot in 2009

The number and area of new landslide, according to the interpreted SPOT images, caused by Typhoon Morakot in 2009 is estimated as 30,223 and 43,996 ha, respectively. The new landslide area in 2009 increased by about 16,392 ha in comparison with the landslide area in 2008. The heavy rainfall with a return period well over 200 years during Typhoon Morakot centralized in southwestern and southeastern Taiwan, and that also resulted in serious landslide disasters in national forest. Four forest working circles, including Chishan, Laonong, Pintung, and Dawu, are the most serious landslide zones with the landslide ratio over 8.0%. The Forestry Bureau assesses and ranks the seriousness of the disasters by using slope, the number of protected objects, the distance from the disaster to the protected objects to execute the restoration of sediment disasters and landslide in national forest. Due to the most torrential rain in the past 50 years caused by Typhoon Morakot, a large number of trees in the mountain area were destroyed. They became the driftwood, with a total weight of about 1.52 million tons, which ended up at the farmlands and ports. In order to recover agricultural products and livelihoods, Forestry Bureau made strategy for disaster prevention and reduction. Based on the strategy, Forestry Bureau sweeps away the driftwood by estimating its distribution, overcomes the issues caused by the heavy rainfall disaster, and helps the victims to recover their life

Intra-abdominal abscess caused by toothpick injury

SummaryWe present the case of a 42-year-old female who presented to our emergency department (ED) complaining of epigastric pain for four days. She had been seen in the outpatient department and ED previously for evaluation, but continued to experience epigastric pain with fever. Emergency panendoscopy was performed and a toothpick was discovered impacted in the duodenal bulb. The gastroenterologist was unable to remove the toothpick endoscopically. Computed tomography of the abdomen revealed a long and straight hyperdense foreign body, and intra-abdominal abscess formation. An emergency laparotomy was performed. The patient recovered gradually and was discharged 11 days later. She could not remember when she swallowed the wooden toothpick, but guessed that it was while out drinking. There is an old wives’ tale in Taiwan that putting a toothpick in the cup while drinking beer reduces the likelihood of abdominal distention from the carbonation of the beer

Effect of the Kinesio tape to muscle activity and vertical jump performance in healthy inactive people

BACKGROUND: Elastic taping applied on the triceps surae has been commonly used to improve the performance of lower extremities. However, little objective evidence has been documented. The purpose of this study was to investigate the effect of elastic taping on the triceps surae during a maximal vertical jump. It was hypothesized that elastic taping to the triceps surae would increase muscle activity and cause positive effect to jump height. METHODS: Thirty-one healthy adults (19 males and 12 females with mean age, body weight and height for 25.3 ± 3.8 years old, 64.1 ± 6.2 kg, and 169.4 ± 7.3 cm, respectively) were recruited. All participants performed vertical jump tests prior to (without taping) and during elastic taping. Two elastic tapes, Kinesio tape and Mplacebo tape from two different manufacturers, were applied to the participants, respectively. RESULTS: The results showed that the vertical ground reaction force increased when Kinesio tape was applied even when the height of jump remained about constant. However, the height of the jump decreased, and there was no difference on the vertical ground reaction force in Mplacebo taping group. Although the EMG activity of medial gastrocnemius tended to increase in Kinesio taping group, we did not see differences in EMG activity for the medial gastrocnemius, tibialis anterior and soleus muscles in either group. CONCLUSIONS: Based on the varied effects of Kinesio tape and Mplacebo tape, different intervention technique was suggested for specific purpose during vertical jump movement. Mplacebo tape was demanded for the benefits of stabilization, protection, and the restriction of motion at the ankle joint. On the other hand, the findings may implicate benefits for medial gastrocnemius muscle strength and push-off force when using Kinesio tape