Ultra-low-phase-noise cryocooled microwave dielectric-sapphire-resonator oscillators with 1 x 10^-16 frequency instability

Two nominally identical ultra-stable cryogenic microwave oscillators are compared. Each incorporates a dielectric-sapphire resonator cooled to near 6 K in an ultra-low vibration cryostat using a low-vibration pulse-tube cryocooler. The phase noise for a single oscillator is measured at -105 dBc/Hz at 1 Hz offset on the 11.2 GHz carrier. The oscillator fractional frequency stability is characterized in terms of Allan deviation by 5.3 x 10^-16 tau^-1/2 + 9 x 10^-17 for integration times 0.1 s < tau < 1000 s and is limited by a flicker frequency noise floor below 1 x 10^-16. This result is better than any other microwave source even those generated from an optical comb phase-locked to a room temperature ultra-stable optical cavity.Comment: 4 pages, 5 figure

Relation Structure-Aware Heterogeneous Information Network Embedding

Heterogeneous information network (HIN) embedding aims to embed multiple types of nodes into a low-dimensional space. Although most existing HIN embedding methods consider heterogeneous relations in HINs, they usually employ one single model for all relations without distinction, which inevitably restricts the capability of network embedding. In this paper, we take the structural characteristics of heterogeneous relations into consideration and propose a novel Relation structure-aware Heterogeneous Information Network Embedding model (RHINE). By exploring the real-world networks with thorough mathematical analysis, we present two structure-related measures which can consistently distinguish heterogeneous relations into two categories: Affiliation Relations (ARs) and Interaction Relations (IRs). To respect the distinctive characteristics of relations, in our RHINE, we propose different models specifically tailored to handle ARs and IRs, which can better capture the structures and semantics of the networks. At last, we combine and optimize these models in a unified and elegant manner. Extensive experiments on three real-world datasets demonstrate that our model significantly outperforms the state-of-the-art methods in various tasks, including node clustering, link prediction, and node classification

Acquisition of L3 Spanish combinations: development in multilingual contexts

There has been little research on the acquisition of Spanish collocation, particularly concerning collocation combinations in a multilingual context. Therefore, this corpus-based study attempted to provide new insights for learning Spanish collocation. The research questions are: (1) What are the usage and error tendencies in acquiring Spanish combinations by learners of L3 Spanish? (2) How do the contrasts between L3 Spanish and the learners’ prior languages (L1 Chinese and L2 English) play a role in acquiring L3 Spanish collocation? The results showed a developmental sequence moving from N-Adj, V-N, to Adj-N combinations. Furthermore, the results of the qualitative analysis suggested that most errors were associated with the learners’ L1 (Chinese) and L2 (English). On the other hand, lexical errors might be attributed to the formal similarity between L2 English and L3 Spanish and the meaning transfer between Chinese (L1) and English (L2). Finally, the analysis suggested the similarity among the three languages in form, and the connections among the linguistic features played an essential role in learning L3 Spanish combinations.Este estudio a partir del corpus tiene como objetivo explorar nuevas perspectivas para la adquisición de las colocaciones en el español. Para ello, se establecen dos preguntas de investigación: (1) ¿Cuáles son los usos incorrectos y las tendencias de equivocación en la adquisición de las combinaciones en español por los aprendices cuya L3 es español? (2) ¿Qué papel juegan las similitudes y las diferencias entre el español y la L1, el chino, para la adquisición de la lengua meta?, y ¿qué papel juegan las similitudes y las diferencias entre el español y la L2, el inglés? Los resultados señalan el desarrollo del lenguaje partiendo desde las combinaciones de N-Adj, V-N a Adj-N. Los mismos demuestran que la mayoría de los errores observados se asocian tanto a la influencia de la L1 (chino) como la L2 (inglés) de los aprendices. Por otra parte, los errores léxicos podrían atribuirse a la conexión de la similitud formal entre la L2 y la L3 y la transferencia de significado entre la L1 y la L2. Por último, la relativa similitud entre los tres idiomas, y la conexión de sus características lingüísticas juegan un papel importante en el aprendizaje de las combinaciones de la L3

SSthreshless Start: A Sender-Side TCP Intelligence for Long Fat Network

Measurement shows that 85% of TCP flows in the internet are short-lived flows that stay most of their operation in the TCP startup phase. However, many previous studies indicate that the traditional TCP Slow Start algorithm does not perform well, especially in long fat networks. Two obvious problems are known to impact the Slow Start performance, which are the blind initial setting of the Slow Start threshold and the aggressive increase of the probing rate during the startup phase regardless of the buffer sizes along the path. Current efforts focusing on tuning the Slow Start threshold and/or probing rate during the startup phase have not been considered very effective, which has prompted an investigation with a different approach. In this paper, we present a novel TCP startup method, called threshold-less slow start or SSthreshless Start, which does not need the Slow Start threshold to operate. Instead, SSthreshless Start uses the backlog status at bottleneck buffer to adaptively adjust probing rate which allows better seizing of the available bandwidth. Comparing to the traditional and other major modified startup methods, our simulation results show that SSthreshless Start achieves significant performance improvement during the startup phase. Moreover, SSthreshless Start scales well with a wide range of buffer size, propagation delay and network bandwidth. Besides, it shows excellent friendliness when operating simultaneously with the currently popular TCP NewReno connections.Comment: 25 pages, 10 figures, 7 table