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A tree T on 2n vertices is called set-sequential if the elements in V (T) ∪ E(T) can be labeled with distinct nonzero (n + 1)-dimensional 01-vectors such that the vector labeling each edge is the component-wise sum modulo 2 of the labels of the endpoints. It has been conjectured that all trees on 2n vertices with only odd degree are set-sequential (the "Odd Tree Conjecture"), and in this paper, we present progress toward that conjecture. We show that certain kinds of caterpillars (with restrictions on the degrees of the vertices, but no restrictions on the diameter) are set-sequential. Additionally, we introduce some constructions of new set-sequential graphs from smaller set-sequential bipartite graphs (not necessarily odd trees). We also make a conjecture about pairings of the elements of Fn2 in a particular way; in the process, we provide a substantial clarification of a proof of a theorem that partitions Fn2 from a paper [P.N. Balister, E. Győri and R.H. Schelp, Coloring vertices and edges of a graph by nonempty subsets of a set, European J. Combin. 32 (2011) 533-537]. Finally, we put forward a result on bipartite graphs that is a modification of a theorem in the aforementioned paper. [ABSTRACT FROM AUTHOR]

This study examined how shyness-sensitivity and unsociability were associated with social, school, and psychological adjustment in Chinese children and adolescents. Participants included 564 children (272 boys, M[sub age]=9 years) and 462 adolescents (246 boys, M[sub age]=13 years) in a suburban region in China. Data were obtained from peer assessments, sociometric nominations, teacher-ratings, self-reports, and school records. The results showed that relations of shyness and unsociability with adjustment differed in middle childhood and early adolescence. Shyness tended to be associated with social and psychological problems more evidently in adolescence than in childhood. In contrast, unsociability was associated with problems more evidently across domains in childhood than in adolescence. The results indicate that the implications of the two main forms of social withdrawal may vary across developmental periods. [ABSTRACT FROM AUTHOR]

This study explored the extent to which loneliness of Indonesian and Chinese adolescents was predicted by their intimacy and conflict with friends and parents. The total sample included 1,833 thirteen-and fifteen-year-old adolescents recruited from urban schools. Boys reported more loneliness than girls, and Chinese boys reported more loneliness than Indonesian boys. Indonesian adolescents reported less intimacy with friends, more intimacy with parents, and more conflict with peers and parents than did Chinese adolescents. Consistent with expectations, loneliness was predicted primarily by low intimacy with friends for Chinese adolescents and by low social preference for Indonesian adolescents. Whereas low intimacy and conflict with parents predicted loneliness for adolescents in both countries, these effects were stronger for Chinese than Indonesian adolescents. These findings suggest that experiences of loneliness across cultures vary as a function of the relative salience of qualities of peer and parent relationships. [ABSTRACT FROM AUTHOR]

The goal of this study was to explore longitudinal associations between peer victimization and academic achievement in Chinese children. Participants were N = 805 3rd-grade students (486 boys, 319 girls; Mage = 9.5 years, SD = 3 months) attending primary schools in Shanghai, People's Republic of China. At Time 1 and Time 2 (2 years later), peers nominated classmates who were victims of peer maltreatment using the Chinese version of the Revised Class Play (Chen, Rubin, & Sun, 1992), and teachers rated students' academic achievement. Among the results, peer victimization was negatively related to academic achievement at both time points. Also, peer victimization and academic achievement displayed considerable stability across the 2 years. Results from cross-lagged hierarchical analyses demonstrated that peer victimization at Grade 3 predicted lower academic achievement at Grade 5. However, academic achievement at Grade 3 was not predictive of peer victimization at Grade 5. These results suggest that peer victimization appears to function more as a precursor rather than a consequence of lower academic achievement. Results are discussed in terms of the cross-cultural similarities in the links between peer maltreatment and academic achievement and their educational implications. [ABSTRACT FROM AUTHOR]

We examined the relationships between internalizing problems and school adjustment in 2 cohorts (1994 and 2008) of Chinese adolescents (N = 540 and 728, respectively; M age = 13 years). The 2 time points occurred during different phases of social and economic reform in Chinese society. Data were obtained from peers, teachers, and school records. The results indicated that whereas, in the 1994 cohort, internalizing problems was only slightly and negatively associated with sociability and academic achievement, and strongly associated with externalizing problems, internalizing problems was significantly associated with social and school adjustment in the 2008 cohort. The results indicated the implications of changing context for adolescent socioemotional functioning. [ABSTRACT FROM AUTHOR]

This study examined relations of social sensitivity to social, school, and psychological adjustment in rural Chinese, urban Chinese, and Canadian children. Participants were 4th to 6th grade students (Mage = 11 years) in China (n = 593 and 443 for the rural and urban samples) and Canada (n = 325). A self-report measure of social sensitivity was developed for the study. In addition to data on social sensitivity, information on adjustment was obtained from multiple sources. The analyses revealed that social sensitivity was associated with positive adjustment in rural Chinese children but with adjustment problems in Canadian children. The relations were largely mixed and nonsignificant in urban Chinese children. These results indicate the role of context in defining the functional meaning of children's social sensitivity. [ABSTRACT FROM AUTHOR]

Isothermal vapor−liquid equilibrium data of the 1,1,2,2-tetrafluoroethane (R134) fluoroethane (R161) system were measured at temperatures ranging from (263.15 to 288.15) K with an apparatus using a recirculation method. The experimental data including temperatures, pressures, and compositions were regressed using the Peng−Robinson equation of state with the Huron−Vidal mixing rule involving the nonrandom two-liquid (NRTL) model. No azeotropic behavior was found in the measured temperature points. [ABSTRACT FROM AUTHOR]

For ultra-wideband (UWB) communications with signal energy dispersed by a large number of multipath components, the design of a Rake receiver that can provide a desirable output signal-to-noise ratio (SNR) using only a moderate number of fingers becomes an important issue. In this paper, we propose a pilot-channel-assisted log-likelihood-ratio selective combining (PCA-LLR-SC) scheme for UWB Rake receivers to be used in long-range low-rate UWB communications envisioned by the IEEE 802.15.4a PHY specification. The pilot and data channels are constructed using quadrature sinusoidal bursts that have the same Gaussian envelope. The system parameters are optimized through jointly minimizing the channel estimation mean square error and maximizing the receiver output SNR. Extensive simulations confirm that the proposed PCA-LLR-SC scheme is capable of providing robust low-rate UWB communications in fast-fading multipath channels and in the presence of multi-user interference. [ABSTRACT FROM AUTHOR]

This study examined loneliness and its associations with social functioning in children across different historical times and contexts in China. We collected data from urban and rural groups of school-age children (N = 2,588; M age = 10 years) using self-reports and peer assessments. The results indicated that children in 2002 and 2005 urban groups had lower scores on loneliness than did children in 1992 and 1998 urban groups, suggesting that as urban China became a more modernized, self-oriented society, children tended to report lower levels of loneliness. Consistent with this trend, urban children reported lower levels of loneliness than did their rural counterparts in recent years. The analysis of associations between social functioning and loneliness revealed that across groups, sociability was negatively associated with loneliness, and aggression was positively associated with loneliness. The association between shyness and loneliness differed among the groups; it was negative in the 1992 urban group, positive in the 2002 and 2005 urban groups, and nonsignificant in the 1998 urban and 2007 rural groups. The different associations suggest that whether shy children feel lonely might depend on context. [ABSTRACT FROM AUTHOR]

The vapor−liquid equilibrium (VLE) data for the binary system of R152a R290 were measured with a recirculation method at five temperature points from (254.31 to 287.94) K. All of the data were correlated by the Peng−Robinson (PR) EoS with the Huron−Vidal (HV) mixing rule involving the nonrandom two-liquid (NRTL) activity coefficient model. The correlated results show good agreement with the experimental data at each temperature. The data were also compared with the results obtained from the literature. Azeotropic behavior can be found at the measured temperature range. [ABSTRACT FROM AUTHOR]

In this work, four approaches based on the UNIFAC model are proposed to predict the azeotropes without any experimental data. The thermodynamic criterion of the four methods is the first derivative of the pressure with respect to the composition which equals zero at the azeotropic point for a binary system. If the vapor phase of the binary mixture is considered as an ideal gas, only the UNIFAC model is used; otherwise, the UNIFAC model, Peng−Robinson equation of state (EoS), and one of the Huron−Vidal (HV), Orbey−Sandler modification of Huron−Vidal (HVOS), or modified Huron−Vidal first-order (MHV1) mixing rules are combined to calculate the azeotrope. According to the positive or negative sign of the second derivative of the pressure with respect to the composition, the azeotropic types can be determined. In total, eight binary systems of ethane (R170) trifluoromethane (R23), pentafluoroethane (R125) cyclopropane (RC270), cyclopropane (RC270) 1,1,1,2-tetrafluoroethane (R134a), pentafluoroethane (R125) propane (R290), 1,1,1,2,3,3,3-heptafluoropropane (R227ea) dimethyl ether (DME, RE170), 1,1,1-trifluoroethane (R143a) butane (R600), and pentafluoroethane (R125) isobutane (R600a) were used to verify the methods. With the results of the prediction, the cost and time of experiments can be saved. [ABSTRACT FROM AUTHOR]