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1. chinaXiv:202005.00043 [pdf]

DEED: A general quantization scheme for saving bits in communication

Tian Ye; Peijun Xiao; Ruoyu Sun
Subjects: Mathematics >> Control and Optimization.

Quantization is a popular technique to reduce communication in distributed optimization. Motivated by the classical work on inexact gradient descent (GD) \cite{bertsekas2000gradient}, we provide a general convergence analysis framework for inexact GD that is tailored for quantization schemes. We also propose a quantization scheme Double Encoding and Error Diminishing (DEED). DEED can achieve small communication complexity in three settings: frequent-communication large-memory, frequent-communication small-memory, and infrequent-communication (e.g. federated learning). More specifically, in the frequent-communication large-memory setting, DEED can be easily combined with Nesterov's method, so that the total number of bits required is $ \tilde{O}( \sqrt{\kappa} \log 1/\epsilon )$, where $\tilde{O}$ hides numerical constant and $\log \kappa $ factors. In the frequent-communication small-memory setting, DEED combined with SGD only requires $\tilde{O}( \kappa \log 1/\epsilon)$ number of bits in the interpolation regime. In the infrequent communication setting, DEED combined with Federated averaging requires a smaller total number of bits than Federated Averaging. All these algorithms converge at the same rate as their non-quantized versions, while using a smaller number of bits.

submitted time 2020-06-16 Hits890Downloads509 Comment 0

2. chinaXiv:202004.00009 [pdf]

CAN Algorithm: An Individual Level Approach to identify Consequences and Norms Sensitivities and Overall Action/inaction Preferences in Moral Decision-making

Chuanjun Liu; Jiangqun Liao
Subjects: Psychology >> Psychological Measurement

Gawronski et al. (2017) developed a CNI model to measure an agent’s norms sensitivity, consequences sensitivity, and generalized inaction/action preferences when making moral decisions. However, the CNI model presupposed that an agent considers consequences—norms—generalized inaction/action preferences sequentially, which is untenable based on recent evidence. Moreover, the CNI model generates parameters at the group level based on binary categoric data. Hence, the C/N/I parameters cannot be used for correlation analyses or other conventional research designs. To solve these limitations, we developed the CAN algorithm to compute norms and consequences sensitivities and overall action/inaction preferences algebraically in a parallel manner. We re-analyzed the raw data of Gawronski et al.(2017) to test the methodological predictions. Our results demonstrate that: (1) the C parameter is approximately equal between the CNI model and CAN algorithm; (2) the N parameter under the CNI model approximately equals N/(1 – C) under the CAN algorithm; (3) the I parameter and A parameter are reversed around 0.5 – the larger the I parameter, the more the generalized inaction versus action preference and the larger the A parameter, the more overall action versus inaction preference; (4) tests of differences in parameters between groups with the CNI model and CAN algorithm led to almost the same statistical conclusion; (5) Parameters from the CAN algorithm can be used for correlational analyses and multiple comparisons, and this is an advantage over the parameters from the CNI model. The theoretical and methodological implications of our study were also discussed.

submitted time 2020-04-03 Hits3538Downloads418 Comment 0

3. chinaXiv:201910.00029 [pdf]

Stand up to Action: The Postural Effect on Deontological Responding and the Boundary Condition of Dual Process

刘传军; 廖江群
Subjects: Psychology >> Social Psychology

Present research aimed to uncover a postural effect on deontological responding and its boundary condition of dual process. Previous literatures demonstrated a possibility that people have a stronger controlled cognitive process propensity, thus being less deontological in standing than sitting postures, and that this postural effect can be moderated by dual process. We conducted two studies in which participant read dilemma scenarios and rated the morally acceptance and action intention of the utilitarian proposal after each scenario when sitting or standing. The hypothesized postural effect was verified in a field study (Study 1) and also replicated in an experimental study (Study 2). Compared with those in sitting postures, participants in standing postures approved more to the utilitarian proposal and became less deontological. Furthermore, the postural effect was dismissed when participants made moral decisions with a dual task to increase cognitive load and reversed when participants made moral decisions after deliberate consideration of the sacrificial proposal (Study 2). Thus, the postural effect was stable across field and experimental studies and moderated by dual process. The present research supports and extends the dual process morality theory by confirming that body posture can affect moral decision-making, and also offers a novel evidence confirming the moderating role of dual process on embodiment effects. It enriches our knowledge that morality is evolutionarily embodied in postures and dual process can moderate the embodiment effects.

submitted time 2020-01-14 Hits13146Downloads1015 Comment 0

4. chinaXiv:201705.00724 [pdf]

Aromatic Residues in the C-terminal Domain 2 Are Required for Nanog to Mediate LIF-independent Self-renewal of Mouse Embryonic Stem Cells

Wang, Zhe(1.2); Ma, Tianhua; Chi, Xiaoke; Pei, Duanqing
Subjects: Biology >> Biomedical Laboratory Science

Nanog was identified by its ability to sustain the LIF-independent self-renewal of mouse embryonic stem (ES) cells and has recently been shown to play a role in reprogramming adult fibroblasts into pluripotent stem cells. However, little is known about the structural basis of these remarkable activities of Nanog. We have previously identified an unusually strong transactivator named CD2 at its C terminus. Here we demonstrate that CD2 is required for Nanog to mediate ES cell self-renewal. Furthermore, deletion and point mutation analysis revealed that CD2 relies on at least seven aromatic amino acid residues to generate its potent transactivating activity. A mutant Nanog bearing alanine substitutions for these seven residues fails to confer LIF-independent self-renewal in mouse ES cells. Substitution of CD2 by the viral transactivator VP16 gave rise to Nanog-VP16, which is 10 times more active than wild-type Nanog in ES cells. Surprisingly, the expression of Nanog-VP16 in mouse ES cells induces differentiation and is thus unable to sustain LIF-independent self-renewal for mouse ES cells. Taken together, our results demonstrate that the CD2 domain of Nanog is a unique transactivator that utilizes aromatic residues to confer specific activity absolutely required for ES self-renewal.

submitted time 2017-05-10 Hits2590Downloads614 Comment 0

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