Supervised Off-Policy Ranking

Off-policy evaluation (OPE) leverages data generated by other policies to evaluate a target policy. Previous OPE methods mainly focus on precisely estimating the true performance of a policy. We observe that in many applications, (1) the end goal of OPE is to compare two or multiple candidate policies and choose a good one, which is actually a much simpler task than evaluating their true performance; and (2) there are usually multiple policies that have been deployed in real-world systems and thus whose true performance is known through serving real users. Inspired by the two observations, in this work, we define a new problem, supervised off-policy ranking (SOPR), which aims to rank a set of new/target policies based on supervised learning by leveraging off-policy data and policies with known performance. We further propose a method for supervised off-policy ranking that learns a policy scoring model by correctly ranking training policies with known performance rather than estimating their precise performance. Our method leverages logged states and policies to learn a Transformer based model that maps offline interaction data including logged states and the actions taken by a target policy on these states to a score. Experiments on different games, datasets, training policy sets, and test policy sets show that our method outperforms strong baseline OPE methods in terms of both rank correlation and performance gap between the truly best and the best of the ranked top three policies. Furthermore, our method is more stable than baseline methods

A compromise-negotiation framework based on Game theory for eliminating requirements inconsistency

Za bilo koji predloženi projekt razvoja softvera, neizbježno je suočiti se s promjenama zahtjeva tijekom razvoja softvera. Nekontrolirane promjene mogu dovesti do loše specifikacije zahtjeva, što čak može rezultirati propadanjem projekta. Rezultat toga je potreba za osiguranjem učinkovitog i fleksibilnog upravljanja promjenama zahtjeva i jedan od osnovnih zadataka je uklanjanje nedosljednosti u zahtjevima izazvanim promjenama. U ovom radu razmatramo postupak pregovora o specifikaciji novih i starih zahtjeva primjenom Teorije igara. Obje strane čine ustupke tijekom igre dok se ne postigne Nashova ravnoteža, tj. dok obje strane ne budu zadovoljne rezultatom pregovora. Točnije, najprije se niz zahtjeva predstavlja logičnom formulom. Tada se odvojeno predlaže metoda pregovora oko zahtjeva, utemeljena na miješanoj strategiji i čistoj strategiji Nashove ravnoteže, a također i okvirno načelo za postizanje kompromisa na temelju Teorije igara. Daje se i analiza slučaja u svrhu provjere učinkovitosti naše metode. Na kraju se daju usporedbe i zaključak.For any proposed software development project, it is inevitable to confront requirements changes during the software development life cycle. Uncontrolled changes may cause bad requirements specification, which even further leads to project’s failure. As a result, it is necessary to provide effective and flexible requirements change management. One of the kernel tasks of requirement change management is to eliminate requirement inconsistency caused by changes. In this paper, we consider negotiation process of the new and the old requirements specifications under Game theory. Both sides concession during the game process until the game achieves Nash equilibrium, i.e. both sides gain satisfied negotiation results. To be specific, firstly, the requirement set is represented in logical formula. Then a requirement conflict negotiation method based on mixed strategy and pure strategy Nash equilibrium is proposed separately, and a Compromise-Negotiation framework based on Game theory is presented as well. A case study will be given in the following part to verify our method’s effectiveness. Finally, it comes to a comparison and conclusion

医学硕士研究生创新能力培养的探索与思考*

The development of medical career in our country has put forward higher requirements for the innovative ability of medical postgraduates of  in China. But the innovative ability of postgraduates does not meet the corresponding requirements. Therefore, cultivating innovative consciousness and improving the innovative ability is the important goal and task of cultivating graduate students. This paper summarizes the idea of cultivating the innovative ability of medical postgraduates, and makes a preliminary exploration and thinking on the cultivation methods of the innovative ability of medical postgraduates from the aspects of the current Situation of innovative ability of medical postgraduates, improving the innovation of the instructors and the cultivation of postgraduates' comprehensive ability and so on. This article on how to cultivate high-level, compound medical graduate students put forward a new view of training. 我国医疗事业发展对我国医学硕士研究生创新能力提出了更高的要求，而硕士研究生的创新能力没有达到相应要求。因此，培养创新意识、提高创新能力是现今培养研究生重要的目标和任务。本文总结了医学硕士研究生创新能力培养的思路，从医学硕士研究生创新能力现况、提高导师创新能力、培养研究生综合能力等方面对医学硕士研究生创新能力的培养方法进行初步探索与思考，就如何培养具有创新能力的高层次、复合型医学硕士研究生提出了培养的新看法

Passive Human Sensing Enhanced by Reconfigurable Intelligent Surface: Opportunities and Challenges

Reconfigurable intelligent surfaces (RISs) have flexible and exceptional performance in manipulating electromagnetic waves and customizing wireless channels. These capabilities enable them to provide a plethora of valuable activity-related information for promoting wireless human sensing. In this article, we present a comprehensive review of passive human sensing using radio frequency signals with the assistance of RISs. Specifically, we first introduce fundamental principles and physical platform of RISs. Subsequently, based on the specific applications, we categorize the state-of-the-art human sensing techniques into three types, including human imaging,localization, and activity recognition. Meanwhile, we would also investigate the benefits that RISs bring to these applications. Furthermore, we explore the application of RISs in human micro-motion sensing, and propose a vital signs monitoring system enhanced by RISs. Experimental results are presented to demonstrate the promising potential of RISs in sensing vital signs for manipulating individuals. Finally, we discuss the technical challenges and opportunities in this field

Formation of hub-filament structure triggered by cloud-cloud collision in W33 complex

Hub-filament systems are suggested to be birth cradles of high-mass stars and clusters, but the formation of hub-filament structure is still unclear. Using the survey data FUGIN $^{13}$CO (1-0), C$^{18}$O (1-0), and SEDIGISM $^{13}$CO (2-1), we investigate formation of hub-filament structure in W33 complex. W33 complex consists of two colliding clouds, called W33-blue and W33-red. We decompose the velocity structures in W33-blue by fitting multiple velocity components, and find a continuous and monotonic velocity field. Virial parameters of Dendrogram structures suggest the dominance of gravity in W33-blue. The strong positive correlation between velocity dispersion and column density indicates the non-thermal motions in W33-blue may originate from gravitationally driven collapse. These signatures suggest that the filamentary structures in W33-blue result from the gravitational collapse of the compressed layer. However, the large scale velocity gradient in W33-blue may mainly originate from the cloud-cloud collision and feedback of active star formation, instead of the filament-rooted longitudinal inflow. From the above observed results, we argue that the cloud-cloud collision triggers formation of hub-filament structures in W33 complex. Meanwhile, the appearance of multiple-scale hub-filament structures in W33-blue is likely an imprint of the transition from the compressed layer to a hub-filament system.Comment: 18 page

D-Serine Contributes to Seizure Development via ERK Signaling

A seizure is one of the leading neurological disorders. NMDA receptor-mediated neuronal excitation has been thought to be essential for epileptogenesis. As an endogenous co-agonist of the NMDA receptor, D-serine has been suggested to play a role in epileptogenesis. However, the underlying mechanisms remain unclear. In the current study, we investigated the effects of antagonizing two key enzymes in D-serine metabolism on the development of seizures and the downstream signaling. Our results showed that serine racemase (SR), a key enzyme in regulating the L-to-D-serine conversion, was significantly up-regulated in hippocampal astrocytes in rats and patients who experienced seizure, in comparison with control rats and patients. L-aspartic acid β-hydroxamate (LaaβH), an inhibitor of SR, significantly prolonged the latencies of seizures, shortened the durations of seizures, and decreased the total EEG power in rats. In contrast, D-amino acid oxidase inhibitor 5-chlorobenzo[d]isoxazol-3-ol (CBIO), which can increase D-serine levels, showed the opposite effects. Furthermore, our data showed that LaaβH and CBIO significantly affected the phosphorylation of Extracellular Signal-regulated Kinase (ERK). Antagonizing or activating ERK could significantly block the effects of LaaβH/CBIO on the occurrence of seizures. In summary, our study revealed that D-serine is involved in the development of epileptic seizures, partially through ERK signaling, indicating that the metabolism of D-serine may be targeted for the treatment of epilepsy

Physical properties and chemical composition of the cores in the California molecular cloud

We aim to reveal the physical properties and chemical composition of the cores in the California molecular cloud (CMC), so as to better understand the initial conditions of star formation. We made a high-resolution column density map (18.2") with Herschel data, and extracted a complete sample of the cores in the CMC with the \textsl{fellwalker} algorithm. We performed new single-pointing observations of molecular lines near 90 GHz with the IRAM 30m telescope along the main filament of the CMC. In addition, we also performed a numerical modeling of chemical evolution for the cores under the physical conditions. We extracted 300 cores, of which 33 are protostellar and 267 are starless cores. About 51\% (137 of 267) of the starless cores are prestellar cores. Three cores have the potential to evolve into high-mass stars. The prestellar core mass function (CMF) can be well fit by a log-normal form. The high-mass end of the prestellar CMF shows a power-law form with an index $\alpha=-0.9\pm 0.1$ that is shallower than that of the Galactic field stellar mass function. Combining the mass transformation efficiency ($\varepsilon$) from the prestellar core to the star of $15\pm 1\%$ and the core formation efficiency (CFE) of 5.5\%, we suggest an overall star formation efficiency of about 1\% in the CMC. In the single-pointing observations with the IRAM 30m telescope, we find that 6 cores show blue-skewed profile, while 4 cores show red-skewed profile. [$\rm {HCO}^{+}$]/[HNC] and [$\rm {HCO}^{+}$]/$\rm [N_{2}H^{+}]$ in protostellar cores are higher than those in prestellar cores; this can be used as chemical clocks. The best-fit chemical age of the cores with line observations is $\sim 5\times 10^4$~years.Comment: Accepted by Astronomy & Astrophysics (A&A

Interactions of the Infrared bubble N4 with the surroundings

The physical mechanisms that induce the transformation of a certain mass of gas in new stars are far from being well understood. Infrared bubbles associated with HII regions have been considered to be good samples of investigating triggered star formation. In this paper we report on the investigation of the dust properties of the infrared bubble N4 around the HII region G11.898+0.747, analyzing its interaction with its surroundings and star formation histories therein, with the aim of determining the possibility of star formation triggered by the expansion of the bubble. Using Herschel PACS and SPIRE images with a wide wavelength coverage, we reveal the dust properties over the entire bubble. Meanwhile, we are able to identify six dust clumps surrounding the bubble, with a mean size of 0.50 pc, temperature of about 22 K, mean column density of 1.7 $\times10^{22}$ cm$^{-2}$, mean volume density of about 4.4 $\times10^{4}$ cm$^{-3}$, and a mean mass of 320 $M_{\odot}$. In addition, from PAH emission seen at 8 $\mu$m, free-free emission detected at 20 cm and a probability density function in special regions, we could identify clear signatures of the influence of the HII region on the surroundings. There are hints of star formation, though further investigation is required to demonstrate that N4 is the triggering source.Comment: Accepted by ApJ (16 pages, 11 figures, 9 tables