1,220 research outputs found
Similarity laws of lunar and terrestrial volcanic flows
A mathematical model of a one dimensional, steady duct flow of a mixture of a gas and small solid particles (rock) was analyzed and applied to the lunar and the terrestrial volcanic flows under geometrically and dynamically similar conditions. Numerical results for the equilibrium two phase flows of lunar and terrestrial volcanoes under similar conditions are presented. The study indicates that: (1) the lunar crater is much larger than the corresponding terrestrial crater; (2) the exit velocity from the lunar volcanic flow may be higher than the lunar escape velocity but the exit velocity of terrestrial volcanic flow is much less than that of the lunar case; and (3) the thermal effects on the lunar volcanic flow are much larger than those of the terrestrial case
Privacy and Truthful Equilibrium Selection for Aggregative Games
We study a very general class of games --- multi-dimensional aggregative
games --- which in particular generalize both anonymous games and weighted
congestion games. For any such game that is also large, we solve the
equilibrium selection problem in a strong sense. In particular, we give an
efficient weak mediator: a mechanism which has only the power to listen to
reported types and provide non-binding suggested actions, such that (a) it is
an asymptotic Nash equilibrium for every player to truthfully report their type
to the mediator, and then follow its suggested action; and (b) that when
players do so, they end up coordinating on a particular asymptotic pure
strategy Nash equilibrium of the induced complete information game. In fact,
truthful reporting is an ex-post Nash equilibrium of the mediated game, so our
solution applies even in settings of incomplete information, and even when
player types are arbitrary or worst-case (i.e. not drawn from a common prior).
We achieve this by giving an efficient differentially private algorithm for
computing a Nash equilibrium in such games. The rates of convergence to
equilibrium in all of our results are inverse polynomial in the number of
players . We also apply our main results to a multi-dimensional market game.
Our results can be viewed as giving, for a rich class of games, a more robust
version of the Revelation Principle, in that we work with weaker informational
assumptions (no common prior), yet provide a stronger solution concept (ex-post
Nash versus Bayes Nash equilibrium). In comparison to previous work, our main
conceptual contribution is showing that weak mediators are a game theoretic
object that exist in a wide variety of games -- previously, they were only
known to exist in traffic routing games
嶺南謌譜 = Songs the whole Lingnan sings
序 - 白序之
嶺南詩歌,通行已久,今始出而重編,亦有故也。緣嶺南立校,迄今三十餘年,歌詠謠辞,集累甚富,或以一時之需,倉卒成章,或襲西洋樂譜,附以嶺南故實,中間雖有刊行,然散佚已久。歷年縱有傳習,隨時印怖,亦鮮保存。遂令先人遺聲,不復聞諸後世,能不悵然。何君安東,掌樂教有年,於審音辯律,尤推獨步。憫南大古樂之絶響,慮其湮沒無聞,逐商諸學校當局,從事蒐集,復爲前鍾校長夫人所鼓勵贊助,許以鳩工鉸桴,以廣其傳。於是窮數月之力,編輯成册,持以示余,要余以課餘之暇,審定其辞焉。余不文,於篇什歌詠,更屬茫然。何敢率爾操觚,弄翰於鐵板銅琶之際,寧不有下里巴人之誚乎。第以勝意難迴,遂允何君按譜度聲,余為按聲填辞,辞有不正,則依聲改纂之,庶歸於諧,至其文字鄙俚工拙,所不計也。
原歌多為英語,而無漢辞,或原為漢文,而辞有未惬,皆改削而另起爐灶。或舍原作而創新格,或依英文而曲盡其義,或半採原意而實以已意,歷時二月,完成十九篇,餘仍其舊。其辞無大支離者,稍加潤色,以葆其真。是否允當,不敢自許,有待於知音之士就正焉。https://commons.ln.edu.hk/lingnan_songs_bks/1000/thumbnail.jp
Protein-ligand binding region prediction (PLB-SAVE) based on geometric features and CUDA acceleration
[[abstract]]Background
Protein-ligand interactions are key processes in triggering and controlling biological functions within cells. Prediction of protein binding regions on the protein surface assists in understanding the mechanisms and principles of molecular recognition. In silico geometrical shape analysis plays a primary step in analyzing the spatial characteristics of protein binding regions and facilitates applications of bioinformatics in drug discovery and design. Here, we describe the novel software, PLB-SAVE, which uses parallel processing technology and is ideally suited to extract the geometrical construct of solid angles from surface atoms. Representative clusters and corresponding anchors were identified from all surface elements and were assigned according to the ranking of their solid angles. In addition, cavity depth indicators were obtained by proportional transformation of solid angles and cavity volumes were calculated by scanning multiple directional vectors within each selected cavity. Both depth and volume characteristics were combined with various weighting coefficients to rank predicted potential binding regions.
Results
Two test datasets from LigASite, each containing 388 bound and unbound structures, were used to predict binding regions using PLB-SAVE and two well-known prediction systems, SiteHound and MetaPocket2.0 (MPK2). PLB-SAVE outperformed the other programs with accuracy rates of 94.3% for unbound proteins and 95.5% for bound proteins via a tenfold cross-validation process. Additionally, because the parallel processing architecture was designed to enhance the computational efficiency, we obtained an average of 160-fold increase in computational time.
Conclusions
In silico binding region prediction is considered the initial stage in structure-based drug design. To improve the efficacy of biological experiments for drug development, we developed PLB-SAVE, which uses only geometrical features of proteins and achieves a good overall performance for protein-ligand binding region prediction. Based on the same approach and rationale, this method can also be applied to predict carbohydrate-antibody interactions for further design and development of carbohydrate-based vaccines. PLB-SAVE is available at http://save.cs.ntou.edu.tw.[[booktype]]電子
Use of Rubber Dams During Root Canal Treatment in Taiwan
Background/PurposeIsolation of teeth with rubber dams is an important procedure for infection control in dentistry, especially in endodontic treatment. This study surveyed the prevalence of rubber dam usage in nonsurgical root canal treatment (RCT) by dentists under the National Health Insurance system in Taiwan.MethodsA total of 1,332 completed RCT cases were randomly selected from a large database from the Bureau of National Health Insurance in Taiwan in 2004. The radiographs and dental charts of the selected cases were evaluated for the prevalence of rubber dam usage in RCT. The frequencies of rubber dam usage for RCT by dentists were compared between hospitals and private dental clinics and among six different regions in Taiwan.ResultsThe overall prevalence of rubber dam usage for RCT by dentists under the National Health Insurance system in Taiwan was 16.5%. The frequency of rubber dam usage for RCT by dentists in hospitals (32.8%) was significantly higher than that (10.3%) in private dental clinics (p < 0.0001). However, there was no significant difference in the frequency of rubber dam usage for RCT by dentists among six different geographic regions in Taiwan.ConclusionThe prevalence of rubber dam usage for RCT by dentists in Taiwan is relatively low. Because rubber dam isolation of an endodontically-treated tooth can provide better infection control, increase patient protection, and improve treatment efficiency, there is an urgent need to advise dentists in Taiwan to use rubber dams for every RCT case
A review and perspective on optical phased array for automotive LiDAR
This paper aims to review the state of the art of Light Detection and Ranging (LiDAR) sensors for automotive applications, and particularly for automated vehicles, focusing on recent advances in the field of integrated LiDAR, and one of its key components: the Optical Phased Array (OPA). LiDAR is still a sensor that divides the automotive community, with several automotive companies investing in it, and some companies stating that LiDAR is a ‘useless appendix’. However, currently there is not a single sensor technology able to robustly and completely support automated navigation. Therefore, LiDAR, with its capability to map in 3 dimensions (3D) the vehicle surroundings, is a strong candidate to support Automated Vehicles (AVs). This manuscript highlights current AV sensor challenges, and it analyses the strengths and weaknesses of the perception sensor currently deployed. Then, the manuscript discusses the main LiDAR technologies emerging in automotive, and focuses on integrated LiDAR, challenges associated with light beam steering on a chip, the use of Optical Phased Arrays, finally discussing current factors hindering the affirmation of silicon photonics OPAs and their future research directions
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