26,755 research outputs found
Wei xing ji he qiao na mi jie gou de he cheng yu biao mian deng li ji yuan te xing yan jiu
No full textRuan, Qifeng = 衛星及核殼納米結構的合成與表面等離激元特性研究 / 阮琦鋒.Thesis Ph.D. Chinese University of Hong Kong 2015.Includes bibliographical references.Abstracts also in Chinese.Title from PDF title page (viewed on 16, December, 2016).Ruan, Qifeng = Wei xing ji he qiao na mi jie gou de he cheng yu biao mian deng li ji yuan te xing yan jiu / Ruan Qifeng
Xun zhao yu zhou can shu de ge xiang yi xing
No full textChan, King Pak Keven = 尋找宇宙參數的各向異性 / 陳景柏.Thesis Ph.D. Chinese University of Hong Kong 2015.Includes bibliographical references (leaves 104-107).Abstracts also in Chinese.Title from PDF title page (viewed on 29, September, 2016).Chan, King Pak Keven = Xun zhao yu zhou can shu de ge xiang yi xing / Chen Jingbo
Studies on Ordinal Ranking with Regression
No full text排序問題的相關研究在近年來漸趨熱門，在網路搜尋引擎、推薦系統等許多方面都有著廣泛的應用。而隨著網路的資訊量爆炸，如何藉由這些大量資料來快速地訓練出一個好的排序系統，便成為日益重要的問題。本篇論文著重於處理龐大的序數資料集，不同於傳統分類問題中的類別，在序數資料集內的類別之間帶有等級差距的資訊。本論文中研究如何於序數資料集上，利用迴歸分析去處理兩種類型的排序相關問題。其中一種排序問題是對資料做評等，排序系統會判斷此資料是屬於哪種序數等級；另外一種排序問題則是頂端排序問題，旨在研究如何讓與搜尋關鍵字相關的資料文件，能依其相關性高低排序產生一個搜尋列表。我們提出一個架構可以和各式迴歸相關演算法結合來處理排序問題，在此架構中導入了成本觀念去處理等級差距的資訊，而在兩個問題上的實驗結果都顯示了此架構可以有效提升排序結果。我們也針對在頂端排序問題上的一個熱門評量標準，進而提出了一個有效的成本函數，實驗結果則顯示此成本函數在此評量標準上更可有效提升排序效果。Ranking is a popular research problem in recent years and has been used in wide range of applications including
web-search engines and recommendation systems.
In this thesis, we study on two ranking problems, the ordinal ranking problem and the top-rank problem.
We propose a novel ranking approach, cost-sensitive ordinal classification via regression (COCR), which respects the discrete nature of the ordinal ranks in real-world data sets. In particular, COCR applies a theoretically-sound reduction from ordinal to binary classification
and solves the binary classification sub-tasks with point-wise regression. Furthermore, COCR allows specifying mis-ranking costs to further boost the ranking performance.
We conduct experiments on two ranking problems respectively.
On the ordinal ranking problem, we compare different approaches based on decision trees.
The results show that the proposed COCR can perform better on many data sets when coupled with the appropriate cost.
Furthermore, on the top-rank problem, we derive the corresponding cost of a popular ranking criterion, Expected Reciprocal Rank (ERR), and plug the cost into the COCR approach. The resulting ERR-tuned COCR enjoys the benefits of both efficiency by using point-wise regression and top-rank prediction accuracy from the ERR criterion.
Evaluations on two large-scale data sets, including
``Yahoo! Learning to Rank Challenge'' and ``Microsoft Learning to Rank'', verify that some basic COCR settings outperform commonly-used regression approaches significantly. In addition, even better performance can often be achieved by the ERR-tuned COCR
Liang zi zi xun ke ji ji yu zuan shi zhong dan-kong que zhong xin
No full textNitrogen-vacancy center has proven a promising candidate in quantum information and quantum sensing due to its excellent optical and spin properties for long coherent time and robust spin state readout, as well as its sensitivity towards multiple tunable parameters such as magnetic field, electric field, mechanical strain and pressure. In this thesis, we study the change of diamagnetic properties of single crystal BaFe₂(As₀.₅₉P₀.₄₁)₂ under high pressure at cryogenic condition by using micron-sized diamond particles as spatially resolved magnetic probes. In addition, we review advanced spin coherent control and readout techniques using cavity quantum electrodynamics in literatures. At last, we demonstrate the interplay between quantum optimal control and machine learning.We extract vectorial information of the local magnetic field at different position on the sample from ODMR spectrum. Through tuning pressure parameter and performing thermal cycle, we determine the lower critical field c₁ and lower critical temperature c₁, together with c₂ dependence of the sample as a function of pressure. This novel sensing technique utilizing NV centers overcomes technical difficulties of employing conventional fragile magnetic probes under extreme pressure, while being a local vector field sensor and readily accessible to most confocal or wide-field microscopy setups. On the other hand, we use deep reinforcement learning and active learning to study the feasibility and outlook for quantum optimal control and suggest hybrid approach to improve current standalone algorithms and methods.鑽石中氮-空缺中心是一個極具潛力的量子工具，其優越的光學及自旋特性使其在量子資訊與測量均受廣泛應用和研究。 本論文將利用微米大小的鑽石顆粒來測量單晶體BaFe₂(As₀.₅₉P₀.₄₁)₂ 在高壓和低溫下的抗磁性特點。另外，我們會做一些簡短的文獻評論來敘述氮-空缺中心與量子電動力學的互補作用。最後，我們會探討如何使用機器學習來達到量子最優控制。我們從光學磁共振的光譜分析在樣本不同位置的局部向量磁場。通過調校壓力和溫度，得出下臨界磁場c₁和下臨界溫度c₁；並取得c₂跟壓力的關係圖。這項新的測量方法解決在高壓下難以使用脆弱的磁力計的問題，同時提供便利的磁向量測量方案。另一方面，我們將利用深度強化學習和主動學習來探索它們在量子最優控制的可行性及其潛質；並提議混合的方法來改善現有單一的算法。Yu, King Yiu = 量子資訊科技基於鑽石中氮-空缺中心 / 余經燿.M.Phil. Chinese University of Hong Kong 2020.Includes bibliographical references (leaves 80-83).Abstracts also in Chinese.Title from PDF title page (viewed on October 19, 2022).Yu, King Yiu = Liang zi zi xun ke ji ji yu zuan shi zhong dan-kong que zhong xin / Yu Jingshuo
Experimental study of collision between a free-free beam and a simply supported beam
No full textRecently, the authors and others have theoretically modeled and comprehensively analyzed the beam-on-beam collision (Yu, et al., Int J Solids Struct 28 (2001) 2001; Ruan et al., Int J Solids Struct 40(12) (2003) 2937-2956; Ruan and Yu, Int J Mech Sci 45(3) (2003) 397-423), as typical examples of collisions between two deformable structures. Particular attention was paid to the energy partitioning in the two colliding beams as well as in the local contact deformation. In order to verify these theoretical models, experiments were conducted on the collision between a flying free-free beam and a stationary simply supported beam. The free-free beam was accelerated by a bullet ejected from an air gun. The energy dissipation was calculated based on the residual flexural profiles of the colliding beams. It is found that most of the curvature change concentrated in the middle portions of the two beams, indicating that most of the plastic deformation occurred in their mid-spans. This fact justifies the modal solution. The energy dissipation ratio of the two beams obtained from the experiments shows a good agreement with the theoretical predictions, verifying the theoretical models previously developed. The contact areas were also clearly identified and measured. The comparison with theoretical modal proposed in Ruan and Yu, Int J Mech Sci 45(3) (2003) 397-423 shows that the Blunt Indentation model is the best one while the elastic response is not negligible if the local deformation is concerned.</p
The Poetry of Ruan Ji and Xi Kang
Get PDFThe poetry of Ruan Ji has been previously translated several times, with one fully scholarly translation of both the poetry and the Fu (poetic expositions). The present translation not only provides a facing page critical Chinese text, it addresses two problems that have been ignored or not adequately treated in earlier works. First, it traces the history of the current text. The rather serious problems with this text will be, if not soluble, at least visible. Second, translations have been shaped by the anachronistic assumption that Ruan Ji was loyal to the declining Wei dynasty, when actual power had been taken by the Suma family, who founded the Jin dynasty after Ruan Ji's death. The introduction shows how and when that assumption took full shape five centuries after Ruan Ji lived and why it is not tenable. This leads to a different kind of translation, closer to what a contemporary reader might have understood and far less certain than referring it to some political event. The Poetry of Xi Kang presents a complete scholarly translation of his poetic works (including "Rhapsody on the Zither") alongside the original texts. Many of Xi Kang's poems are difficult and most are laden with allusions and quotations, adding another level of challenge to interpretation. Basic explanatory notes are provided. The translations are based on the critical modern edition of Xi Kang's work by Dai Mingyang, generally considered to be the best edition available. Important editions by Lu Xun and Lu Qinli are consulted on matters of variants, arrangement, and interpretation
The Poetry of Ruan Ji and Xi Kang
Get PDFThe poetry of Ruan Ji has been previously translated several times, with one fully scholarly translation of both the poetry and the Fu (poetic expositions). The present translation not only provides a facing page critical Chinese text, it addresses two problems that have been ignored or not adequately treated in earlier works. First, it traces the history of the current text. The rather serious problems with this text will be, if not soluble, at least visible. Second, translations have been shaped by the anachronistic assumption that Ruan Ji was loyal to the declining Wei dynasty, when actual power had been taken by the Suma family, who founded the Jin dynasty after Ruan Ji's death. The introduction shows how and when that assumption took full shape five centuries after Ruan Ji lived and why it is not tenable. This leads to a different kind of translation, closer to what a contemporary reader might have understood and far less certain than referring it to some political event. The Poetry of Xi Kang presents a complete scholarly translation of his poetic works (including "Rhapsody on the Zither") alongside the original texts. Many of Xi Kang's poems are difficult and most are laden with allusions and quotations, adding another level of challenge to interpretation. Basic explanatory notes are provided. The translations are based on the critical modern edition of Xi Kang's work by Dai Mingyang, generally considered to be the best edition available. Important editions by Lu Xun and Lu Qinli are consulted on matters of variants, arrangement, and interpretation
JBA905181 Supplemental Material - Supplemental material for Synthetic CD47 antibody-chitosan/hyaluronic acid polyelectrolyte complex mediates targeted inhibition of atherosclerotic plaques by exogenous foam-like cells via the NLRP3 pathway
No full textSupplemental material, JBA905181 Supplemental Material for Synthetic CD47 antibody-chitosan/hyaluronic acid polyelectrolyte complex mediates targeted inhibition of atherosclerotic plaques by exogenous foam-like cells via the NLRP3 pathway by Jun Yu, Qiurong Ruan, Xiu Nie, Lan Yu and Bangxing Huang in Journal of Biomaterials Applications</p
- …
