347 research outputs found
Post-larval development in deep-sea echinoderms
No full textThe post-larval phase is an essential period in the life history of marine invertebrates; vulnerable to high mortality, it ultimately influences the distribution and abundance of adult populations. The post metamorphic ontogenesis of thirty species of deep-sea echinoderms, belonging to three classes (Ophiuroidea, Asteroidea and Echinoidea), is described using scanning electron microscopy. The life history of Ophiocten gracilis is also examined as a case study for future research on post-larval organisms. The analysis of development in ophiuroids reveals that species can be identified from a very early post metamorphic stage, even in congeneric species, contrary to the findings of other authors. The ontogeny of homologous structures is similar within related groups, but may give rise to different adult structures indifferent taxa. The mouth papillae within the ophiurids are serially homologous, originating from the jaw, but the fourth mouth papilla may have a different origin. In the families Ophiactidae, Ophiacanthidae and Amphilepididae examined, the mouth papillae have different origins, as, for instance, the adoral shieldspine or tentacle scale. Data on the post-larval development of Ophiura affinis suggest that this species is more closely related to the genus Ophiocten and a change in the generic status is proposed. Ophiocten gracilis is a bathyal brittle star occurring on both sides of the North Atlantic and its life history is studied in the eastern side of the North Atlantic. In this area, O. gracilis spawns in February/March of each year producing a large number of eggs. Fecundity is estimated to be around 40,000 eggs/ind, with the population of the Hebridean Slope being able to produce probably up to 16 million eggs/m2. Post-larvae start settling in May and numbers settling reached over 3,200 post-larvae/m2. The settling speed of post-larvae in the water column is estimated to be around 500 m/day, settling faster in warmer than colder water. Settling speeds appear to be similar for post-larvae ranging from 0.6 to 0.9 mm in disk diameter. Size at settlement is around 0.6 mm in disk diameter and 5-6 arm segments. The settlement of post-larval O. gracilis on the bottom of the Hebridean Slope also represented a considerable fraction of the particulate organic carbon (POC) flux in the area, reaching over 7% of the total daily flux. This is likely to have a considerable impact in the benthic community as competition and predation and as an additional food source for demersal and benthic organisms. The occurrence of post-larvae of O. gracilis in sediment traps also represented a large problem for POC flux measurements, with ophiuroids consuming part of the flux. In future works with sediment traps, such errors must be taken into account and ophiuroids must be included in the total POC flux. The deep-sea juvenile asteroids of the NE Atlantic could be distinguished to species level from a very early stage of development. The ontogenesis of Porcellanaster ceruleus shows that this species is likely to undergo a shift in habitat and diet during the juvenile phase. This is evidenced by the appearance of the epiproctal cone, the changing of the furrow and apical spines, the early development of the cribriform organ adjacent to the madreporite and the appearance of sediment in the stomach. P. ceruleus is probably a predator on meiofauna and small macrofaunal organisms during the early stages of life, changing to a burrowed life style ingesting sediment particles. Most juvenile sea stars analysed during the present study showed wider bathymetric distribution than their adult counterparts, suggesting that events occurring during the early stages of life are important for the maintenance of the local population structure and diversity in the deep NE Atlantic.The post-metamorphic development of three deep-sea spatangoid echinoids is very similar, but the morphology and formation of fascioles facilitate the distinction of the species examined. Whereas in Hemiaster expergitus and Spatangus raschi the fascioles present in the post-larvae develop to form the adult fascioles, in Brissopsis lyrifera post-larvae there is a juvenile fasciole, which disappears during ontogenesis giving way to the adult fascioles. The function of the juvenile fasciole is unknown in B.lyrifera. The development of the periproct in all spatangoids examined is similar to that described by other authors, with the periproct being initially endocyclic and migrating towards the rear of the animal as development progresses. Post-larvae of the genus Echinus could not be separated into different species, which may be linked to the recent diversification of the genus in the North Atlantic. The widespread settlement of echinoderm post-larvae reported in the present thesis and in other works is thought to have been very important for the colonization of the deep-sea through the supply of stages to deeper areas and selection of pressure adapted animals and subsequent speciation
Mechanical Parameter Identification of Hydraulic Engineering with the Improved Deep Q-Network Algorithm
No full textDuring the long-term operating period, the mechanical parameters of hydraulic structures and foundation deteriorated gradually because of the environmental factors. In order to evaluate the overall safety and durability, these parameters should be calculated by some accurate analysis methods, which are hindered by slow computational efficiency and optimization performance. The improved deep Q-network (DQN) algorithm combined with the deep neural network (DNN) surrogate model was proposed in this paper to ameliorate the above problems. Through the study cases of different zoning in the dam body and the actual engineering foundation, it is shown that the improved DQN algorithm has a good application effect on inversion analysis of material mechanical parameters in this paper. Safety and Security Scienc
Evaluation of different registration methods and dental restorations on the registration duration and accuracy of cone beam computed tomography data and intraoral scans: a retrospective clinical study
No full text© 2022, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.Objectives: To evaluate whether the accuracy and duration of registration for cone beam computed tomography (CBCT) and intraoral scans differ according to the method of registration and ratio of dental restorations to natural teeth. Materials and methods: CBCT data and intraoral scans of eligible patients were grouped as follows according to the ratio of the number of dental restorations to the number of natural teeth (N): group 1, N = 0%; group 2, 0% < N < 50%; group 3, 50% ≤ N < 100%; and group 4, 100% ≤ N. Marker-free registration was performed with a deep learning-based platform and four implant planning software with different registration methods (two point-based, one surface-based, and one manual registration software) by a single operator, and the time consumption was recorded. Registration accuracy was evaluated by measuring the distances between the three-dimensional models of CBCT data and intraoral scans. Results: A total of 36 patients, one jaw per patient, were enrolled. Although registration accuracy was similar, the time consumed for registration significantly differed for the different methods. The deep learning-based registration method consumed the least time. Greater proportions of dental restorations significantly reduced the registration accuracy for semi-automatic and deep learning-based methods and reduced the time consumed for semi-automatic registration. Conclusions: No superiority in registration accuracy was found. The proportion of dental restorations significantly affects the accuracy and duration of registration for CBCT data and intraoral scans. Clinical trial registration: ClinicalTrials.gov Identifier: KCT0006710 Clinical relevance: Registration accuracy for virtual implant planning decreases when the proportion of dental restorations increases regardless of registration methods.N
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
Reciprocating compressor fault diagnosis using an optimized convolutional deep belief network
No full text© The Author(s) 2020. This article proposes an optimized convolutional deep belief network for fault diagnosis of reciprocating compressors. Sparse filtering is first used to compress raw signal into compact time series by refining the most representative information and to reduce the computational burden. Then, the proposed convolutional deep belief network is adopted to learn the unsupervised features of the compressed signal without the need of feature extraction by human effort. To improve the generalization ability of the network, an optimized probabilistic pooling out is proposed in this article to replace the standard one in the pooling layer of the convolutional deep belief network. Finally, the unsupervised features calculated by the optimized convolutional deep belief network are fed as the input of the softmax regression classifier for fault identification. Four types of vibration signals reflecting different operating conditions are collected from the industry to validate the effectiveness of the proposed method. The obtained results demonstrate that the proposed convolutional deep belief network method can achieve a higher classification accuracy rate of up to 91% for fault diagnosis than the traditional methods and accomplish the fault diagnosis of reciprocating compressor effectively
Low voltage driven interleaved silicon optical modulator
No full textMay 2019School of EngineeringSilicon electro-optical (EO) modulator is one of the key devices in achieving high performance chip-scale optical interconnections. The modulators have been improved dramatically in recent years, especially increasing its bandwidth range to the multiple gigahertz regime. The optical modulator performance metrics in energy consumption, footprint, device structure simplicity, maximum bandwidth and modulation efficiency have become more crucial than ever. Up to date, the smallest dimension of reported optically efficient interleaved PN junction based silicon optical modulator has a pitch width of 400 nm. This large pitch width results in a π-phase shift length of 1.5 to 3 mm, and requires a high driving voltage over 3V.Interleaved modulators of 60nm pitch size, 100nm and 200nm was modeled at various doping levels. The designed and fabricated 178 nm PN junction pitched interleaved silicon optical modulator is projected to show the modulation efficiency of 0.45 V-cm at 1 V and 0.47 V-cm at 2 V. In comparison with the state of art device with modulation efficiency of 0.8 V-cm at 4 V, our projection improves the efficiency by approximately twice at half the driving voltage.This research focuses on the design and fabrication of interleaved PN junction based silicon optical modulator. The key challenge is to determine the process parameters of the ion implantation process to form the interleaved P and N junction with a pitch size of 60 nm to 200 nm. The ion energy, tilt angle, dose have been studied using Monte Carlo based the Stopping of Range of Ions in Matter computational method to determine the ion implantation depth and lateral and longitudinal straggle. Sentaurus Process Monte Carlo simulation is also carried on compute the interleaved PN junction doping concentration profile, which later on was imported to Lumerical for the modulator π-phase shift length calculation. The fabrication of the designed interleaved modulator was carried on at Center for Functional Nanomaterials at Brookhaven National Laboratory cleanroom. The major steps include ion implantation mask definitions and silicon waveguide formation through electron beam lithography and Deep Reaction Ion Etching.Ph
Noninvasive optical activation of Flp recombinase for genetic manipulation in deep mouse brain regions
No full textSpatiotemporal control of gene expression or labeling is a valuable strategy for identifying functions of genes within complex neural circuits. Here, we develop a highly light-sensitive and efficient photoactivatable Flp recombinase (PA-Flp) that is suitable for genetic manipulation in vivo. The highly light-sensitive property of PA-Flp is ideal for activation in deep mouse brain regions by illumination with a noninvasive light-emitting diode. In addition, PA-Flp can be extended to the Cre-lox system through a viral vector as Flp-dependent Cre expression platform, thereby activating both Flp and Cre. Finally, we demonstrate that PA-Flp-dependent, Cre-mediated Ca(v)3.1 silencing in the medial septum increases object-exploration behavior in mice. Thus, PA-Flp is a noninvasive, highly efficient, and easy-to-use optogenetic module that offers a side-effect-free and expandable genetic manipulation tool for neuroscience research. © The Author(s) 2019.11Nsciescopu
INFLUENCE OF GIBBERELLIC ACID AND PLANT GEOMETRY ON GROWTH, FLOWERING AND CORM PRODUCTION IN GLADIOLUS (GLADIOLUS GRANDIFLORUS) UNDER JAMMU AGROCLIMATE
No full textThe present investigation was conducted to study the effect of gibberellic acid and plant geometry on growth, flowering and corm production in gladiolus cv. ‘Novalux ’ under Jammu conditions. Four concentrations of GA3 (0, 100, 200 and 300 ppm) and three levels of spacing (20x40cm, 30x40cm and 40x40 cm) were tested in Factorial RBD with three replications. The analyzed data indicated that maximum plant height, number of leaves, leaf width, spike length, rachis length, corm diameter, corm weight and early flowering was recorded at 300 ppm GA3. Corms planted at a spacing of 40x40cm exhibited highest plant height, rachis length, number of florets per spike, floret diameter, number of corms per plant, corm diameter, corm and cormel weight. Among interactions, treatment of corms with 300ppm GA3 and spacing at 40x40 cm was found more effective in the enhancement of vegetative and floral attributes
The Analysis of Zou Tao's 《Jiao Chou Ji》
No full text摘要： 成書於清光緒年間的《澆愁集》是鄒弢早年從學累積的著作，小說史上 將之列於仿擬《聊齋誌異》之作。因現今相關研究及著述不多，故存在 較大研究空間。本論文嘗試將小說文本逐篇分析，以主題式的統整歸類研究解讀小說內容，以此審視小說家如何以敘事手法藉題言志與抒情，為此書展現不同以往的詮釋面貌。 本論文共分為五個部分： 第一部分：提出研究動機，回顧前人研究文獻，梳理《澆愁集》相關研究， 整理學者對此小說集的分析成果。並提出《澆愁集》可能的研究面向。即《澆愁集》與《聊齋誌異》、《紅樓夢》與近代報刊之關聯性。 第二部分：著眼鄒弢的生平經歷，將其生平劃分為三個階段，綜觀其一生多 變的經歷，從早年就學於江蘇無錫縣，歷經戰亂遷徙。又因個人興趣接觸《紅樓夢》與西方新學。《澆愁集》出版後，作者便往上海擔任報刊編輯，接觸海派文化甚深。晚年，回歸故里，從事文化教育事業。透過本部分說明可知《澆愁集》與作者早年所學緊密的相關性。 第三部分：首先，從《澆愁集》繼承《聊齋誌異》的勸善懲惡精神分析文 本內涵，該章節分析聚焦於鬼神主題、人與異類女性遇合情節。最後，論析小說場景出現的江蘇景觀如何被作者轉化書寫，成為文人對原生地方文化的記憶與想像，呈現文人如何藉小說表達儒家倫理教化觀，並以此融合民間宗教文化的書寫策略。 第四部分：裁剪小說出現的各種人間女性群像：閨閣才女、孝女、節婦、名妓、悍妻與賢婦。其中，從作者不注重女性身分地位高低，而重在擷取其深情、重義、忠貞、才德兼備的人格特質，表現儒家對理想女性形象與道德價值觀，藉由戀愛與婚姻情節，反映清代女性展現的至情與自主性。另一方面，小說從悍妻與賢婦的行為對比，表達中國文人擬構家庭與婚姻的理想心態，觀察《澆愁集》從此方向承續《聊齋誌異》及《紅樓夢》的精神主旨，並以之延伸轉化的女性面貌。從女子不屈服傳統文化壓力，顯示女性主動的行動力來歌頌女性地位。 第五部分：整理《澆愁集》符合時代話題的文本，分析小說書寫日常生活與親身經歷。研究小說如何建構知識體系與早期近代報刊新聞在書寫時的相似性。藉此說明《澆愁集》與近代報刊的關係。 由以上各分論整理分析，可知《澆愁集》雖被稱為仿擬之作，實則有作者自出機杼的新創性與時代價值意義。從歸納《澆愁集》模擬與新創之處展現鄒弢如何在《聊齋》風氣盛行的時代，利用志怪題材、才子佳人婚戀題材與《紅樓夢》知己戀情的模式，從虛構的情節細節寄託真實理想，映照出文人懷才不遇的失落感觸，營造自我表現的文學空間，呼應千古文人共同的悲鳴與憤世，發揮抒情與言志的一面，紀錄個人考察的社會現象與評論，進而建立個人生命情調與時代關懷。使《澆愁集》成為風格多元化的一本文言小說著作，於清代小說林中實有可研究之價值。Summary The Ching Dynasty fiction Jiao Chou Ji, as Zou Tao’s accumulation of his early study, is the imitation of Liao Zhai Zhi Yi. Since there is little research about Jiao Chou Ji, this fiction leaves more possibilities for researchers. This paper, in order to know the author''s intention and re-criticize this fiction, attempts to analyze the main idea of texts by Thematic Study. We are going to find out how the author described his wish and his concern of society with narrative skills to express deep feelings. Therefore, we can present different interpretations in the previous research. This paper includes of five parts: I. The First Part: The first part is a review of previous studies, organizing scholars’ analysis of Jiao Chou Ji, and proposes the research motivation of this paper--That is, the relevance between Jiao Chou Ji and others fictions such as Liao Zhai Zhi Yi, The Dream of Red Chamber, and modern Chinese newspaper. II. The Second Part: This part presents the author Zou Tao’s unsteady and painful lifetime. His life can be divided into three sections. At first, he studied in Jiang-su Wu-xi, and then he leaves during wartime. In his early age, he has read The Dream of Red Chamber and loves it deeply since then. Meanwhile, he has known about Western science. After Jiao Chou Ji being published, he went to Shang-hai and became an editor of newspaper and was deeply influenced by the cultural atmosphere of Shang-hai. In his later years, he returned to his hometown and dedicated himself to education and culture career. The review of Zou Tao’s lifetime allows us to see the close connection between the fiction Jiao Chou Ji and Zou Tao’s early lifetime as a learner. III. The Third Part: This chapter first analyzes the text connotation in order to carefully examine how Jiao Chou Ji inherits one of the theme of Liao Zhai Zhi Yi, that is, encouraging the virtuous and punishing the evil. The focuses of this chapter are on the themes of Ghosts and God, and the romance between men and unusual kinds of females. Finally, there is a discuss on the Jiang-su landscape rewritten by the author’s imagination in the text, which becomes his cultural memory towards his hometown Jiang-su. This chapter explores the author''s writing strategies to convey Confucianism ethics and educational thought combined with folk religious culture. IV. The Fourth Part: This chapter analyses a variety of female characters in the text--talented women, good daughters, loyal widows, famous courtesans, shrews and virtuous women. The author doesn’t care about their social status while focusing on capturing their personality traits--soulful heart, attention to justice, loyalty, both talented and virtuous. We can see ideal female image of Confucianism moral value in these characteristics. In addition, it reflects the women’s genuine feelings and autonomy in the romance and marriage plots in Ching Dynasty. In addition, the contrast between the behavior of shrews and virtuous women in the fiction shows Chinese literati’s ideal image of family and marriage. Through struggling traditional cultural pressures, the status of women raised. As a consequence, it proves the spirit of the subject and transforming among Jiao Chou Ji, Liao Zhai Zhi Yi and The Dream of Red Chamber. V. The Fifth Part: This part summarizes anachronistic topic of Jiao Chou Ji, which is related to daily life and personal experience to establish knowledge structure. Furthermore, this chapter also explores the similarity and connection between Jiao Chou Ji and modern Chinese newspapers. In conclusion, although Jiao Chou Ji is known as the imitation of Liao Zhai Zhi Yi, actually there exist the author’s original ideas and reflects values during that period. While Liao Zhai Zhi Yi was popular, Zou Tao rewrote the Ghost and God theme, romantic and marriage themes, and confidant love model of The Dream of Red Chamber to create this fiction. His ambition and the feeling of loss are conveyed in the fictional plots. In the imaginary literary space, he not only echoes with ancient literati’s common sorrow, but also with the contemporary common anger of that period. In this way, Zou Tao expresses the lyrical aspect and “Yan Zhi” aspect. He establishes a personal lifestyle and the concern towards society by means of composing Jiao Chou Ji. Therefore, this fiction becomes a fiction featuring a variety of styles, which is worthwhile researching among fictions in Ching Dynasty
Feature Extracted Deep Neural Collaborative Filtering for E-Book Service Recommendations
No full textThe electronic publication market is growing along with the electronic commerce market. Electronic publishing companies use recommendation systems to increase sales to recommend various services to consumers. However, due to data sparsity, the recommendation systems have low accuracy. Also, previous deep neural collaborative filtering models utilize various variables of datasets such as user information, author information, and book information, and these models have the disadvantage of requiring significant computing resources and training time for their training. To address this issue, we propose a deep neural collaborative filtering model with feature extraction that uses minimal data such as user number, book number, and rating information. The proposed model comprises an input layer for inputting and embedding the product and user data, a feature extraction layer for extracting the features through data correlation analysis between the embedded user and product data, a multilayer perceptron, and an output layer. To improve the performance of the proposed model, Bayesian optimization was used to determine hyperparameters. To evaluate the deep neural collaborative filtering model with feature extraction, a comparative analysis experiment was conducted with currently used collaborative filtering models. The goodbooks-10k public dataset was used, and the results of the experiment show that the low accuracy caused by data sparsity was considerably improved
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