5,328 research outputs found
Receding Horizon H (infinity) Control for Input-Delayed Systems
Get PDFWe propose the receding horizon H (infinity) control (RHHC) for input-delayed systems. A new cost function for a finite horizon dynamic game problem is first introduced, which includes two terminal weighting terms parameterized by a positive definite matrix, called a terminal weighing matrix. Secondly, the RHHC is obtained from the solution to the finite dynamic game problem. Thirdly, we propose an LMI condition under which the saddle point value satisfies the nonincreasing monotonicity. Finally, we show the asymptotic stability and H (infinity) boundedness of the closed-loop system controlled by the proposed RHHC. The proposed RHHC has a guaranteed H (infinity) performance bound for nonzero external disturbances and the quadratic cost can be improved by adjusting the prediction horizon length for nonzero initial condition and zero disturbance, which is not the case for existing memoryless state-feedback controllers. It is shown through a numerical example that the proposed RHHC is stabilizing and satisfies the infinite horizon H (infinity) performance bound. Furthermore, the performance in terms of the quadratic cost is shown to be improved by adjusting the prediction horizon length when there exists no external disturbance with nonzero initial condition.Delft Center for Systems and ControlMechanical, Maritime and Materials Engineerin
Designing bidding strategies in sequential auctions for risk averse agents
Get PDFDesigning efficient bidding strategies for sequential auctions represents an important, open problem area in agent-mediated electronic markets. In existing literature, a variety of bidding strategies have been proposed and have been shown to perform with varying degrees of efficiency. However, most of strategies proposed so far do not explicitly model bidders attitudes towards risk which, in mainstream economic literature, is considered an essential attribute in modeling agent preferences and decision making under uncertainty. This paper studies the effect that risk profiles (modeled through the standard Arrow-Pratt risk aversion measure), have on the bidders strategies in sequential auctions. First, the sequential decision process involved in bidding is modeled as a Markov Decision Process. Then, the effect that a bidders risk aversion has on her decision theoretic optimal bidding policy is analyzed, for a category of expectations of future price distributions. This analysis is performed separately for the case of first price and second-price sequential auctions. Next, the bidding strategies developed above are simulated, in order to study the effect that an agents risk aversion has on the chances of winning a set of complementary-valued items. The paper concludes with an experimental study of how the presence of risk-averse bidders affects both bidder profits and auctioneer revenue, for different market scenarios of increasing complexity
'Conventions are conventions.....’: Some thoughts about the techniques of direction and misdirection – with particular reference to genre features - in the novels of Vladimir Nabokov, and an assessment of their intentions and effects.
Get PDFThe thesis deals with the development of Nabokov's treatment of a number of the more common routes and courses which are traditionally supplied by the author to ease the passage of the reader through fiction. It attempts to show how these marked paths and familiar signposts - 'melodrama,' 'totalitarian novel,' 'biography,' 'erotic confession,' 'critical edition,' 'family chronicle, 'mystery story,' and 'autobiographical confession' - emerge in the books as equally misguiding and misguided. The satisfactory application of such labels is demonstrated as becoming progressively more difficult as the novels proceed, with a rising degree of sophistication, to incorporate distinctive combinations of genre features usually considered as mutually exclusive. Further inquiries into the manner of fictional orientation and location encouraged by this regular disappointment of apparently familiar leads and landmarks, however, is increasingly seen to disclose the underlying procedures and desires of the reader to place and confine narrative. The manner in which Nabokov's reader is repeatedly obliged to return to a non-metaphorical 'first base' by way of these false trails, which seemingly point towards an authoritative text, and there to re-examine his own imaginative input is also traced..... Dull work recounting all this bores me to death. But yearn as I may to reach the crucial point quickly, a few preliminary explanations seem necessary
Also By The Same Author: AKTiveAuthor, a Citation Graph Approach to Name Disambiguation
No full textThe desire for definitive data and the semantic web drive for inference over heterogeneous data sources requires co-reference resolution to be performed on those data. In particular, name disambiguation is required to allow accurate publication lists, citation counts and impact measures to be determined. This paper describes a graph-based approach to author disambiguation on large-scale citation networks. Using self-citation, co-authorship and document source analyses, AKTiveAuthor clusters papers, achieving precision of 0.997 and recall of 0.818 over a test group of eight surname clusters
Textbook of neonatal medicine : a Chinese perspective
No full textThis authoritative and comprehensive text is written by an internationally renowned group of medical experts of Chinese ethnic origin from the mainland, Taiwan, Hong Kong and six other countries. As a scientific and clinically practical review of current knowledge on medical care of normal and high-risk infants, this book covers the essentials of modern neonatal medicine. Conditions which are common or life-threatening have been selected for detailed description, while sufficient information is provided on uncommon or less serious problems to help gain an understanding of how they are best managed. A special emphasis has been put on describing experiences which are unique to Chinese infants. The 91 chapters reflect the personal interest and experience of the 77 contributors whose contemporary view and practical approach should prove useful for postgraduate trainees and specialists wishing to keep themselves up to date in neonatal medicinepublished_or_final_versionEditorsContributorsForewordsPrefaceIndex p8971 Organisation of Perinatal Care / Shoo K. Lee p32 Organisation of Neonatal Intensive Care / Keng-Wee Tan p93 The Expanded Role of Neonatal Nursing / Thomas T. W. Chiu p214 Perinatal-Neonatal Audit / Pak-Cheung Ng p335 Neonatal Intensive Care in Developing Countries / Chap -Yung Yeung p436 Prenatal Diagnosis for Paediatricians / Emily W. Y. Ling p517 Maternal Diseases Affecting the Fetus / Xing-Guo Liu p638 Antepartum Fetal Assessment / David T. Y. Liu p699 Intrapartum Fetal Assessment / Sze-Ya Yeh p7710 Prematurity / Tai-Fai Fok p8511 Small for Gestational Age Infants / Kuo-Inn Tsou Yau p9912 Drugs Used in Pregnancy Affecting the Fetus / Xing- Guo Liu p10913 Delivery Room Resuscitation / Gary M. Chan p11714 Perinatal Asphyxia / Victor Y. H. Yu p12515 Physical Examination / Chin-Theam Lim p13516 Birth Injuries / Nem-Yun Boo p14517 Neonatal Screening / Louis C. K. Low p15918 Care of the Normal Neonate / Michael C. K. Chan p17119 Thermoregulation / Yuh-Jyh Lin p17720 Neonatal Hypothermia and Scleroedema / Wen-Lan Hong p18721 Fluid Homeostasis / Paul Y. K. Wu p19522 Feeding the Normal Term Infant / Gary M. Chan p20723 Feeding the Preterm Infant / Victor Y. H. Yu p21524 Mineral Requirements / Winston W. K. Koo p22525 Parenteral Nutrition / Victor Y. H. Yu p23526 Respiratory Physiology / Kei Liu p24527 Prevention of Respiratory Distress Syndrome / Victor Y. H. Yu p25528 Respiratory Distress Syndrome / Tai-Fai Fok p26529 Meconium Aspiration Syndrome / Chyi-Her Lin p27530 Pneumonia / Zhi-Zhi Xu p27931 Pulmonary Haemorrhage / Yan-Ming Xie p28532 Pulmonary Air Leak / Yu-Ming Zhang p28933 Assisted Ventilation / Jen-Tien Wung p29734 Chronic Lung Disease / Victor Y. H. Yu p30935 Apnoea / Lai-Yun Ho p31936 Congenital Diaphragmatic Hernia / Jen-Tien Wung p33337 Cardiovascular Adaptation to Postnatal Life / Alice C. Yao p34338 Persistent Pulmonary Hypertension / Victor Y. H. Yu p35539 Patent Ductus Arteriosus / Yuh-Jyh Lin p36340 Evaluation and Management of Cardiac Disease / Maurice P. Leung p37141 Medical and Surgical Therapy of Cardiac Disease / Maurice P. Leung p38342 Arrhythmias / Pierre C. Wong p39543 Neonatal Shock / Yu-Kun Han p40944 Neonatal Jaundice / Kim-Leong Tan p41745 Feeding Problems / De-Ming Huang p42946 Necrotising Enterocolitis / Victor Y. H. Yu p43747 Cholestasis in Infancy / Mei-Hwei Chang p45148 Disorders of Blood Glucose Homeostasis / Katherine C. H. King p46549 Infant of the Diabetic Mother / Hun-Seng Chao p47950 Metabolic Bone Diseases / Winston W. K. Koo p48751 Congenital Hypothyroidism / Xi-Ji Guan p49552 Hereditary Metabolic Diseases / Paul W. K. Wong p50353 Miscellaneous Endocrine Problems / Louis C. K. Low p51354 Haemolytic Disease of the Newborn / Shu-Zhong Shi p52555 Polycythaemia-Hyperviscosity Syndrome / Wan-Jun Liu p53156 Miscellaneous Haematological Disorders / Ka-Wah Chan p53757 Red Blood Cell Transfusion / Victor Y. H. Yu p54558 Acute Renal Failure / Ke-Lun Wei p55359 Neonatal Renal Disorders / Sik-Nin Wong p55960 Neonatal Neurological Assessment / Barbara Lam p57161 Hypoxic-Ischaemic Encephalopathy / Victor Y. H. Yu p57962 Intracranial Haemorrhage / Barbara Lam p58963 Neonatal Seizures / Zi-Li Chen p59964 Neonatal Pain / T. H. H. Guan Koh p60765 Intrauterine Infections / Cheng T. Cho p61966 Immunological Defences / Yu-Lung Lau p63567 Bacterial Infections / Cheng T. Cho p64968 Neonatal Tetanus / Michael C. K. Chan p66169 Fungal Infections / Pak-Cheung Ng p66570 Nosocomial Infections and Infection Control / Tom D. Y. Chin p67771 Neonatal Immunisation / Yu-Lung Lau p68572 Applications of DNA Technology in Clinical Genetics / Ivy Ng p69973 Chromosome Abnormalities / Lai-Yun Ho p70574 Congenital Malformations / Nai-Kiong Ho p71775 The Dysmorphic Infant / Lai-Yun Ho p72376 Mode of Inheritance / Lai-Yun Ho p73177 Genetic Counselling / Lai-Yun Ho p74178 Practical Neonatal Procedures / Chin-Theam Lim p75179 Neonatal Pharmacology / Emily W. Y. Ling p76380 Neonatal Anaesthesia / Lena S. Sun p79381 Neonatal Surgery / Chung-Kwong Yeung p80382 Communicating with Parents of Sick Babies / T. H. H. Guan Koh p81983 Outcome of Very Low Birthweight Infants / Victor Y. H. Yu p82984 Costs of Neonatal Intensive Care and Long-Term Disabilities / Shoo K. Lee p83985 Ethical Issues in Neonatal Intensive Care / Emily W. Y. Ling p84786 Perinatal-Neonatal Health Care in China / Xiao-Cheng Ji p85987 Intrauterine Growth Retardation in China: Fetal Aspects / Xing-Hua Huang p86588 Intrauterine Growth Retardation in China: Neonatal Aspects / Shi-Min Zhao p87189 Chinese Neonates Are Different / Chap-Yung Yeung p87790 Neonatal Sepsis in China / Shi-Xiao Wu p88591 Traditional Chinese Neonatal Medicine / Bao-Lin Zhang p88
Sensory cue integration of visual and vestibular stimuli: a case study for 4D rides
No full textThis paper investigated human self-motion perception through the visual and vestibular sensory systems under the context of virtual reality (VR) and 4D. Consistently with general 4D riding applications, we designed and used sinusoidal motions as stimuli, which resembled simple roller coaster rides moving in three directions of pitch, surge, and heave. Based on the Bayesian integration model, we experimented to determine the uncertainty involved in the two sensory systems and their relative contributions. We factored in small sensory discrepancies between the visual and vestibular cues and visually noticeable obstacles that could distract viewers. We found that the vestibular system contributed more dominantly to the perception in the ratio of 7:3 than the vision, demonstrating vestibular capture. We also discovered that the visual scenes that contain eye-catching elements and pure optical flows can hamper self-motion perception while increasing the perceptual uncertainty. Our findings can serve as a basis for designing motion effects for VR and 4D applications, especially in situations where multiple sensory systems are stimulated simultaneously. © 2023, The Author(s), under exclusive licence to Springer-Verlag London Ltd., part of Springer Nature.11Nsciescopu
Application of Smart Materials to Improve the structural Performance
No full textAdvanced structural systems are required to have specific functions associated with operating environments. For the purpose of realizing these functions of smart structures, many research activities have been performed. Functional materials and their characteristics, analysis method of smart structures, sensor and actuator placement, controller design, and many other relevant topics have been studied. This article introduces some analytic and experimental research on the application of smart materials, especially shape memory alloys (SMAs), optical fiber, and piezoelectric materials. The numerical analysis of the thermomechanical responses of the structures with initial strained SMA layer has been performed. For the numerical simulation in this research, the incremental formulation of the 3-D SMA constitutive model is used to predict the thermomechanical responses of SMAs. The unique SMA responses such as pseudoelasticity and the shape memory effect are investigated by using finite element procedure. The actuation force applied by SMA layer is used to suppress the deflection induced by thermal buckling of the host structure. In addition, the controllable recovery force or displacement of the SMA strip placed on host structure is used to modify or control the host structural shape. Also, the application of fiber optic sensor, extrinsic Fabry-Perot interferometer (EFPI) and fiber Bragg grating (FBG) sensors has been investigated. The dynamic sensing characteristics of fiber optic sensors were explored and the vibration measurement and suppression of composite structures have been performed. In addition, the stability boundary characteristics and the suppression of dynamic aeroelastic instability have been investigated utilizing piezoceramic actuators and adaptive controller. It is expected that more realistic functions of smart composite structures can be developed and the multi-functional smart structures can be realized. (author abst.
Filtering techniques in the dynamic deformation estimation using multiple strains measured by FBGs
No full textThe first author would like to thank the members of Smart Systems and Structures laboratory at KAIST for
their technical and financial support of the presented research project. The authors also wish to thank Prof.
Chun-Gon Kim and his fiber optic sensor group at the Department of Aerospace Engineering of KAIST for their
help for preparation of the optical sensors and sensing systems
Dynamic Shape Estimation by Modal Approach Using Fiber Bragg Grating Strain Sensors
No full textThe first author wishes to thank ASEM-DUO Fellowship Program for the support throughout the duration of this work.
The authors also wish to thank Prof. Chun-Gon Kim and his fiber optic sensor group at Aerospace Engineering
Department of KAIST for their help for preparation of the sensors and sensing systems
VICtoR: Learning Hierarchical Vision-Instruction Correlation Rewards for Long-horizon Manipulation
Get PDFWe study reward models for long-horizon manipulation tasks by learning from
action-free videos and language instructions, which we term the
visual-instruction correlation (VIC) problem. Recent advancements in
cross-modality modeling have highlighted the potential of reward modeling
through visual and language correlations. However, existing VIC methods face
challenges in learning rewards for long-horizon tasks due to their lack of
sub-stage awareness, difficulty in modeling task complexities, and inadequate
object state estimation. To address these challenges, we introduce VICtoR, a
novel hierarchical VIC reward model capable of providing effective reward
signals for long-horizon manipulation tasks. VICtoR precisely assesses task
progress at various levels through a novel stage detector and motion progress
evaluator, offering insightful guidance for agents learning the task
effectively. To validate the effectiveness of VICtoR, we conducted extensive
experiments in both simulated and real-world environments. The results suggest
that VICtoR outperformed the best existing VIC methods, achieving a 43%
improvement in success rates for long-horizon tasks
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