Multimode optical feedback dynamics in InAs/GaAs quantum dot lasers emitting exclusively on ground or excited states: transition from short- to long-delay regimes

© 2018 Optical Society of America. Users may use, reuse, and build upon the article, or use the article for text or data mining, so long as such uses are for non-commercial purposes and appropriate attribution is maintained. All other rights are reserved.The optical feedback dynamics of two multimode InAs/GaAs quantum dot lasers emitting exclusively on sole ground or excited lasing states is investigated. The transition from long- to short-delay regimes is analyzed, while the boundaries associated to the birth of periodic and chaotic oscillations are unveiled to be a function of the external cavity length. The results show that depending on the initial lasing state, different routes to chaos are observed. These results are of importance for the development of isolator-free transmitters in short-reach networks

Solving the paradox of the folded falling chain by considering horizontal kinetic energy and link geometry

A folded chain, with one end fixed at the ceiling and the other end released from the same elevation, is commonly modeled as an energy-conserving system in one-dimension. However, the analytical paradigms in previous literature is unsatisfying: The theoretical prediction of the tension at the fixed end becomes infinitely large when the free end reaches the bottom, contradicting to the experimental observations. Furthermore, the dependence of the total falling time on the link number demonstrated in numerical simulations is still unexplained. Here, considering the horizontal kinetic energy and the geometry of each link, we derived analytical solutions of the maximal tension as well as the total falling time, in agreement with simulation results and experimental data reported in previous studies. This theoretical perspective shows a simple representation of the complicated two-dimensional falling chain system and, in particular, specifies the signature of the chain properties.Comment: 13 pages, 4 figure

Low-rank matrix recovery with structural incoherence for robust face recognition

We address the problem of robust face recognition, in which both training and test image data might be corrupted due to occlusion and disguise. From standard face recog-nition algorithms such as Eigenfaces to recently proposed sparse representation-based classification (SRC) methods, most prior works did not consider possible contamination of data during training, and thus the associated performance might be degraded. Based on the recent success of low-rank matrix recovery, we propose a novel low-rank matrix ap-proximation algorithm with structural incoherence for ro-bust face recognition. Our method not only decomposes raw training data into a set of representative basis with corre-sponding sparse errors for better modeling the face images, we further advocate the structural incoherence between the basis learned from different classes. These basis are en-couraged to be as independent as possible due to the regu-larization on structural incoherence. We show that this pro-vides additional discriminating ability to the original low-rank models for improved performance. Experimental re-sults on public face databases verify the effectiveness and robustness of our method, which is also shown to outper-form state-of-the-art SRC based approaches. 1

Implementation of an RFID Medical Center Allocation and Picking up Process Support Cloud System

Abstract: In this study, the expendable medical supplies warehouse of the Medical Center can be seen as a logistics center. The users act as the front-end clients and the medical material is a cargo. The concept combines RFID, PDA technology and cloud computing to design and implement the system. The main purpose of the system is to reduce the errors when the operating personnel distribute the expendable medical supplies

Substituting or Complementing?---The Influence of Chinese Overseas Direct Investment on Domestic Exports

The aim of this paper is to verify whether overseas direct investment activities of China can substitute or complement domestic exports. Using panel data of 85 host countries from 2003 to 2011 we conduct detailed empirical examinations within the framework of the gravity model. After correcting for bias caused by synchronism between trade flow and investment flow and also for econometrical misspecifications we discover that, contrary to all existing studies, Chinese overseas direct investment has a very weak substituting relationship with domestic exports. Sub-sample regressions show that Chinese overseas direct investment substitutes exports to developed countries but complements exports to developing countries. Panel threshold model further confirms the role of host country’s economic developmental stage (measured by per capita GDP) in determining the influence of overseas direct investment on exports and detects two thresholds. Thus the sample is divided into three regimes: (1) in the first regime where per capita GDP is lower than 1150.39 dollars, overseas direct investment complements exports to the host country; (2) in the second regime where per capita GDP falls between 1150.39 and 11601.63 dollars, the “gray zone”, overseas direct investment has very weak influence on domestic exports; (3) in the third regime where per capita GDP exceeds 11601.63 dollars, overseas direct investment substitutes exports to the host country. This paper concludes with possible explanations to the empirical results and the threshold phenomenon

Substituting or Complementing?---The Influence of Chinese Overseas Direct Investment on Domestic Exports

The aim of this paper is to verify whether overseas direct investment activities of China can substitute or complement domestic exports. Using panel data of 85 host countries from 2003 to 2011 we conduct detailed empirical examinations within the framework of the gravity model. After correcting for bias caused by synchronism between trade flow and investment flow and also for econometrical misspecifications we discover that, contrary to all existing studies, Chinese overseas direct investment has a very weak substituting relationship with domestic exports. Sub-sample regressions show that Chinese overseas direct investment substitutes exports to developed countries but complements exports to developing countries. Panel threshold model further confirms the role of host country’s economic developmental stage (measured by per capita GDP) in determining the influence of overseas direct investment on exports and detects two thresholds. Thus the sample is divided into three regimes: (1) in the first regime where per capita GDP is lower than 1150.39 dollars, overseas direct investment complements exports to the host country; (2) in the second regime where per capita GDP falls between 1150.39 and 11601.63 dollars, the “gray zone”, overseas direct investment has very weak influence on domestic exports; (3) in the third regime where per capita GDP exceeds 11601.63 dollars, overseas direct investment substitutes exports to the host country. This paper concludes with possible explanations to the empirical results and the threshold phenomenon

Current Proceedings of Childhood Stroke

Stroke is a sudden onset neurological deficit due to a cerebrovascular event. In children, the recognition of stroke is often delayed due to the low incidence of stroke and the lack of specific assessment measures to this entity. The causes of pediatric stroke are significantly different from that of adult stroke. The lack of safety and efficiency data in the treatment is the challenge while facing children with stroke. Nearly half of survivors of pediatric stroke may have neurologic deficits affecting functional status and quality of life. They may cause a substantial burden on health care resources. Hence, an accurate history, including onset and duration of symptoms, risk factors, and a complete investigation, including hematologic, neuroimaging, and metabolic studies is the key to make a corrective diagnosis. A prompt and optimal treatment without delay may minimize the damage to the brain