Semiconductor saturable absorber mirror passively Q-switched 2.97 μm fluoride fiber laser

A diode-cladding-pumped mid-infrared passively Q-switched Ho 3+-doped fluoride fiber laser using a reverse designed broad band semiconductor saturable mirror (SESAM) was demonstrated. Nonlinear reflectivity of the SESAM was measured using an in-house Yb3+-doped mode-locked fiber laser at 1062 nm. Stable pulse train was produced at a slope efficient of 12.1% with respect to the launched pump power. Maximum pulse energy of 6.65 μJ with a pulse width of 1.68 μs and signal to noise ratio (SNR) of ~50 dB was achieved at a repetition rate of 47.6 kHz and center wavelength of 2.971 μm. To the best of our knowledge, this is the first 3 μm region SESAM based Q-switched fiber laser with the highest average power and pulse energy, as well as the longest wavelength from mid-infrared passively Q-switched fluoride fiber lasers. © 2014 SPIE.

Well-Posedness, Conditioning and Regularization of Minimization, Inclusion and Fixed-Point Problems

AMS subject classification: 65K10, 49M07, 90C25, 90C48.

Programming and Testing a Two-Tree Algorithm

ACM Computing Classification System (1998): G.2.2, F.2.2.

Nonlinear Normalization in Limit Theorems for Extremes

2000 Mathematics Subject Classification: 60G70, 60F05.

Properties of the Bellman Gamma Distribution

2000 Mathematics Subject Classification: 62H10.

An Algorithm to Mine Normalized Weighted Sequential Patterns Using a Prefix-projected Database

Sequential pattern mining is an important subject in data mining with broad applications in many different areas. However, previous sequential mining algorithms mostly aimed to calculate the number of occurrences (the support) without regard to the degree of importance of different data items. In this paper, we propose to explore the search space of subsequences with normalized weights. We are not only interested in the number of occurrences of the sequences (supports of sequences), but also concerned about importance of sequences (weights). When generating subsequence candidates we use both the support and the weight of the candidates while maintaining the downward closure property of these patterns which allows to accelerate the process of candidate generation.

An extension of Lorentz's almost convergence and applications in Banach spaces

2000 Mathematics Subject Classification: Primary 40C99, 46B99.

Zeros of Sequences of Partial Sums and Overconvergence

2000 Mathematics Subject Classification: 30B40, 30B10, 30C15, 31A15.

Editorial

Full text: Welcome to issue 1 of 2012 and a belated Happy New Year to all CLAE readers and BCLA members. The hardest job I had for this issue was to decide which papers to include and which papers to hang on to and save for issue 2 of 2012. At the end of December when I was choosing the content for this issue there were additional 5 papers that could have been included. The final choice came down to various factors; such as first come first served – i.e. which papers had been ready and waiting the longest; secondly which papers had been submitted the earliest; are there similar papers so that it may be beneficial to publish them alongside this paper; and also was the content something which needed to be out there quicker than other papers as it was a current hot topic? But it should be noted that once papers are proofed and deemed ready by authors they are published in the epub version and put online for others to see in their final version. An epub version is given a DOI number (digital object identifier) so that it can be cited by other authors. Apart from being on line the only other difference is that an epub version is essentially waiting to be assigned to a particular issue. So those papers that are being held off for issue 2 of this year are actually already available for you to read (and cite) on line. In this issue there is a paper related to the cost of different contact lens replacement schedules – this may be a topic that is debated more in the future since as a society we are thinking more ‘green’ and all trying to help by reducing our carbon footprint, whether that be by recycling or using less in the first place. A timely review paper on the management of allergic eye disease may help us to better manage those patients we see in the spring with pollen allergies. We have two papers looking at different aspects in keratoconus patients, another looking at a modified fluoret strip and its application in measuring tear break up time and a review paper on corneal erosions. Another interesting paper comes from Professor Harminder Dua and his team. Professor Dua is the UK Royal College of Ophthalmologists’ president and has been interested in corneal anatomy and physiology for much of his research career. Finally, an unusual case of an ocular injury related to a snake bite. Overall I would say there is enough to sink your ‘fangs’ into! Finally, it gives me great pleasure in announcing the newest person to join our Editorial Board, Dr Florence Malet. Dr Malet is an Ophthalmologist and since September 2000 she has been at the Bordeaux Hospital in France developing the Contact Lens Unit of in the Ophthalmology University Department. She is ex-president of the French Contact Lens Society and president of the European Contact Lens Society of Ophthalmologists.

Transmission performance improvement using random DFB laser based Raman amplification and bidirectional second-order pumping

We demonstrate that a distributed Raman amplification scheme based on random distributed feedback (DFB) fiber laser enables bidirectional second-order Raman pumping without increasing relative intensity noise (RIN) of the signal. This extends the reach of 10 × 116 Gb/s DP-QPSK WDM transmission up to 7915 km, compared with conventional Raman amplification schemes. Moreover, this scheme gives the longest maximum transmission distance among all the Raman amplification schemes presented in this paper, whilst maintaining relatively uniform and symmetric signal power distribution, and is also adjustable in order to be highly compatible with different nonlinearity compensation techniques, including mid-link optical phase conjugation (OPC) and nonlinear Fourier transform (NFT).

The Shapley value for shortest path games

In this paper shortest path games are considered. The transportation of a good in a network has costs and benet too. The problem is to divide the prot of the transportation among the players. Fragnelli et al (2000) introduce the class of shortest path games, which coincides with the class of monotone games. They also give a characterization of the Shapley value on this class of games. In this paper we consider further four characterizations of the Shapley value (Shapley (1953)'s, Young (1985)'s, Chun (1989)'s, and van den Brink (2001)'s axiomatizations), and conclude that all the mentioned axiomatizations are valid for shortest path games. Fragnelli et al (2000)'s axioms are based on the graph behind the problem, in this paper we do not consider graph specic axioms, we take TU axioms only, that is, we consider all shortest path problems and we take the view of abstract decision maker who focuses rather on the abstract problem than on the concrete situations.

The Shapley value for shortest path games

In this paper shortest path games are considered. The transportation of a good in a network has costs and benet too. The problem is to divide the prot of the transportation among the players. Fragnelli et al (2000) introduce the class of shortest path games, which coincides with the class of monotone games. They also give a characterization of the Shapley value on this class of games. In this paper we consider further four characterizations of the Shapley value (Shapley (1953)'s, Young (1985)'s, Chun (1989)'s, and van den Brink (2001)'s axiomatizations), and conclude that all the mentioned axiomatizations are valid for shortest path games. Fragnelli et al (2000)'s axioms are based on the graph behind the problem, in this paper we do not consider graph specic axioms, we take TU axioms only, that is, we consider all shortest path problems and we take the view of abstract decision maker who focuses rather on the abstract problem than on the concrete situations.

Stable sets in one-seller assignment games

We consider von Neumann -- Morgenstern stable sets in assignment games with one seller and many buyers. We prove that a set of imputations is a stable set if and only if it is the graph of a certain type of continuous and monotone function. This characterization enables us to interpret the standards of behavior encompassed by the various stable sets as possible outcomes of well-known auction procedures when groups of buyers may form bidder rings. We also show that the union of all stable sets can be described as the union of convex polytopes all of whose vertices are marginal contribution payoff vectors. Consequently, each stable set is contained in the Weber set. The Shapley value, however, typically falls outside the union of all stable sets.

Dean of the school board: An oral history of the distinguished career of G. Holmes Braddock

Effective school board leadership is often an ephemeral ideal in today's highly politicized public education arena. However, effective leadership is necessary in order to ensure a fair and equitable education for all students. This dissertation described and explained one school board member's perspective of his career as a lens from which to view and assess public educational policy making in Miami-Dade County. ^ Now retired after thirty-eight years of service, G. Holmes Braddock is the longest serving, contemporary, urban school board member in the country. Spanning nearly four decades, his perspective provides a comprehensive view of urban education both locally and nationally. The significance of his longevity and the impact of his leadership on educational policy-making was the focus of indepth interviews with Mr. Braddock and other key educational “influentials.” From this transcript data, recurring themes were revealed and categorized. Five elements of his perspective, i.e., teacher professionalization; desegregation; athletics; bilingual education; and his comprehensive leadership role, were identified and analyzed, as were five variables of his perspective, i.e., fairness; integrity; honesty; courage; and the situational context. Other secondary source material, such as excerpts from newspaper articles, school board minutes, and items from Mr. Braddock's own personal effects further augmented and triangulated the data. ^ Given that the purpose of this study was to describe and explain Mr. Braddock's perspective of his school board career, the findings can be understood from two different viewpoints. The elements of Mr. Braddock's perspective describe or characterize his career and represent the significant policy issues in which he demonstrated exceptional vision and leadership. However, taken alone, these elements cannot fully explain his distinguished career. Rather, an analysis of the variables of Mr. Braddock's perspective provides an explanation for the effectiveness of his leadership role. Personality traits such as fairness, integrity, honesty and courage and the impact of the situational context were factors that strongly influenced Mr. Braddock's decision-making. Thus, Mr. Braddock's school board career can be holistically understood as the intersection of person, place and time with significant public education policy issues. ^ The results of this study provide a unique and historical perspective of school board politics in Miami-Dade County. From Mr. Braddock's perspective, we are able to view one individual's leadership role over time and its impact on local public education policy. ^

Human impacts on pig frog (Rana grylio) populations in south Florida wetlands: Harvest, water management and mercury contamination

This study investigated how harvest and water management affected the ecology of the Pig Frog, Rana grylio. It also examined how mercury levels in leg muscle tissue vary spatially across the Everglades. Rana grylio is an intermediate link in the Everglades food web. Although common, this inconspicuous species can be affected by three forms of anthropogenic disturbance: harvest, water management and mercury contamination. This frog is harvested both commercially and recreationally for its legs, is aquatic and thus may be susceptible to water management practices, and can transfer mercury throughout the Everglades food web. ^ This two-year study took place in three major regions: Everglades National Park (ENP), Water Conservation Areas 3A (A), and Water Conservation Area 3B (B). The study categorized the three sites by their relative harvest level and hydroperiod. During the spring of 2001, areas of the Everglades dried completely. On a regional and local scale Pig Frog abundance was highest in Site A, the longest hydroperiod, heavily harvested site, followed by ENP and B. More frogs were found along survey transects and in capture-recapture plots before the dry-down than after the dry-down in Sites ENP and B. Individual growth patterns were similar across all sites, suggesting differences in body size may be due to selective harvest. Frogs from Site A, the flooded and harvested site, had no differences in survival rates between adults and juveniles. Site B populations shifted from a juvenile to adult dominated population after the dry-down. Dry-downs appeared to affect survival rates more than harvest. ^ Total mercury in frog leg tissue was highest in protected areas of Everglades National Park with a maximum concentration of 2.3 mg/kg wet mass where harvesting is prohibited. Similar spatial patterns in mercury levels were found among pig frogs and other wildlife throughout parts of the Everglades. Pig Frogs may be transferring substantial levels of mercury to other wildlife species in ENP. ^ In summary, although it was found that abundance and survival were reduced by dry-down, lack of adult size classes in Site A, suggest harvest also plays a role in regulating population structure. ^