Minimum Time Duration Research Articles

Optimal Satellite Orbit Design for Prioritized Multiple Targets with Threshold Observation Time Using Self-Adaptive Differential Evolution

AbstractThis study considers a satellite orbit design when a given set of target sites needs to be visited within an assigned period. Optimization of the orbit design takes into account target properties such as priority and minimum duration of observation time. Equations describing satellite orbit are used to compute the satellite’s field of view and ground track. Scheduling of visits to the targets is carried out by maximizing the observation time over priority-weighted targets and minimizing the distance between the ground track and the target position while satisfying the constraints with respect to the minimum duration of observation time and revisit requirement. A self-adaptive differential evolution (SA-DE) algorithm with the ability to adjust its search parameters is used to find the best solution. The proposed design methodology computes the optimal values of design variables and also the start and end observation time points of each target. Regional and global case studies demonstrate that the S...

Optimal control of impulsive switched systems with minimum subsystem durations

This paper presents a new computational approach for solving optimal control problems governed by impulsive switched systems. Such systems consist of multiple subsystems operating in succession, with possible instantaneous state jumps occurring when the system switches from one subsystem to another. The control variables are the subsystem durations and a set of system parameters influencing the state jumps. In contrast with most other papers on the control of impulsive switched systems, we do not require every potential subsystem to be active during the time horizon (it may be optimal to delete certain subsystems, especially when the optimal number of switches is unknown). However, any active subsystem must be active for a minimum non-negligible duration of time. This restriction leads to a disjoint feasible region for the subsystem durations. The problem of choosing the subsystem durations and the system parameters to minimize a given cost function is a non-standard optimal control problem that cannot be solved using conventional techniques. By combining a time-scaling transformation and an exact penalty method, we develop a computational algorithm for solving this problem. We then demonstrate the effectiveness of this algorithm by considering a numerical example on the optimization of shrimp harvesting operations.

Swarm Based Fault Tolerant Routing in MPLS Networks

In MPLS/GMPLS networks, during fault prevalence, heavy data loss occurs within minimum duration of time. Also it is difficult to handle these faults as it may cause critical network survivability issue. Most of the existing literature works estimates the failure probability, bandwidth and delay of all routes using the traditional shortest path algorithm which leads to huge delay and overhead. In order to overcome these issues, in this paper, we propose ant colony optimization (ACO) algorithm for routing in GMLPS/MPLS. In this technique, swarm intelligence based fault tolerant routing is performed. This involves the selection of optimal path with maximum available bandwidth and minimum delay. In order to enhance the security of MPLS network, the threshold secret sharing mechanism is considered. By simulation results, we show that the proposed approach minimizes the delay and route failures while increasing the bandwidth utilization and throughput.

The Barremian-Aptian shallow-marine carbonates of Monte Faito and of S. Maria bore cores (central-southern Apennines, Italy). Regional correlation based on cyclostratigraphy

In the last twenty years, high-resolution (cm scale) studies of several Cretaceous carbonate platform successions in centralsouthern Italy have demonstrated that they carry clear evidence ofastronomically controlled eustatic oscillations refl ected on their hierarchical stacking patterns (elementary cycles, bundles and superbundles) and exhibit a sequence-stratigraphic configuration, that is well evident in their superbundles (long eccentricity cycles) as well as in the composite mode of their aggradational pattern, laterally consistent also at more than 100 km distance. Here are presented the centimetre-scale facies analysis of the S. Maria 6 and 4 Agip bore cores (east of Maiella Mountain, Abruzzi region, Early Barremian- Late Aptian in age) and of the Monte Faito section (Monti Lattari, Campania Region, Barremian – Early Aptian in age). Taking into account the cyclic stacking patterns of the lithofacies and their grouping as well as of the early diagenetic features, the environmental oscillations have been constrained in well defi ned time intervals, typical of the Milankovitch periodicities (from ≈ 20 to ≈ 400ky).Based on cyclostratigraphy and sequence stratigraphy criteria and using appropriate biostratigraphic, isotopic and paleomagnetic markers, high-resolution physical correlations (precision 100 ky) have been traced at regional scale among S. Maria composite core, Monte Faito and the previous studied Monte Raggeto (Monte Maggiore) sections. A chronostratigraphic diagram has been assembled for each of the above sections showing that bundles may be locally missing. Moreover, a Barremian-Aptian composite orbital chronostratigraphy has been assembled suggesting the minimum time duration recorded in the considered interval, so that a regional sea-level oscillations history may be restored with a precision of ≤400 ky. On these bases, a minimum duration of 5.2 my for the Barremian interval (13 superbundles) has been estimated, close to the 5 my calculated for the whole Barremian from OGG et alii (2008). These results show as cyclostratigraphy of carbonate platform sequences, integrated with other stratigraphic methodologies and high-precision long distance correlations, is a valid tool to estimate the time duration of stratigraphic intervals and to assemble a floating orbital time scale.

Measuring the thermophysical properties of porous fibrous materials with a new unsteady-state method

Abstract In this article, the authors first introduced a theoretical model dealing with unsteady-state heat conduction in porous fabric to assess the effects due to local convection during the testing. A few important issues are analyzed including the criterion for local thermal equilibrium in the fibrous materials and the confidence time region (tmin–tmax) during measuring process. The influence due to different heat source capacities can be ignored if the measuring time is greater than the minimum time duration tmin, yet the heat loss via outside surface becomes negligible if the testing duration is below the maximum allowable value tmax. Accordingly an apparatus that can simultaneously measure two thermophysical properties (the thermal conductivity k and thermal diffusivity a) of fibrous materials is developed in this study, which then leads to the determination of the volumetric capacity via ρC = k/a. In order to minimize the influence of potential local micro heat convection and the contact resistanc...

Dasatinib Compared with Imatinib In Newly Diagnosed Chronic Myelogenous Leukemia In Chronic Phase (CML-CP):Results of Japanese Subset Analysis In DASISION Trial.

AbstractAbstract 4484 Background:Dasatinib is a highly potent BCR-ABL kinase inhibitor. The previous report from the global DASISION trial showed dasatinib 100 mg once daily resulted in significantly higher and faster rates of complete cytogenetic response (CCyR) and major molecular response (MMR) compared with imatinib; both treatment arms were well-tolerated (N Engl J Med. 2010;362:2260-70). The objective of this subset analysis was to assess the efficacy and safety of dasatinib compared with imatinib in the Japanese population. Methods:Forty-nine Japanese patients (total 519 pts) with newly diagnosed CML-CP were randomly assigned to receive dasatinib 100 mg QD or imatinib 400 mg QD. Confirmed CCyR (cCCyR; CCyR on 2 consecutive assessments at least 28 days apart) was the primary efficacy endpoint with MMR as an important secondary endpoint. The safety profiles were also evaluated. Results:Minimum follow-up time and median treatment duration were 12 months and 15 months, respectively. Twenty-six patients with median age 56 (range, 21–70) years were treated with dasatinib and 23 patients with median age 52 (range, 22–77) years were treated with imatinib. Overall 89% of patients receiving dasatinib and 83% of patients receiving imatinib continue to receive treatment. The cCCyR rate by 12 months (primary endpoint), CCyR rate by 12 months and MMR rate at any time in dasatinib arm were higher than those in imatinib for Japanese patients (96% vs 70%, 96% vs 78%, and 73% vs 48%, respectively). Grade 3/4 cytopenias in dasatinib arm and imatinib arm were as follows: anemia (8% vs 4%), neutropenia (27% vs 39%), and thrombocytopenia (8% vs 9%). Non-hematologic and drug-related adverse events occurring in ≥10% of patients are shown as Table. No deaths were reported in either group. Drug-related serious adverse events were rarely reported and all events were not severe (Grade 1–2, including vomiting, hypoxia and cardiomyopathy in dasatinib arm). Conclusion:Dasatinib showed higher rates of cCCyR and MMR compared with imatinib. Both treatments were well tolerated. Given the predictive value of 12 months cCCyR, dasatinib may improve long-term outcomes in Japanese patients with newly diagnosed CML-CP. Disclosures:Ueda:Bristol-Myers K.K.: Employment. Seriu:Bristol-Myers K.K.: Employment. Bradley-Garelik:Bristol-Myers Squibb: Employment. Zhu:Bristol-Myers Squibb: Employment.

PLANNING LENGTH OF LONG -TERM FIELD EXPERIMENTS THROUGH DECISION SUPPORT SYSTEMS – A CASE STUDY

Long-term field experiments are the conventional means for developing; evaluating and demonstrating site-specific land/water use plans. However, it has been often observed that at times they are unable to propose sustainable practices, when planned for shorter time durations (say 2-3 years) or become cost-ineffective and obsolete, when planned for longer time durations (say more than 15 years or so). Hence, what should be the ideal length of such long-term experiments has always been a debatable issue. The present study attempts to demonstrate application of one indigenously developed decision support system (DSS) for planning appropriate length of long term conjunctive water use experiments on a test salt affected farmer’s field. Before application the proposed DSS was extensively validated on several farmers and controlled experimental fields in Haryana (India). Validation of DSS showed its potential to give realistic estimates of root zone soil salinity; sodicity and salt stress induced relative crop yield reductions under local resource management conditions. Long term impact assessment of varied conjunctive water use strategies, on the test farmer’s field, with the so validated DSS showed that the time required for achieving stable crop yields could be treated as a good measure of the minimum length of such experiments. For the test (rice-wheat growing) farmer’s field, this time ranged between 5.5 – 6.0 years. It was observed that at shorter time scale (i.e. 2 years), though application of 50% canal waters (CW) blended with 50% tube well waters (TW), was as productive and superior as cyclic applications of (2CW, 1TW, 1CW); (1CW, 1TW, 2CW) and (CW: TW) during wheat cropping season yet it could not maintain its superior performance at DSS proposed time duration of 6 years or more. Similarly irrigation practice of (4CW, 5TW) during rice cropping season, though beneficial at shorter time scale, was much inferior to the cyclic application of canal and tube well waters (i.e. CW: TW) at longer time scales (i.e. at ≥ 6 years). Hence, limiting the proposed long-term conjunctive water use experiment to the DSS proposed minimum time duration of 6 years lead to the selection of the most stable and sustainable irrigation practice(s) for the test farm.

Therapeutic Options for Sleep‐Maintenance and Sleep‐Onset Insomnia

Insomnia, defined as difficulty falling asleep, staying asleep, and/or experiencing restorative sleep with associated impairment or significant distress, is a common condition resulting in significant clinical and economic consequences. Many options are available to treat insomnia, to assist with either falling asleep (sleep onset) or maintaining sleep. We searched MEDLINE for articles published between January 1996 and January 2006, evaluated abstracts from recent professional meetings, and contacted the manufacturer of the most recent addition to the pharmacologic armamentarium for insomnia treatment (ramelteon) to gather information. Nonpharmacologic options include stimulus control, sleep hygiene education, sleep restriction, paradoxical intention, relaxation therapy, biofeedback, and cognitive behavioral therapy. Prescription and over-the-counter drug therapies include benzodiazepine and nonbenzodiazepine sedative-hypnotic agents; ramelteon, a melatonin receptor agonist; trazodone; and sedating antihistamines. Herbal and alternative preparations include melatonin and valerian. Before recommending any treatment, clinicians should consider patient-specific criteria such as age, medical history, and other drug use, as well as the underlying cause of the sleep disturbance. All pharmacotherapy should be used with appropriate caution, at minimum effective doses, and for minimum duration of time.

A Simple Procedure for Mesophyll Protoplast Culture and Plant Regeneration in Brassica oleracea L. and Brassica napus L.

An improved protocol for Brassica protoplast culture and plant regeneration was developed. Isolated protoplasts from four-weeks-old in vitro shoot tip culture of Brassica oleracea var. botrytis cv. Siria F1 and Brassica napus doubled haploid of breeding line OP-1 were cultured at a density of 9.8–11.2 × 10<sup>4 </sup>protoplasts/ml in darkness at 25°C in a modified medium containing 2% glucose, 0.25 mg/l 2,4-D, 1 mg/l BAP and 1 mg/l NAA. The first divisions of protoplasts were observed on the third day of culture in B. oleracea and on the fourth day in B. napus. The protoplast cultures were diluted with low osmotic medium on 7<sup>th</sup> and 11<sup>th</sup> day. The frequency of dividing cells was about 80% in B. oleracea and 50% in B. napus. After one month, the microcalli of approximately 0.5–1 mm in size were transferred into an induction medium with various combinations of growth regulators. Minimum duration of enzyme treatment time and extended dark period in the initial phase of culture increased the survival rate of protoplasts. Organogenesis started when the calli enlarged in size on an induction medium (1 mg/l NAA, 0.02 mg/l GA<sub>3</sub>, 1 mg/l 2iP) with 2% sucrose and 0.8% agar. Regeneration frequency of calli was found to be 69–75% in B. oleracea and 2–3% in B. napus. Well-developed shoots were transferred for rooting to a half-strength MS medium without growth regulators. More than 100 B. oleracea regenerants were transferred into soil, and they produced normal heads and set seeds. This very simple procedure is efficient and suitable mainly for B. oleracea var. botrytis and represents a background for fusion experiments.  

Efficient algorithms for mining maximal valid groups

A valid group is defined as a group of moving users that are within a distance threshold from one another for at least a minimum time duration. Unlike grouping of users determined by traditional clustering algorithms, members of a valid group are expected to stay close to one another during their movement. Each valid group suggests some social grouping that can be used in targeted marketing and social network analysis. The existing valid group mining algorithms are designed to mine a complete set of valid groups from time series of user location data, known as the user movement database. Unfortunately, there are considerable redundancy in the complete set of valid groups. In this paper, we therefore address this problem of mining the set of maximal valid groups. We first extend our previous valid group mining algorithms to mine maximal valid groups, leading to AMG and VGMax algorithms. We further propose the VGBK algorithm based on maximal clique enumeration to mine the maximal valid groups. The performance results of these algorithms under different sets of mining parameters are also reported.

Crystal-Grain Refinement of Materials under an Ultra-Strong Gravitational Field

In this study, we investigate the crystalline states and conditions for the grain-refinement of Bi70Sb30 (at.%) alloy. It was considered under an ultra strong gravity field, the crystals were fine-grained from the primary grain sizes of several mm to several tens of mm, and the crystal growth followed with formation of graded-composition structure due to sedimentation of atoms along the direction of gravity. It was found that for the crystal-grain refinement in Bi70Sb30 alloy the minimum gravitational field and the minimum time duration were at least 160,000 G and 10 hours, respectively at about 200 °C.

Negative cloud‐to‐ground lightning properties from high‐speed video observations

From analysis of digital high‐speed video records of 233 negative cloud‐to‐ground (CG) lightning flashes associated with 27 thunderstorms in southeastern Brazil, various lightning properties have been determined. The analysis of the video records showed that although 20% of them were single‐stroke flashes and the average number of strokes per flash was 3.8, a significant variation was observed in these parameters from storm to storm. In a smaller subset containing 138 flashes, 70 (51%) had multiple terminations on the ground. As 138 flashes produced 235 different strike points, the average number of strike points per CG flash was 1.70. Considering that in this study the missing of strokes is practically negligible, we can say from the average multiplicity and from the average number of strike points per flash that each ground contact point is, on average, struck 2.2 times. The 608 time intervals between strokes of 186 negative multiple‐stroke flashes presented a geometric mean value of 61 ms. Although time intervals preceding subsequent strokes that create a new termination tend to be greater than intervals between subsequent strokes that follow the previously formed channel, the difference was not statistically significant. A strong positive correlation between the number of subsequent strokes in a flash and the flash minimum duration may indicate that some processes concerning the time requisite for the channel decay and for the positive leader in the cloud to provide more charges for the next stroke do not permit multiple strokes to occur under a certain minimum time duration.

A SIMPLIFIED ALGORITHM FOR THE IDENTIFICATION OF LONGITUDINAL DYNAMICS OF AN AIRCRAFT

This paper presents a simple and efficient identification algorithm. The proposed algorithm can be used in a large class of plants whose dynamics can be fairly approximated by an under-damped second-order model. The presented study, determines the minimum time duration of a step pulse input, in order to produce output response, rich enough to generate the model parameters, within accepted accuracy limits. The proposed approach can be applied for on-line estimation, of basic model parameters of an aircraft longitudinal dynamics, during flight. Computer simulation results showed that the proposed simplified technique is capable to determine the unknown model parameters, within acceptable accuracy, and shorter time. Due to easy application, and great reduction of computation time, which is a major problem in most indirect adaptive control algorithms, the proposed scheme can be used for adaptive control of a large class of real plants under actual practical conditions.

Criteria for evaluating disease response and progression in patients with multiple myeloma treated by high-dose therapy and haemopoietic stem cell transplantation. Myeloma Subcommittee of the EBMT. European Group for Blood and Marrow Transplant.

Criteria for evaluating disease response and progression in patients with multiple myeloma treated by high-dose therapy and haemopoietic stem cell transplantation. Myeloma Subcommittee of the EBMT. European Group for Blood and Marrow Transplant.

Job‐shop sequencing problems via network scheduling technique

Examines a new approach to job‐shop sequencing problems. This is based on a network scheduling technique on the premiss of limited resource availability to achieve minimum total processing time. The method utilizes a resource allocation procedure based on random activity (job element) selection and the method of finding the optimal solution is that of selecting the trial run with the minimum time duration. With its random nature of selecting activities at the completion of one or more activities, the greater the number of trial runs, the greater the chances are of getting the exact solution which would have been derived had the more conventional mathematical techniques been used. Also aims to find solutions to the more practical job sequencing problems, which are difficult to solve using existing heuristics, mathematical methods and procedures. Highlights these practical examples in the different sections.

Kochia (Kochia scoparia) and Green Foxtail (Setaria viridis) Interference in Sugarbeets (Beta vulgaris)

Two field experiments were conducted between 1990 and 1992 under sprinkler irrigation at the Research and Extension Center, Torrington, WY to determine the influence of mixed densities and durations of kochia and green foxtail interference in sugarbeet. Sugarbeet root yield and top weight generally decreased as densities of green foxtail and kochia increased whether alone or in combination. Reductions in sugarbeet root yield and above ground biomass from mixed densities of kochia and green foxtail were additive at the low and intermediate density but less than additive at the high density of either species. Sugarbeet root yield decreased as the duration of interference after sugarbeet emergence from a mixed density of kochia and green foxtail increased. Since sugarbeet plants were irrigated to avoid water stress and adequate nutrients were applied, it appears that kochia and green foxtail interfered with sugarbeet primarily for light, based on light and height measurements. Season-long as well as duration of interference did not show any significant effect on sucrose content. Based on regression analysis the lowest densities of kochia and green foxtail required to reduce root yield were approximately 0.3 and 0.06 plants/m of row, respectively. The minimum duration of time that 0.5 kochia and 3.0 green foxtail plants/m of row can interfere with sugarbeets before root yield is economically reduced was approximately 3.5 wk after sugarbeet emergence.

Evolution of Low-Mass Stars. V. Minimum Mass for the Deuterium Main Sequence

An evolutionary sequence of stellar models has been calculated to determine the minimum mass and maximum time duration of stars on the low-mass end of the deuterium main sequence. The chemical composition chosen is (X = 0.68, Y = 0.29), with the terrestrial value XD = 1.9 x and l!Hp = 1. Evolutionary tracks have been calculated for 0.008, 0.01, 0.012, 0.015, and 0.02 M0. The mass limit for the deuterium main sequence is at or slightly below 0.012 M0, and the maximum time duration is 7.5 x 10 years. The luminosity of the minimum-mass deuterium-burning model is very slightly higher than that of the minimum-mass hydrogen-burning model, with a Tv smaller by soo K. The low-mass ends of the deuterium and hydrogen main sequences thus bracket the observations of Van Biesbroeck's star and W359. Stars with masses M %< 0.01 M0 enter strong deuterium-burning phases, but do not stabilize in a main-sequence configuration. Subject headitigs: interiors, stellar late-type stars pre-main-sequence stars