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Sample records for age-matched controls methods

  1. Comparison of Conditioning Impairments in Children with Down Syndrome, Autistic Spectrum Disorders and Mental Age-Matched Controls

    ERIC Educational Resources Information Center

    Reed, P.; Staytom, L.; Stott, S.; Truzoli, R.

    2011-01-01

    Background: This study investigated the relative ease of learning across four tasks suggested by an adaptation of Thomas's hierarchy of learning in children with Down syndrome, autism spectrum disorders and mental age-matched controls. Methods: Learning trials were carried out to investigate observational learning, instrumental learning, reversal…

  2. Pitch Characteristics Before Ulnar Collateral Ligament Reconstruction in Major League Pitchers Compared With Age-Matched Controls

    PubMed Central

    Prodromo, John; Patel, Nimit; Kumar, Neil; Denehy, Kevin; Tabb, Loni Philip; Tom, James

    2016-01-01

    Background: Ulnar collateral ligament reconstruction (UCLR) is commonly performed in Major League Baseball (MLB) pitchers, but little is known about the preoperative pitch type and velocity characteristics of pitchers who go on to undergo UCLR. Hypothesis: Pitchers who required UCLR have thrown a greater percentage of fastballs and have greater pitch velocities compared with age-matched controls in the season before injury. Study Design: Case-control study; Level of evidence, 3. Methods: MLB pitchers active during the 2002 to 2015 seasons were included. The UCLR group consisted of MLB pitchers who received UCLR between 2003 and 2015, utilizing the season before surgery (2002-2014) for analysis. The control group comprised age-matched controls of the same season. Players who pitched less than 20 innings in the season before surgery were excluded. Pitch types were recorded as percentage of total pitches thrown. Pitch velocities were recorded for each pitch type. Pitch type and pitch velocities during preoperative seasons for UCLR pitchers were compared with age-matched controls using univariate and multivariate models. Results: A total of 114 cases that went on to UCLR and 3780 controls were included in the study. Pitchers who went on to UCLR appear to have greater fastball, slider, curveball, changeup, and split-fingered fastball velocities; there were no significant differences in pitch selection between the 2 groups. Conclusion: In the season before surgery, MLB pitchers who underwent UCLR demonstrated greater fastball, slider, curveball, changeup, and split-fingered fastball velocities, with no significant difference in pitch type. PMID:27350954

  3. A Comparison of Substantia Nigra T1 Hyperintensity in Parkinson's Disease Dementia, Alzheimer's Disease and Age-Matched Controls: Volumetric Analysis of Neuromelanin Imaging

    PubMed Central

    Park, Ju-Yeon; Yun, Won-Sung; Jeon, Ji Yeong; Moon, Yeon Sil; Kim, Heejin; Kwak, Ki-Chang; Lee, Jong-Min; Han, Seol-Heui

    2016-01-01

    Objective Neuromelanin loss of substantia nigra (SN) can be visualized as a T1 signal reduction on T1-weighted high-resolution imaging. We investigated whether volumetric analysis of T1 hyperintensity for SN could be used to differentiate between Parkinson's disease dementia (PDD), Alzheimer's disease (AD) and age-matched controls. Materials and Methods This retrospective study enrolled 10 patients with PDD, 18 patients with AD, and 13 age-matched healthy elderly controls. MR imaging was performed at 3 tesla. To measure the T1 hyperintense area of SN, we obtained an axial thin section high-resolution T1-weighted fast spin echo sequence. The volumes of interest for the T1 hyperintense SN were drawn onto heavily T1-weighted FSE sequences through midbrain level, using the MIPAV software. The measurement differences were tested using the Kruskal-Wallis test followed by a post hoc comparison. Results A comparison of the three groups showed significant differences in terms of volume of T1 hyperintensity (p < 0.001, Bonferroni corrected). The volume of T1 hyperintensity was significantly lower in PDD than in AD and normal controls (p < 0.005, Bonferroni corrected). However, the volume of T1 hyperintensity was not different between AD and normal controls (p = 0.136, Bonferroni corrected). Conclusion The volumetric measurement of the T1 hyperintensity of SN can be an imaging marker for evaluating neuromelanin loss in neurodegenerative diseases and a differential in PDD and AD cases. PMID:27587951

  4. Comparative gait analysis between children with autism and age-matched controls: analysis with temporal-spatial and foot pressure variables

    PubMed Central

    Lim, Bee-Oh; O’Sullivan, David; Choi, Bum-Gwon; Kim, Mi-Young

    2016-01-01

    [Purpose] The purpose of this study was to investigate the gait pattern of children with autism by using a gait analysis system. [Subjects] Thirty children were selected for this study: 15 with autism (age, 11.2 ± 2.8 years; weight, 48.1 ± 14.1 kg; height, 1.51 ± 0.11 m) and 15 healthy age-matched controls (age, 11.0 ± 2.9 years; weight, 43.6 ± 10 kg; height, 1.51 ± 0.011 m). [Methods] All participants walked three times on the GAITRite® system while their plantar pressure was being recorded. [Results] The results showed a reduction in cadence, gait velocity, and step length, and an increase in step width in children with autism. Plantar pressure variables highlight the differences between the active pressure areas, especially in the hindfoot of children with autism. [Conclusion] The results suggest that children with autism have an abnormal gait compared with that of age-matched controls, and thus they need extra attention to correct these abnormal gait patterns. PMID:26957776

  5. Prematurely Delivered Rats Show Improved Motor Coordination During Sensory-evoked Motor Responses Compared to Age-matched Controls

    PubMed Central

    Roberto, Megan E.; Brumley, Michele R.

    2014-01-01

    The amount of postnatal experience for perinatal rats was manipulated by delivering pups one day early (postconception day 21; PC21) by cesarean delivery and comparing their motor behavior to age-matched controls on PC22 (the typical day of birth). On PC22, pups were tested on multiple measures of motor coordination: leg extension response (LER), facial wiping, contact righting, and fore- and hindlimb stepping. The LER and facial wiping provided measures of synchronous hind- and forelimb coordination, respectively, and were sensory-evoked. Contact righting also was sensory-evoked and provided a measure of axial coordination. Stepping provided a measure of alternated forelimb and hindlimb coordination and was induced with the serotonin receptor agonist quipazine. Pups that were delivered prematurely and spent an additional day in the postnatal environment showed more bilateral limb coordination during expression of the LER and facial wiping, as well as a more mature righting strategy, compared to controls. These findings suggest that experience around the time of birth shapes motor coordination and the expression of species-typical behavior in the developing rat. PMID:24680729

  6. Stable Schizophrenia Patients Learn Equally Well as Age-Matched Controls and Better than Elderly Controls in Two Sensorimotor Rotary Pursuit Tasks

    PubMed Central

    De Picker, Livia J.; Cornelis, Claudia; Hulstijn, Wouter; Dumont, Glenn; Fransen, Erik; Timmers, Maarten; Janssens, Luc; Morrens, Manuel; Sabbe, Bernard G. C.

    2014-01-01

    Objective: To compare sensorimotor performance and learning in stable schizophrenia patients, healthy age- and sex-matched controls and elderly controls on two variations of the rotary pursuit: circle pursuit (true motor learning) and figure pursuit (motor and sequence learning). Method: In the circle pursuit, a target circle, rotating with increasing speed along a predictable circular path on the computer screen, must be followed by a cursor controlled by a pen on a writing tablet. In the eight-trial figure pursuit, subjects learn to draw a complex figure by pursuing the target circle that moves along an invisible trajectory between and around several goals. Tasks were administered thrice (day 1, day 2, day 7) to 30 patients with stable schizophrenia (S), 30 healthy age- and sex-matched controls (C), and 30 elderly participants (>65 years; E) and recorded with a digitizing tablet and pressure-sensitive pen. The outcome measure accuracy (% of time that cursor is within the target) was used to assess performance. Results: We observed significant group differences in accuracy, both in circle and figure pursuit tasks (E < S < C, p < 0.01). Strong learning effects were found in each group. Learning curves were similar in circle pursuit but differed between groups in figure pursuit. When corrected for group differences in starting level, the learning gains over the three sessions of schizophrenia patients and age-matched controls were equal and both were larger than those of the elderly controls. Conclusion: Despite the reduced sensorimotor performance that was found in the schizophrenia patients, their sensorimotor learning seems to be preserved. The relevance of this finding for the evaluation of procedural learning in schizophrenia is discussed. The better performance and learning rate of the patients compared to the elderly controls was unexpected and deserves further study. PMID:25505425

  7. No consistent difference in gray matter volume between individuals with fibromyalgia and age-matched healthy subjects when controlling for affective disorder.

    PubMed

    Hsu, Michael C; Harris, Richard E; Sundgren, Pia C; Welsh, Robert C; Fernandes, Carlo R; Clauw, Daniel J; Williams, David A

    2009-06-01

    Fibromyalgia (FM) is thought to involve abnormalities in central pain processing. Recent studies involving small samples have suggested alterations in gray matter volume (GMV) in brains of FM patients. Our objective was to verify these findings in a somewhat larger sample using voxel-based morphometry (VBM), while controlling for the presence of affective disorders (AD). T1-weighted magnetic resonance image (MRI) brain scans were obtained on 29 FM patients with AD, 29 FM patients without AD, and 29 age-matched healthy controls (HCs) using a 3T scanner. Segmentation, spatial normalization, and volumetric modulation were performed using an automated protocol within SPM5. Smoothed gray matter segments were entered into a voxel-wise one-way ANOVA, and a search for significant clusters was performed using thresholding methods published in previous studies (whole-brain threshold of p<.05 correcting for multiple comparisons; region-of-interest (ROI) threshold of p< or =.001 uncorrected, or p<.05 small-volume corrected). The whole-brain analysis did not reveal any significant clusters. ROI-based analysis revealed a significant difference in left anterior insula GMV among the three groups (xyz={-28, 21, 9}; p=.026, corrected). However, on post-hoc testing, FM patients without AD did not differ significantly from HC with respect to mean GMV extracted from this cluster. A significant negative correlation was found between mean cluster GMV and scores of trait anxiety (State-Trait Personality Inventory, Trait Anxiety scale; rho=-.470, p<.001). No other significant clusters were found on ROI-based analysis. Our results emphasize the importance of correcting for AD when carrying out VBM studies in chronic pain. PMID:19375224

  8. No Consistent Difference in Gray Matter Volume between Individuals with Fibromyalgia and Age-Matched Healthy Subjects when Controlling for Affective Disorder

    PubMed Central

    Hsu, Michael C.; Harris, Richard E.; Sundgren, Pia C.; Welsh, Robert C.; Fernandes, Carlo R.; Clauw, Daniel J.; Williams, David A.

    2009-01-01

    Fibromyalgia (FM) is thought to involve abnormalities in central pain processing. Recent studies involving small samples have suggested alterations in gray matter volume (GMV) in brains of FM patients. Our objective was to verify these findings in a somewhat larger sample using voxel-based morphometry (VBM), while controlling for presence of affective disorders (AD). T1-weighted magnetic resonance image (MRI) brain scans were obtained on 29 FM patients with AD, 29 FM patients without AD, and 29 age-matched healthy controls (HC) using a 3T scanner. Segmentation, spatial normalization, and volumetric modulation were performed using an automated protocol within SPM5. Smoothed gray matter segments were entered into a voxel-wise one-way ANOVA, and a search for significant clusters was performed using thresholding methods published in previous studies (whole-brain threshold of p<.05 correcting for multiple comparisons; region-of-interest (ROI) threshold of p≤.001 uncorrected, or p<.05 small-volume corrected). The whole-brain analysis did not reveal any significant clusters. ROI-based analysis revealed a significant difference in left anterior insula GMV among the three groups (xyz={−28, 21, 9}; p=.026, corrected). However, on post-hoc testing, FM patients without AD did not differ significantly from HC with respect to mean GMV extracted from this cluster. A significant negative correlation was found between mean cluster GMV and scores of trait anxiety (State-Trait Personality Inventory, Trait Anxiety scale; rho=−.470, p<.001). No other significant clusters were found on ROI-based analysis. Our results emphasize the importance of correcting for AD when carrying out VBM studies in chronic pain. PMID:19375224

  9. Sensorimotor Control of Tracking Movements at Various Speeds for Stroke Patients as Well as Age-Matched and Young Healthy Subjects

    PubMed Central

    Ao, Di; Song, Rong; Tong, Kai-yu

    2015-01-01

    There are aging- and stroke-induced changes on sensorimotor control in daily activities, but their mechanisms have not been well investigated. This study explored speed-, aging-, and stroke-induced changes on sensorimotor control. Eleven stroke patients (affected sides and unaffected sides) and 20 control subjects (10 young and 10 age-matched individuals) were enrolled to perform elbow tracking tasks using sinusoidal trajectories, which included 6 target speeds (15.7, 31.4, 47.1, 62.8, 78.5, and 94.2 deg/s). The actual elbow angle was recorded and displayed on a screen as visual feedback, and three indicators, the root mean square error (RMSE), normalized integrated jerk (NIJ) and integral of the power spectrum density of normalized speed (IPNS), were used to investigate the strategy of sensorimotor control. Both NIJ and IPNS had significant differences among the four groups (P<0.01), and the values were ranked in the following order: young controls < age-matched controls control. The RMSE increased with the increase in the target speed and the NIJ and IPNS initially declined and then remained steady for all four groups, which indicated a shift from feedback to feedforward control as the target speed increased. The feedback-feedforward trade-off induced by stroke, aging and speed might be explained by a change in the transmission delay and neuromotor noise. The findings in this study improve our understanding of the mechanism underlying the sensorimotor control and neurological changes caused by stroke and aging. PMID:26030289

  10. Immunity in young adult survivors of childhood leukemia is similar to the elderly rather than age-matched controls: Role of cytomegalovirus.

    PubMed

    Azanan, Mohamad Shafiq; Abdullah, Noor Kamila; Chua, Ling Ling; Lum, Su Han; Abdul Ghafar, Sayyidatul Syahirah; Kamarulzaman, Adeeba; Kamaruzzaman, Shahrul; Lewin, Sharon R; Woo, Yin Ling; Ariffin, Hany; Rajasuriar, Reena

    2016-07-01

    Many treatment complications that occur late in childhood cancer survivors resemble age-related comorbidities observed in the elderly. An immune phenotype characterized by increased immune activation, systemic inflammation, and accumulation of late-differentiated memory CD57(+) CD28(-) T cells has been associated with comorbidities in the elderly. Here, we explored if this phenotype was present in young adult leukemia survivors following an average of 19 years from chemotherapy and/or radiotherapy completion, and compared this with that in age-matched controls. We found that markers of systemic inflammation-IL-6 and human C-reactive protein and immune activation-CD38 and HLA-DR on T cells, soluble CD (sCD)163 from monocytes and macrophages-were increased in survivors compared to controls. T-cell responses specific to cytomegalovirus (CMV) were also increased in survivors compared to controls while CMV IgG levels in survivors were comparable to levels measured in the elderly (>50years) and correlated with IL-6, human C-reactive protein, sCD163, and CD57(+) CD28(-) memory T cells. Immune activation and inflammation markers correlated poorly with prior chemotherapy and radiotherapy exposure. These data suggest that CMV infection/reactivation is strongly correlated with the immunological phenotype seen in young childhood leukemia survivors and these changes may be associated with the early onset of age-related comorbidities in this group. PMID:27129782

  11. Training understanding of reversible sentences: a study comparing language-impaired children with age-matched and grammar-matched controls

    PubMed Central

    Hsu, Hsinjen Julie

    2014-01-01

    Introduction. Many children with specific language impairment (SLI) have problems with language comprehension, and little is known about how to remediate these. We focused here on errors in interpreting sentences such as “the ball is above the cup”, where the spatial configuration depends on word order. We asked whether comprehension of such short reversible sentences could be improved by computerized training, and whether learning by children with SLI resembled that of younger, typically-developing children. Methods. We trained 28 children with SLI aged 6–11 years, 28 typically-developing children aged from 4 to 7 years who were matched to the SLI group for raw scores on a test of receptive grammar, and 20 typically-developing children who were matched to the SLI group on chronological age. A further 20 children with SLI were given pre- and post-test assessments, but did not undergo training. Those in the trained groups were given training on four days using a computer game adopting an errorless learning procedure, during which they had to select pictures to correspond to spoken sentences such as “the cup is above the drum” or “the bird is below the hat”. Half the trained children heard sentences using above/below and the other half heard sentences using before/after (with a spatial interpretation). A total of 96 sentences was presented over four sessions. Half the sentences were unique, whereas the remainder consisted of 12 repetitions of each of four sentences that became increasingly familiar as training proceeded. Results. Age-matched control children performed near ceiling (≥ 90% correct) in the first session and were excluded from the analysis. Around half the trained SLI children also performed this well. Training effects were examined in 15 SLI and 16 grammar-matched children who scored less than 90% correct on the initial training session. Overall, children’s scores improved with training. Memory span was a significant predictor of

  12. RELN-expressing Neuron Density in Layer I of the Superior Temporal Lobe is Similar in Human Brains with Autism and in Age-Matched Controls

    PubMed Central

    Camacho, Jasmin; Ejaz, Ehsan; Ariza, Jeanelle; Noctor, Stephen C.; Martínez-Cerdeño, Verónica

    2015-01-01

    Reelin protein (RELN) level is reduced in the cerebral cortex and cerebellum of subjects with autism. RELN is synthesized and secreted by a subpopulation of neurons in the developing cerebral cortex termed Cajal-Retzius (CR) cells. These cells are abundant in the marginal zone during cortical development, many die after development is complete, but a small population persists into adulthood. In adult brains, RELN is secreted by the surviving CR cells, by a subset of GABAergic interneurons in layer I, and by pyramidal cells and GABAergic interneurons in deeper cortical layers. It is widely believed that decreased RELN in layer I of the cerebral cortex of subjects with autism may result from a decrease in the density of RELN expressing neurons in layer I; however, this hypothesis has not been tested. We examined RELN expression in layer I of the adult human cortex and found that 70% of cells express RELN in both control and autistic subjects. We quantified the density of neurons in layer I of the superior temporal cortex of subjects with autism and age-matched control subjects. Our data show that there is no change in the density of neurons in layer I of the cortex of subjects with autism, and therefore suggest that reduced RELN expression in the cerebral cortex of subjects with autism is not a consequence of decreased numbers of RELN-expressing neurons in layer I. Instead reduced RELN may result from abnormal RELN processing, or a decrease in the number of other RELN-expressing neuronal cell types. PMID:25067827

  13. Assessment of the cardiac autonomic neuropathy among the known diabetics and age-matched controls using noninvasive cardiovascular reflex tests in a South-Indian population: A case–control study

    PubMed Central

    Sukla, Pradeep; Shrivastava, Saurabh RamBihariLal; Shrivastava, Prateek Saurabh; Rao, Nambaru Lakshmana

    2016-01-01

    Aim: Diabetes mellitus is a chronic condition characterized by hyperglycemia. The objective of the study was to estimate the prevalence of cardiac autonomic neuropathy in a rural area of South India, among the known diabetics after comparing them with the age-matched healthy controls, utilizing noninvasive cardiac autonomic neuropathy reflex tests. Materials and Methods: A case–control study was conducted for 4 months (October 2014 to January 2015) at an Urban Health and Training Center (UHTC) of a Medical College located in Kancheepuram district, Tamil Nadu. The study was conducted among 126 diagnosed Type 2 diabetes patients and in 152 age- and sex-matched healthy controls to ensure comparability between the cases and controls and, thus, reduce variability due to demographic variables. All the study subjects (cases and controls) were selected from the patients attending UHTC during the study duration, provided they satisfied the inclusion and exclusion criteria. Study participants were subjected to undergo noninvasive cardiac autonomic neuropathy reflex tests. The associations were tested using paired t-test for the continuous (mean ± standard deviation) variables. Results: The overall prevalence of cardiac autonomic neuropathy among diabetic patients was found to be as 53.2% (67/126). On further classification, positive (abnormal) results were obtained in 56 (sympathetic – 44.4%) and 51 (parasympathetic – 40.5%) diabetic cases. Overall, heart rate variation during deep breathing was found to be the most sensitive test to detect parasympathetic autonomic neuropathy while the diastolic blood pressure response to sustained handgrip exercise was the most sensitive method to detect sympathetic neuropathy dysfunction. Conclusion: The overall prevalence of cardiac autonomic neuropathy among diabetic patients was found to be as 53.2%. Even though cardiac autonomic neuropathy can be detected by various invasive tests, noninvasive tests remain a key tool to detect

  14. Intensively managed young children with type 1 diabetes consume high-fat, low-fiber diets similar to age-matched controls.

    PubMed

    Mehta, Sanjeev N; Volkening, Lisa K; Quinn, Nicolle; Laffel, Lori M B

    2014-05-01

    Despite significant emphasis on nutrition, older children with diabetes demonstrate poor dietary quality. We tested the hypothesis that dietary quality in young children with type 1 diabetes (T1D) would be better than age-matched children in the US population. Dietary data from children with T1D (n = 67) aged 2 to 12 years attending a pediatric diabetes clinic were compared with a nationally representative, age-matched sample from the National Health and Nutrition Examination Survey (NHANES; n = 1691). Multiple 24-hour dietary recalls were used. Recommended intakes were based on national guidelines, and dietary quality was assessed using the Healthy Eating Index-2005. More children with T1D were overweight or obese compared with children participating in NHANES (42% vs 30%, P = .04). Greater proportions of children with T1D met daily recommendations for vegetables (22% vs 13%, P = .03), whole grains (12% vs 5%, P = .005), and dairy (55% vs 36%, P = .001) compared with NHANES children, whereas similar proportions met daily fruit recommendations (40% vs 33%, P = .2). Less than one-third of all children limited total fat to recommended levels; children with T1D consumed more saturated fat than did NHANES children (14% vs 12% total energy intake, P = .0009). Fiber intakes were very low in both groups. Compared with NHANES children, children with T1D had higher Healthy Eating Index-2005 scores (59.6 vs 49.7, P = .0006) primarily because of lower intakes of added sugars. The nutritional intake of young children with T1D remains suboptimal in the contemporary era of diabetes management. Despite focused nutrition management, young children with T1D consume high-fat, low-fiber diets comparable with youth in the general population. PMID:24916556

  15. A comparative autoradiography study in post mortem whole hemisphere human brain slices taken from Alzheimer patients and age-matched controls using two radiolabelled DAA1106 analogues with high affinity to the peripheral benzodiazepine receptor (PBR) system.

    PubMed

    Gulyás, Balázs; Makkai, Boglárka; Kása, Péter; Gulya, Károly; Bakota, Lidia; Várszegi, Szilvia; Beliczai, Zsuzsa; Andersson, Jan; Csiba, László; Thiele, Andrea; Dyrks, Thomas; Suhara, Tetsua; Suzuki, Kazutoshi; Higuchi, Makato; Halldin, Christer

    2009-01-01

    The binding of two radiolabelled analogues (N-(5-[125I]Iodo-2-phenoxyphenyl)-N-(2,5-dimethoxybenzyl)acetamide ([125I]desfluoro-DAA1106) and N-(5-[125I]Fluoro-2-phenoxyphenyl)-N-(2-[125I]Iodo-5-methoxybenzyl)acetamide ([125I]desmethoxy-DAA1106) of the peripheral benzodiazepine receptor (PBR) (or TSPO, 18kDa translocator protein) ligand DAA1106 was examined by in vitro autoradiography on human post mortem whole hemisphere brain slices obtained from Alzheimer's disease (AD) patients and age-matched controls. Both [(125)I]desfluoro-IDAA1106 and [(125)I]desmethoxy-IDAA1106 were effectively binding to various brain structures. The binding could be blocked by the unlabelled ligand as well as by other PBR specific ligands. With both radiolabelled compounds, the binding showed regional inhomogeneity and the specific binding values proved to be the highest in the hippocampus, temporal and parietal cortex, the basal ganglia and thalamus in the AD brains. Compared with age-matched control brains, specific binding in several brain structures (temporal and parietal lobes, thalamus and white matter) in Alzheimer brains was significantly higher, indicating that the radioligands can effectively label-activated microglia and the up-regulated PBR/TSPO system in AD. Complementary immunohistochemical studies demonstrated reactive microglia activation in the AD brain tissue and indicated that increased ligand binding coincides with increased regional microglia activation due to neuroinflammation. These investigations yield further support to the PBR/TSPO binding capacity of DAA1106 in human brain tissue, demonstrate the effective usefulness of its radio-iodinated analogues as imaging biomarkers in post mortem human studies, and indicate that its radiolabelled analogues, labelled with short half-time bioisotopes, can serve as prospective in vivo imaging biomarkers of activated microglia and the up-regulated PBR/TSPO system in the human brain. PMID:18984021

  16. Soluble BACE-1 Activity and sAβPPβ Concentrations in Alzheimer's Disease and Age-Matched Healthy Control Cerebrospinal Fluid from the Alzheimer's Disease Neuroimaging Initiative-1 Baseline Cohort.

    PubMed

    Savage, Mary J; Holder, Daniel J; Wu, Guoxin; Kaplow, June; Siuciak, Judith A; Potter, William Z

    2015-01-01

    β-site amyloid precursor protein-cleaving enzyme 1 (BACE1) plays an important role in the development of Alzheimer's disease (AD), freeing the amyloid-β (Aβ) N-terminus from the amyloid-β protein precursor (AβPP), the first step in Aβ formation. Increased BACE1 activity in AD brain or cerebrospinal fluid (CSF) has been reported. Other studies, however, found either no change or a decrease with AD diagnosis in either BACE1 activity or sAβPPβ, the N-terminal secreted product of BACE1 (sBACE1) activity on AβPP. Here, sBACE1 enzymatic activity and secreted AβPPβ (sAβPPβ) were measured in Alzheimer's Disease Neuroimaging Initiative-1 (ADNI-1) baseline CSF samples and no statistically significant changes were found in either measure comparing healthy control, mild cognitively impaired, or AD individual samples. While CSF sBACE1 activity and sAβPPβ demonstrated a moderate yet significant degree of correlation with each other, there was no correlation of either analyte to CSF Aβ peptide ending at residue 42. Surprisingly, a stronger correlation was demonstrated between CSF sBACE1 activity and tau, which was comparable to that between CSF Aβ₄₂ and tau. Unlike for these latter two analytes, receiver-operator characteristic curves demonstrate that neither CSF sBACE1 activity nor sAβPPβ concentrations can be used to differentiate between healthy elderly and AD individuals. PMID:25790831

  17. Electrophysiological Neuroimaging using sLORETA Comparing 22 Age Matched Male and Female Schizophrenia Patients

    PubMed Central

    Eugene, Andy R.; Masiak, Jolanta; Kapica, Jacek; Masiak, Marek

    2015-01-01

    Introduction The purpose of this electrophysiological neuroimaging study was to provide a deeper mechanistic understanding of both olanzapine and risperidone pharmacodynamics relative to gender. In doing so, we age-matched 22 men and women and evaluated their resting-state EEG recordings and later used standard low resolution brain Electrotomography to visualize the differences in brain activity amongst the two patient groups. Methods In this investigation, electroencephalogram (EEG) data were analyzed from male and female schizophrenia patients treated with either olanzapine or risperidone, both atypical antipsychotics, during their in-patient stay at the Department of Psychiatry. Twenty-two males and females were age-matched and EEG recordings were analyzed from 19 Ag/AgCl electrodes. Thirty-seconds of resting EEG were spectrally transformed in standardized low resolution electromagnetic tomography (sLORETA). 3D statistical non-paramentric maps for the sLORETA Global Field Power within each band were finally computed. Results The results indicated that, relative to males patients, females schizophrenia patients had increased neuronal synchronization in delta frequency, slow-wave, EEG band located in the dorsolateral prefrontal cortex, within the middle frontal gyrus (t= -2.881, p < 0.03580). These findings suggest that females experience greater dopamine (D2) receptor and serotonin (5-HT2) receptor neuronal blockade relative to age-matched males. Further, our finding provided insight to the pharmacodynamics of second-generation antipsychotics olanzapine and risperidone. Conclusion When compared to male patients, female patients, suffering from schizophrenia, have D2 and 5-HT2 receptors that are blocked more readily than age-matched male schizophrenia patients. Clinically, this may translate into a quicker time to treatment-response in females as compared to male patients. PMID:26617679

  18. Electrical stimulation directs engineered cardiac tissue to an age-matched native phenotype

    PubMed Central

    Lasher, Richard A; Pahnke, Aric Q; Johnson, Jeffrey M; Sachse, Frank B

    2012-01-01

    Quantifying structural features of native myocardium in engineered tissue is essential for creating functional tissue that can serve as a surrogate for in vitro testing or the eventual replacement of diseased or injured myocardium. We applied three-dimensional confocal imaging and image analysis to quantitatively describe the features of native and engineered cardiac tissue. Quantitative analysis methods were developed and applied to test the hypothesis that environmental cues direct engineered tissue toward a phenotype resembling that of age-matched native myocardium. The analytical approach was applied to engineered cardiac tissue with and without the application of electrical stimulation as well as to age-matched and adult native tissue. Individual myocytes were segmented from confocal image stacks and assigned a coordinate system from which measures of cell geometry and connexin-43 spatial distribution were calculated. The data were collected from 9 nonstimulated and 12 electrically stimulated engineered tissue constructs and 5 postnatal day 12 and 7 adult hearts. The myocyte volume fraction was nearly double in stimulated engineered tissue compared to nonstimulated engineered tissue (0.34 ± 0.14 vs 0.18 ± 0.06) but less than half of the native postnatal day 12 (0.90 ± 0.06) and adult (0.91 ± 0.04) myocardium. The myocytes under electrical stimulation were more elongated compared to nonstimulated myocytes and exhibited similar lengths, widths, and heights as in age-matched myocardium. Furthermore, the percentage of connexin-43-positive membrane staining was similar in the electrically stimulated, postnatal day 12, and adult myocytes, whereas it was significantly lower in the nonstimulated myocytes. Connexin-43 was found to be primarily located at cell ends for adult myocytes and irregularly but densely clustered over the membranes of nonstimulated, stimulated, and postnatal day 12 myocytes. These findings support our hypothesis and reveal that the

  19. Comparison of serum sodium and potassium levels in patients with senile cataract and age-matched individuals without cataract

    PubMed Central

    Mathur, Gaurav; Pai, Vijaya

    2016-01-01

    Aim: The study was to analyze mean serum sodium and potassium levels in cataract patients and age-matched individuals without cataract. Methods and Materials: It was a prospective case-control study. Individuals more than 50 years of age who attended our ophthalmic center in the year 2007-2010 were grouped into those having cataract and those without cataract. Mean serum sodium and potassium levels in the cataract groups were calculated and compared with the control group. Statistical software SPSS14 was used for statistical analysis. Results: Mean serum sodium levels in cataract group was 135.1 meqv/l and 133 meqv/l in the control group. Mean potassium was 3.96 meqv/l in the case study group and 3.97 meqv/l in controls. Mean sodium levels among cases were significantly higher than control group. No difference was seen in the PSC group and control. The difference in mean potassium among the two groups was statistically insignificant. Conclusion: Diets with high sodium contents are a risk factor for senile cataract formation and dietary modifications can possibly reduce the rate of progression cataract. PMID:23552357

  20. Analysis of abstract and concrete word processing in persons with aphasia and age-matched neurologically healthy adults using fMRI.

    PubMed

    Sandberg, Chaleece; Kiran, Swathi

    2014-08-01

    The concreteness effect occurs in both normal and language-disordered populations. Research suggests that abstract and concrete concepts elicit differing neural activation patterns in healthy young adults, but this is undocumented in persons with aphasia (PWA). Three PWA and three age-matched controls were scanned using fMRI while processing abstract and concrete words. Consistent with current theories of abstract and concrete word processing, abstract words elicited activation in verbal areas, whereas concrete words additionally activated multimodal association areas. PWA show greater differences in neural activation than age-matched controls between abstract and concrete words, possibly due to an exaggerated concreteness effect. PMID:23548150

  1. Which oropharyngeal factors are significant risk factors for obstructive sleep apnea? An age-matched study and dentist perspectives

    PubMed Central

    Ruangsri, Supanigar; Jorns, Teekayu Plangkoon; Puasiri, Subin; Luecha, Thitisan; Chaithap, Chariya; Sawanyawisuth, Kittisak

    2016-01-01

    Objective Obstructive sleep apnea (OSA) is a common sleep breathing disorder. Untreated OSA may lead to a number of cardiovascular complications. Dentists may play an important role in OSA detection by conducting careful oral examinations. This study focused on the correlation of oral anatomical features in Thai patients who presented with OSA. Methods We conducted a prospective comparative study at a sleep/hypertension clinic and a dental clinic at Khon Kaen University in Thailand. Patients with OSA were enrolled in the study, along with age-matched patients with non-OSA (controls). Baseline characteristics, clinical data, and oropharyngeal data of all patients were compared between the two groups. Oropharyngeal measurements included tongue size, torus mandibularis, Mallampati classification, palatal space, and lateral pharyngeal wall area. Multivariate logistic regression analysis was used to identify the factors associated with OSA. Results During the study period, there were 156 patients who met the study criteria; 78 were patients with OSA and the other 78 were healthy control subjects. In the OSA group, there were 43 males with a mean age of 53 (standard deviation 12.29) years and a mean BMI of 30.86 kg/mm2. There were 37 males in the control group with a mean age of 50 (standard deviation 12.04) years and a mean BMI of 24.03 kg/mm2. According to multivariate logistic analysis, three factors were perfectly associated with OSA, including torus mandibularis class 6, narrow lateral pharyngeal wall, and Mallampati class 4. There were two other significant factors associated with having OSA, namely, BMI and Mallampati classification. The adjusted odds ratios (95% confidence interval) of these two factors were 1.445 (1.017, 2.052) and 5.040 (1.655, 15.358), respectively. Conclusion Dentists may play an important role in the detection of OSA in patients with high BMI through careful oropharyngeal examination in routine dental treatment. A large torus mandibularis

  2. Evaluation of visual stress symptoms in age-matched dyslexic, Meares-Irlen syndrome and normal adults

    PubMed Central

    Alanazi, Mana A.; Alanazi, Saud A.; Osuagwu, Uchechukwu L.

    2016-01-01

    AIM To examine the prevalence of dyslexia and Meares-Irlen syndrome (MIS) among female students and determine their level of visual stress in comparison with normal subjects. METHODS A random sample of 450 female medical students of King Saud University Riyadh (age range, 18-30y) responded to a wide range of questions designed to accomplish the aims of this study. The detailed questionnaire consisted of 54 questions with 12 questions enquiring on ocular history and demography of participants while 42 questions were on visual symptoms. Items were categorized into critical and non-critical questions (CQ and NCQ) and were rated on four point Likert scale. Based on the responses obtained, the subjects were grouped into normal (control), dyslexic with or without MIS (Group 1) and subjects with MIS only (Group 2). Responses were analysed as averages and mean scores were calculated and compared between groups using one way analysis of variance to evaluate total visual stress score (TVSS=NCQ+CQ), critical and non-critical visual stress scores. The relationship between categorical variables such as age, handedness and condition were assessed with Chi-square test. RESULTS The completion rate was 97.6% and majority of the respondents (92%) were normal readers, 2% dyslexic and 6% had MIS. They were age-matched. More than half of the participants had visited an eye care practitioner in the last 2y. About 13% were recommended eye exercises and one participant experienced pattern glare. Hand preference was not associated with any condition but Group 1 subjects (3/9, 33%) were significantly more likely to be diagnosed of lazy eye than Group 2 (2/27, 7%) and control (27/414, 7%) subjects. The mean±SD of TVSS responses were 63±14 and it was 44±9 for CQ and 19±5 for NCQ. Responses from all three variables were normally distributed but the CQ responses were on the average more positive (82%) in Group 2 and less positive (46%) in Group 1 than control. With NCQ, the responses were

  3. Prevalence of temporomandibular disorder pain in Chinese adolescents compared to an age-matched Swedish population.

    PubMed

    Hongxing, L; Astrøm, A N; List, T; Nilsson, I-M; Johansson, A

    2016-04-01

    This study aimed to (i) assess the prevalence and perceived need for treatment of TMD pain, and its association with socio-economic factors and gender, in adolescents in Xi᾽an, Shaanxi Province, China, and (ii) compare the prevalence and association with gender of TMD pain in Xi᾽an to an age-matched Swedish population. We surveyed Chinese adolescents aged 15 to 19 years in Xi'an, China (n = 5524), using a questionnaire with two-stage stratified sampling and the school as the sampling unit. The study included second-year students at selected high schools. It also included an age-matched Swedish population (n = 17 015) surveyed using the same diagnostic criteria for TMD pain as that used in the Chinese sample. The survey found TMD pain in 14·8% (n = 817) of the Chinese sample and 5·1% (n = 871) of the Swedish sample (P < 0·0001). Girls had significantly more TMD pain than boys in both the Chinese (P < 0·05) and Swedish (P < 0·001) samples. TMD pain increased with age in the Chinese population. Of the Chinese adolescents with TMD pain, 47% reported that they felt a need for treatment. Rural schools, low paternal education levels, poverty, living outside the home, poor general and oral health, and dissatisfaction with teeth all showed significant positive correlations with TMD pain. Prevalence of TMD pain in Chinese adolescents was significantly higher than in the Swedish sample. PMID:26538188

  4. Heroin snorters versus injectors: comparison on drug use and treatment outcome in age-matched samples.

    PubMed

    Carpenter, M J; Chutuape, M A; Stitzer, M L

    1998-12-01

    Drug use histories and treatment outcomes were compared for age, race and gender-matched samples of intravenous (IV; n = 28) versus intranasal (IN; n = 28) opiate abusers entering a 3-day inpatient detoxification unit. Data were derived from the Addiction Severity Index (ASI) interview. Both groups reported daily heroin use prior to detoxification, but IV users reported more days of alcohol and multiple drug use during the past 30 days. Despite age matching, IV users also started using alcohol at an earlier age and accumulated more lifetime months of regular alcohol, cocaine and multidrug use. IV users were more likely to enter treatment following the detox, but no significant outcome differences were noted at 1 and 3 months post-detoxification. The results show that intravenous, as compared to intranasal, opiate users have both a more severe pattern and a more extensive history of the use of non-opiate drugs. PMID:10933336

  5. Neural mechanisms of verb argument structure processing in agrammatic aphasic and healthy age-matched listeners

    PubMed Central

    Thompson, C.K.; Bonakdarpour, B.; Fix, S.F.

    2010-01-01

    Processing of lexical verbs involves automatic access to argument structure entries entailed within the verb's representation. Recent neuroimaging studies with young normal listeners suggest that this involves bilateral posterior perisylvian tissue, with graded activation in these regions based on argument structure complexity. The aim of the present study was to examine the neural mechanisms of verb processing using functional magnetic resonance imaging (fMRI) in older normal volunteers and patients with stroke-induced agrammatic aphasia, a syndrome in which verb, as compared to noun, production often is selectively impaired, but verb comprehension in both on-line and off-line tasks is spared. Fourteen healthy listeners and five age-matched aphasic patients performed a lexical decision task, which examined verb processing by argument structure complexity, i.e., one-argument (i.e., intransitive (v1)); two-argument (i.e., transitive (v2)), and three-argument (v3) verbs. Results for the age-matched listeners largely replicated those for younger participants studied by Thompson et al. (2007): v3-v1 comparisons showed activation of the angular gyrus in both hemispheres and this same heteromodal region was activated in the left hemisphere in the (v2+v3)-v1 contrast. Similar results were derived for the agrammatic aphasic patients, however, activation was unilateral (in the right hemisphere for 3 participants) rather than bilateral likely because these patients' lesions extended to the left temporoparietal region. All performed the task with high accuracy and, despite differences in lesion site and extent, they recruited spared tissue in the same regions as healthy normals. Consistent with psycholinguistic models of sentence processing, these findings indicate that the posterior language network is engaged for processing verb argument structure and is crucial for semantic integration of argument structure information. PMID:19702460

  6. Control system design method

    DOEpatents

    Wilson, David G.; Robinett, III, Rush D.

    2012-02-21

    A control system design method and concomitant control system comprising representing a physical apparatus to be controlled as a Hamiltonian system, determining elements of the Hamiltonian system representation which are power generators, power dissipators, and power storage devices, analyzing stability and performance of the Hamiltonian system based on the results of the determining step and determining necessary and sufficient conditions for stability of the Hamiltonian system, creating a stable control system based on the results of the analyzing step, and employing the resulting control system to control the physical apparatus.

  7. Methods of inventory control.

    PubMed

    Lindley, C; Mackowiak, J

    1985-01-01

    Various methods for controlling inventory are described, and the advantages and disadvantages of each are discussed. The open-to-buy (OTB) budget method limits purchases to a specific amount of funds available for purchasing pharmaceuticals during a specified period. The emphasis of the OTB method is financial control of the pharmacy inventory. Although it is useful in monitoring and adjusting the dollar value of the inventory, it should be combined with other methods for a total inventory control system. The primary emphasis of the short-list method is to provide accurate and timely inventory information to the person responsible for order placement. The short list identifies the items that are in short supply. It is the most common feedback and control mechanism in use, but it is best suited for settings where duplicate or reserve stock is maintained and monitored by more rigorous methods. The main objective of the minimum and maximum method is to determine when and how much to order of each item. It also provides limited dollar control. The major disadvantage of this method is the time it requires to establish the minimum and maximum levels and to update them regularly to reflect changes in demand. The stock record card method is used to record information on the movement of goods in and out of the storage area. Stock cards can also be used to monitor inventory levels and facilitate order initiation. It is probably the optimum method to be used alone. The most effective system of inventory control is one employing a combination of these methods tailored to meet the institution's needs and available resources. PMID:3970028

  8. Compressor surge control method

    SciTech Connect

    Dziubakowski, D.J.; Keys, M.A.I.V.; Shaffer, J.J.

    1990-02-13

    This patent describes a method of controlling surge in a centrifugal compressor having a predetermined surge condition line and providing a combined output with a base load means. It comprises: establishing a main surge control line offset from the centrifugal compressor surge condition line according to a function of pressure differentials across the centrifugal compressor and across an orifice in the inlet line of the centrifugal compressor; establishing a feed forward control signal which is a function of a variable associated with the base load means which may cause the surge condition in the centrifugal compressor; and establishing an anticipatory surge control line offset from the main surge control line as a function of the established main surge control line and the established feed forward control signal.

  9. Single-port laparoscopic cholecystectomy vs standard laparoscopic cholecystectomy: A non-randomized, age-matched single center trial

    PubMed Central

    van der Linden, Yoen TK; Bosscha, Koop; Prins, Hubert A; Lips, Daniel J

    2015-01-01

    AIM: To compare the safety of single-port laparoscopic cholecystectomies with standard four-port cholecystectomies. METHODS: Between January 2011 and December 2012 datas were gathered from 100 consecutive patients who received a single-port cholecystectomy. Patient baseline characteristics of all 100 single-port cholecystectomies were collected (body mass index, age, etc.) in a database. This group was compared with 100 age-matched patients who underwent a conventional laparoscopic cholecystectomy in the same period. Retrospectively, per- and postoperative data were added. The two groups were compared to each other using independent t-tests and χ2-tests, P values below 0.05 were considered significantly different. RESULTS: No differences were found between both groups regarding baseline characteristics. Operating time was significantly shorter in the total single-port group (42 min vs 62 min, P < 0.05); in procedures performed by surgeons the same trend was seen (45 min vs 59 min, P < 0.05). Peroperative complications between both groups were equal (3 in the single-port group vs 5 in the multiport group; P = 0.42). Although not significant less postoperative complications were seen in the single-port group compared with the multiport group (3 vs 9; P = 0.07). No statistically significant differences were found between both groups with regard to length of hospital stay, readmissions and mortality. CONCLUSION: Single-port laparoscopic cholecystectomy has the potential to be a safe technique with a low complication rate, short in-hospital stay and comparable operating time. Single-port cholecystectomy provides the patient an almost non-visible scar while preserving optimal quality of surgery. Further prospective studies are needed to prove the safety of the single-port technique. PMID:26328034

  10. Secreted proteome profiling in human RPE cell cultures derived from donors with age related macular degeneration and age matched healthy donors.

    PubMed

    An, Eunkyung; Lu, Xiaoning; Flippin, Jessica; Devaney, Joseph M; Halligan, Brian; Hoffman, Eric P; Hoffman, Eric; Strunnikova, Nataly; Csaky, Karl; Hathout, Yetrib

    2006-10-01

    Age-related macular degeneration (AMD) is characterized by progressive loss of central vision, which is attributed to abnormal accumulation of macular deposits called "drusen" at the interface between the basal surface of the retinal pigment epithelium (RPE) and Bruch's membrane. In the most severe cases, drusen deposits are accompanied by the growth of new blood vessels that breach the RPE layer and invade photoreceptors. In this study, we hypothesized that RPE secreted proteins are responsible for drusen formation and choroidal neovascularization. We used stable isotope labeling by amino acids in cell culture (SILAC) in combination with LC-MS/MS analysis and ZoomQuant quantification to assess differential protein secretion by RPE cell cultures prepared from human autopsy eyes of AMD donors (diagnosed by histological examinations of the macula and genotyped for the Y402H-complement factor H variant) and age-matched healthy control donors. In general, RPE cells were found to secrete a variety of extracellular matrix proteins, complement factors, and protease inhibitors that have been reported to be major constituents of drusen (hallmark deposits in AMD). Interestingly, RPE cells from AMD donors secreted 2 to 3-fold more galectin 3 binding protein, fibronectin, clusterin, matrix metalloproteinase-2 and pigment epithelium derived factor than RPE cells from age-matched healthy donors. Conversely, secreted protein acidic and rich in cysteine (SPARC) was found to be down regulated by 2-fold in AMD RPE cells versus healthy RPE cells. Ingenuity pathway analysis grouped these differentially secreted proteins into two groups; those involved in tissue development and angiogenesis and those involved in complement regulation and protein aggregation such as clusterin. Overall, these data strongly suggest that RPE cells are involved in the biogenesis of drusen and the pathology of AMD. PMID:17022631

  11. Birth control - slow release methods

    MedlinePlus

    Contraception - hormonal methods; Progestin implants; Progestin injections; Skin patch; Vaginal ring ... might want to consider a different birth control method. SKIN PATCH The skin patch is placed on ...

  12. Method for controlling brazing

    DOEpatents

    Hosking, F. Michael; Hall, Aaron C.; Givler, Richard C.; Walker, Charles A.

    2006-08-01

    A method for making a braze joint across a discontinuity in a work piece using alternating current. A filler metal is pre-placed at a location sufficiently close to the discontinuity such that, when an alternating current is applied across a work piece to heat the work piece and melt the filler metal, the filler metal is drawn into the discontinuity. The alternating current is maintained for a set residence time, generally less than 10 seconds and more particularly less than 3 seconds. The alternating current is then altered, generally by reducing the current and/or voltage such that the filler metal can solidify to form a braze joint of desired quality and thickness.

  13. Method of controlling gene expression

    DOEpatents

    Peters, Norman K.; Frost, John W.; Long, Sharon R.

    1991-12-03

    A method of controlling expression of a DNA segment under the control of a nod gene promoter which comprises administering to a host containing a nod gene promoter an amount sufficient to control expression of the DNA segment of a compound of the formula: ##STR1## in which each R is independently H or OH, is described.

  14. The Left Hand Second to Fourth Digit Ratio (2D:4D) Does Not Discriminate World-Class Female Gymnasts from Age Matched Sedentary Girls

    PubMed Central

    Peeters, Maarten W.; Claessens, Albrecht L.

    2012-01-01

    Introduction The second to fourth-digit-ratio (2D:4D), a putative marker of prenatal androgen action and a sexually dimorphic trait, has been suggested to be related with sports performance, although results are not univocal. If this relation exists, it is most likely to be detected by comparing extreme groups on the continuum of sports performance. Methods In this study the 2D:4D ratio of world-class elite female artistic gymnasts (n = 129), competing at the 1987 Rotterdam World-Championships was compared to the 2D:4D ratio of sedentary age-matched sedentary girls (n = 129), alongside with other anthropometric characteristics including other sexually dimorphic traits such as an androgyny index (Bayer & Bayley) and Heath-Carter somatotype components (endomorphy, mesomorphy, ectomorphy) using AN(C)OVA. 2D:4D was measured on X-rays of the left hand. Results Left hand 2D:4D digit ratio in world class elite female gymnasts (0.921±0.020) did not differ significantly from 2D:4D in age-matched sedentary girls (0.924±0.018), either with or without inclusion of potentially confounding covariates such as skeletal age, height, weight, somatotype components or androgyny index. Height (161.9±6.4 cm vs 155.4±6.6 cm p<0.01), weight (53.9±7.6 kg vs 46.2 6.3 kg p<0.01), BMI (20.51±2.41 kg/m2 vs 19.05±1.56 kg/m2), skeletal age (15.2±1.1 y vs 14.5±1.2 y p>0.01), somatotype components (4.0/3.0/2.9 vs 1.7/3.7/3.2 for endomorphy (p<0.01), mesomorphy (p<0.01) and ectomorphy (p<0.05) respectively) all differed significantly between sedentary girls and elite gymnasts. As expressed by the androgyny index, gymnasts have, on average, broader shoulders relative to their hips, compared to the reference sample. Correlations between the 2D:4D ratio and chronological age, skeletal age, and the anthropometric characteristics are low and not significant. Conclusion Although other anthropometric characteristics of sexual dimorphism were significantly different between the two samples

  15. Aircraft digital control design methods

    NASA Technical Reports Server (NTRS)

    Powell, J. D.; Parsons, E.; Tashker, M. G.

    1976-01-01

    Variations in design methods for aircraft digital flight control are evaluated and compared. The methods fall into two categories; those where the design is done in the continuous domain (or s plane) and those where the design is done in the discrete domain (or z plane). Design method fidelity is evaluated by examining closed loop root movement and the frequency response of the discretely controlled continuous aircraft. It was found that all methods provided acceptable performance for sample rates greater than 10 cps except the uncompensated s plane design method which was acceptable above 20 cps. A design procedure based on optimal control methods was proposed that provided the best fidelity at very slow sample rates and required no design iterations for changing sample rates.

  16. Method for controlling powertrain pumps

    DOEpatents

    Sime, Karl Andrew; Spohn, Brian L; Demirovic, Besim; Martini, Ryan D; Miller, Jean Marie

    2013-10-22

    A method of controlling a pump supplying a fluid to a transmission includes sensing a requested power and an excess power for a powertrain. The requested power substantially meets the needs of the powertrain, while the excess power is not part of the requested power. The method includes sensing a triggering condition in response to the ability to convert the excess power into heat in the transmission, and determining that an operating temperature of the transmission is below a maximum. The method also includes determining a calibrated baseline and a dissipation command for the pump. The calibrated baseline command is configured to supply the fluid based upon the requested power, and the dissipation command is configured to supply additional fluid and consume the excess power with the pump. The method operates the pump at a combined command, which is equal to the calibrated baseline command plus the dissipation command.

  17. Novel method for controlled oxidation

    SciTech Connect

    Benjamin, B.M.; Raaen, V.F.

    1981-03-29

    A novel method for the oxidative degradation of coal or other organic material is described. The procedure is potentially useful for structure determination. As originally conceived, this method was intended for use with aqueous potassium permanganate as oxidant, but it is equally applicable with other oxidizing agents. Sodium hypochlorite can be substituted for KMnO, except that controlling the pH and monitoring the end point become more difficult. Results with potassium permanganate only are described here but sodium hypochlorite was tried. An advantageous feature of the method is the simultaneous removal of soluble products from further contact with oxidizing agent as the oxidizing agent attacks the substrate. In principle, the experimental approach resembles that of column chromatography. The compounds were characterized by nuclear magnetic resonance measurements, and gas chromatography.

  18. Control method for prosthetic devices

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J., Jr. (Inventor)

    1995-01-01

    A control system and method for prosthetic devices is provided. The control system comprises a transducer for receiving movement from a body part for generating a sensing signal associated with that movement. The sensing signal is processed by a linearizer for linearizing the sensing signal to be a linear function of the magnitude of the distance moved by the body part. The linearized sensing signal is normalized to be a function of the entire range of body part movement from the no-shrug position of the moveable body part. The normalized signal is divided into a plurality of discrete command signals. The discrete command signals are used by typical converter devices which are in operational association with the prosthetic device. The converter device uses the discrete command signals for driving the moveable portions of the prosthetic device and its sub-prosthesis. The method for controlling a prosthetic device associated with the present invention comprises the steps of receiving the movement from the body part, generating a sensing signal in association with the movement of the body part, linearizing the sensing signal to be a linear function of the magnitude of the distance moved by the body part, normalizing the linear signal to be a function of the entire range of the body part movement, dividing the normalized signal into a plurality of discrete command signals, and implementing the plurality of discrete command signals for driving the respective moveable prosthesis device and its sub-prosthesis.

  19. Novel method for controlled oxidation

    SciTech Connect

    Benjamin, B.M.; Raaen, V.F.

    1981-01-01

    The purpose of this paper is to describe a novel method for the oxidative degradation of coal or other organic material. The procedure is potentially useful for structure determination. As originally conceived, this method was intended for use with aqueous potassium permanganate as oxidant, but it is equally applicable with other oxidizing agents. Sodium hyprochlorite can be substituted for KMnO/sub 4/ except that controlling the pH and monitoring the end pilot become more difficult. Results with potassium permanganate only are described here but sodium hypochlorite was tried. An advantageous feature of the method is the simultaneous removal of soluble products from further contact with oxidizing agent as the oxidizing agent attacks the substrate. In principle, the experimental approach resembles that of column chromatography. Any oxidative degradation of a natural product for structure determination is of little use if carried out too far; for example, to the smallest, most oxidation-resistant materials such as carbon dioxide, acetic acid, and benzoic acid. Potassium permanganate oxidations of reactive species such as coal and kerogen are particularly difficult to control. Partially oxidized fragments which go into solution can be attacked more effectively than the solid starting phase, a situation which results in loss of structural information. Another difficulty is that phenolic materials can undergo coupling reactions thus generating larger molecules and giving misleading results due to a larger number of substituents. The procedure used is described.

  20. Methanol tailgas combustor control method

    DOEpatents

    Hart-Predmore, David J.; Pettit, William H.

    2002-01-01

    A method for controlling the power and temperature and fuel source of a combustor in a fuel cell apparatus to supply heat to a fuel processor where the combustor has dual fuel inlet streams including a first fuel stream, and a second fuel stream of anode effluent from the fuel cell and reformate from the fuel processor. In all operating modes, an enthalpy balance is determined by regulating the amount of the first and/or second fuel streams and the quantity of the first air flow stream to support fuel processor power requirements.

  1. Aircraft digital control design methods

    NASA Technical Reports Server (NTRS)

    Tashker, M. G.; Powell, J. D.

    1975-01-01

    Investigations were conducted in two main areas: the first area is control system design, and the goals were to define the limits of 'digitized S-Plane design techniques' vs. sample rate, to show the results of a 'direct digital design technique', and to compare the two methods; the second area was to evaluate the roughness of autopilot designs parametrically versus sample rate. Goals of the first area were addressed by (1) an analysis of a 2nd order example using both design methods, (2) a linear analysis of the complete 737 aircraft with an autoland obtained using the digitized S-plane technique, (3) linear analysis of a high frequency 737 approximation with the autoland from a direct digital design technique, and (4) development of a simulation for evaluation of the autopilots with disturbances and nonlinearities included. Roughness evaluation was studied by defining an experiment to be carried out on the Langley motion simulator and coordinated with analysis at Stanford.

  2. Method for controlling protein crystallization

    NASA Technical Reports Server (NTRS)

    Noever, David A. (Inventor)

    1993-01-01

    A method and apparatus for controlling the crystallization of protein by solvent evaporation including placing a drop of protein solution between and in contact with a pair of parallel plates and driving one of the plates toward and away from the other plate in a controlled manner to adjust the spacing between the plates is presented. The drop of solution forms a liquid cylinder having a height dependent upon the plate spacing thereby effecting the surface area available for solvent evaporation. When the spacing is close, evaporation is slow. Evaporation is increased by increasing the spacing between the plates until the breaking point of the liquid cylinder. One plate is mounted upon a fixed post while the other plate is carried by a receptacle movable relative to the post and driven by a belt driven screw drive. The temperature and humidity of the drop of protein solution are controlled by sealing the drop within the receptacle and mounting a heater and dessicant within the receptacle.

  3. QT Is Longer in Drug-Free Patients with Schizophrenia Compared with Age-Matched Healthy Subjects

    PubMed Central

    Fujii, Kumiko; Ozeki, Yuji; Okayasu, Hiroaki; Takano, Yumiko; Shinozaki, Takahiro; Hori, Hiroaki; Orui, Masami; Horie, Minoru; Kunugi, Hiroshi; Shimoda, Kazutaka

    2014-01-01

    The potassium voltage-gated channel KCNH2 is a well-known gene in which mutations induce familial QT interval prolongation. KCNH2 is suggested to be a risk gene for schizophrenia. Additionally, the disturbance of autonomic control, which affects the QT interval, is known in schizophrenia. Therefore, we speculate that schizophrenic patients have characteristic features in terms of the QT interval in addition to the effect of antipsychotic medication. The QT interval of patients with schizophrenia not receiving antipsychotics (n = 85) was compared with that of patients with schizophrenia receiving relatively large doses of antipsychotics (n = 85) and healthy volunteers (n = 85). The QT interval was corrected using four methods (Bazett, Fridericia, Framingham or Hodges method). In ANCOVA with age and heart rate as covariates, patients not receiving antipsychotic treatment had longer QT intervals than did the healthy volunteers, but antipsychotics prolonged the QT interval regardless of the correction method used (P<0.01). Schizophrenic patients with and without medication had a significantly higher mean heart rate than did the healthy volunteers, with no obvious sex-related differences in the QT interval. The QT interval prolongation may be manifestation of a certain biological feature of schizophrenia. PMID:24887423

  4. Integrated control system and method

    SciTech Connect

    Wang, Paul Sai Keat; Baldwin, Darryl; Kim, Myoungjin

    2013-10-29

    An integrated control system for use with an engine connected to a generator providing electrical power to a switchgear is disclosed. The engine receives gas produced by a gasifier. The control system includes an electronic controller associated with the gasifier, engine, generator, and switchgear. A gas flow sensor monitors a gas flow from the gasifier to the engine through an engine gas control valve and provides a gas flow signal to the electronic controller. A gas oversupply sensor monitors a gas oversupply from the gasifier and provides an oversupply signal indicative of gas not provided to the engine. A power output sensor monitors a power output of the switchgear and provide a power output signal. The electronic controller changes gas production of the gasifier and the power output rating of the switchgear based on the gas flow signal, the oversupply signal, and the power output signal.

  5. Method For Model-Reference Adaptive Control

    NASA Technical Reports Server (NTRS)

    Seraji, Homayoun

    1990-01-01

    Relatively simple method of model-reference adaptive control (MRAC) developed from two prior classes of MRAC techniques: signal-synthesis method and parameter-adaption method. Incorporated into unified theory, which yields more general adaptation scheme.

  6. Birth control - slow release methods

    MedlinePlus

    Contraception - hormonal methods; Progestin implants; Progestin injections; Skin patch; Vaginal ring ... PROGESTIN IMPLANTS A progestin implant is a small rod that is implanted under the skin, usually on the upper ...

  7. Methods for improved hemorrhage control

    PubMed Central

    2004-01-01

    Trauma is the leading cause of death from age 1 to 34 years and is the fifth leading cause of death overall in the USA, with uncontrolled hemorrhage being the leading cause of potentially preventable death. Improving our ability to control hemorrhage may represent the next major hurdle in reducing trauma mortality. New techniques, devices, and drugs for hemorrhage control are being developed and applied across the continuum of trauma care: prehospital, emergency room, and operative and postoperative critical care. This brief review focuses on drugs directed at life-threatening hemorrhage. The most important of these new drugs are injectable hemostatics, fibrin foams, and dressings. The available animal studies are encouraging and human studies are required. PMID:15196327

  8. Method for crystal growth control

    DOEpatents

    Yates, Douglas A.; Hatch, Arthur E.; Goldsmith, Jeff M.

    1981-01-01

    The growth of a crystalline body of a selected material is controlled so that the body has a selected cross-sectional shape. The apparatus is of the type which includes the structure normally employed in known capillary die devices as well as means for observing at least the portion of the surfaces of the growing crystalline body and the meniscus (of melt material from which the body is being pulled) including the solid/liquid/vapor junction in a direction substantially perpendicular to the meniscus surface formed at the junction when the growth of the crystalline body is under steady state conditions. The cross-sectional size of the growing crystalline body can be controlled by determining which points exhibit a sharp change in the amount of reflected radiation of a preselected wavelength and controlling the speed at which the body is being pulled or the temperature of the growth pool of melt so as to maintain those points exhibiting a sharp change at a preselected spatial position relative to a predetermined reference position. The improvement comprises reference object means positioned near the solid/liquid/vapor junction and capable of being observed by the means for observing so as to define said reference position so that the problems associated with convection current jitter are overcome.

  9. Toxicologic methods: controlled human exposures.

    PubMed Central

    Utell, M J; Frampton, M W

    2000-01-01

    The assessment of risk from exposure to environmental air pollutants is complex, and involves the disciplines of epidemiology, animal toxicology, and human inhalation studies. Controlled, quantitative studies of exposed humans help determine health-related effects that result from breathing the atmosphere. The major unique feature of the clinical study is the ability to select, control, and quantify pollutant exposures of subjects of known clinical status, and determine their effects under ideal experimental conditions. The choice of outcomes to be assessed in human clinical studies can be guided by both scientific and practical considerations, but the diversity of human responses and responsiveness must be considered. Subjects considered to be among the most susceptible include those with asthma, chronic obstructive lung disease, and cardiovascular disease. New experimental approaches include exposures to concentrated ambient air particles, diesel engine exhaust, combustion products from smoking machines, and experimental model particles. Future investigations of the health effects of air pollution will benefit from collaborative efforts among the disciplines of epidemiology, animal toxicology, and human clinical studies. PMID:10931779

  10. Power control system and method

    DOEpatents

    Steigerwald, Robert Louis; Anderson, Todd Alan

    2006-11-07

    A power system includes an energy harvesting device, a battery coupled to the energy harvesting device, and a circuit coupled to the energy harvesting device and the battery. The circuit is adapted to deliver power to a load by providing power generated by the energy harvesting device to the load without delivering excess power to the battery and to supplement the power generated by the energy harvesting device with power from the battery if the power generated by the energy harvesting device is insufficient to fully power the load. A method of operating the power system is also provided.

  11. Power control system and method

    DOEpatents

    Steigerwald, Robert Louis [Burnt Hills, NY; Anderson, Todd Alan [Niskayuna, NY

    2008-02-19

    A power system includes an energy harvesting device, a battery coupled to the energy harvesting device, and a circuit coupled to the energy harvesting device and the battery. The circuit is adapted to deliver power to a load by providing power generated by the energy harvesting device to the load without delivering excess power to the battery and to supplement the power generated by the energy harvesting device with power from the battery if the power generated by the energy harvesting device is insufficient to fully power the load. A method of operating the power system is also provided.

  12. Methods for control over learning individual trajectory

    NASA Astrophysics Data System (ADS)

    Mitsel, A. A.; Cherniaeva, N. V.

    2015-09-01

    The article discusses models, methods and algorithms of determining student's optimal individual educational trajectory. A new method of controlling the learning trajectory has been developed as a dynamic model of learning trajectory control, which uses score assessment to construct a sequence of studied subjects.

  13. Model reduction methods for control design

    NASA Technical Reports Server (NTRS)

    Dunipace, K. R.

    1988-01-01

    Several different model reduction methods are developed and detailed implementation information is provided for those methods. Command files to implement the model reduction methods in a proprietary control law analysis and design package are presented. A comparison and discussion of the various reduction techniques is included.

  14. Strike Point Control on EAST Using an Isoflux Control Method

    NASA Astrophysics Data System (ADS)

    Xing, Zhe; Xiao, Bingjia; Luo, Zhengping; L. Walker, M.; A. Humphreys, D.

    2015-09-01

    For the advanced tokamak, the particle deposition and thermal load on the divertor is a big challenge. By moving the strike points on divertor target plates, the position of particle deposition and thermal load can be shifted. We could adjust the Poloidal Field (PF) coil current to achieve the strike point position feedback control. Using isoflux control method, the strike point position can be controlled by controlling the X point position. On the basis of experimental data, we establish relational expressions between X point position and strike point position. Benchmark experiments are carried out to validate the correctness and robustness of the control methods. The strike point position is successfully controlled following our command in the EAST operation. supported by the National Magnetic Confinement Fusion Science Program of China (Nos. 2012GB105000 and 2014GB103000)

  15. Method for controlled hydrogen charging of metals

    DOEpatents

    Cheng, Bo-Ching; Adamson, Ronald B.

    1984-05-29

    A method for controlling hydrogen charging of hydride forming metals through a window of a superimposed layer of a non-hydriding metal overlying the portion of the hydride forming metals to be charged.

  16. Simple method for model reference adaptive control

    NASA Technical Reports Server (NTRS)

    Seraji, H.

    1989-01-01

    A simple method is presented for combined signal synthesis and parameter adaptation within the framework of model reference adaptive control theory. The results are obtained using a simple derivation based on an improved Liapunov function.

  17. Barrier methods of birth control - slideshow

    MedlinePlus

    ... gov/ency/presentations/100107.htm Barrier methods of birth control - series—Female normal anatomy To use the sharing ... A.M. Editorial team. Related MedlinePlus Health Topics Birth Control A.D.A.M., Inc. is accredited by ...

  18. Method and apparatus for controlling electroslag remelting

    DOEpatents

    Maguire, Michael C.; Zanner, Frank J.; Damkroger, Brian K.; Miszkiel, Mark E.; Aronson, Eugene A.

    1994-01-01

    Method and apparatus for controlling electrode immersion depth in an electroslag remelting furnace. The phase difference of the alternating current circuit established in the furnace is calculated in real time and employed to more accurately control immersion depth than possible with voltage-swing systems.

  19. Method of controlling fusion reaction rates

    DOEpatents

    Kulsrud, Russell M.; Furth, Harold P.; Valeo, Ernest J.; Goldhaber, Maurice

    1988-03-01

    A method of controlling the reaction rates of the fuel atoms in a fusion reactor comprises the step of polarizing the nuclei of the fuel atoms in a particular direction relative to the plasma confining magnetic field. Fusion reaction rates can be increased or decreased, and the direction of emission of the reaction products can be controlled, depending on the choice of polarization direction.

  20. Method of controlling fusion reaction rates

    DOEpatents

    Kulsrud, Russell M.; Furth, Harold P.; Valeo, Ernest J.; Goldhaber, Maurice

    1988-01-01

    A method of controlling the reaction rates of the fuel atoms in a fusion reactor comprises the step of polarizing the nuclei of the fuel atoms in a particular direction relative to the plasma confining magnetic field. Fusion reaction rates can be increased or decreased, and the direction of emission of the reaction products can be controlled, depending on the choice of polarization direction.

  1. Daylight control system device and method

    DOEpatents

    Paton, John Douglas

    2009-12-01

    A system and device for and a method of programming and controlling light fixtures is disclosed. A system in accordance with the present invention includes a stationary controller unit that is electrically coupled to the light fixtures. The stationary controller unit is configured to be remotely programmed with a portable commissioning device to automatically control the lights fixtures. The stationary controller unit and the portable commissioning device include light sensors, micro-computers and transceivers for measuring light levels, running programs, storing data and transmitting data between the stationary controller unit and the portable commissioning device. In operation, target light levels selected with the portable commissioning device and the controller unit is remotely programmed to automatically maintain the target level.

  2. Daylight control system, device and method

    DOEpatents

    Paton, John Douglas

    2012-08-28

    A system and device for and a method of programming and controlling light fixtures is disclosed. A system in accordance with the present invention includes a stationary controller unit that is electrically coupled to the light fixtures. The stationary controller unit is configured to be remotely programmed with a portable commissioning device to automatically control the lights fixtures. The stationary controller unit and the portable commissioning device include light sensors, micro-computers and transceivers for measuring light levels, running programs, storing data and transmitting data between the stationary controller unit and the portable commissioning device. In operation, target light levels selected with the portable commissioning device and the controller unit is remotely programmed to automatically maintain the target level.

  3. Daylight control system device and method

    DOEpatents

    Paton, John Douglas

    2007-03-13

    A system and device for and a method of programming and controlling light fixtures is disclosed. A system in accordance with the present invention includes a stationary controller unit that is electrically coupled to the light fixtures. The stationary controller unit is configured to be remotely programmed with a portable commissioning device to automatically control the lights fixtures. The stationary controller unit and the portable commissioning device include light sensors, micro-computers and transceivers for measuring light levels, running programs, storing data and transmitting data between the stationary controller unit and the portable commissioning device. In operation, target light levels selected with the portable commissioning device and the controller unit is remotely programmed to automatically maintain the target level.

  4. LED lamp color control system and method

    SciTech Connect

    Gaines, James; Clauberg, Bernd; Van Erp, Josephus A.M.

    2013-02-05

    An LED lamp color control system and method including an LED lamp having an LED controller 58; and a plurality of LED channels 60 operably connected to the LED controller 58, each of the plurality of LED channels 60 having a channel switch 62 in series with at least one shunted LED circuit 83, the shunted LED circuit 83 having a shunt switch 68 in parallel with an LED source 80. The LED controller 58 determines whether the LED source 80 is in a feedback controllable range, stores measured optical flux for the LED source 80 when the LED source 80 is in the feedback controllable range, and bypasses storing the measured optical flux when the LED source 80 is not in the feedback controllable range.

  5. OVERVIEW ON ALTERNATIVE ASBESTOS CONTROL METHOD RESEARCH

    EPA Science Inventory

    The alternative asbestos control method (AACM) is an experimental approach to building demolition. Unlike the NESHAP method, the AACM allows some regulated asbestos-containing material to remain in the building and a surfactant-water solution is used to suppress asbestos fibers ...

  6. Controlling flexible structures: A survey of methods

    NASA Technical Reports Server (NTRS)

    Benson, Russell A.; Coleman, Edward E.

    1989-01-01

    Most of the presently available control system design techniques applicable to flexible structure problems were developed to design controllers for rigid body systems. Although many of these design methods can be applied to flexible dynamics problems, recently developed techniques may be more suitable for flexible structure controller design. The purpose of this presentation is to examine briefly the peculiarities of the dynamics of flexible structures and to stimulate discussion about top level controller design approaches when designing controllers for flexible structures. Presented here is a suggestion of a set of categories of design methods for designing controllers for flexible structures as well as a discussion of the advantages and disadvantages of each category. No attempt has been made herein to select one category of design techniques as the best for flexible structure controller design. Instead, it is hoped that the structure suggested by these categories will facilitate further discussion on the merits of particular methods that will eventually point to those design techniques suitable for further development.

  7. Control method for physical systems and devices

    DOEpatents

    Guckenheimer, John

    1997-01-01

    A control method for stabilizing systems or devices that are outside the control domain of a linear controller is provided. When applied to nonlinear systems, the effectiveness of this method depends upon the size of the domain of stability that is produced for the stabilized equilibrium. If this domain is small compared to the accuracy of measurements or the size of disturbances within the system, then the linear controller is likely to fail within a short period. Failure of the system or device can be catastrophic: the system or device can wander far from the desired equilibrium. The method of the invention presents a general procedure to recapture the stability of a linear controller, when the trajectory of a system or device leaves its region of stability. By using a hybrid strategy based upon discrete switching events within the state space of the system or device, the system or device will return from a much larger domain to the region of stability utilized by the linear controller. The control procedure is robust and remains effective under large classes of perturbations of a given underlying system or device.

  8. Temperature Effects and Compensation-Control Methods

    PubMed Central

    Xia, Dunzhu; Chen, Shuling; Wang, Shourong; Li, Hongsheng

    2009-01-01

    In the analysis of the effects of temperature on the performance of microgyroscopes, it is found that the resonant frequency of the microgyroscope decreases linearly as the temperature increases, and the quality factor changes drastically at low temperatures. Moreover, the zero bias changes greatly with temperature variations. To reduce the temperature effects on the microgyroscope, temperature compensation-control methods are proposed. In the first place, a BP (Back Propagation) neural network and polynomial fitting are utilized for building the temperature model of the microgyroscope. Considering the simplicity and real-time requirements, piecewise polynomial fitting is applied in the temperature compensation system. Then, an integral-separated PID (Proportion Integration Differentiation) control algorithm is adopted in the temperature control system, which can stabilize the temperature inside the microgyrocope in pursuing its optimal performance. Experimental results reveal that the combination of microgyroscope temperature compensation and control methods is both realizable and effective in a miniaturized microgyroscope prototype. PMID:22408509

  9. A Survey of Quantum Lyapunov Control Methods

    PubMed Central

    2013-01-01

    The condition of a quantum Lyapunov-based control which can be well used in a closed quantum system is that the method can make the system convergent but not just stable. In the convergence study of the quantum Lyapunov control, two situations are classified: nondegenerate cases and degenerate cases. For these two situations, respectively, in this paper the target state is divided into four categories: the eigenstate, the mixed state which commutes with the internal Hamiltonian, the superposition state, and the mixed state which does not commute with the internal Hamiltonian. For these four categories, the quantum Lyapunov control methods for the closed quantum systems are summarized and analyzed. Particularly, the convergence of the control system to the different target states is reviewed, and how to make the convergence conditions be satisfied is summarized and analyzed. PMID:23766732

  10. Control system health test system and method

    DOEpatents

    Hoff, Brian D.; Johnson, Kris W.; Akasam, Sivaprasad; Baker, Thomas M.

    2006-08-15

    A method is provided for testing multiple elements of a work machine, including a control system, a component, a sub-component that is influenced by operations of the component, and a sensor that monitors a characteristic of the sub-component. In one embodiment, the method is performed by the control system and includes sending a command to the component to adjust a first parameter associated with an operation of the component. Also, the method includes detecting a sensor signal from the sensor reflecting a second parameter associated with a characteristic of the sub-component and determining whether the second parameter is acceptable based on the command. The control system may diagnose at least one of the elements of the work machine when the second parameter of the sub-component is not acceptable.

  11. Method of Controlling Lasing Wavelength(s)

    NASA Technical Reports Server (NTRS)

    Barnes, Norman P. (Inventor); Murray, Keith E. (Inventor); Hutcheson, Ralph L. (Inventor)

    2000-01-01

    A method is provided to control the lasing wavelength of a laser material without changing or adjusting the mechanical components of a laser device, The rate at which the laser material is pumped with the pumping energy is controlled so that lasing occurs at one or more lasing wavelengths based on the rate. The lasing wavelengths are determined by transition lifetimes and/or energy transfer rates.

  12. Novel Methods for Mosquito Control using RNAi.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The discovery and development of novel insecticides for vector control is a primary focus of toxicology research conducted at the Mosquito and Fly Research Unit, Gainesville, FL. Targeting critical genes/proteins in mosquitoes using RNA interference (RNAi) is being investigated as a method to devel...

  13. Alternative Asbestos Control Method (AACM), Washington

    EPA Science Inventory

    This presentation describes the status to date of the Alternative Asbestos Control Method research, which is intended as a possible alternative technology for use in the demolition of buildings that contain asbestos and are covered under the regulatory requirements of the Asbesto...

  14. Adaptive Accommodation Control Method for Complex Assembly

    NASA Astrophysics Data System (ADS)

    Kang, Sungchul; Kim, Munsang; Park, Shinsuk

    Robotic systems have been used to automate assembly tasks in manufacturing and in teleoperation. Conventional robotic systems, however, have been ineffective in controlling contact force in multiple contact states of complex assemblythat involves interactions between complex-shaped parts. Unlike robots, humans excel at complex assembly tasks by utilizing their intrinsic impedance, forces and torque sensation, and tactile contact clues. By examining the human behavior in assembling complex parts, this study proposes a novel geometry-independent control method for robotic assembly using adaptive accommodation (or damping) algorithm. Two important conditions for complex assembly, target approachability and bounded contact force, can be met by the proposed control scheme. It generates target approachable motion that leads the object to move closer to a desired target position, while contact force is kept under a predetermined value. Experimental results from complex assembly tests have confirmed the feasibility and applicability of the proposed method.

  15. Survey on large scale system control methods

    NASA Technical Reports Server (NTRS)

    Mercadal, Mathieu

    1987-01-01

    The problem inherent to large scale systems such as power network, communication network and economic or ecological systems were studied. The increase in size and flexibility of future spacecraft has put those dynamical systems into the category of large scale systems, and tools specific to the class of large systems are being sought to design control systems that can guarantee more stability and better performance. Among several survey papers, reference was found to a thorough investigation on decentralized control methods. Especially helpful was the classification made of the different existing approaches to deal with large scale systems. A very similar classification is used, even though the papers surveyed are somehow different from the ones reviewed in other papers. Special attention is brought to the applicability of the existing methods to controlling large mechanical systems like large space structures. Some recent developments are added to this survey.

  16. Actively controlled vibration welding system and method

    SciTech Connect

    Cai, Wayne W.; Kang, Bongsu; Tan, Chin-An

    2013-04-02

    A vibration welding system includes a controller, welding horn, an active material element, and anvil assembly. The assembly may include an anvil body connected to a back plate and support member. The element, e.g., a piezoelectric stack or shape memory alloy, is positioned with respect to the assembly. The horn vibrates in a desirable first direction to form a weld on a work piece. The element controls any vibrations in a second direction by applying calibrated response to the anvil body in the second direction. A method for controlling undesirable vibrations in the system includes positioning the element with respect to the anvil assembly, connecting the anvil body to the support member through the back plate, vibrating the horn in a desirable first direction, and transmitting an input signal to the element to control vibration in an undesirable second direction.

  17. Birth control method should suit your lifestyle.

    PubMed

    1986-01-01

    In choosing a method of birth control, effectiveness and safety are the key considerations. Yet, one's decisions about contraception also must be balanced against important considerations regarding children and family. Many other factors play a role in the choice. Women who live in rural areas where medical services are not easily available may not want to use oral contraceptives (OCs) or IUDs because both carry the risk of serious complications. Costs of the contraceptive method and of related medical examinations are a consideration for women in some financial circumstances. A partner's attitude also is crucial to selecting a birth control method. Methods such as condoms, withdrawal, spermicides, and diaphragm require his cooperation if they are to be effective. Health problems which might be worsened by a particular type of contraception require the advice of a physician. The physician should take a woman's health history and sexual pattern into account when prescribing a birth control technique. The contraceptive decision should be based on whether a woman plans to have children eventually. A woman who has several partners may find condoms, foams, and diaphragms inconvenient, even though they help prevention infection, but she should not use in IUD, which is convenient but carries a high risk of infection for women who have more than 1 sexual partner. OCs might be the best choice under these circumstances. A chart identifies the relative advantages and disadvantages of contraceptive methods. PMID:12314112

  18. Processing Words Varying in Personal Familiarity (Based on Reading and Spelling) by Poor Readers and Age-Matched and Reading-Matched Controls

    ERIC Educational Resources Information Center

    Corcos, Evelyne; Willows, Dale M.

    2009-01-01

    To evaluate whether performance differences between good and poor readers relate to reading-specific cognitive factors that result from engaging in reading activities and other experiential factors, the authors gave students in Grades 4 and 6 a perceptual identification test of words not only drawn from their personal lexicon but also varying in…

  19. System and method for controlling remote devices

    DOEpatents

    Carrender, Curtis Lee; Gilbert, Ronald W.; Scott, Jeff W.; Clark, David A.

    2006-02-07

    A system and method for controlling remote devices utilizing a radio frequency identification (RFID) tag device having a control circuit adapted to render the tag device, and associated objects, permanently inoperable in response to radio-frequency control signals. The control circuit is configured to receive the control signals that can include an enable signal, and in response thereto enable an associated object, such as a weapon; and in response to a disable signal, to disable the tag itself, or, if desired, to disable the associated weapon or both the device and the weapon. Permanent disabling of the tag can be accomplished by several methods, including, but not limited to, fusing a fusable link, breaking an electrically conductive path, permanently altering the modulation or backscattering characteristics of the antenna circuit, and permanently erasing an associated memory. In this manner, tags in the possession of unauthorized employees can be remotely disabled, and weapons lost on a battlefield can be easily tracked and enabled or disabled automatically or at will.

  20. Investigation of the Multiple Method Adaptive Control (MMAC) method for flight control systems

    NASA Technical Reports Server (NTRS)

    Athans, M.; Baram, Y.; Castanon, D.; Dunn, K. P.; Green, C. S.; Lee, W. H.; Sandell, N. R., Jr.; Willsky, A. S.

    1979-01-01

    The stochastic adaptive control of the NASA F-8C digital-fly-by-wire aircraft using the multiple model adaptive control (MMAC) method is presented. The selection of the performance criteria for the lateral and the longitudinal dynamics, the design of the Kalman filters for different operating conditions, the identification algorithm associated with the MMAC method, the control system design, and simulation results obtained using the real time simulator of the F-8 aircraft at the NASA Langley Research Center are discussed.

  1. Method for controlling a vehicle attitude

    SciTech Connect

    Ise, K.; Minegishi, H.; Harada, H.

    1989-02-14

    This patent describes a method for controlling a suspension characteristic of a vehicle comprising the steps of: detecting a slippage of the one drive wheel of the vehicle; determining whether or not the detected slippage is greater than a reference value; controlling a drive force of the drive wheel by means of the braking system when the slippage is determined to be greater than the reference value; and altering an original state suspension characteristic of at least the drive wheel to a harder state when the slippage is determined to be greater than the reference value.

  2. Synthesis Methods for Robust Passification and Control

    NASA Technical Reports Server (NTRS)

    Kelkar, Atul G.; Joshi, Suresh M. (Technical Monitor)

    2000-01-01

    The research effort under this cooperative agreement has been essentially the continuation of the work from previous grants. The ongoing work has primarily focused on developing passivity-based control techniques for Linear Time-Invariant (LTI) systems. During this period, there has been a significant progress made in the area of passivity-based control of LTI systems and some preliminary results have also been obtained for nonlinear systems, as well. The prior work has addressed optimal control design for inherently passive as well as non- passive linear systems. For exploiting the robustness characteristics of passivity-based controllers the passification methodology was developed for LTI systems that are not inherently passive. Various methods of passification were first proposed in and further developed. The robustness of passification was addressed for multi-input multi-output (MIMO) systems for certain classes of uncertainties using frequency-domain methods. For MIMO systems, a state-space approach using Linear Matrix Inequality (LMI)-based formulation was presented, for passification of non-passive LTI systems. An LMI-based robust passification technique was presented for systems with redundant actuators and sensors. The redundancy in actuators and sensors was used effectively for robust passification using the LMI formulation. The passification was designed to be robust to an interval-type uncertainties in system parameters. The passification techniques were used to design a robust controller for Benchmark Active Control Technology wing under parametric uncertainties. The results on passive nonlinear systems, however, are very limited to date. Our recent work in this area was presented, wherein some stability results were obtained for passive nonlinear systems that are affine in control.

  3. Method and apparatus for large motor control

    DOEpatents

    Rose, Chris R.; Nelson, Ronald O.

    2003-08-12

    Apparatus and method for providing digital signal processing method for controlling the speed and phase of a motor involves inputting a reference signal having a frequency and relative phase indicative of a time based signal; modifying the reference signal to introduce a slew-rate limited portion of each cycle of the reference signal; inputting a feedback signal having a frequency and relative phase indicative of the operation of said motor; modifying the feedback signal to introduce a slew-rate limited portion of each cycle of the feedback signal; analyzing the modified reference signal and the modified feedback signal to determine the frequency of the modified reference signal and of the modified feedback signal and said relative phase between said modified reference signal and said modified feedback signal; and outputting control signals to the motor for adjusting said speed and phase of the motor based on the frequency determination and determination of the relative phase.

  4. Method and apparatus for controlling fluid flow

    DOEpatents

    Miller, J.R.

    1980-06-27

    A method and apparatus for precisely controlling the rate (and hence amount) of fluid flow are given. The controlled flow rate is finely adjustable, can be extremely small (on the order of microliter-atmospheres per second), can be adjusted to zero (flow stopped), and is stable to better than 1% with time. The dead volume of the valve can be made arbitrarily small, in fact essentially zero. The valve employs no wearing mechanical parts (including springs, stems, or seals). The valve is finely adjustable, has a flow rate dynamic range of many decades, can be made compatible with any fluid, and is suitable for incorporation into an open or closed loop servo-control system.

  5. New method of control of tooth whitening

    NASA Astrophysics Data System (ADS)

    Angelov, I.; Mantareva, V.; Gisbrecht, A.; Valkanov, S.; Uzunov, Tz.

    2010-10-01

    New methods of control of tooth bleaching stages through simultaneous measurements of a reflected light and a fluorescence signal are proposed. It is shown that the bleaching process leads to significant changes in the intensity of a scattered signal and also in the shape and intensity of the fluorescence spectra. Experimental data illustrate that the bleaching process causes essential changes in the teeth discoloration in short time as 8-10 min from the beginning of the application procedure. The continuation of the treatment is not necessary moreover the probability of the enamel destroy increases considerably. The proposed optical back control of tooth surface is a base for development of a practical set up to control the duration of the bleaching procedure.

  6. Pressurized fluid torque driver control and method

    NASA Technical Reports Server (NTRS)

    Cook, Joseph S., Jr. (Inventor)

    1994-01-01

    Methods and apparatus are provided for a torque driver including a displaceable gear to limit torque transfer to a fastener at a precisely controlled torque limit. A biasing assembly biases a first gear into engagement with a second gear for torque transfer between the first and second gear. The biasing assembly includes a pressurized cylinder controlled at a constant pressure that corresponds to a torque limit. A calibrated gage and valve is used to set the desired torque limit. One or more coiled output linkages connect the first gear with the fastener adaptor which may be a socket for a nut. A gear tooth profile provides a separation force that overcomes the bias to limit torque at the desired torque limit. Multiple fasteners may be rotated simultaneously to a desired torque limit if additional output spur gears are provided. The torque limit is adjustable and may be different for fasteners within the same fastener configuration.

  7. Method for controlling gas metal arc welding

    DOEpatents

    Smartt, Herschel B.; Einerson, Carolyn J.; Watkins, Arthur D.

    1989-01-01

    The heat input and mass input in a Gas Metal Arc welding process are controlled by a method that comprises calculating appropriate values for weld speed, filler wire feed rate and an expected value for the welding current by algorithmic function means, applying such values for weld speed and filler wire feed rate to the welding process, measuring the welding current, comparing the measured current to the calculated current, using said comparison to calculate corrections for the weld speed and filler wire feed rate, and applying corrections.

  8. Method for controlling gas metal arc welding

    DOEpatents

    Smartt, H.B.; Einerson, C.J.; Watkins, A.D.

    1987-08-10

    The heat input and mass input in a Gas Metal Arc welding process are controlled by a method that comprises calculating appropriate values for weld speed, filler wire feed rate and an expected value for the welding current by algorithmic function means, applying such values for weld speed and filler wire feed rate to the welding process, measuring the welding current, comparing the measured current to the calculated current, using said comparison to calculate corrections for the weld speed and filler wire feed rate, and applying corrections. 3 figs., 1 tab.

  9. Duodeno-Gastric-Esophageal Reflux—What is Pathologic? Comparison of Patients with Barrett’s Esophagus and Age-Matched Volunteers

    PubMed Central

    Wolfgarten, Eva; Pütz, Benito; Hölscher, Arnulf H.

    2007-01-01

    Introduction The aim of the study was to analyse pH- and bile-monitoring data in patients with Barrett’s esophagus and in age- and gender-matched controls. Subjects and Methods Twenty-four consecutive Barrett’s patients (8 females, 16 males, mean age 57 years), 21 patients with esophagitis (10 females, 11 males, mean age 58 years), and 19 healthy controls (8 females, 11 males, mean age 51 years), were included. Only patients underwent endoscopy with biopsy. All groups were investigated with manometry, gastric and esophageal 24-h pH, and simultaneous bile monitoring according to a standardized protocol. A bilirubin absorption >0.25 was determined as noxious bile reflux. The receiver operator characteristic (ROC) method was applied to determine the optimal cutoff value of pathologic bilirubin levels. Results Of Barrett’s patients, 79% had pathologic acidic gastric reflux (pH<4 >5% of total measuring time). However, 32% of healthy controls also had acid reflux (p < 0.05) without any symptoms. The median of esophageal bile reflux was 7.8% (lower quartile (LQ)–upper quartile (UQ) = 1.6–17.8%) in Barrett’s patients, in patients with esophagitis, 3.5% (LQ–UQ = 0.1–13.5), and in contrast to 0% (LQ–UQ = 0–1.0%) in controls, p = 0.001. ROC analysis showed the optimal dividing value for patients at more than 1% bile reflux over 24 h (75% sensitivity, 84% specificity). Conclusion An optimal threshold to differentiate between normal and pathological bile reflux into the esophagus is 1% (24-h bile monitoring with an absorbance >0.25). PMID:17436133

  10. Method of controlling a reclamation furnace

    SciTech Connect

    Mainord, K. R.

    1985-12-10

    This invention relates to an improved method of controlling temperatures within a cleaning or reclamation furnace which is normally used to reclaim metal parts contaminated with combustible materials by pyrolyzing the combustible materials. A reclamation furnace usually includes a primary heat-input burner employed to heat the contaminated parts in the primary heating chamber, an afterburner chamber contained within the heating chamber having a secondary burner to burn volatile gases which are given off by the combustible materials as the parts are heated, and two separately-controlled automatic valve and spray nozzle assemblies connected to the primary heating chamber. Each nozzle assembly is connected to a pressurized water source to deliver a water-spray injection into the heating chamber. First and second temperature sensors are located in the discharge stack leading from the afterburner chamber and in the furnace heating chamber respectively to actuate either one or both of the separately-controlled automatic valve and spray nozzle assemblies responsive to the temperature of the burned stack gases and the furnace interior temperature.

  11. Method for enhanced control of welding processes

    SciTech Connect

    Sheaffer, D.A.; Renzi, R.F.; Tung, D.M.; Schroder, K.

    2000-07-04

    Method and system for producing high quality welds in welding processes, in general, and gas tungsten arc (GTA) welding, in particular by controlling weld penetration are disclosed. Light emitted from a weld pool is collected from the backside of a workpiece by optical means during welding and transmitted to a digital video camera for further processing, after the emitted light is first passed through a short wavelength pass filter to remove infrared radiation. By filtering out the infrared component of the light emitted from the backside weld pool image, the present invention provides for the accurate determination of the weld pool boundary. Data from the digital camera is fed to an imaging board which focuses on a 100 x 100 pixel portion of the image. The board performs a thresholding operation and provides this information to a digital signal processor to compute the backside weld pool dimensions and area. This information is used by a control system, in a dynamic feedback mode, to automatically adjust appropriate parameters of a welding system, such as the welding current, to control weld penetration and thus, create a uniform weld bead and high quality weld.

  12. Method for enhanced control of welding processes

    DOEpatents

    Sheaffer, Donald A.; Renzi, Ronald F.; Tung, David M.; Schroder, Kevin

    2000-01-01

    Method and system for producing high quality welds in welding processes, in general, and gas tungsten arc (GTA) welding, in particular by controlling weld penetration. Light emitted from a weld pool is collected from the backside of a workpiece by optical means during welding and transmitted to a digital video camera for further processing, after the emitted light is first passed through a short wavelength pass filter to remove infrared radiation. By filtering out the infrared component of the light emitted from the backside weld pool image, the present invention provides for the accurate determination of the weld pool boundary. Data from the digital camera is fed to an imaging board which focuses on a 100.times.100 pixel portion of the image. The board performs a thresholding operation and provides this information to a digital signal processor to compute the backside weld pool dimensions and area. This information is used by a control system, in a dynamic feedback mode, to automatically adjust appropriate parameters of a welding system, such as the welding current, to control weld penetration and thus, create a uniform weld bead and high quality weld.

  13. Control system and method for prosthetic devices

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J., Jr. (Inventor)

    1992-01-01

    A control system and method for prosthetic devices is provided. The control system comprises a transducer for receiving movement from a body part for generating a sensing signal associated with that movement. The sensing signal is processed by a linearizer for linearizing the sensing signal to be a linear function of the magnitude of the distance moved by the body part. The linearized sensing signal is normalized to be a function of the entire range of body part movement from the no-shrug position of the movable body part through the full-shrug position of the movable body part. The normalized signal is divided into a plurality of discrete command signals. The discrete command signals are used by typical converter devices which are in operational association with the prosthetic device. The converter device uses the discrete command signals for driving the movable portions of the prosthetic device and its sub-prosthesis. The method for controlling a prosthetic device associated with the present invention comprises the steps of receiving the movement from the body part, generating a sensing signal in association with the movement of the body part, linearizing the sensing signal to be a linear function of the magnitude of the distance moved by the body part, normalizing the linear signal to be a function of the entire range of the body part movement, dividing the normalized signal into a plurality of discrete command signals, and implementing the plurality of discrete command signals for driving the respective movable prosthesis device and its sub-prosthesis.

  14. Control method for video guidance sensor system

    NASA Technical Reports Server (NTRS)

    Howard, Richard T. (Inventor); Book, Michael L. (Inventor); Bryan, Thomas C. (Inventor)

    2005-01-01

    A method is provided for controlling operations in a video guidance sensor system wherein images of laser output signals transmitted by the system and returned from a target are captured and processed by the system to produce data used in tracking of the target. Six modes of operation are provided as follows: (i) a reset mode; (ii) a diagnostic mode; (iii) a standby mode; (iv) an acquisition mode; (v) a tracking mode; and (vi) a spot mode wherein captured images of returned laser signals are processed to produce data for all spots found in the image. The method provides for automatic transition to the standby mode from the reset mode after integrity checks are performed and from the diagnostic mode to the reset mode after diagnostic operations are carried out. Further, acceptance of reset and diagnostic commands is permitted only when the system is in the standby mode. The method also provides for automatic transition from the acquisition mode to the tracking mode when an acceptable target is found.

  15. Experimental implementation of the modified independent modal space control method

    NASA Technical Reports Server (NTRS)

    Baz, A.; Poh, S.

    1990-01-01

    An experimental realization of a modified independent modal space control (MIMSC) method to control the vibration of a flexible cantilevered beam is presented. In its operation the method relies on the use of one piezoelectric actuator to control several vibration modes through a time-sharing strategy. The effectiveness of the MIMSC method in damping out the beam vibration is demonstrated by comparing the results with those obtained by other modal control methods. Two methods are considered, the independent modal space control method and the pseudo-inverse method. The feasibility of the MIMSC method as a viable alternative for controlling large flexible structures with a very small number of actuators is emphasized.

  16. Method and apparatus for controlling multiple motors

    DOEpatents

    Jones, Rollin G.; Kortegaard, Bert L.; Jones, David F.

    1987-01-01

    A method and apparatus are provided for simultaneously controlling a plurality of stepper motors. Addressing circuitry generates address data for each motor in a periodic address sequence. Memory circuits respond to the address data for each motor by accessing a corresponding memory location containing a first operational data set functionally related to a direction for moving the motor, speed data, and rate of speed change. First logic circuits respond to the first data set to generate a motor step command. Second logic circuits respond to the command from the first logic circuits to generate a third data set for replacing the first data set in memory with a current operational motor status, which becomes the first data set when the motor is next addressed.

  17. Control method for a reclamation furnace

    SciTech Connect

    Kelly, S.B.

    1981-06-02

    A method is presented for preventing fires and explosions and thus controlling excess temperature within a burn-off or reclamation furnace including a water injection nozzle within the furnace, an automatic valve assembly connected to a source of water under pressure to turn the water on and off, an input burner to heat contaminate materials, an afterburner to burn volatile gases given off by the contaminate materials as they are heated, a temperature sensor located in the discharge from the afterburner to actuate the automatic valve assembly open and closed responsive to the temperature of the discharge. The temperature of the discharge depends on the rate of emission of volatile gases from the contaminate material so that if a high emission rate causes a predetermined temperature to be exceeded the valve assembly opens and the water injection nozzle sprays water on the contaminate materials to cool them and decrease the emission rate until the valve assembly closes.

  18. Modal methods in optimal control synthesis

    NASA Technical Reports Server (NTRS)

    Bryson, A. E., Jr.; Hall, W. E., Jr.

    1980-01-01

    Efficient algorithms for solving linear smoother-follower problems with quadratic criteria are presented. For time-invariant systems, the algorithm consists of one backward integration of a linear vector equation and one forward integration of another linear vector equation. Furthermore, the backward and forward Riccati matrices can be expressed in terms of the eigenvalues and eigenvectors of the Euler-Lagrange equations. Hence, the gains of the forward and backward Kalman-Bucy filters and of the optimal state-feedback regulator can be determined without integration of matrix Riccati equations. A computer program has been developed, based on this method of determining the gains, to synthesize the optimal time-invariant compensator in the presence of random disturbance inputs and random measurement errors. The program also computes the rms state and control variables of the optimal closed-loop system.

  19. A Course in... Multivariable Control Methods.

    ERIC Educational Resources Information Center

    Deshpande, Pradeep B.

    1988-01-01

    Describes an engineering course for graduate study in process control. Lists four major topics: interaction analysis, multiloop controller design, decoupling, and multivariable control strategies. Suggests a course outline and gives information about each topic. (MVL)

  20. Speech recognition control system and method

    SciTech Connect

    Lemelson, J.H.

    1986-08-12

    This invention relates to a system and method for weighing articles and quantities of material wherein computing functions are performed to effect calculations and the control of a visual presentation means such as a display or printer or the generation of signals for use in recording a transaction. In particular, the invention relates to such a weighing and computing apparatus and method which operates or varies in response to speech signals generated by selected words of speech spoken into a microphone by an operator of the apparatus. It is known in the art to electronically detect the weight of articles and containers of material and to generate electrical signals which are indicative of such weight. It is also known to effect a computation with respect to such signals and additional signals generated by manually operating selected keys of a keyboard wherein the additional signals represent one or more additional variables which must be divided into or multiplied by the numerical representation of the weights of articles weighed by such apparatus.

  1. Synchronous Control Method and Realization of Automated Pharmacy Elevator

    NASA Astrophysics Data System (ADS)

    Liu, Xiang-Quan

    Firstly, the control method of elevator's synchronous motion is provided, the synchronous control structure of double servo motor based on PMAC is accomplished. Secondly, synchronous control program of elevator is implemented by using PMAC linear interpolation motion model and position error compensation method. Finally, the PID parameters of servo motor were adjusted. The experiment proves the control method has high stability and reliability.

  2. Furnace combustion zone temperature control method

    SciTech Connect

    McIntyre, G.C.; Lacombe, R.J.; Forbess, R.G.

    1991-05-28

    This patent describes a method for controlling temperature in a combustion zone in a furnace, independent of flue gas oxygen content. It comprises: supplying combustion air to the furnace for combustion of a fuel therein; providing a plurality of low volume gas flow entry ports to the combustion zone in the furnace with carrier gas continuously flowing through the ports into the combustion zone; selecting a set point value for the combustion zone temperature which, upon the temperature exceeding the set point value, commences generation of a fine water mist external the combustion zone by mist generating means within the carrier gas, the mist flowing into the combustion zone with the carrier gas and reducing temperature within the combustion zone by vaporization therein; and adding a proportionately greater amount of water mist to the carrier gas as the temperature of the combustion zone deviates above the set point value, the amount of water mist added limited by the capacity of the mist generating means, and ceasing the water mist generation upon the combustion zone temperature falling to or below the set point value.

  3. Method for controlling an internal combustion engine

    SciTech Connect

    Krebs, S.; Achleitner, E.

    1993-07-13

    In a method for controlling an internal combustion engine having cylinders operating in cycles and an intake tube for intake air, which includes determining a fuel mass to be injected into each cylinder for each cycle as a function of operating parameters of the internal combustion engine by reading a basic fuel value out of a basic family of characteristics and correcting the basic fuel value as a function of a temperature of the intake air, and multiplying the basic fuel value by a correction factor FK = A/B, wherein the denominator B is a temperature value, the improvement is described which comprises: selecting the variables of the basic family of characteristics as a pressure in the intake tube and an rpm, and reading a correction temperature contained in the temperature value out of a family of temperature characteristics in dependence on a variable dependent on an air flow and of a heating temperature being determinative for heating up the intake air in the intake tube.

  4. Internal combustion engine and method for control

    SciTech Connect

    Brennan, Daniel G

    2013-05-21

    In one exemplary embodiment of the invention an internal combustion engine includes a piston disposed in a cylinder, a valve configured to control flow of air into the cylinder and an actuator coupled to the valve to control a position of the valve. The internal combustion engine also includes a controller coupled to the actuator, wherein the controller is configured to close the valve when an uncontrolled condition for the internal engine is determined.

  5. A STUDY OF METHODS OF CONTROLLING IMPULSES.

    ERIC Educational Resources Information Center

    WHITESIDE, RAY

    THE PERSON LESS ABLE TO CONTROL HIS IMPULSES IS ALSO APT TO EXHIBIT SOCIALLY DISVALUED BEHAVIOR. VOCATIONAL AND ACADEMIC FAILURE IS A PARTIAL CONSEQUENCE OF IMPULSIVENESS AND LACK OF SELF-CONTROL. TO INVESTIGATE IMPULSE CONTROL, TWO INSTRUMENTS BELIEVED TO MEASURE ATTRIBUTES OF OPPOSITE POLES OF THIS CONCEPT (SEQUENTIAL TESTS OF EDUCATIONAL…

  6. Feedwater temperature control methods and systems

    SciTech Connect

    Moen, Stephan Craig; Noonan, Jack Patrick; Saha, Pradip

    2014-04-22

    A system for controlling the power level of a natural circulation boiling water nuclear reactor (NCBWR) is disclosed. The system, in accordance with an example embodiment of the present invention, may include a controller configured to control a power output level of the NCBWR by controlling a heating subsystem to adjust a temperature of feedwater flowing into an annulus of the NCBWR. The heating subsystem may include a steam diversion line configured to receive steam generated by a core of the NCBWR and a steam bypass valve configured to receive commands from the controller to control a flow of the steam in the steam diversion line, wherein the steam received by the steam diversion line has not passed through a turbine. Additional embodiments of the invention may include a feedwater bypass valve for controlling an amount of flow of the feedwater through a heater bypass line to the annulus.

  7. Assessment of heliostat control system methods

    SciTech Connect

    Pearson, J; Chen, B

    1986-01-01

    Automatic control and communication between the major components in solar thermal central receiver systems is critically needed for the optimal and safe operation of these systems. This report assesses novel and cost-effective approaches to the control of the solar collector field and the communication with the central plant computer/control system. The authors state that radio frequency and carrier-current communication approaches have the greatest potential to improve cost-effectiveness relative to the current dedicated control wiring approaches. In addition, based on their analysis, the authors recommend distributed control, which is becoming an industry-wide control standard, for the individual concentrators within the collector field rather than the current central computer approach. The vastly improved cost and performance ofmicroprocessors and other solid-state electronics, which has continually and rapidly proceeded for more than five years, is the major reason for these conclusions.

  8. Computational methods to obtain time optimal jet engine control

    NASA Technical Reports Server (NTRS)

    Basso, R. J.; Leake, R. J.

    1976-01-01

    Dynamic Programming and the Fletcher-Reeves Conjugate Gradient Method are two existing methods which can be applied to solve a general class of unconstrained fixed time, free right end optimal control problems. New techniques are developed to adapt these methods to solve a time optimal control problem with state variable and control constraints. Specifically, they are applied to compute a time optimal control for a jet engine control problem.

  9. System and method for controlling microgrid

    DOEpatents

    Bose, Sumit; Achilles, Alfredo Sebastian; Liu, Yan; Ahmed, Emad Ezzat; Garces, Luis Jose

    2011-07-19

    A system for controlling a microgrid includes microgrid assets and a tieline for coupling the microgrid to a bulk grid; and a tieline controller coupled to the tieline. At least one of the microgrid assets comprises a different type of asset than another one of the microgrid assets. The tieline controller is configured for providing tieline control signals to adjust active and reactive power in respective microgrid assets in response to commands from the bulk grid operating entity, microgrid system conditions, bulk grid conditions, or combinations thereof.

  10. Methods and apparatus for controlling rotary machines

    DOEpatents

    Bagepalli, Bharat Sampathkumaran; Jansen, Patrick Lee; Barnes, Gary R.; Fric, Thomas Frank; Lyons, James Patrick Francis; Pierce, Kirk Gee; Holley, William Edwin; Barbu, Corneliu

    2009-09-01

    A control system for a rotary machine is provided. The rotary machine has at least one rotating member and at least one substantially stationary member positioned such that a clearance gap is defined between a portion of the rotating member and a portion of the substantially stationary member. The control system includes at least one clearance gap dimension measurement apparatus and at least one clearance gap adjustment assembly. The adjustment assembly is coupled in electronic data communication with the measurement apparatus. The control system is configured to process a clearance gap dimension signal and modulate the clearance gap dimension.

  11. BOILING SLURRY REACTOR AND METHOD FO CONTROL

    DOEpatents

    Petrick, M.; Marchaterre, J.F.

    1963-05-01

    The control of a boiling slurry nuclear reactor is described. The reactor consists of a vertical tube having an enlarged portion, a steam drum at the top of the vertical tube, and at least one downcomer connecting the steam drum and the bottom of the vertical tube, the reactor being filled with a slurry of fissionabie material in water of such concentration that the enlarged portion of the vertical tube contains a critical mass. The slurry boils in the vertical tube and circulates upwardly therein and downwardly in the downcomer. To control the reactor by controlling the circulation of the slurry, a gas is introduced into the downcomer. (AEC)

  12. Investigating Item Exposure Control Methods in Computerized Adaptive Testing

    ERIC Educational Resources Information Center

    Ozturk, Nagihan Boztunc; Dogan, Nuri

    2015-01-01

    This study aims to investigate the effects of item exposure control methods on measurement precision and on test security under various item selection methods and item pool characteristics. In this study, the Randomesque (with item group sizes of 5 and 10), Sympson-Hetter, and Fade-Away methods were used as item exposure control methods. Moreover,…

  13. Advanced particulate matter control apparatus and methods

    DOEpatents

    Miller, Stanley J.; Zhuang, Ye; Almlie, Jay C.

    2012-01-10

    Apparatus and methods for collection and removal of particulate matter, including fine particulate matter, from a gas stream, comprising a unique combination of high collection efficiency and ultralow pressure drop across the filter. The apparatus and method utilize simultaneous electrostatic precipitation and membrane filtration of a particular pore size, wherein electrostatic collection and filtration occur on the same surface.

  14. Multimodel methods for optimal control of aeroacoustics.

    SciTech Connect

    Chen, Guoquan; Collis, Samuel Scott

    2005-01-01

    A new multidomain/multiphysics computational framework for optimal control of aeroacoustic noise has been developed based on a near-field compressible Navier-Stokes solver coupled with a far-field linearized Euler solver both based on a discontinuous Galerkin formulation. In this approach, the coupling of near- and far-field domains is achieved by weakly enforcing continuity of normal fluxes across a coupling surface that encloses all nonlinearities and noise sources. For optimal control, gradient information is obtained by the solution of an appropriate adjoint problem that involves the propagation of adjoint information from the far-field to the near-field. This computational framework has been successfully applied to study optimal boundary-control of blade-vortex interaction, which is a significant noise source for helicopters on approach to landing. In the model-problem presented here, the noise propagated toward the ground is reduced by 12dB.

  15. Method and apparatus for emission control

    SciTech Connect

    Kempf, T.W.; Corcoran, R.F.; Sikora, D.

    1992-01-01

    The invention includes process and apparatus for removing pollutants from a gas including fluidizing a bed of particles in a container, introducing a gas containing pollutant into the bed, removing the pollutant through deposition on the particles, controlling temperatures in the container by injecting coolant fluid through a coolant nozzle, and reducing clogging or fouling on the coolant nozzle. The process and apparatus includes controlling temperatures in the container within narrowly specified ranges of temperatures and providing a constant pressure of coolant fluid and constant pressure of purge gas to the coolant nozzle such that interchangeable selection made between the coolant fluid and purge gas in a time period sufficiently short provides accurate temperature control and reduces clogging or fouling on the coolant nozzle.

  16. METHOD AND APPARATUS FOR REACTOR SAFETY CONTROL

    DOEpatents

    Huston, N.E.

    1961-06-01

    A self-contained nuclear reactor fuse controlled device tron absorbing material, normally in a compact form but which can be expanded into an extended form presenting a large surface for neutron absorption when triggered by an increase in neutron flux, is described.

  17. Method and system for controlled combustion engines

    DOEpatents

    Oppenheim, A. K.

    1990-01-01

    A system for controlling combustion in internal combustion engines of both the Diesel or Otto type, which relies on establishing fluid dynamic conditions and structures wherein fuel and air are entrained, mixed and caused to be ignited in the interior of a multiplicity of eddies, and where these structures are caused to sequentially fill the headspace of the cylinders.

  18. Sinusoidal modulation control method in a chaotic neural network

    NASA Astrophysics Data System (ADS)

    Zhang, Qihanyue; Xie, Xiaoping; Zhu, Ping; Chen, Hongping; He, Guoguang

    2014-08-01

    Chaotic neural networks (CNNs) have chaotic dynamic associative memory properties: The memory states appear non-periodically, and cannot be converged to a stored pattern. Thus, it is necessary to control chaos in a CNN in order to recognize associative memory. In this paper, a novel control method, the sinusoidal modulation control method, has been proposed to control chaos in a CNN. In this method, a sinusoidal wave simplified from brain waves is used as a control signal to modulate a parameter of the CNN. The simulation results demonstrate the effectiveness of this control method. The controlled CNN can be applied to information processing. Moreover, the method provides a way to associate brain waves by controlling CNNs.

  19. Method for control of subsurface coal gasification

    DOEpatents

    Komar, Charles A.

    1976-12-14

    The burn front in an in situ underground coal gasification operation is controlled by utilizing at least two parallel groups of vertical bore holes disposed in the coalbed at spaced-apart locations in planes orthogonal to the plane of maximum permeability in the coalbed. The combustion of the coal is initiated in the coalbed adjacent to one group of the bore holes to establish a combustion zone extending across the group while the pressure of the combustion supporting gas mixture and/or the combustion products is regulated at each well head by valving to control the burn rate and maintain a uniform propagation of the burn front between the spaced-apart hole groups to gasify virtually all the coal lying therebetween.

  20. Apparatus and methods for humidity control

    NASA Technical Reports Server (NTRS)

    Dinauer, William R. (Inventor); Otis, David R. (Inventor); El-Wakil, Mohamed M. (Inventor); Vignali, John C. (Inventor); Macaulay, Philip D. (Inventor)

    1994-01-01

    Apparatus is provided which controls humidity in a gas. The apparatus employs a porous interface that is preferably a manifolded array of stainless steel tubes through whose porous surface water vapor can pass. One side of the porous interface is in contact with water and the opposing side is in contact with gas whose humidity is being controlled. Water vapor is emitted from the porous surface of the tubing into the gas when the gas is being humidified, and water vapor is removed from the gas through the porous surfaces when the gas is being dehumidified. The temperature of the porous interface relative to the gas temperature determines whether humidification or dehumidification is being carried out. The humidity in the gas is sensed and compared to the set point humidity. The water temperature, and consequently the porous interface temperature, are automatically controlled in response to changes in the gas humidity level above or below the set point. Any deviation from the set point humidity is thus corrected.

  1. Apparatus and method for controlling autotroph cultivation

    SciTech Connect

    Fuxman, Adrian M; Tixier, Sebastien; Stewart, Gregory E; Haran, Frank M; Backstrom, Johan U; Gerbrandt, Kelsey

    2013-07-02

    A method includes receiving at least one measurement of a dissolved carbon dioxide concentration of a mixture of fluid containing an autotrophic organism. The method also includes determining an adjustment to one or more manipulated variables using the at least one measurement. The method further includes generating one or more signals to modify the one or more manipulated variables based on the determined adjustment. The one or more manipulated variables could include a carbon dioxide flow rate, an air flow rate, a water temperature, and an agitation level for the mixture. At least one model relates the dissolved carbon dioxide concentration to one or more manipulated variables, and the adjustment could be determined by using the at least one model to drive the dissolved carbon dioxide concentration to at least one target that optimize a goal function. The goal function could be to optimize biomass growth rate, nutrient removal and/or lipid production.

  2. Immunoassay control method based on light scattering

    NASA Astrophysics Data System (ADS)

    Bilyi, Olexander I.; Kiselyov, Eugene M.; Petrina, R. O.; Ferensovich, Yaroslav P.; Yaremyk, Roman Y.

    1999-11-01

    The physics principle of registration immune reaction by light scattering methods is concerned. The operation of laser nephelometry for measuring antigen-antibody reaction is described. The technique of obtaining diagnostic and immune reactions of interaction latex agglutination for diphtheria determination is described.

  3. Controlled synthesis of polyenes by catalytic methods

    SciTech Connect

    Schrock, R.R.

    1991-01-01

    A study concerned with the controlled synthesis of polyenes by ring opening metathesis polymerization using tricyclo(4.2.2.0{sup 2,5})deca-3,7,9-trienes (TCDT's) and a molybdenum catalyst (Mo(CH-t-Bu)(NAr)(O-t-Bu){sub 2}; Ar = 2,6-C{sub 6}H{sub 3}-i-Pr{sub 2}) has now appeared. We have continued to search for a catalyst that will polymerize terminal acetylenes in a regiospecific manner. Recent applications of polyparaphenylenevinylenes include photo and electroluminescence. We would like to prepare polyparaphenylenevinylenes and related materials for evaluation in similar applications. 7 refs.

  4. Method and apparatus for controlling a microturbine

    DOEpatents

    Garces, Luis Jose; Cardinal, Mark Edward; Sinha, Gautam; Dame, Mark Edward

    2005-08-02

    An apparatus for controlling a microturbine, the apparatus including: a rectifier adapted for converting at least one generated voltage from the microturbine to a DC link voltage; an inverter adapted for converting the DC link voltage to at least one inverter output voltage, the at least one inverter output voltage being electrically coupled to an external power bus; a starter drive adapted for converting at least one starter input voltage to at least one starter output voltage, the at least one starter input voltage being electrically coupled to the external power bus, the at least one starter output voltage being electrically coupled to the microturbine.

  5. Alternative methods for the design of jet engine control systems

    NASA Technical Reports Server (NTRS)

    Sain, M. K.; Leake, R. J.; Basso, R.; Gejji, R.; Maloney, A.; Seshadri, V.

    1976-01-01

    Various alternatives to linear quadratic design methods for jet engine control systems are discussed. The main alternatives are classified into two broad categories: nonlinear global mathematical programming methods and linear local multivariable frequency domain methods. Specific studies within these categories include model reduction, the eigenvalue locus method, the inverse Nyquist method, polynomial design, dynamic programming, and conjugate gradient approaches.

  6. Method for controlling a motor vehicle powertrain

    DOEpatents

    Burba, J.C.; Landman, R.G.; Patil, P.B.; Reitz, G.A.

    1990-05-22

    A multiple forward speed automatic transmission produces its lowest forward speed ratio when a hydraulic clutch and hydraulic brake are disengaged and a one-way clutch connects a ring gear to the transmission casing. Second forward speed ratio results when the hydraulic clutch is engaged to connect the ring gear to the planetary carrier of a second gear set. Reverse drive and regenerative operation result when an hydraulic brake fixes the planetary and the direction of power flow is reversed. Various sensors produce signals representing the position of the gear selector lever operated manually by the vehicle operator, the speed of the power source, the state of the ignition key, and the rate of release of an accelerator pedal. A control algorithm produces input data representing a commanded upshift, a commanded downshift and a torque command and various constant torque signals. A microprocessor processes the input and produces a response to them in accordance with the execution of a control algorithm. Output or response signals cause selective engagement and disengagement of the clutch and brake to produce the forward drive, reverse and regenerative operation of the transmission. 7 figs.

  7. Polynomial method for PLL controller optimization.

    PubMed

    Wang, Ta-Chung; Lall, Sanjay; Chiou, Tsung-Yu

    2011-01-01

    The Phase-Locked Loop (PLL) is a key component of modern electronic communication and control systems. PLL is designed to extract signals from transmission channels. It plays an important role in systems where it is required to estimate the phase of a received signal, such as carrier tracking from global positioning system satellites. In order to robustly provide centimeter-level accuracy, it is crucial for the PLL to estimate the instantaneous phase of an incoming signal which is usually buried in random noise or some type of interference. This paper presents an approach that utilizes the recent development in the semi-definite programming and sum-of-squares field. A Lyapunov function will be searched as the certificate of the pull-in range of the PLL system. Moreover, a polynomial design procedure is proposed to further refine the controller parameters for system response away from the equilibrium point. Several simulation results as well as an experiment result are provided to show the effectiveness of this approach. PMID:22163973

  8. Method for controlling a motor vehicle powertrain

    DOEpatents

    Burba, Joseph C.; Landman, Ronald G.; Patil, Prabhakar B.; Reitz, Graydon A.

    1990-01-01

    A multiple forward speed automatic transmission produces its lowest forward speed ratio when a hydraulic clutch and hydraulic brake are disengaged and a one-way clutch connects a ring gear to the transmission casing. Second forward speed ratio results when the hydraulic clutch is engaged to connect the ring gear to the planetary carrier of a second gear set. Reverse drive and regenerative operation result when an hydraulic brake fixes the planetary and the direction of power flow is reversed. Various sensors produce signals representing the position of the gear selector lever operated manually by the vehicle operator, the speed of the power source, the state of the ignition key, and the rate of release of an accelerator pedal. A control algorithm produces input data representing a commanded upshift, a commanded downshift and a torque command and various constant torque signals. A microprocessor processes the input and produces a response to them in accordance with the execution of a control algorithm. Output or response signals cause selective engagement and disengagement of the clutch and brake to produce the forward drive, reverse and regenerative operation of the transmission.

  9. Stirling engine control mechanism and method

    DOEpatents

    Dineen, John J.

    1983-01-01

    A reciprocating-to-rotating motion conversion and power control device for a Stirling engine includes a hub mounted on an offset portion of the output shaft for rotation relative to the shaft and for sliding motion therealong which causes the hub to tilt relative to the axis of rotation of the shaft. This changes the angle of inclination of the hub relative to the shaft axis and changes the axial stroke of a set of arms connected to the hub and nutating therewith. A hydraulic actuating mechanism is connected to the hub for moving its axial position along the shaft. A balancing wheel is linked to the hub and changes its angle of inclination as the angle of inclination of the hub changes to maintain the mechanism in perfect balance throughout its range of motion.

  10. Water control well treating solution and method

    SciTech Connect

    Boles, J. L.; Mancillas, G.

    1984-10-16

    A well treating solution is shown for changing the relative permeability of a formation being treated to water. The solution is made by mixing an amphoteric polymeric material, a mutual solvent and a surface active agent in a brine carrier liquid. The well treating solution is injected into the formation at pump rates below the fracture gradient of the formation. The well is briefly shut-in, after which production can be resumed. The treating solution and method taught lower the permeability of the producing formation to water without substantially affecting the formation's permeability to oil and gas.

  11. Sliding mode control method having terminal convergence in finite time

    NASA Technical Reports Server (NTRS)

    Venkataraman, Subramanian T. (Inventor); Gulati, Sandeep (Inventor)

    1994-01-01

    An object of this invention is to provide robust nonlinear controllers for robotic operations in unstructured environments based upon a new class of closed loop sliding control methods, sometimes denoted terminal sliders, where the new class will enforce closed-loop control convergence to equilibrium in finite time. Improved performance results from the elimination of high frequency control switching previously employed for robustness to parametric uncertainties. Improved performance also results from the dependence of terminal slider stability upon the rate of change of uncertainties over the sliding surface rather than the magnitude of the uncertainty itself for robust control. Terminal sliding mode control also yields improved convergence where convergence time is finite and is to be controlled. A further object is to apply terminal sliders to robot manipulator control and benchmark performance with the traditional computed torque control method and provide for design of control parameters.

  12. Interactive robot control system and method of use

    NASA Technical Reports Server (NTRS)

    Sanders, Adam M. (Inventor); Reiland, Matthew J. (Inventor); Abdallah, Muhammad E. (Inventor); Linn, Douglas Martin (Inventor); Platt, Robert (Inventor)

    2012-01-01

    A robotic system includes a robot having joints, actuators, and sensors, and a distributed controller. The controller includes command-level controller, embedded joint-level controllers each controlling a respective joint, and a joint coordination-level controller coordinating motion of the joints. A central data library (CDL) centralizes all control and feedback data, and a user interface displays a status of each joint, actuator, and sensor using the CDL. A parameterized action sequence has a hierarchy of linked events, and allows the control data to be modified in real time. A method of controlling the robot includes transmitting control data through the various levels of the controller, routing all control and feedback data to the CDL, and displaying status and operation of the robot using the CDL. The parameterized action sequences are generated for execution by the robot, and a hierarchy of linked events is created within the sequence.

  13. A decentralized linear quadratic control design method for flexible structures

    NASA Technical Reports Server (NTRS)

    Su, Tzu-Jeng; Craig, Roy R., Jr.

    1990-01-01

    A decentralized suboptimal linear quadratic control design procedure which combines substructural synthesis, model reduction, decentralized control design, subcontroller synthesis, and controller reduction is proposed for the design of reduced-order controllers for flexible structures. The procedure starts with a definition of the continuum structure to be controlled. An evaluation model of finite dimension is obtained by the finite element method. Then, the finite element model is decomposed into several substructures by using a natural decomposition called substructuring decomposition. Each substructure, at this point, still has too large a dimension and must be reduced to a size that is Riccati-solvable. Model reduction of each substructure can be performed by using any existing model reduction method, e.g., modal truncation, balanced reduction, Krylov model reduction, or mixed-mode method. Then, based on the reduced substructure model, a subcontroller is designed by an LQ optimal control method for each substructure independently. After all subcontrollers are designed, a controller synthesis method called substructural controller synthesis is employed to synthesize all subcontrollers into a global controller. The assembling scheme used is the same as that employed for the structure matrices. Finally, a controller reduction scheme, called the equivalent impulse response energy controller (EIREC) reduction algorithm, is used to reduce the global controller to a reasonable size for implementation. The EIREC reduced controller preserves the impulse response energy of the full-order controller and has the property of matching low-frequency moments and low-frequency power moments. An advantage of the substructural controller synthesis method is that it relieves the computational burden associated with dimensionality. Besides that, the SCS design scheme is also a highly adaptable controller synthesis method for structures with varying configuration, or varying mass

  14. Performance Comparison of Capacity Control Methods for Reciprocating Compressors

    NASA Astrophysics Data System (ADS)

    Wang, L.; Liu, G. B.; Zhao, Y. Y.; Li, L. L.

    2015-08-01

    Different capacity control methods are used for adjusting suction flow of reciprocating compressors to meet process need. Compared with recycle or bypass and suction throttling, three capacity control methods of speed control, clearance pockets and suction valve unloading are preferred due to their energy-saving at operating condition of partial load. The paper reviewed state of the art of the current capacity control technologies and their principles. A comprehensive mathematical model was developed to predict thermodynamic and dynamic performance of reciprocating compressors equipped with the capacity control systems of four above-mentioned methods. Comparison of shaft work and mechanical efficiency were conducted for different capacity control methods at the same condition. In addition, their influence on p-v diagram and valve motion were also studied, which is important for reliability and life of the reciprocating compressors. These results were helpful for selection of the capacity control systems by end-users and optimum design by manufacturers.

  15. Rate control method for hydraulic fracturing

    SciTech Connect

    Pearson, C.M.

    1991-10-08

    This paper describes a method of forming a fracture in an earth formation, the fracture extending from a wellbore, the fracture being formed for the eventual production of fluids from the formation through the fracture and into the wellbore. It comprises: pumping a liquid into the wellbore at a pressure sufficient to extend a fracture having opposed faces and a tip portion into the formation until a predetermined fracture length is indicated; injecting a liquid containing a proppant of relatively low concentration and decreasing the rate of injection to a rate approximately equal to the fluid leak off rate from the faces; and injecting liquid containing higher concentrations of proppant than previously mentioned until screenout of the tip portion.

  16. Method for controlling corrosion using molybdate compositions

    SciTech Connect

    Boffardi, B.P.; Rey, S.P.

    1989-01-17

    A method is described for inhibiting corrosion in an aqueous system comprising adding to the system an effective amount of a corrosion inhibiting composition comprising: (a) a molybdate ion source; and (b) a water-soluble component selected from the group consisting of polymaleic anhydride; amine adducts of polymaleic anhydride; polymers prepared by polymerizing maleic anhydride with dimethyl diallyl ammonium chloride or homologs thereof; polymers prepared from 50-70%, by weight, acrylic acid or methacrylic acid, 10-40%, by weight, 2-acrylamido-2-methylpropyl sulfonic acid or 2-methyacrylamido-2-methylpropyl sulfonic acid and 10-30%, by weight, of a polyalkyleneoxide compound; salts of the above described polymers; phosphonates selected from the group consisting of 2-phosnphonobutane-1,2,4 tricarboxylic acid and hydroxyphosphono acetic acid; phosphino carboxylic acids; polyphosphoric acid and polyhydroxy esters of polyphosphoric acid; wherein the weight of (a):(b), on an active basis, ranges from about 10:1 to about 1:10.

  17. Nuclear reactor flow control method and apparatus

    DOEpatents

    Church, John P.

    1993-01-01

    Method and apparatus for improving coolant flow in a nuclear reactor during accident as well as nominal conditions. The reactor has a plurality of fuel elements in sleeves and a plenum above the fuel and through which the sleeves penetrate. Holes are provided in the sleeve so that coolant from the plenum can enter the sleeve and cool the fuel. The number and size of the holes are varied from sleeve to sleeve with the number and size of holes being greater for sleeves toward the center of the core and less for sleeves toward the periphery of the core. Preferably the holes are all the same diameter and arranged in rows and columns, the rows starting from the bottom of every sleeve and fewer rows in peripheral sleeves and more rows in the central sleeves.

  18. Nuclear reactor flow control method and apparatus

    DOEpatents

    Church, J.P.

    1993-03-30

    Method and apparatus for improving coolant flow in a nuclear reactor during accident as well as nominal conditions. The reactor has a plurality of fuel elements in sleeves and a plenum above the fuel and through which the sleeves penetrate. Holes are provided in the sleeve so that coolant from the plenum can enter the sleeve and cool the fuel. The number and size of the holes are varied from sleeve to sleeve with the number and size of holes being greater for sleeves toward the center of the core and less for sleeves toward the periphery of the core. Preferably the holes are all the same diameter and arranged in rows and columns, the rows starting from the bottom of every sleeve and fewer rows in peripheral sleeves and more rows in the central sleeves.

  19. Control methods and systems for indirect evaporative coolers

    SciTech Connect

    Woods, Jason; Kozubal, Erik

    2015-09-22

    A control method for operating an indirect evaporative cooler to control temperature and humidity. The method includes operating an airflow control device to provide supply air at a flow rate to a liquid desiccant dehumidifier. The supply air flows through the dehumidifier and an indirect evaporative cooler prior to exiting an outlet into a space. The method includes operating a pump to provide liquid desiccant to the liquid desiccant dehumidifier and sensing a temperature of an airstream at the outlet of the indirect evaporative cooler. The method includes comparing the temperature of the airstream at the outlet to a setpoint temperature at the outlet and controlling the pump to set the flow rate of the liquid desiccant. The method includes sensing space temperature, comparing the space temperature with a setpoint temperature, and controlling the airflow control device to set the flow rate of the supply air based on the comparison.

  20. COMSAC: Computational Methods for Stability and Control. Part 1

    NASA Technical Reports Server (NTRS)

    Fremaux, C. Michael (Compiler); Hall, Robert M. (Compiler)

    2004-01-01

    Work on stability and control included the following reports:Introductory Remarks; Introduction to Computational Methods for Stability and Control (COMSAC); Stability & Control Challenges for COMSAC: a NASA Langley Perspective; Emerging CFD Capabilities and Outlook A NASA Langley Perspective; The Role for Computational Fluid Dynamics for Stability and Control:Is it Time?; Northrop Grumman Perspective on COMSAC; Boeing Integrated Defense Systems Perspective on COMSAC; Computational Methods in Stability and Control:WPAFB Perspective; Perspective: Raytheon Aircraft Company; A Greybeard's View of the State of Aerodynamic Prediction; Computational Methods for Stability and Control: A Perspective; Boeing TacAir Stability and Control Issues for Computational Fluid Dynamics; NAVAIR S&C Issues for CFD; An S&C Perspective on CFD; Issues, Challenges & Payoffs: A Boeing User s Perspective on CFD for S&C; and Stability and Control in Computational Simulations for Conceptual and Preliminary Design: the Past, Today, and Future?

  1. A Particle Population Control Method for Dynamic Monte Carlo

    NASA Astrophysics Data System (ADS)

    Sweezy, Jeremy; Nolen, Steve; Adams, Terry; Zukaitis, Anthony

    2014-06-01

    A general particle population control method has been derived from splitting and Russian Roulette for dynamic Monte Carlo particle transport. A well-known particle population control method, known as the particle population comb, has been shown to be a special case of this general method. This general method has been incorporated in Los Alamos National Laboratory's Monte Carlo Application Toolkit (MCATK) and examples of it's use are shown for both super-critical and sub-critical systems.

  2. Control system and method for a hybrid electric vehicle

    DOEpatents

    Tamor, Michael Alan

    2001-03-06

    Several control methods are presented for application in a hybrid electric vehicle powertrain including in various embodiments an engine, a motor/generator, a transmission coupled at an input thereof to receive torque from the engine and the motor generator coupled to augment torque provided by the engine, an energy storage device coupled to receive energy from and provide energy to the motor/generator, an engine controller (EEC) coupled to control the engine, a transmission controller (TCM) coupled to control the transmission and a vehicle system controller (VSC) adapted to control the powertrain.

  3. Mixed mode control method and engine using same

    DOEpatents

    Kesse, Mary L.; Duffy, Kevin P.

    2007-04-10

    A method of mixed mode operation of an internal combustion engine includes the steps of controlling a homogeneous charge combustion event timing in a given engine cycle, and controlling a conventional charge injection event to be at least a predetermined time after the homogeneous charge combustion event. An internal combustion engine is provided, including an electronic controller having a computer readable medium with a combustion timing control algorithm recorded thereon, the control algorithm including means for controlling a homogeneous charge combustion event timing and means for controlling a conventional injection event timing to be at least a predetermined time from the homogeneous charge combustion event.

  4. A Robust Cooperated Control Method with Reinforcement Learning and Adaptive H∞ Control

    NASA Astrophysics Data System (ADS)

    Obayashi, Masanao; Uchiyama, Shogo; Kuremoto, Takashi; Kobayashi, Kunikazu

    This study proposes a robust cooperated control method combining reinforcement learning with robust control to control the system. A remarkable characteristic of the reinforcement learning is that it doesn't require model formula, however, it doesn't guarantee the stability of the system. On the other hand, robust control system guarantees stability and robustness, however, it requires model formula. We employ both the actor-critic method which is a kind of reinforcement learning with minimal amount of computation to control continuous valued actions and the traditional robust control, that is, H∞ control. The proposed system was compared method with the conventional control method, that is, the actor-critic only used, through the computer simulation of controlling the angle and the position of a crane system, and the simulation result showed the effectiveness of the proposed method.

  5. Methods to control for unmeasured confounding in pharmacoepidemiology: an overview.

    PubMed

    Uddin, Md Jamal; Groenwold, Rolf H H; Ali, Mohammed Sanni; de Boer, Anthonius; Roes, Kit C B; Chowdhury, Muhammad A B; Klungel, Olaf H

    2016-06-01

    Background Unmeasured confounding is one of the principal problems in pharmacoepidemiologic studies. Several methods have been proposed to detect or control for unmeasured confounding either at the study design phase or the data analysis phase. Aim of the Review To provide an overview of commonly used methods to detect or control for unmeasured confounding and to provide recommendations for proper application in pharmacoepidemiology. Methods/Results Methods to control for unmeasured confounding in the design phase of a study are case only designs (e.g., case-crossover, case-time control, self-controlled case series) and the prior event rate ratio adjustment method. Methods that can be applied in the data analysis phase include, negative control method, perturbation variable method, instrumental variable methods, sensitivity analysis, and ecological analysis. A separate group of methods are those in which additional information on confounders is collected from a substudy. The latter group includes external adjustment, propensity score calibration, two-stage sampling, and multiple imputation. Conclusion As the performance and application of the methods to handle unmeasured confounding may differ across studies and across databases, we stress the importance of using both statistical evidence and substantial clinical knowledge for interpretation of the study results. PMID:27091131

  6. Active controls: A look at analytical methods and associated tools

    NASA Technical Reports Server (NTRS)

    Newsom, J. R.; Adams, W. M., Jr.; Mukhopadhyay, V.; Tiffany, S. H.; Abel, I.

    1984-01-01

    A review of analytical methods and associated tools for active controls analysis and design problems is presented. Approaches employed to develop mathematical models suitable for control system analysis and/or design are discussed. Significant efforts have been expended to develop tools to generate the models from the standpoint of control system designers' needs and develop the tools necessary to analyze and design active control systems. Representative examples of these tools are discussed. Examples where results from the methods and tools have been compared with experimental data are also presented. Finally, a perspective on future trends in analysis and design methods is presented.

  7. The control method for the lattice hydrodynamic model

    NASA Astrophysics Data System (ADS)

    Ge, Hong-Xia; Cui, Yu; Zhu, Ke-Qiang; Cheng, Rong-Jun

    2015-05-01

    The delayed-feedback control method is applied for lattice hydrodynamic model of traffic flow. The linear stability condition with and without control signal are derived through linear and nonlinear analysis. Numerical simulation is carried out and the results confirm that the traffic congested can be suppressed efficiently by considering the control signal.

  8. SPC without Control Limits and Normality Assumption: A New Method

    NASA Astrophysics Data System (ADS)

    Vazquez-Lopez, J. A.; Lopez-Juarez, I.

    Control Charts (CC) are important Statistic Process Control (SPC) tools developed in the 20's to control and improve the quality of industrial production. The use of CC requires visual inspection and human judgement to diagnoses the process quality properly. CC assume normal distribution in the observed variables to establish the control limits. However, this is a requirement difficult to meet in practice since skewness distributions are commonly observed. In this research, a novel method that neither requires control limits nor data normality is presented. The core of the method is based on the FuzzyARTMAP (FAM) Artificial Neural Network (ANN) that learns special and non-special patterns of variation and whose internal parameters are determined through experimental design to increase its efficiency. The proposed method was implemented successfully in a manufacturing process determining the statistical control state that validate our method.

  9. A Method for Implementing Force-Limited Vibration Control

    NASA Technical Reports Server (NTRS)

    Worth, Daniel B.

    1997-01-01

    NASA/GSFC has implemented force-limited vibration control on a controller which can only accept one profile. The method uses a personal computer based digital signal processing board to convert force and/or moment signals into what appears to he an acceleration signal to the controller. This technique allows test centers with older controllers to use the latest force-limited control techniques for random vibration testing. The paper describes the method, hardware, and test procedures used. An example from a test performed at NASA/GSFC is used as a guide.

  10. Development and applications of Krotov method of global control improvement

    NASA Astrophysics Data System (ADS)

    Rasina, Irina V.; Trushkova, Ekaterina A.; Baturina, Olga V.; Bulatov, Alexander V.; Guseva, Irina S.

    2016-06-01

    This is a survey of works on main properties, application and development of the Krotov method of global control improvement very popular among researchers of modern problems in quantum physics and quantum chemistry, applying actively optimal control methods. The survey includes a brief description of the method in comparison with well known gradient method demonstrating such its serious advantage as absence of tuning parameters; investigations aimed to make its special version for the quantum system well defined and more effective; and generalization for wide classes of control systems, including the systems of heterogeneous structure.

  11. A novel adaptive force control method for IPMC manipulation

    NASA Astrophysics Data System (ADS)

    Hao, Lina; Sun, Zhiyong; Li, Zhi; Su, Yunquan; Gao, Jianchao

    2012-07-01

    IPMC is a type of electro-active polymer material, also called artificial muscle, which can generate a relatively large deformation under a relatively low input voltage (generally speaking, less than 5 V), and can be implemented in a water environment. Due to these advantages, IPMC can be used in many fields such as biomimetics, service robots, bio-manipulation, etc. Until now, most existing methods for IPMC manipulation are displacement control not directly force control, however, under most conditions, the success rate of manipulations for tiny fragile objects is limited by the contact force, such as using an IPMC gripper to fix cells. Like most EAPs, a creep phenomenon exists in IPMC, of which the generated force will change with time and the creep model will be influenced by the change of the water content or other environmental factors, so a proper force control method is urgently needed. This paper presents a novel adaptive force control method (AIPOF control—adaptive integral periodic output feedback control), based on employing a creep model of which parameters are obtained by using the FRLS on-line identification method. The AIPOF control method can achieve an arbitrary pole configuration as long as the plant is controllable and observable. This paper also designs the POF and IPOF controller to compare their test results. Simulation and experiments of micro-force-tracking tests are carried out, with results confirming that the proposed control method is viable.

  12. A comparison of digital flight control design methods

    NASA Technical Reports Server (NTRS)

    Powell, J. D.; Parsons, E.; Tashker, M. G.

    1976-01-01

    Many variations in design methods for aircraft digital flight control have been proposed in the literature. In general, the methods fall into two categories: those where the design is done in the continuous domain (or s-plane), and those where the design is done in the discrete domain (or z-plane). This paper evaluates several variations of each category and compares them for various flight control modes of the Langley TCV Boeing 737 aircraft. Design method fidelity is evaluated by examining closed loop root movement and the frequency response of the discretely controlled continuous aircraft. It was found that all methods provided acceptable performance for sample rates greater than 10 cps except the 'uncompensated s-plane design' method which was acceptable above 20 cps. A design procedure based on optimal control methods was proposed that provided the best fidelity at very slow sample rates and required no design iterations for changing sample rates.

  13. Control system and method for payload control in mobile platform cranes

    DOEpatents

    Robinett, III, Rush D.; Groom, Kenneth N.; Feddema, John T.; Parker, Gordon G.

    2002-01-01

    A crane control system and method provides a way to generate crane commands responsive to a desired payload motion to achieve substantially pendulation-free actual payload motion. The control system and method apply a motion compensator to maintain a payload in a defined payload configuration relative to an inertial coordinate frame. The control system and method can further comprise a pendulation damper controller to reduce an amount of pendulation between a sensed payload configuration and the defined payload configuration. The control system and method can further comprise a command shaping filter to filter out a residual payload pendulation frequency from the desired payload motion.

  14. Two Reconfigurable Flight-Control Design Methods: Robust Servomechanism and Control Allocation

    NASA Technical Reports Server (NTRS)

    Burken, John J.; Lu, Ping; Wu, Zheng-Lu; Bahm, Cathy

    2001-01-01

    Two methods for control system reconfiguration have been investigated. The first method is a robust servomechanism control approach (optimal tracking problem) that is a generalization of the classical proportional-plus-integral control to multiple input-multiple output systems. The second method is a control-allocation approach based on a quadratic programming formulation. A globally convergent fixed-point iteration algorithm has been developed to make onboard implementation of this method feasible. These methods have been applied to reconfigurable entry flight control design for the X-33 vehicle. Examples presented demonstrate simultaneous tracking of angle-of-attack and roll angle commands during failures of the fight body flap actuator. Although simulations demonstrate success of the first method in most cases, the control-allocation method appears to provide uniformly better performance in all cases.

  15. A tuning method of two degrees of freedom PID controller

    SciTech Connect

    Kasahara, Masato; Kimbara, Akiomi; Kurosu, Shigeru; Matsuba, Tadahiko; Kamimura, Kazuyuki; Murasawa, Itaru; Hashimoto, Yukihiro

    1997-12-31

    This paper proposes a new tuning method when using a two degrees of freedom proportional-integral-derivative (PID) controller. Its control performance for a first-order lag plus deadtime system is shown as an example of the commonly approximated controlled plants in the heating, ventilating, and air-conditioning (HVAC) field. Reference and disturbance input changes to a conventional PID controller do not necessarily give a satisfactory response. To overcome this problem, several two degrees of freedom PID (2 DOF PID) algorithms have been developed to replace the conventional PID controllers. However, when these techniques are applied to real plants, it is not usually easy to obtain a set of optimum tuning parameters. To evaluate the control performance, a comparison is carried out between the two tuning methods--the optimization technique and the partial model matching method--using simulation. Graphs by which the controller parameters can be related to dynamics of a popular plant are developed. The 2 DOF PID control is studied taking into account modeling error due to a change in plant characteristics. It is found that the 2 DOF PID controller designed based on the partial model matching method is robust and useful in simulations where a traditional PID controller would be used.

  16. Tripless control method for general-purpose inverters

    SciTech Connect

    Mutoh, N.; Ueda, A. . Hitachi Research Lab.); Nandoh, K.; Ibori, S. )

    1992-09-01

    In this paper a new control method is described. This method prevents general-purpose inverters without current regulators from tripping easily, i.e., to be tripless no matter how their load is varied, and enables motors to rotate stably at high frequencies. This control is performed using only current sensors and is a combination of PWM control and torque control. This approach for PWM control changes an asynchronized mode to a synchronized mode when the modulation ratio becomes more than one. This enables the carrier wave frequency to be continuously varied with the inverter frequency. As a result, motors can rotate stably over a wide frequency range. The torque control uses a real and reactive component detector, magnetic flux compensator, slip compensator, and current limit controller.

  17. Investigation of the Multiple Model Adaptive Control (MMAC) method for flight control systems

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The application was investigated of control theoretic ideas to the design of flight control systems for the F-8 aircraft. The design of an adaptive control system based upon the so-called multiple model adaptive control (MMAC) method is considered. Progress is reported.

  18. Predicting survival in heart failure case and control subjects by use of fully automated methods for deriving nonlinear and conventional indices of heart rate dynamics

    NASA Technical Reports Server (NTRS)

    Ho, K. K.; Moody, G. B.; Peng, C. K.; Mietus, J. E.; Larson, M. G.; Levy, D.; Goldberger, A. L.

    1997-01-01

    BACKGROUND: Despite much recent interest in quantification of heart rate variability (HRV), the prognostic value of conventional measures of HRV and of newer indices based on nonlinear dynamics is not universally accepted. METHODS AND RESULTS: We have designed algorithms for analyzing ambulatory ECG recordings and measuring HRV without human intervention, using robust methods for obtaining time-domain measures (mean and SD of heart rate), frequency-domain measures (power in the bands of 0.001 to 0.01 Hz [VLF], 0.01 to 0.15 Hz [LF], and 0.15 to 0.5 Hz [HF] and total spectral power [TP] over all three of these bands), and measures based on nonlinear dynamics (approximate entropy [ApEn], a measure of complexity, and detrended fluctuation analysis [DFA], a measure of long-term correlations). The study population consisted of chronic congestive heart failure (CHF) case patients and sex- and age-matched control subjects in the Framingham Heart Study. After exclusion of technically inadequate studies and those with atrial fibrillation, we used these algorithms to study HRV in 2-hour ambulatory ECG recordings of 69 participants (mean age, 71.7+/-8.1 years). By use of separate Cox proportional-hazards models, the conventional measures SD (P<.01), LF (P<.01), VLF (P<.05), and TP (P<.01) and the nonlinear measure DFA (P<.05) were predictors of survival over a mean follow-up period of 1.9 years; other measures, including ApEn (P>.3), were not. In multivariable models, DFA was of borderline predictive significance (P=.06) after adjustment for the diagnosis of CHF and SD. CONCLUSIONS: These results demonstrate that HRV analysis of ambulatory ECG recordings based on fully automated methods can have prognostic value in a population-based study and that nonlinear HRV indices may contribute prognostic value to complement traditional HRV measures.

  19. An historical survey of computational methods in optimal control.

    NASA Technical Reports Server (NTRS)

    Polak, E.

    1973-01-01

    Review of some of the salient theoretical developments in the specific area of optimal control algorithms. The first algorithms for optimal control were aimed at unconstrained problems and were derived by using first- and second-variation methods of the calculus of variations. These methods have subsequently been recognized as gradient, Newton-Raphson, or Gauss-Newton methods in function space. A much more recent addition to the arsenal of unconstrained optimal control algorithms are several variations of conjugate-gradient methods. At first, constrained optimal control problems could only be solved by exterior penalty function methods. Later algorithms specifically designed for constrained problems have appeared. Among these are methods for solving the unconstrained linear quadratic regulator problem, as well as certain constrained minimum-time and minimum-energy problems. Differential-dynamic programming was developed from dynamic programming considerations. The conditional-gradient method, the gradient-projection method, and a couple of feasible directions methods were obtained as extensions or adaptations of related algorithms for finite-dimensional problems. Finally, the so-called epsilon-methods combine the Ritz method with penalty function techniques.

  20. Control selection methods in recent case-control studies conducted as part of infectious disease outbreaks.

    PubMed

    Waldram, Alison; McKerr, Caoimhe; Gobin, Maya; Adak, Goutam; Stuart, James M; Cleary, Paul

    2015-06-01

    Successful investigation of national outbreaks of communicable disease relies on rapid identification of the source. Case-control methodologies are commonly used to achieve this. We assessed control selection methods used in recently published case-control studies for methodological and resource issues to determine if a standard approach could be identified. Neighbourhood controls were the most frequently used method in 53 studies of a range of different sizes, infections and settings. The most commonly used method of data collection was face to face interview. Control selection issues were identified in four areas: method of identification of controls, appropriateness of controls, ease of recruitment of controls, and resource requirements. Potential biases arising from the method of control selection were identified in half of the studies assessed. There is a need to develop new ways of selecting controls in a rapid, random and representative manner to improve the accuracy and timeliness of epidemiological investigations and maximise the effectiveness of public health interventions. Innovative methods such as prior recruitment of controls could improve timeliness and representativeness of control selection. PMID:25762171

  1. A method for reducing sampling jitter in digital control systems

    NASA Technical Reports Server (NTRS)

    Anderson, T. O.; HURBD W. J.; Hurd, W. J.

    1969-01-01

    Digital phase lock loop system is designed by smoothing the proportional control with a low pass filter. This method does not significantly affect the loop dynamics when the smoothing filter bandwidth is wide compared to loop bandwidth.

  2. Surface control alloy substrates and methods of manufacture therefor

    DOEpatents

    Fritzemeier, Leslie G.; Li, Qi; Rupich, Martin W.; Thompson, Elliott D.; Siegal, Edward J.; Thieme, Cornelis Leo Hans; Annavarapu, Suresh; Arendt, Paul N.; Foltyn, Stephen R.

    2004-05-04

    Methods and articles for controlling the surface of an alloy substrate for deposition of an epitaxial layer. The invention includes the use of an intermediate layer to stabilize the substrate surface against oxidation for subsequent deposition of an epitaxial layer.

  3. Method of Controlling Steering of a Ground Vehicle

    NASA Technical Reports Server (NTRS)

    Dawson, Andrew D. (Inventor); Bluethmann, William J. (Inventor); Lee, Chunhao J. (Inventor); Vitale, Robert L. (Inventor); Guo, Raymond (Inventor); Atluri, Venkata Prasad (Inventor)

    2016-01-01

    A method of controlling steering of a vehicle through setting wheel angles of a plurality of modular electronic corner assemblies (eModules) is provided. The method includes receiving a driving mode selected from a mode selection menu. A position of a steering input device is determined in a master controller. A velocity of the vehicle is determined, in the master controller, when the determined position of the steering input device is near center. A drive mode request corresponding to the selected driving mode to the plurality of steering controllers is transmitted to the master controller. A required steering angle of each of the plurality of eModules is determined, in the master controller, as a function of the determined position of the steering input device, the determined velocity of the vehicle, and the selected first driving mode. The eModules are set to the respective determined steering angles.

  4. Adaptive method with intercessory feedback control for an intelligent agent

    DOEpatents

    Goldsmith, Steven Y.

    2004-06-22

    An adaptive architecture method with feedback control for an intelligent agent provides for adaptively integrating reflexive and deliberative responses to a stimulus according to a goal. An adaptive architecture method with feedback control for multiple intelligent agents provides for coordinating and adaptively integrating reflexive and deliberative responses to a stimulus according to a goal. Re-programming of the adaptive architecture is through a nexus which coordinates reflexive and deliberator components.

  5. Simplex method in problems of light-beam phase control.

    PubMed

    Chesnokov, S S; Davletshina, I V

    1995-12-20

    The possibility of the application of the simplex method to problems of wave-front control for light beams propagating in a nonlinear medium is investigated. A numerical analysis of simplex-method effectiveness in comparison with the gradient procedure of hill climbing is carried out. The regimes of stationary and nonstationary wind refraction are considered. The simplest optimization of the simplex size and the control basis is done. PMID:21068958

  6. Method and apparatus for precision control of radiometer

    NASA Technical Reports Server (NTRS)

    Estey, R. S.; Hanna, M. F. (Inventor)

    1984-01-01

    A radiometer controller of a radiation detector is provided with a calibration method and apparatus comprised of mounting all temperature sensitive elements of the controller in thermostatically controlled ovens during calibration and measurements, using a selected temperature that is above any which might be reached in the field. The instrument is calibrated in situ by adjusting heater power (EI) to the receptor cavity in the radiometer detector to a predetermined full scale level and is displayed by a meter.

  7. Cost-Effectiveness of Aflatoxin Control Methods: Economic Incentives

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Multiple sectors in U.S. crop industries – growers, elevators, handlers/shellers, processors, distributors, and consumers – are affected by aflatoxin contamination of commodities, and have the potential to control it. Aflatoxin control methods at both preharvest and postharvest levels have been dev...

  8. Nonlinear Robust Control Synthesis Methods for Spacecraft Applications

    NASA Astrophysics Data System (ADS)

    LeBel, Stefan

    This thesis focuses on practical methods for constructing robust nonlinear control systems. In general, the development of such control systems is characterized by the solution to one or more Hamilton-Jacobi partial differential equations (HJE). However, no general analytical solution has yet been obtained to solve this optimization problem. Solutions have thus far only been obtained under certain conditions. Therefore, the first significant contribution of this thesis is a method for obtaining analytical expressions for approximate solutions to a common form of HJE (under certain assumptions regarding the class of nonlinear systems used). Additionally, modern state space controller synthesis techniques typically result in state estimators of equal or greater dimension than the plant model. However, it is often desirable, or even necessary, to approximate these controllers by models of lower state dimension. Presently, methods for developing nonlinear state balancing transformations are not very well understood. Therefore, the second significant contribution of this thesis is a proper algorithm for the application of state balancing techniques to nonlinear control systems and the subsequent reduction of the number of control states. The method to be developed for state balancing is based on the above framework for constructing analytical solutions to the HJE. In this thesis we will make use of three existing robust nonlinear control methods from the literature. These three methods have the advantage that they can all be constructed from solutions to a single form of HJE. Thus, by developing a method for obtaining analytical expressions for the solution to a single form of HJE, we are able to develop explicit polynomial solutions for each of these three control methods. Due to the difficulties associated with quantifying robustness and performance properties for nonlinear systems, the effectiveness of the three control methods considered shall be demonstrated via

  9. Fracture control methods for space vehicles. Volume 1: Fracture control design methods. [for space shuttle configuration planning

    NASA Technical Reports Server (NTRS)

    Liu, A. F.

    1974-01-01

    A systematic approach for applying methods for fracture control in the structural components of space vehicles consists of four major steps. The first step is to define the primary load-carrying structural elements and the type of load, environment, and design stress levels acting upon them. The second step is to identify the potential fracture-critical parts by means of a selection logic flow diagram. The third step is to evaluate the safe-life and fail-safe capabilities of the specified part. The last step in the sequence is to apply the control procedures that will prevent damage to the fracture-critical parts. The fracture control methods discussed include fatigue design and analysis methods, methods for preventing crack-like defects, fracture mechanics analysis methods, and nondestructive evaluation methods. An example problem is presented for evaluation of the safe-crack-growth capability of the space shuttle crew compartment skin structure.

  10. Research of intelligent control method for the temperature of fermentation

    NASA Astrophysics Data System (ADS)

    Feng, Dongqing; Fei, Minrui; Chen, Tiejun; Dong, Lingjiao

    2003-09-01

    Fermentation process of the microorganism is a comprehensive course of organism growth and chemical reaction and the fermentation temperature is one of its most important parameters. Though an analysis of the fermented mechanism, this paper has introduced an intelligent control method for the fermentation temperature based on the apery intelligent control algorithm. During control processes, the function of human's control behavior is mimiced by the computer, and the characteristic information obtained from the dynamic processes of the control system is fully used to analyze, judge and decide so that the effective control of the object lacking of accurate model can be made. The system that adopted the apery intelligent control algorithm has been applied to a bio-pharmaceutical enterprise and has achieved a satisfied result.

  11. Nonlinear Performance Seeking Control using Fuzzy Model Reference Learning Control and the Method of Steepest Descent

    NASA Technical Reports Server (NTRS)

    Kopasakis, George

    1997-01-01

    Performance Seeking Control (PSC) attempts to find and control the process at the operating condition that will generate maximum performance. In this paper a nonlinear multivariable PSC methodology will be developed, utilizing the Fuzzy Model Reference Learning Control (FMRLC) and the method of Steepest Descent or Gradient (SDG). This PSC control methodology employs the SDG method to find the operating condition that will generate maximum performance. This operating condition is in turn passed to the FMRLC controller as a set point for the control of the process. The conventional SDG algorithm is modified in this paper in order for convergence to occur monotonically. For the FMRLC control, the conventional fuzzy model reference learning control methodology is utilized, with guidelines generated here for effective tuning of the FMRLC controller.

  12. A method of automatic control procedures cardiopulmonary resuscitation

    NASA Astrophysics Data System (ADS)

    Bureev, A. Sh.; Zhdanov, D. S.; Kiseleva, E. Yu.; Kutsov, M. S.; Trifonov, A. Yu.

    2015-11-01

    The study is to present the results of works on creation of methods of automatic control procedures of cardiopulmonary resuscitation (CPR). A method of automatic control procedure of CPR by evaluating the acoustic data of the dynamics of blood flow in the bifurcation of carotid arteries and the dynamics of air flow in a trachea according to the current guidelines for CPR is presented. Evaluation of the patient is carried out by analyzing the respiratory noise and blood flow in the interspaces between the chest compressions and artificial pulmonary ventilation. The device operation algorithm of automatic control procedures of CPR and its block diagram has been developed.

  13. Rock sampling. [method for controlling particle size distribution

    NASA Technical Reports Server (NTRS)

    Blum, P. (Inventor)

    1971-01-01

    A method for sampling rock and other brittle materials and for controlling resultant particle sizes is described. The method involves cutting grooves in the rock surface to provide a grouping of parallel ridges and subsequently machining the ridges to provide a powder specimen. The machining step may comprise milling, drilling, lathe cutting or the like; but a planing step is advantageous. Control of the particle size distribution is effected primarily by changing the height and width of these ridges. This control exceeds that obtainable by conventional grinding.

  14. Methods to study the tumor microenvironment under controlled oxygen conditions

    PubMed Central

    Byrne, Matthew B.; Leslie, Matthew T.; Gaskins, H. Rex; Kenis, Paul J.A.

    2014-01-01

    The tumor microenvironment is a complex heterogeneous assembly composed of a variety of cell types and physical features. One such feature, hypoxia, is associated with metabolic reprogramming, the epithelial-mesenchymal transition, and therapeutic resistance. Many questions remain regarding the effects of hypoxia on these outcomes, yet only few experimental methods enable both precise control over oxygen concentration and real-time imaging of cell behavior. Recent efforts with microfluidic platforms offer a promising solution to these limitations. We discuss conventional methods and tools used to control oxygen concentration for cell studies then highlight recent advances in microfluidic-based approaches for controlling oxygen in engineered platforms. PMID:25282035

  15. Overview On Alternative Asbestos Control Method Research - St. Louis, MO

    EPA Science Inventory

    The alternative asbestos control method (AACM) is an experimental approach to building demolition. Unlike the NESHAP method, the AACM allows some regulated asbestos-containing material to remain in the building and a surfactant-water solution is used to suppress asbestos fibers ...

  16. Overview On Alternative Asbestos Control Method Research - Wisconsin Dells

    EPA Science Inventory

    The alternative asbestos control method (AACM) is an experimental approach to building demolition. Unlike the NESHAP method, the AACM allows some regulated asbestos containing material to remain in the building and a surfactant-water solution is used to suppress asbestos fibers ...

  17. Overview On Alternative Asbestos Control Method Research - Nashville, TN

    EPA Science Inventory

    The alternative asbestos control method (AACM) is an experimental approach to building demolition. Unlike the NESHAP method, the AACM allows some regulated asbestos-containing material to remain in the building and a surfactant-water solution is used to suppress asbestos fibers ...

  18. Improved Continuous-Time Higher Harmonic Control Using Hinfinity Methods

    NASA Astrophysics Data System (ADS)

    Fan, Frank H.

    The helicopter is a versatile aircraft that can take-off and land vertically, hover efficiently, and maneuver in confined space. This versatility is enabled by the main rotor, which also causes undesired harmonic vibration during operation. This unwanted vibration has a negative impact on the practicality of the helicopter and also increases its operational cost. Passive control techniques have been applied to helicopter vibration suppression, but these methods are generally heavy and are not robust to changes in operating conditions. Feedback control offers the advantages of robustness and potentially higher performance over passive control techniques, and amongst the various feedback schemes, Shaw's higher harmonic control algorithm has been shown to be an effective method for attenuating harmonic disturbance in helicopters. In this thesis, the higher harmonic disturbance algorithm is further developed to achieve improved performance. One goal in this thesis is to determine the importance of periodicity in the helicopter rotor dynamics for control synthesis. Based on the analysis of wind tunnel data and simulation results, we conclude the helicopter rotor can be modeled reasonably well as linear and time-invariant for control design purposes. Modeling the helicopter rotor as linear time-invariant allows us to apply linear control theory concepts to the higher harmonic control problem. Another goal in this thesis is to find the limits of performance in harmonic disturbance rejection. To achieve this goal, we first define the metrics to measure the performance of the controller in terms of response speed and robustness to changes in the plant dynamics. The performance metrics are incorporated into an Hinfinity control problem. For a given plant, the resulting Hinfinity controller achieves the maximum performance, thus allowing us to identify the performance limitation in harmonic disturbance rejection. However, the Hinfinity controllers are of high order, and may

  19. Computational methods of robust controller design for aerodynamic flutter suppression

    NASA Technical Reports Server (NTRS)

    Anderson, L. R.

    1981-01-01

    The development of Riccati iteration, a tool for the design and analysis of linear control systems is examined. First, Riccati iteration is applied to the problem of pole placement and order reduction in two-time scale control systems. Order reduction, yielding a good approximation to the original system, is demonstrated using a 16th order linear model of a turbofan engine. Next, a numerical method for solving the Riccati equation is presented and demonstrated for a set of eighth order random examples. A literature review of robust controller design methods follows which includes a number of methods for reducing the trajectory and performance index sensitivity in linear regulators. Lastly, robust controller design for large parameter variations is discussed.

  20. Deterministic methods for multi-control fuel loading optimization

    NASA Astrophysics Data System (ADS)

    Rahman, Fariz B. Abdul

    We have developed a multi-control fuel loading optimization code for pressurized water reactors based on deterministic methods. The objective is to flatten the fuel burnup profile, which maximizes overall energy production. The optimal control problem is formulated using the method of Lagrange multipliers and the direct adjoining approach for treatment of the inequality power peaking constraint. The optimality conditions are derived for a multi-dimensional multi-group optimal control problem via calculus of variations. Due to the Hamiltonian having a linear control, our optimal control problem is solved using the gradient method to minimize the Hamiltonian and a Newton step formulation to obtain the optimal control. We are able to satisfy the power peaking constraint during depletion with the control at beginning of cycle (BOC) by building the proper burnup path forward in time and utilizing the adjoint burnup to propagate the information back to the BOC. Our test results show that we are able to achieve our objective and satisfy the power peaking constraint during depletion using either the fissile enrichment or burnable poison as the control. Our fuel loading designs show an increase of 7.8 equivalent full power days (EFPDs) in cycle length compared with 517.4 EFPDs for the AP600 first cycle.

  1. A pseudospectral method for optimal control of open quantum systems.

    PubMed

    Li, Jr-Shin; Ruths, Justin; Stefanatos, Dionisis

    2009-10-28

    In this paper, we present a unified computational method based on pseudospectral approximations for the design of optimal pulse sequences in open quantum systems. The proposed method transforms the problem of optimal pulse design, which is formulated as a continuous-time optimal control problem, to a finite-dimensional constrained nonlinear programming problem. This resulting optimization problem can then be solved using existing numerical optimization suites. We apply the Legendre pseudospectral method to a series of optimal control problems on open quantum systems that arise in nuclear magnetic resonance spectroscopy in liquids. These problems have been well studied in previous literature and analytical optimal controls have been found. We find an excellent agreement between the maximum transfer efficiency produced by our computational method and the analytical expressions. Moreover, our method permits us to extend the analysis and address practical concerns, including smoothing discontinuous controls as well as deriving minimum-energy and time-optimal controls. The method is not restricted to the systems studied in this article and is applicable to optimal manipulation of both closed and open quantum systems. PMID:19894930

  2. Transformation ray method: controlling high frequency elastic waves (L).

    PubMed

    Chang, Zheng; Liu, Xiaoning; Hu, Gengkai; Hu, Jin

    2012-10-01

    Elastic ray theory is a high frequency asymptotic approximation of solution of elastodynamic equation, and is widely used in seismology. In this paper, the form invariance under a general spatial mapping and high frequency wave control have been examined by transformation method. It is showed that with the constraint of major and minor symmetry of the transformed elastic tensor, the eikonal equation keeps its form under a general mapping, however, the transport equation loses its form except for conformal mapping. Therefore, the elastic ray path can be controlled in an exact manner by a transformation method, whereas energy distribution along the ray is only approximately controlled. An elastic rotator based on ray tracing method is also provided to illustrate the method and to access the approximation. PMID:23039561

  3. Modified independent modal space control method for active control of flexible systems

    NASA Technical Reports Server (NTRS)

    Baz, A.; Poh, S.

    1987-01-01

    A modified independent modal space control (MIMSC) method is developed for designing active vibration control systems for large flexible structures. The method accounts for the interaction between the controlled and residual modes. It incorporates also optimal placement procedures for selecting the optimal locations of the actuators in the structure in order to minimize the structural vibrations as well as the actuation energy. The MIMSC method relies on an important feature which is based on time sharing of a small number of actuators, in the modal space, to control effectively a large number of modes. Numerical examples are presented to illustrate the application of the method to generic flexible systems. The results obtained suggest the potential of the devised method in designing efficient active control systems for large flexible structures.

  4. Method and apparatus for automatic control of a humanoid robot

    NASA Technical Reports Server (NTRS)

    Abdallah, Muhammad E (Inventor); Platt, Robert (Inventor); Wampler, II, Charles W. (Inventor); Reiland, Matthew J (Inventor); Sanders, Adam M (Inventor)

    2013-01-01

    A robotic system includes a humanoid robot having a plurality of joints adapted for force control with respect to an object acted upon by the robot, a graphical user interface (GUI) for receiving an input signal from a user, and a controller. The GUI provides the user with intuitive programming access to the controller. The controller controls the joints using an impedance-based control framework, which provides object level, end-effector level, and/or joint space-level control of the robot in response to the input signal. A method for controlling the robotic system includes receiving the input signal via the GUI, e.g., a desired force, and then processing the input signal using a host machine to control the joints via an impedance-based control framework. The framework provides object level, end-effector level, and/or joint space-level control of the robot, and allows for functional-based GUI to simplify implementation of a myriad of operating modes.

  5. Spectral radiative property control method based on filling solution

    NASA Astrophysics Data System (ADS)

    Jiao, Y.; Liu, L. H.; Hsu, P.-f.

    2014-01-01

    Controlling thermal radiation by tailoring spectral properties of microstructure is a promising method, can be applied in many industrial systems and have been widely researched recently. Among various property tailoring schemes, geometry design of microstructures is a commonly used method. However, the existing radiation property tailoring is limited by adjustability of processed microstructures. In other words, the spectral radiative properties of microscale structures are not possible to change after the gratings are fabricated. In this paper, we propose a method that adjusts the grating spectral properties by means of injecting filling solution, which could modify the thermal radiation in a fabricated microstructure. Therefore, this method overcomes the limitation mentioned above. Both mercury and water are adopted as the filling solution in this study. Aluminum and silver are selected as the grating materials to investigate the generality and limitation of this control method. The rigorous coupled-wave analysis is used to investigate the spectral radiative properties of these filling solution grating structures. A magnetic polaritons mechanism identification method is proposed based on LC circuit model principle. It is found that this control method could be used by different grating materials. Different filling solutions would enable the high absorption peak to move to longer or shorter wavelength band. The results show that the filling solution grating structures are promising for active control of spectral radiative properties.

  6. Immediate processing of erotic stimuli in paedophilia and controls: a case control study

    PubMed Central

    2013-01-01

    Background Most neuroimaging studies investigating sexual arousal in paedophilia used erotic pictures together with a blocked fMRI design and long stimulus presentation time. While this approach allows the detection of sexual arousal, it does not enable the assessment of the immediate processing of erotically salient stimuli. Our study aimed to identify neuronal networks related to the immediate processing of erotic stimuli in heterosexual male paedophiles and healthy age-matched controls. Methods We presented erotic pictures of prepubescent children and adults in an event related fMRI-design to eight paedophilic subjects and age-matched controls. Results Erotic pictures of females elicited more activation in the right temporal lobe, the right parietal lobe and both occipital lobes and erotic pictures of children activated the right dorsomedial prefrontal cortex in both groups. An interaction of sex, age and group was present in the right anteriolateral oribitofrontal cortex. Conclusions Our event related study design confirmed that erotic pictures activate some of the brain regions already known to be involved in the processing of erotic pictures when these are presented in blocks. In addition, it revealed that erotic pictures of prepubescent children activate brain regions critical for choosing response strategies in both groups, and that erotically salient stimuli selectively activate a brain region in paedophilic subjects that had previously been attributed to reward and punishment, and that had been shown to be implicated in the suppression of erotic response and deception. PMID:23510246

  7. Control methods against invasive Aedes mosquitoes in Europe: a review.

    PubMed

    Baldacchino, Frédéric; Caputo, Beniamino; Chandre, Fabrice; Drago, Andrea; della Torre, Alessandra; Montarsi, Fabrizio; Rizzoli, Annapaola

    2015-11-01

    Five species of invasive Aedes mosquitoes have recently become established in Europe: Ae. albopictus, Ae. aegypti, Ae. japonicus japonicus, Ae. koreicus and Ae. atropalpus. These mosquitoes are a serious nuisance for people and are also competent vectors for several exotic pathogens such as dengue and chikungunya viruses. As they are a growing public health concern, methods to control these mosquitoes need to be implemented to reduce their biting and their potential for disease transmission. There is a crucial need to evaluate methods as part of an integrated invasive mosquito species control strategy in different European countries, taking into account local Aedes infestations and European regulations. This review presents the control methods available or in development against invasive Aedes mosquitoes, with a particular focus on those that can be implemented in Europe. These control methods are divided into five categories: environmental (source reduction), mechanical (trapping), biological (e.g. copepods, Bacillus thuringiensis var. israelensis, Wolbachia), chemical (insect growth regulators, pyrethroids) and genetic (sterile insect technique and genetically modified mosquitoes). We discuss the effectiveness, ecological impact, sustainability and stage of development of each control method. PMID:26037532

  8. Robust current control of AC machines using the internal model control method

    SciTech Connect

    Harnefors, L.; Nee, H.P.

    1995-12-31

    In the present paper, the internal model control (IMC) method is introduced and applied to ac machine current control. A permanent-magnet synchronous machine is used as an example. It is shown that the IMC design is straightforward and the resulting controller is simple to implement. The controller parameters are expressed in the machine parameters and the desired closed-loop rise time. The extra cost of implementation compared to PI control is negligible. It is further shown that IMC is able to outperform PI control with as well as without decoupling with respect to dq variable interaction in the presence of parameter deviations.

  9. Problems of Mathematical Finance by Stochastic Control Methods

    NASA Astrophysics Data System (ADS)

    Stettner, Łukasz

    The purpose of this paper is to present main ideas of mathematics of finance using the stochastic control methods. There is an interplay between stochastic control and mathematics of finance. On the one hand stochastic control is a powerful tool to study financial problems. On the other hand financial applications have stimulated development in several research subareas of stochastic control in the last two decades. We start with pricing of financial derivatives and modeling of asset prices, studying the conditions for the absence of arbitrage. Then we consider pricing of defaultable contingent claims. Investments in bonds lead us to the term structure modeling problems. Special attention is devoted to historical static portfolio analysis called Markowitz theory. We also briefly sketch dynamic portfolio problems using viscosity solutions to Hamilton-Jacobi-Bellman equation, martingale-convex analysis method or stochastic maximum principle together with backward stochastic differential equation. Finally, long time portfolio analysis for both risk neutral and risk sensitive functionals is introduced.

  10. Battery charging control methods, electric vehicle charging methods, battery charging apparatuses and rechargeable battery systems

    SciTech Connect

    Tuffner, Francis K.; Kintner-Meyer, Michael C. W.; Hammerstrom, Donald J.; Pratt, Richard M.

    2012-05-22

    Battery charging control methods, electric vehicle charging methods, battery charging apparatuses and rechargeable battery systems. According to one aspect, a battery charging control method includes accessing information regarding a presence of at least one of a surplus and a deficiency of electrical energy upon an electrical power distribution system at a plurality of different moments in time, and using the information, controlling an adjustment of an amount of the electrical energy provided from the electrical power distribution system to a rechargeable battery to charge the rechargeable battery.

  11. Systems and Methods for Peak-Seeking Control

    NASA Technical Reports Server (NTRS)

    Ryan, John J (Inventor); Speyer, Jason L (Inventor)

    2013-01-01

    A computerized system and method for peak-seeking-control that uses a unique Kalman filter design to optimize a control loop, in real time, to either maximize or minimize a performance function of a physical object ("plant"). The system and method achieves more accurate and efficient peak-seeking-control by using a time-varying Kalman filter to estimate both the performance function gradient (slope) and Hessian (curvature) based on direct position measurements of the plant, and does not rely upon modeling the plant response to persistent excitation. The system and method can be naturally applied in various applications in which plant performance functions have multiple independent parameters, and it does not depend upon frequency separation to distinguish between system dimensions.

  12. Analog neural network control method proposed for use in a backup satellite control mode

    SciTech Connect

    Frigo, J.R.; Tilden, M.W.

    1998-03-01

    The authors propose to use an analog neural network controller implemented in hardware, independent of the active control system, for use in a satellite backup control mode. The controller uses coarse sun sensor inputs. The field of view of the sensors activate the neural controller, creating an analog dead band with respect to the direction of the sun on each axis. This network controls the orientation of the vehicle toward the sunlight to ensure adequate power for the system. The attitude of the spacecraft is stabilized with respect to the ambient magnetic field on orbit. This paper develops a model of the controller using real-time coarse sun sensor data and a dynamic model of a prototype system based on a satellite system. The simulation results and the feasibility of this control method for use in a satellite backup control mode are discussed.

  13. One shot methods for optimal control of distributed parameter systems 1: Finite dimensional control

    NASA Technical Reports Server (NTRS)

    Taasan, Shlomo

    1991-01-01

    The efficient numerical treatment of optimal control problems governed by elliptic partial differential equations (PDEs) and systems of elliptic PDEs, where the control is finite dimensional is discussed. Distributed control as well as boundary control cases are discussed. The main characteristic of the new methods is that they are designed to solve the full optimization problem directly, rather than accelerating a descent method by an efficient multigrid solver for the equations involved. The methods use the adjoint state in order to achieve efficient smoother and a robust coarsening strategy. The main idea is the treatment of the control variables on appropriate scales, i.e., control variables that correspond to smooth functions are solved for on coarse grids depending on the smoothness of these functions. Solution of the control problems is achieved with the cost of solving the constraint equations about two to three times (by a multigrid solver). Numerical examples demonstrate the effectiveness of the method proposed in distributed control case, pointwise control and boundary control problems.

  14. Learning styles: The learning methods of air traffic control students

    NASA Astrophysics Data System (ADS)

    Jackson, Dontae L.

    In the world of aviation, air traffic controllers are an integral part in the overall level of safety that is provided. With a number of controllers reaching retirement age, the Air Traffic Collegiate Training Initiative (AT-CTI) was created to provide a stronger candidate pool. However, AT-CTI Instructors have found that a number of AT-CTI students are unable to memorize types of aircraft effectively. This study focused on the basic learning styles (auditory, visual, and kinesthetic) of students and created a teaching method to try to increase memorization in AT-CTI students. The participants were asked to take a questionnaire to determine their learning style. Upon knowing their learning styles, participants attended two classroom sessions. The participants were given a presentation in the first class, and divided into a control and experimental group for the second class. The control group was given the same presentation from the first classroom session while the experimental group had a group discussion and utilized Middle Tennessee State University's Air Traffic Control simulator to learn the aircraft types. Participants took a quiz and filled out a survey, which tested the new teaching method. An appropriate statistical analysis was applied to determine if there was a significant difference between the control and experimental groups. The results showed that even though the participants felt that the method increased their learning, there was no significant difference between the two groups.

  15. A method for the control of multigrasp myoelectric prosthetic hands.

    PubMed

    Dalley, Skyler Ashton; Varol, Huseyin Atakan; Goldfarb, Michael

    2012-01-01

    This paper presents the design and preliminary experimental validation of a multigrasp myoelectric controller. The described method enables direct and proportional control of multigrasp prosthetic hand motion among nine characteristic postures using two surface electromyography electrodes. To assess the efficacy of the control method, five nonamputee subjects utilized the multigrasp myoelectric controller to command the motion of a virtual prosthesis between random sequences of target hand postures in a series of experimental trials. For comparison, the same subjects also utilized a data glove, worn on their native hand, to command the motion of the virtual prosthesis for similar sequences of target postures during each trial. The time required to transition from posture to posture and the percentage of correctly completed transitions were evaluated to characterize the ability to control the virtual prosthesis using each method. The average overall transition times across all subjects were found to be 1.49 and 0.81 s for the multigrasp myoelectric controller and the native hand, respectively. The average transition completion rates for both were found to be the same (99.2%). Supplemental videos demonstrate the virtual prosthesis experiments, as well as a preliminary hardware implementation. PMID:22180515

  16. Delayed feedback control method for dynamical systems with chaotic saddles

    NASA Astrophysics Data System (ADS)

    Kobayashi, Miki U.; Aihara, Kazuyuki

    2012-08-01

    We consider systems whose orbits diverge after chaotic transient for a finite time, and propose a controlmethod for preventing the divergence. These systems generally possess not chaotic attractors but some chaotic saddles. Our aim of control, i.e., the prevention of divergence, is achieved through the stabilization of unstable periodic orbits embedded in the chaotic saddle by making use of the delayed feedback controlmethod. The key concept of our control strategy is the application of the Proper Interior Maximum (PIM) triple method and the method to detect unstable periodic orbits from time series, originally developed by Lathrop and Kostelich, as initial steps before adding the delayed feedback control input. We show that our control method can be applied to the Hénon map and an intermittent androgen suppression (IAS) therapy model, which is a model for therapy of advanced prostate cancer. The fact that our method can be applied to the IAS therapy model indicates that our control strategy may be useful in the therapy of advanced prostate cancer.

  17. Robust Optimal Adaptive Control Method with Large Adaptive Gain

    NASA Technical Reports Server (NTRS)

    Nguyen, Nhan T.

    2009-01-01

    In the presence of large uncertainties, a control system needs to be able to adapt rapidly to regain performance. Fast adaptation is referred to the implementation of adaptive control with a large adaptive gain to reduce the tracking error rapidly. However, a large adaptive gain can lead to high-frequency oscillations which can adversely affect robustness of an adaptive control law. A new adaptive control modification is presented that can achieve robust adaptation with a large adaptive gain without incurring high-frequency oscillations as with the standard model-reference adaptive control. The modification is based on the minimization of the Y2 norm of the tracking error, which is formulated as an optimal control problem. The optimality condition is used to derive the modification using the gradient method. The optimal control modification results in a stable adaptation and allows a large adaptive gain to be used for better tracking while providing sufficient stability robustness. Simulations were conducted for a damaged generic transport aircraft with both standard adaptive control and the adaptive optimal control modification technique. The results demonstrate the effectiveness of the proposed modification in tracking a reference model while maintaining a sufficient time delay margin.

  18. Teaching Thermal Hydraulics & Numerical Methods: An Introductory Control Volume Primer

    SciTech Connect

    Lucas, D.S.

    2004-10-03

    This paper covers the basics of the implementation of the control volume method in the context of the Homogeneous Equilibrium Model (HEM)(T/H) code using the conservation equations of mass, momentum, and energy. This primer uses the advection equation as a template. The discussion will cover the basic equations of the control volume portion of the course in the primer, which includes the advection equation, numerical methods, along with the implementation of the various equations via FORTRAN into computer programs and the final result for a three equation HEM code and its validation.

  19. Simulation of automatic gain control method for laser radar receiver

    NASA Astrophysics Data System (ADS)

    Cai, Xiping; Shang, Hongbo; Wang, Lina; Yang, Shuang

    2008-12-01

    A receiver with high dynamic response and wide control range are necessary for a laser radar system. In this paper, an automatic gain control scheme for laser radar receiver is proposed. The scheme is based on a closed-loop logarithmic feedback method. Signal models for pulse laser radar system are created and as the input to the AGC model. The signal is supposed to be very weak and with a nanosecond order of pulse width in the light of the property of the laser radar. The method and the simulation for the AGC will be presented in detail.

  20. A Method to Control the Cushion Pressure of Oscillating SES

    NASA Astrophysics Data System (ADS)

    Senba, Hiromitsu; Matsuo, Hideo; Takahashi, Hidehiko; Yoshimoto, Shintarou; Matsuo, Kensuke; Kanazawa, Koji; Hiroe, Tetsuyuki; Fujiwara, Kazuhito

    A method is proposed to control the variation of cushion pressure of SES oscillating vertically. The peripheral nozzle is attached along the periphery and swings changing the discharge angle. The angle varies in accordance with the motion of the craft. A method is proposed to analyze the mechanism of this setup. The result is compared with experiments to show the agreement of the two results. It has been shown both theoretically and experimentally that the variation of the cushion pressure is effectively controlled adjusting the amplitude and the phase of the swinging motion of the nozzle.

  1. Pendulation control system and method for rotary boom cranes

    SciTech Connect

    Robinett, III, Rush D.; Groom, Kenneth N.; Feddema, John T.; Parker, Gordon G.

    2002-01-01

    A command shaping control system and method for rotary boom cranes provides a way to reduce payload pendulation caused by real-time input signals, from either operator command or automated crane maneuvers. The method can take input commands and can apply a command shaping filter to reduce contributors to payload pendulation due to rotation, elevation, and hoisting movements in order to control crane response and reduce tangential and radial payload pendulation. A filter can be applied to a pendulation excitation frequency to reduce residual radial pendulation and tangential pendulation amplitudes.

  2. Methods for control of tick vectors of Lyme Borreliosis

    USGS Publications Warehouse

    Jaenson, T.G.T.; Fish, D.; Ginsberg, H.S.; Gray, J.S.; Mather, T.N.; Piesman, J.

    1991-01-01

    During the IVth International Conference on Lyme Borreliosis in Stockholm, 1990, a workshop on control of Lyme disease vectors briefly reviewed: basic ecological principles for tick control; biocontrol of ticks; chemical control, including the use of repellents and use of permethrin-treated rodent nest material; tick control by habitat modification; and reduction of tick host availability. It was concluded that, although much research work remains, Lyme borreliosis is to a large extent a preventable infection. Avoidance of heavily tick-infested areas, personal protection using proper clothing, and prompt removal of attached ticks remain the most effective protective measures. Many other prophylactic measures are available and could be efficiently integrated into schemes to reduce the abundance of vectors. However, since the ecology of the infection varies greatly between different localities it may be necessary to apply different combinations of control methods in different endemic regions.

  3. Method and apparatus for loss of control inhibitor systems

    NASA Technical Reports Server (NTRS)

    A'Harrah, Ralph C. (Inventor)

    2007-01-01

    Active and adaptive systems and methods to prevent loss of control incidents by providing tactile feedback to a vehicle operator are disclosed. According to the present invention, an operator gives a control input to an inceptor. An inceptor sensor measures an inceptor input value of the control input. The inceptor input is used as an input to a Steady-State Inceptor Input/Effector Output Model that models the vehicle control system design. A desired effector output from the inceptor input is generated from the model. The desired effector output is compared to an actual effector output to get a distortion metric. A feedback force is generated as a function of the distortion metric. The feedback force is used as an input to a feedback force generator which generates a loss of control inhibitor system (LOCIS) force back to the inceptor. The LOCIS force is felt by the operator through the inceptor.

  4. Method and System for Active Noise Control of Tiltrotor Aircraft

    NASA Technical Reports Server (NTRS)

    Betzina, Mark D. (Inventor); Nguyen, Khanh Q. (Inventor)

    2003-01-01

    Methods and systems for reducing noise generated by rotating blades of a tiltrotor aircraft. A rotor-blade pitch angle associated with the tiltrotor aircraft can be controlled utilizing a swashplate connected to rotating blades of the tiltrotor aircraft. One or more Higher Harmonic Control (HHC) signals can be transmitted and input to a swashplate control actuator associated with the swashplate. A particular blade pitch oscillation (e.g., four cycles per revolution) is there-after produced in a rotating frame of reference associated with the rotating blades in response to input of an HHC signal to the swashplate control actuator associated with the swashplate to thereby reduce noise associated with the rotating blades of the tiltrotor aircraft. The HHC signal can be transmitted and input to the swashplate control actuator to reduce noise of the tiltrotor aircraft in response to a user input utilizing an open-loop configuration.

  5. Method for making a micromachined microwave signal control device

    DOEpatents

    Forman, Michael A.

    2011-02-15

    A method for fabricating a signal controller, e.g., a filter or a switch, for a coplanar waveguide during the LIGA fabrication process of the waveguide. Both patterns for the waveguide and patterns for the signal controllers are created on a mask. Radiation travels through the mask and reaches a photoresist layer on a substrate. The irradiated portions are removed and channels are formed on the substrate. A metal is filled into the channels to form the conductors of the waveguide and the signal controllers. Micromachined quasi-lumped elements are used alone or together as filters. The switch includes a comb drive, a spring, a metal plunger, and anchors.

  6. Micromachined microwave signal control device and method for making same

    DOEpatents

    Forman, Michael A.

    2008-09-02

    A method for fabricating a signal controller, e.g., a filter or a switch, for a coplanar waveguide during the LIGA fabrication process of the waveguide. Both patterns for the waveguide and patterns for the signal controllers are created on a mask. Radiation travels through the mask and reaches a photoresist layer on a substrate. The irradiated portions are removed and channels are formed on the substrate. A metal is filled into the channels to form the conductors of the waveguide and the signal controllers. Micromachined quasi-lumped elements are used alone or together as filters. The switch includes a comb drive, a spring, a metal plunger, and anchors.

  7. Method and apparatus for controlling cross contamination of microfluid channels

    DOEpatents

    Hasselbrink, Jr., Ernest F.; Rehm, Jason E.; Paul, Phillip H.; Arnold, Don W.

    2006-02-07

    A method for controlling fluid flow at junctions in microchannel systems. Control of fluid flow is accomplished generally by providing increased resistance to electric-field and pressure-driven flow in the form of regions of reduced effective cross-sectional area within the microchannels and proximate a channel junction. By controlling these flows in the region of a microchannel junction it is possible to eliminate sample dispersion and cross contamination and inject well-defined volumes of fluid from one channel to another.

  8. Acoustic boundary control method for interior sound suppression

    NASA Astrophysics Data System (ADS)

    Sun, Jian Q.; Hirsch, S. M.

    1997-06-01

    Suppressing interior sound radiation in helicopters, fixed- wing aircraft and land vehicles is a very important problem. It has been studied quite extensively in the past few decades. There are two mainstream methods for this problem: active noise cancellation (ANC) using loudspeakers and sound radiation reduction via structural controls (often called active structural acoustic control or ASAC). An ANC system often requires an impractically high dimensionality to achieve the level of global noise reduction in a three dimensional volume that ASAC systems with a relatively low dimensionality are capable of, while actuators for structural control systems are power intensive and less reliable. This paper presents an acoustic boundary control method that may reserve the advantages of both ANC and ASAC. Numerical simulation results of interior noise control are presented to demonstrate the ability of the acoustic boundary control to cancel sound fields due to different primary sources. A discussion is also presented on the spatial characteristics of the acoustic boundary control as a function of frequency. An interesting phenomenon is discovered that may have significant implications to the actuator grouping studies.

  9. Covariant Tarpeian Method for Bloat Control in Genetic Programming

    NASA Astrophysics Data System (ADS)

    Poli, Riccardo

    In this paper a simple modification of the Tarpeian bloat-control method is presented which allows one to dynamically set the parameters of the method in such a way to guarantee that the mean program size will either keep a particular value (e.g., its initial value) or will follow a schedule chosen by the user. The mathematical derivation of the technique as well as its numerical and empirical corroboration are presented.

  10. A Fuzzy Permutation Method for False Discovery Rate Control.

    PubMed

    Yang, Ya-Hui; Lin, Wan-Yu; Lee, Wen-Chung

    2016-01-01

    Biomedical researchers often encounter the large-p-small-n situations-a great number of variables are measured/recorded for only a few subjects. The authors propose a fuzzy permutation method to address the multiple testing problem for small sample size studies. The method introduces fuzziness into standard permutation analysis to produce randomized p-values, which are then converted into q-values for false discovery rate controls. Simple algebra shows that the fuzzy permutation method is at least as powerful as the standard permutation method under any alternative. Monte-Carlo simulations show that the proposed method has desirable statistical properties whether the study variables are normally or non-normally distributed. A real dataset is analyzed to illustrate its use. The proposed fuzzy permutation method is recommended for use in the large-p-small-n settings. PMID:27328860

  11. A Fuzzy Permutation Method for False Discovery Rate Control

    PubMed Central

    Yang, Ya-Hui; Lin, Wan-Yu; Lee, Wen-Chung

    2016-01-01

    Biomedical researchers often encounter the large-p-small-n situations—a great number of variables are measured/recorded for only a few subjects. The authors propose a fuzzy permutation method to address the multiple testing problem for small sample size studies. The method introduces fuzziness into standard permutation analysis to produce randomized p-values, which are then converted into q-values for false discovery rate controls. Simple algebra shows that the fuzzy permutation method is at least as powerful as the standard permutation method under any alternative. Monte-Carlo simulations show that the proposed method has desirable statistical properties whether the study variables are normally or non-normally distributed. A real dataset is analyzed to illustrate its use. The proposed fuzzy permutation method is recommended for use in the large-p-small-n settings. PMID:27328860

  12. Multigrid one shot methods for optimal control problems: Infinite dimensional control

    NASA Technical Reports Server (NTRS)

    Arian, Eyal; Taasan, Shlomo

    1994-01-01

    The multigrid one shot method for optimal control problems, governed by elliptic systems, is introduced for the infinite dimensional control space. ln this case, the control variable is a function whose discrete representation involves_an increasing number of variables with grid refinement. The minimization algorithm uses Lagrange multipliers to calculate sensitivity gradients. A preconditioned gradient descent algorithm is accelerated by a set of coarse grids. It optimizes for different scales in the representation of the control variable on different discretization levels. An analysis which reduces the problem to the boundary is introduced. It is used to approximate the two level asymptotic convergence rate, to determine the amplitude of the minimization steps, and the choice of a high pass filter to be used when necessary. The effectiveness of the method is demonstrated on a series of test problems. The new method enables the solutions of optimal control problems at the same cost of solving the corresponding analysis problems just a few times.

  13. Non-Contact Electromagnetic Exciter Design with Linear Control Method

    NASA Astrophysics Data System (ADS)

    Wang, Lin; Xiong, Xianzhi; Xu, Hua

    2016-04-01

    A non-contact type force actuator is necessary for studying the dynamic performance of a high-speed spindle system owing to its high-speed operating conditions. A non-contact electromagnetic exciter is designed for identifying the dynamic coefficients of journal bearings in high-speed grinding spindles. A linear force control method is developed based on PID controller. The influence of amplitude and frequency of current, misalignment and rotational speed on magnetic field and excitation force is investigated based on two-dimensional finite element analysis. The electromagnetic excitation force is measured with the auxiliary coils and calibrated by load cells. The design is validated by the experimental results. Theoretical and experimental investigations show that the proposed design can accurately generate linear excitation force with sufficiently large amplitude and higher signal to noise ratio. Moreover, the fluctuations in force amplitude are reduced to a greater extent with the designed linear control method even when the air gap changes due to the rotor vibration at high-speed conditions. Besides, it is possible to apply various types of excitations: constant, synchronous, and non-synchronous excitation forces based on the proposed linear control method. This exciter can be used as linear-force exciting and controlling system for dynamic performance study of different high-speed rotor-bearing systems.

  14. Control of large flexible spacecraft by the independent modal-space control method

    NASA Technical Reports Server (NTRS)

    Meirovitch, L.; Shenar, J.

    1984-01-01

    The problem of control of a large-order flexible structure in the form of a plate-like lattice by the Independent Modal-Space Control (IMSC) method is presented. The equations of motion are first transformed to the modal space, thus obtaining internal (plant) decoupling of the system. Then, the control laws are designed in the modal space for each mode separately, so that the modal equations of motion are rendered externally (controller) decoupled. This complete decoupling applies both to rigid-body modes and elastic modes. The application of linear optimal control, in conjunction with a quadratic performance index, is first reviewed. A solution for high-order systems is proposed here by the IMSC method, whereby the problem is reduced to a number of modal minimum-fuel problems for the controlled modes.

  15. METHOD AND APPARATUS FOR CONTROL OF A NUCLEAR REACTOR

    DOEpatents

    Cawley, W.E.

    1962-12-11

    A method and apparatus are described for controlling an overmoderated nuclear reactor containing columns of fuel elements aligned in a plurality of coolant tubes in a stream of coolant water. The invention includes means for adjusting the distance between halves of the fuel element column to vary the relative proportion of fuel and moderator at the center of the reactor. (AEC)

  16. 40 CFR 63.469 - Equivalent methods of control.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Section 63.469 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES National Emission Standards for Halogenated Solvent Cleaning § 63.469 Equivalent methods of control. Upon written...

  17. A Conditional Exposure Control Method for Multidimensional Adaptive Testing

    ERIC Educational Resources Information Center

    Finkelman, Matthew; Nering, Michael L.; Roussos, Louis A.

    2009-01-01

    In computerized adaptive testing (CAT), ensuring the security of test items is a crucial practical consideration. A common approach to reducing item theft is to define maximum item exposure rates, i.e., to limit the proportion of examinees to whom a given item can be administered. Numerous methods for controlling exposure rates have been proposed…

  18. A METHOD TO CONTROL MULTIPASS BEAM BREAKUP IN RECIRCULATING LINACS

    SciTech Connect

    Byung Yunn

    2003-05-01

    We investigate a method to control the multipass dipole beam breakup instability in a recirculating linac including energy recovery. Effectiveness of an external feedback system for such a goal is shown clearly in a simplified model. We also verify the theoretical result with a simulation study.

  19. ALTERNATIVE ASBESTOS CONTROL METHOD (AACM) RESEARCH - BALTIMORE, MD

    EPA Science Inventory

    This presentation describes the status to date of the Alternative Asbestos Control Method research, which is intended as a possible alternative technology for use in the demolition of buildings that contain asbestos and are covered under the regulatory requirements of the Asbesto...

  20. Active control of vibration using a fuzzy control method based on scaling universes of discourse

    NASA Astrophysics Data System (ADS)

    Si, Hongwei; Li, Dongxu

    2007-06-01

    Large flexible space structures are complex in structural dynamic characteristics. The control method based on custom control theory and modern control theory is difficult to solve for the complex problem. The fuzzy controller is not dependent on the accurate model. But the precision of a conventional fuzzy controller is not good, and the adaptive ability of a conventional fuzzy controller is limited. The fuzzy controller can make the system surge. Scaling universes of discourse is an effective method to improve the performance of the fuzzy controller. This paper is aimed at the difficult problem of designing a stable adaptive controller based on scaling universes of discourse, and letting input membership function and output membership function be denoted as input universes of discourse and the center value of output membership function, respectively. A kind of Lyapunov function, designed as an adaptive law of input universes of discourse and the center value of output membership function, was then adopted. A kind of stable self-adaptive fuzzy controller based on scaling universes of discourse is designed in this paper for the vibration control of a large flexible space truss driven by piezoelectric sensors and actuators (PZTs).

  1. Control method for turbocharged diesel engines having exhaust gas recirculation

    DOEpatents

    Kolmanovsky, Ilya V.; Jankovic, Mrdjan J; Jankovic, Miroslava

    2000-03-14

    A method of controlling the airflow into a compression ignition engine having an EGR and a VGT. The control strategy includes the steps of generating desired EGR and VGT turbine mass flow rates as a function of the desired and measured compressor mass airflow values and exhaust manifold pressure values. The desired compressor mass airflow and exhaust manifold pressure values are generated as a function of the operator-requested fueling rate and engine speed. The EGR and VGT turbine mass flow rates are then inverted to corresponding EGR and VGT actuator positions to achieve the desired compressor mass airflow rate and exhaust manifold pressure. The control strategy also includes a method of estimating the intake manifold pressure used in generating the EGR valve and VGT turbine positions.

  2. Exact methods for modal transient response analysis including feedback control

    NASA Technical Reports Server (NTRS)

    Anderson, Melvin S.; Belvin, W. Keith

    1993-01-01

    This paper presents a modal method for the analysis of controlled structural systems that retains the uncoupled nature of the classical transient response analysis of a structure subjected to a prescribed time-varying load. The control force is expanded as a Taylor series that remains on the right side of the equations, and it does not lead to a computational approach that requires coupling between modes on the left side. Retaining a sufficient number of terms in the series produces a solution to the modal equations that is accurate to machine precision. The approach is particularly attractive for large problems in which standard matrix exponential methods become computationally prohibitive. Numerical results are presented to show the accuracy and efficiency of the proposed approach for dynamic feedback compensation of a truss structure with local member modes in the controller bandwidth.

  3. Computer controlled fluorometer device and method of operating same

    DOEpatents

    Kolber, Z.; Falkowski, P.

    1990-07-17

    A computer controlled fluorometer device and method of operating same, said device being made to include a pump flash source and a probe flash source and one or more sample chambers in combination with a light condenser lens system and associated filters and reflectors and collimators, as well as signal conditioning and monitoring means and a programmable computer means and a software programmable source of background irradiance that is operable according to the method of the invention to rapidly, efficiently and accurately measure photosynthetic activity by precisely monitoring and recording changes in fluorescence yield produced by a controlled series of predetermined cycles of probe and pump flashes from the respective probe and pump sources that are controlled by the computer means. 13 figs.

  4. Computer controlled fluorometer device and method of operating same

    DOEpatents

    Kolber, Zbigniew; Falkowski, Paul

    1990-01-01

    A computer controlled fluorometer device and method of operating same, said device being made to include a pump flash source and a probe flash source and one or more sample chambers in combination with a light condenser lens system and associated filters and reflectors and collimators, as well as signal conditioning and monitoring means and a programmable computer means and a software programmable source of background irradiance that is operable according to the method of the invention to rapidly, efficiently and accurately measure photosynthetic activity by precisely monitoring and recording changes in fluorescence yield produced by a controlled series of predetermined cycles of probe and pump flashes from the respective probe and pump sources that are controlled by the computer means.

  5. Helicopter flight-control design using an H(2) method

    NASA Technical Reports Server (NTRS)

    Takahashi, Marc D.

    1991-01-01

    Rate-command and attitude-command flight-control designs for a UH-60 helicopter in hover are presented and were synthesized using an H(2) method. Using weight functions, this method allows the direct shaping of the singular values of the sensitivity, complementary sensitivity, and control input transfer-function matrices to give acceptable feedback properties. The designs were implemented on the Vertical Motion Simulator, and four low-speed hover tasks were used to evaluate the control system characteristics. The pilot comments from the accel-decel, bob-up, hovering turn, and side-step tasks indicated good decoupling and quick response characteristics. However, an underlying roll PIO tendency was found to exist away from the hover condition, which was caused by a flap regressing mode with insufficient damping.

  6. Process control monitoring systems, industrial plants, and process control monitoring methods

    DOEpatents

    Skorpik, James R [Kennewick, WA; Gosselin, Stephen R [Richland, WA; Harris, Joe C [Kennewick, WA

    2010-09-07

    A system comprises a valve; a plurality of RFID sensor assemblies coupled to the valve to monitor a plurality of parameters associated with the valve; a control tag configured to wirelessly communicate with the respective tags that are coupled to the valve, the control tag being further configured to communicate with an RF reader; and an RF reader configured to selectively communicate with the control tag, the reader including an RF receiver. Other systems and methods are also provided.

  7. ISS Contingency Attitude Control Recovery Method for Loss of Automatic Thruster Control

    NASA Technical Reports Server (NTRS)

    Bedrossian, Nazareth; Bhatt, Sagar; Alaniz, Abran; McCants, Edward; Nguyen, Louis; Chamitoff, Greg

    2008-01-01

    In this paper, the attitude control issues associated with International Space Station (ISS) loss of automatic thruster control capability are discussed and methods for attitude control recovery are presented. This scenario was experienced recently during Shuttle mission STS-117 and ISS Stage 13A in June 2007 when the Russian GN&C computers, which command the ISS thrusters, failed. Without automatic propulsive attitude control, the ISS would not be able to regain attitude control after the Orbiter undocked. The core issues associated with recovering long-term attitude control using CMGs are described as well as the systems engineering analysis to identify recovery options. It is shown that the recovery method can be separated into a procedure for rate damping to a safe harbor gravity gradient stable orientation and a capability to maneuver the vehicle to the necessary initial conditions for long term attitude hold. A manual control option using Soyuz and Progress vehicle thrusters is investigated for rate damping and maneuvers. The issues with implementing such an option are presented and the key issue of closed-loop stability is addressed. A new non-propulsive alternative to thruster control, Zero Propellant Maneuver (ZPM) attitude control method is introduced and its rate damping and maneuver performance evaluated. It is shown that ZPM can meet the tight attitude and rate error tolerances needed for long term attitude control. A combination of manual thruster rate damping to a safe harbor attitude followed by a ZPM to Stage long term attitude control orientation was selected by the Anomaly Resolution Team as the alternate attitude control method for such a contingency.

  8. A weak Hamiltonian finite element method for optimal control problems

    NASA Technical Reports Server (NTRS)

    Hodges, Dewey H.; Bless, Robert R.

    1989-01-01

    A temporal finite element method based on a mixed form of the Hamiltonian weak principle is developed for dynamics and optimal control problems. The mixed form of Hamilton's weak principle contains both displacements and momenta as primary variables that are expanded in terms of nodal values and simple polynomial shape functions. Unlike other forms of Hamilton's principle, however, time derivatives of the momenta and displacements do not appear therein; instead, only the virtual momenta and virtual displacements are differentiated with respect to time. Based on the duality that is observed to exist between the mixed form of Hamilton's weak principle and variational principles governing classical optimal control problems, a temporal finite element formulation of the latter can be developed in a rather straightforward manner. Several well-known problems in dynamics and optimal control are illustrated. The example dynamics problem involves a time-marching problem. As optimal control examples, elementary trajectory optimization problems are treated.

  9. Nonlinear feedback method of robot control - A preliminary experimental study

    NASA Technical Reports Server (NTRS)

    Tarn, T. J.; Ganguly, S.; Li, Z.; Bejczy, A. K.

    1990-01-01

    The nonlinear feedback method of robot control has been experimentally implemented on two PUMA 560 robot arms. The feasibility of the proposed controller, which was shown viable through simulation results earlier, is stressed. The servomechanism operates in task space, and the nonlinear feedback takes care of the necessary transformations to compute the necessary joint currents. A discussion is presented of the implementation with details of the experiments performed. The performance of the controller is encouraging but was limited to 100-Hz sampling frequency and to derived velocity information at the time of the experimentation. The setup of the lab, the software aspects, results, and the control hardware architecture that has recently been implemented are discussed.

  10. Jerk Minimization Method for Vibration Control in Buildings

    NASA Technical Reports Server (NTRS)

    Abatan, Ayo O.; Yao, Leummim

    1997-01-01

    In many vibration minimization control problems for high rise buildings subject to strong earthquake loads, the emphasis has been on a combination of minimizing the displacement, the velocity and the acceleration of the motion of the building. In most cases, the accelerations that are involved are not necessarily large but the change in them (jerk) are abrupt. These changes in magnitude or direction are responsible for most building damage and also create discomfort like motion sickness for inhabitants of these structures because of the element of surprise. We propose a method of minimizing also the jerk which is the sudden change in acceleration or the derivative of the acceleration using classical linear quadratic optimal controls. This was done through the introduction of a quadratic performance index involving the cost due to the jerk; a special change of variable; and using the jerk as a control variable. The values of the optimal control are obtained using the Riccati equation.

  11. A Method to Control Compliance of Blades and Flaps

    NASA Astrophysics Data System (ADS)

    Cosse, Julia; Gharib, Morteza

    2011-11-01

    Compliant plates experience lower drag forces than rigid plates primarily due to reconfiguration. From this concept it follows that through modifying the compliance of a plate, the aerodynamic forces can be controlled. To achieve this control, the concept of hydroskeletons - which are fluid filled cavities that resist deformation through the pressure of an internal fluid - were used. Using this notion a compliant structure with an internal chamber was developed. Shape change was detected when filling the chamber with fluid and controlling the pressure. Preliminary testing involved simple internal geometries filled with water and pressurized up to 20 psi. Using this method a plate was built with several internal chambers, each with individual pressure control. The plate was attached to a force balance perpendicularly in a wind tunnel. Drag and lift forces were modified through changing the internal pressure both globally and locally. This research is supported by the Gordon and Betty Moore foundation.

  12. Method for Controlling Space Transportation System Life Cycle Costs

    NASA Technical Reports Server (NTRS)

    McCleskey, Carey M.; Bartine, David E.

    2006-01-01

    A structured, disciplined methodology is required to control major cost-influencing metrics of space transportation systems during design and continuing through the test and operations phases. This paper proposes controlling key space system design metrics that specifically influence life cycle costs. These are inclusive of flight and ground operations, test, and manufacturing and infrastructure. The proposed technique builds on today's configuration and mass properties control techniques and takes on all the characteristics of a classical control system. While the paper does not lay out a complete math model, key elements of the proposed methodology are explored and explained with both historical and contemporary examples. Finally, the paper encourages modular design approaches and technology investments compatible with the proposed method.

  13. A weak Hamiltonian finite element method for optimal control problems

    NASA Technical Reports Server (NTRS)

    Hodges, Dewey H.; Bless, Robert R.

    1990-01-01

    A temporal finite element method based on a mixed form of the Hamiltonian weak principle is developed for dynamics and optimal control problems. The mixed form of Hamilton's weak principle contains both displacements and momenta as primary variables that are expanded in terms of nodal values and simple polynomial shape functions. Unlike other forms of Hamilton's principle, however, time derivatives of the momenta and displacements do not appear therein; instead, only the virtual momenta and virtual displacements are differentiated with respect to time. Based on the duality that is observed to exist between the mixed form of Hamilton's weak principle and variational principles governing classical optimal control problems, a temporal finite element formulation of the latter can be developed in a rather straightforward manner. Several well-known problems in dynamics and optimal control are illustrated. The example dynamics problem involves a time-marching problem. As optimal control examples, elementary trajectory optimization problems are treated.

  14. Weak Hamiltonian finite element method for optimal control problems

    NASA Technical Reports Server (NTRS)

    Hodges, Dewey H.; Bless, Robert R.

    1991-01-01

    A temporal finite element method based on a mixed form of the Hamiltonian weak principle is developed for dynamics and optimal control problems. The mixed form of Hamilton's weak principle contains both displacements and momenta as primary variables that are expanded in terms of nodal values and simple polynomial shape functions. Unlike other forms of Hamilton's principle, however, time derivatives of the momenta and displacements do not appear therein; instead, only the virtual momenta and virtual displacements are differentiated with respect to time. Based on the duality that is observed to exist between the mixed form of Hamilton's weak principle and variational principles governing classical optimal control problems, a temporal finite element formulation of the latter can be developed in a rather straightforward manner. Several well-known problems in dynamics and optimal control are illustrated. The example dynamics problem involves a time-marching problem. As optimal control examples, elementary trajectory optimization problems are treated.

  15. EVALUATION OF STATIONARY SOURCE PARTICULATE MEASUREMENT METHODS. VOLUME III. GAS TEMPERATURE CONTROL DURING METHOD 5 SAMPLING

    EPA Science Inventory

    A study was conducted to measure changes in gas temperature along the length of a Method 5 sampling train due to variations in stack gas temperature, sampling rate, filter box temperature and method for controlling the probe heating element. For each run condition, temperatures w...

  16. Overview On Alternative Asbestos Control Method Research: Alternative Methods To Demolition

    EPA Science Inventory

    The Alternative Asbestos Control Method (AACM) is an experimental approach to building demolition. Unlike the NESHAP method, the AACM allows some regulated asbestos-containing material to remain in the building and a surfactant-water solution is used to suppress asbestos fibers ...

  17. Implicit methods for efficient musculoskeletal simulation and optimal control

    PubMed Central

    van den Bogert, Antonie J.; Blana, Dimitra; Heinrich, Dieter

    2011-01-01

    The ordinary differential equations for musculoskeletal dynamics are often numerically stiff and highly nonlinear. Consequently, simulations require small time steps, and optimal control problems are slow to solve and have poor convergence. In this paper, we present an implicit formulation of musculoskeletal dynamics, which leads to new numerical methods for simulation and optimal control, with the expectation that we can mitigate some of these problems. A first order Rosenbrock method was developed for solving forward dynamic problems using the implicit formulation. It was used to perform real-time dynamic simulation of a complex shoulder arm system with extreme dynamic stiffness. Simulations had an RMS error of only 0.11 degrees in joint angles when running at real-time speed. For optimal control of musculoskeletal systems, a direct collocation method was developed for implicitly formulated models. The method was applied to predict gait with a prosthetic foot and ankle. Solutions were obtained in well under one hour of computation time and demonstrated how patients may adapt their gait to compensate for limitations of a specific prosthetic limb design. The optimal control method was also applied to a state estimation problem in sports biomechanics, where forces during skiing were estimated from noisy and incomplete kinematic data. Using a full musculoskeletal dynamics model for state estimation had the additional advantage that forward dynamic simulations, could be done with the same implicitly formulated model to simulate injuries and perturbation responses. While these methods are powerful and allow solution of previously intractable problems, there are still considerable numerical challenges, especially related to the convergence of gradient-based solvers. PMID:22102983

  18. Electrical power distribution control methods, electrical energy demand monitoring methods, and power management devices

    DOEpatents

    Chassin, David P.; Donnelly, Matthew K.; Dagle, Jeffery E.

    2006-12-12

    Electrical power distribution control methods, electrical energy demand monitoring methods, and power management devices are described. In one aspect, an electrical power distribution control method includes providing electrical energy from an electrical power distribution system, applying the electrical energy to a load, providing a plurality of different values for a threshold at a plurality of moments in time and corresponding to an electrical characteristic of the electrical energy, and adjusting an amount of the electrical energy applied to the load responsive to an electrical characteristic of the electrical energy triggering one of the values of the threshold at the respective moment in time.

  19. Electrical power distribution control methods, electrical energy demand monitoring methods, and power management devices

    DOEpatents

    Chassin, David P.; Donnelly, Matthew K.; Dagle, Jeffery E.

    2011-12-06

    Electrical power distribution control methods, electrical energy demand monitoring methods, and power management devices are described. In one aspect, an electrical power distribution control method includes providing electrical energy from an electrical power distribution system, applying the electrical energy to a load, providing a plurality of different values for a threshold at a plurality of moments in time and corresponding to an electrical characteristic of the electrical energy, and adjusting an amount of the electrical energy applied to the load responsive to an electrical characteristic of the electrical energy triggering one of the values of the threshold at the respective moment in time.

  20. Monotonic convergent quantum optimal control method with exact equality constraints on the optimized control fields

    NASA Astrophysics Data System (ADS)

    Shu, Chuan-Cun; Ho, Tak-San; Rabitz, Herschel

    2016-05-01

    We present a monotonic convergent quantum optimal control method that can be utilized to optimize the control field while exactly enforcing multiple equality constraints for steering quantum systems from an initial state towards desired quantum states. For illustration, special consideration is given to finding optimal control fields with (i) exact zero area and (ii) exact zero area along with constant pulse fluence. The method combined with these two types of constraints is successfully employed to maximize the state-to-state transition probability in a model vibrating diatomic molecule.

  1. Monotonically convergent optimization in quantum control using Krotov's method

    SciTech Connect

    Reich, Daniel M.; Koch, Christiane P.; Ndong, Mamadou

    2012-03-14

    The non-linear optimization method developed by A. Konnov and V. Krotov [Autom. Remote Cont. (Engl. Transl.) 60, 1427 (1999)] has been used previously to extend the capabilities of optimal control theory from the linear to the non-linear Schroedinger equation [S. E. Sklarz and D. J. Tannor, Phys. Rev. A 66, 053619 (2002)]. Here we show that based on the Konnov-Krotov method, monotonically convergent algorithms are obtained for a large class of quantum control problems. It includes, in addition to nonlinear equations of motion, control problems that are characterized by non-unitary time evolution, nonlinear dependencies of the Hamiltonian on the control, time-dependent targets, and optimization functionals that depend to higher than second order on the time-evolving states. We furthermore show that the nonlinear (second order) contribution can be estimated either analytically or numerically, yielding readily applicable optimization algorithms. We demonstrate monotonic convergence for an optimization functional that is an eighth-degree polynomial in the states. For the ''standard'' quantum control problem of a convex final-time functional, linear equations of motion and linear dependency of the Hamiltonian on the field, the second-order contribution is not required for monotonic convergence but can be used to speed up convergence. We demonstrate this by comparing the performance of first- and second-order algorithms for two examples.

  2. New advanced control methods for doubly salient permanent magnet motor

    SciTech Connect

    Blaabjerg, F.; Christensen, L.; Rasmussen, P.O.; Oestergaard, L.; Pedersen, P.

    1995-12-31

    High performance and high efficiency in adjustable speed drives are needed and new motor constructions are world wide investigated and analyzed. This paper deals with advanced control of a recently developed Doubly Salient Permanent Magnet (DSPM) motor. The construction of the DSPM motor is shown and a dynamical model of the motor is used for simulations. As supply to the DSPM motor, a power converter with a split capacitor is used to reduce the number of devices, and a basic control method for this converter is explained. This control method will cause an unequal voltage distribution across the capacitors because the motor is asymmetrical and a decrease in efficiency and a poorer dynamic performance are the results. To minimize the problems with the unequal load of the capacitors in the converter, a new charge control strategy is developed. The efficiency of the motor can also be improved by using a power minimizing scheme based on changing the turn-on and turn-off angles of the current. The two different strategies are implemented in an adjustable-speed drive, and it is concluded that both control strategies improve the performance of the drive.

  3. Method and apparatus for configuration control of redundant robots

    NASA Technical Reports Server (NTRS)

    Seraji, Homayoun (Inventor)

    1991-01-01

    A method and apparatus to control a robot or manipulator configuration over the entire motion based on augmentation of the manipulator forward kinematics is disclosed. A set of kinematic functions is defined in Cartesian or joint space to reflect the desirable configuration that will be achieved in addition to the specified end-effector motion. The user-defined kinematic functions and the end-effector Cartesian coordinates are combined to form a set of task-related configuration variables as generalized coordinates for the manipulator. A task-based adaptive scheme is then utilized to directly control the configuration variables so as to achieve tracking of some desired reference trajectories throughout the robot motion. This accomplishes the basic task of desired end-effector motion, while utilizing the redundancy to achieve any additional task through the desired time variation of the kinematic functions. The present invention can also be used for optimization of any kinematic objective function, or for satisfaction of a set of kinematic inequality constraints, as in an obstacle avoidance problem. In contrast to pseudoinverse-based methods, the configuration control scheme ensures cyclic motion of the manipulator, which is an essential requirement for repetitive operations. The control law is simple and computationally very fast, and does not require either the complex manipulator dynamic model or the complicated inverse kinematic transformation. The configuration control scheme can alternatively be implemented in joint space.

  4. A method for obtaining practical flutter-suppression control laws using results of optimal control theory

    NASA Technical Reports Server (NTRS)

    Newson, J. R.

    1979-01-01

    The results of optimal control theory are used to synthesize a feedback filter. The feedback filter is used to force the output of the filtered frequency response to match that of a desired optimal frequency response over a finite frequency range. This matching is accomplished by employing a nonlinear programing algorithm to search for the coefficients of the feedback filter that minimize the error between the optimal frequency response and the filtered frequency response. The method is applied to the synthesis of an active flutter-suppression control law for an aeroelastic wind-tunnel model. It is shown that the resulting control law suppresses flutter over a wide range of subsonic Mach numbers. This is a promising method for synthesizing practical control laws using the results of optimal control theory.

  5. Thermal energy storage apparatus, controllers and thermal energy storage control methods

    DOEpatents

    Hammerstrom, Donald J.

    2016-05-03

    Thermal energy storage apparatus, controllers and thermal energy storage control methods are described. According to one aspect, a thermal energy storage apparatus controller includes processing circuitry configured to access first information which is indicative of surpluses and deficiencies of electrical energy upon an electrical power system at a plurality of moments in time, access second information which is indicative of temperature of a thermal energy storage medium at a plurality of moments in time, and use the first and second information to control an amount of electrical energy which is utilized by a heating element to heat the thermal energy storage medium at a plurality of moments in time.

  6. Approximate method for controlling solid elastic waves by transformation media

    NASA Astrophysics Data System (ADS)

    Hu, Jin; Chang, Zheng; Hu, Gengkai

    2011-11-01

    By idealizing a general mapping as a series of local affine ones, we derive approximately transformed material parameters necessary to control solid elastic waves within classical elasticity theory. The transformed elastic moduli are symmetric, and can be used with Navier's equation to manipulate elastic waves. It is shown numerically that the method can provide a powerful tool to control elastic waves in solids in case of high frequency or small material gradient. Potential applications can be anticipated in nondestructive testing, structure impact protection, petroleum exploration, and seismology.

  7. Methods of detecting and controlling mucoid pseudomonas biofilm production

    NASA Technical Reports Server (NTRS)

    Yu, Hongwei D. (Inventor); Qiu, Dongru (Inventor)

    2010-01-01

    Compositions and methods for detecting and controlling the conversion to mucoidy in Pseudomonas aeruginosa are disclosed. The present invention provides for detecting the switch from nonmucoid to mucoid state of P. aeruginosa by measuring mucE expression or MucE protein levels. The interaction between MucE and AlgW controls the switch to mucoidy in wild type P. aeruginosa. Also disclosed is an alginate biosynthesis heterologous expression system for use in screening candidate substances that inhibit conversion to mucoidy.

  8. Methods of detecting and controlling mucoid Pseudomonas biofilm production

    NASA Technical Reports Server (NTRS)

    Yu, Hongwei D. (Inventor); Qiu, Dongru (Inventor)

    2013-01-01

    Compositions and methods for detecting and controlling the conversion to mucoidy in Pseudomonas aeruginosa are disclosed. The present invention provides for detecting the switch from nonmucoid to mucoid state of P. aeruginosa by measuring mucE expression or MucE protein levels. The interaction between MucE and AlgW controls the switch to mucoidy in wild type P. aeruginosa. Also disclosed is an alginate biosynthesis heterologous expression system for use in screening candidate substances that inhibit conversion to mucoidy.

  9. Robust time and frequency domain estimation methods in adaptive control

    NASA Technical Reports Server (NTRS)

    Lamaire, Richard Orville

    1987-01-01

    A robust identification method was developed for use in an adaptive control system. The type of estimator is called the robust estimator, since it is robust to the effects of both unmodeled dynamics and an unmeasurable disturbance. The development of the robust estimator was motivated by a need to provide guarantees in the identification part of an adaptive controller. To enable the design of a robust control system, a nominal model as well as a frequency-domain bounding function on the modeling uncertainty associated with this nominal model must be provided. Two estimation methods are presented for finding parameter estimates, and, hence, a nominal model. One of these methods is based on the well developed field of time-domain parameter estimation. In a second method of finding parameter estimates, a type of weighted least-squares fitting to a frequency-domain estimated model is used. The frequency-domain estimator is shown to perform better, in general, than the time-domain parameter estimator. In addition, a methodology for finding a frequency-domain bounding function on the disturbance is used to compute a frequency-domain bounding function on the additive modeling error due to the effects of the disturbance and the use of finite-length data. The performance of the robust estimator in both open-loop and closed-loop situations is examined through the use of simulations.

  10. A fabrication method of microneedle molds with controlled microstructures.

    PubMed

    Wang, Qi Lei; Zhu, Dan Dan; Chen, Yang; Guo, Xin Dong

    2016-08-01

    Microneedle (MN) offers an attractive, painless and minimally invasive approach for transdermal drug delivery. Polymer microneedles are normally fabricated by using the micromolding method employing a MN mold, which is suitable for mass production due to high production efficiency and repeat-using of the mold. Most of the MN molds are prepared by pouring sylgard polymer over a MN master to make an inverse one after curing, which is limited in optimizing or controlling the MN structures and failing to keep the sharpness of MNs. In this work we describe a fabrication method of MN mold with controlled microstructures, which is meaningful for the fabrication of polymer MNs with different geometries. Laser micro-machining method was employed to drill on the surface of PDMS sheets to obtain MN molds. In the fabrication process, the microstructures of MN molds are precisely controlled by changing laser parameters and imported patterns. The MNs prepared from these molds are sharp enough to penetrate the skin. This scalable MN mold fabrication method is helpful for future applications of MNs. PMID:27157736

  11. Linearization Method for Starting Control of Speed-Sensorless Vector-Controlled Induction Motors

    NASA Astrophysics Data System (ADS)

    Fujinami, Kazuki; Kondo, Keiichiro

    A linearization method is proposed for controlling the start-up operation of a rotating induction motor. The dynamics of this motor are deteriorated when the starting operation is carried out at high frequencies. In this method, the characteristics of the method are analyzed to reveal that the aforementioned problem is caused by the low equivalent gain of the induced voltage during the rotor flux establishment. A method to compensate for the angle of the rotor-flux-induced voltage vector is proposed to overcome this problem. The proposed method is experimentally verified by a test set, and the influence of changes in the rotor resistance is analyzed.

  12. Preliminary demonstration of a robust controller design method

    NASA Technical Reports Server (NTRS)

    Anderson, L. R.

    1980-01-01

    Alternative computational procedures for obtaining a feedback control law which yields a control signal based on measurable quantitites are evaluated. The three methods evaluated are: (1) the standard linear quadratic regulator design model; (2) minimization of the norm of the feedback matrix, k via nonlinear programming subject to the constraint that the closed loop eigenvalues be in a specified domain in the complex plane; and (3) maximize the angles between the closed loop eigenvectors in combination with minimizing the norm of K also via the constrained nonlinear programming. The third or robust design method was chosen to yield a closed loop system whose eigenvalues are insensitive to small changes in the A and B matrices. The relationship between orthogonality of closed loop eigenvectors and the sensitivity of closed loop eigenvalues is described. Computer programs are described.

  13. Accelerometer Method and Apparatus for Integral Display and Control Functions

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J., Jr. (Inventor)

    1998-01-01

    Method and apparatus for detecting mechanical vibrations and outputting a signal in response thereto is discussed. An accelerometer package having integral display and control functions is suitable for mounting upon the machinery to be monitored. Display circuitry provides signals to a bar graph display which may be used to monitor machine conditions over a period of time. Control switches may be set which correspond to elements in the bar graph to provide an alert if vibration signals increase in amplitude over a selected trip point. The circuitry is shock mounted within the accelerometer housing. The method provides for outputting a broadband analog accelerometer signal, integrating this signal to produce a velocity signal, integrating and calibrating the velocity signal before application to a display driver, and selecting a trip point at which a digitally compatible output signal is generated.

  14. Accelerometer Method and Apparatus for Integral Display and Control Functions

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J., Jr. (Inventor)

    1996-01-01

    Method and apparatus for detecting mechanical vibrations and outputting a signal in response thereto. Art accelerometer package having integral display and control functions is suitable for mounting upon the machinery to be monitored. Display circuitry provides signals to a bar graph display which may be used to monitor machine conditions over a period of time. Control switches may be set which correspond to elements in the bar graph to provide an alert if vibration signals increase in amplitude over a selected trip point. The circuitry is shock mounted within the accelerometer housing. The method provides for outputting a broadband analog accelerometer signal, integrating this signal to produce a velocity signal, integrating and calibrating the velocity signal before application to a display driver, and selecting a trip point at which a digitally compatible output signal is generated.

  15. Systems and Methods of Coordination Control for Robot Manipulation

    NASA Technical Reports Server (NTRS)

    Chang, Chu-Yin (Inventor); English, James (Inventor); Tardella, Neil (Inventor); Bacon, James (Inventor)

    2013-01-01

    Disclosed herein are systems and methods for controlling robotic apparatus having several movable elements or segments coupled by joints. At least one of the movable elements can include one or more mobile bases, while the others can form one or more manipulators. One of the movable elements can be treated as an end effector for which a certain motion is desired. The end effector may include a tool, for example, or represent a robotic hand (or a point thereon), or one or more of the one or more mobile bases. In accordance with the systems and methods disclosed herein, movement of the manipulator and the mobile base can be controlled and coordinated to effect a desired motion for the end effector. In many cases, the motion can include simultaneously moving the manipulator and the mobile base.

  16. Apparatus and method for gas turbine active combustion control system

    NASA Technical Reports Server (NTRS)

    Umeh, Chukwueloka (Inventor); Kammer, Leonardo C. (Inventor); Shah, Minesh (Inventor); Fortin, Jeffrey B. (Inventor); Knobloch, Aaron (Inventor); Myers, William J. (Inventor); Mancini, Alfred Albert (Inventor)

    2011-01-01

    An Active Combustion Control System and method provides for monitoring combustor pressure and modulating fuel to a gas turbine combustor to prevent combustion dynamics and/or flame extinguishments. The system includes an actuator, wherein the actuator periodically injects pulsed fuel into the combustor. The apparatus also includes a sensor connected to the combustion chamber down stream from an inlet, where the sensor generates a signal detecting the pressure oscillations in the combustor. The apparatus controls the actuator in response to the sensor. The apparatus prompts the actuator to periodically inject pulsed fuel into the combustor at a predetermined sympathetic frequency and magnitude, thereby controlling the amplitude of the pressure oscillations in the combustor by modulating the natural oscillations.

  17. An analysis method for control reconfigurability of linear systems

    NASA Astrophysics Data System (ADS)

    Wang, Dayi; Duan, Wenjie; Liu, Chengrui

    2016-01-01

    The reconfigurability of control systems is further researched based on the function-objective model (FOM). The establishment of the FOM has been published in the authors' former paper, solving the problem whether the system is reconfigurable without losing the desired control objective. Based on the FOM, the importance factor, the risk factor and the k th reconfigurability factor are proposed to evaluate the fault risks of all components and the system reconfigurability with k faults. These factors show which components should be improved and which faults cannot be tolerated. The analysis results are very useful for enhancing the fault-tolerance performances of the control systems by improving system designs. A satellite model is utilized to illustrate the proposed method.

  18. A forward method for optimal stochastic nonlinear and adaptive control

    NASA Technical Reports Server (NTRS)

    Bayard, David S.

    1988-01-01

    A computational approach is taken to solve the optimal nonlinear stochastic control problem. The approach is to systematically solve the stochastic dynamic programming equations forward in time, using a nested stochastic approximation technique. Although computationally intensive, this provides a straightforward numerical solution for this class of problems and provides an alternative to the usual dimensionality problem associated with solving the dynamic programming equations backward in time. It is shown that the cost degrades monotonically as the complexity of the algorithm is reduced. This provides a strategy for suboptimal control with clear performance/computation tradeoffs. A numerical study focusing on a generic optimal stochastic adaptive control example is included to demonstrate the feasibility of the method.

  19. Method and apparatus for controlling gas evolution from chemical reactions

    DOEpatents

    Skorpik, J.R.; Dodson, M.G.

    1999-05-25

    The present invention is directed toward monitoring a thermally driven gas evolving chemical reaction with an acoustic apparatus. Signals from the acoustic apparatus are used to control a heater to prevent a run-away condition. A digestion module in combination with a robotic arm further automate physical handling of sample material reaction vessels. The invention is especially useful for carrying out sample procedures defined in EPA Methods SW-846. 8 figs.

  20. Method for controlling corrosion in thermal vapor injection gases

    DOEpatents

    Sperry, John S.; Krajicek, Richard W.

    1981-01-01

    An improvement in the method for producing high pressure thermal vapor streams from combustion gases for injection into subterranean oil producing formations to stimulate the production of viscous minerals is described. The improvement involves controlling corrosion in such thermal vapor gases by injecting water near the flame in the combustion zone and injecting ammonia into a vapor producing vessel to contact the combustion gases exiting the combustion chamber.

  1. Method and means for diesel exhaust particulate emission control

    SciTech Connect

    Ludecke, O.A.

    1983-04-19

    A method and means for controlling diesel particulate emissions involves providing an exhaust trap filter to collect exhaust particulates at a point near the engine exhaust ports and providing means to periodically vent burning combustion chamber gases to the exhaust filter to initiate combustion and incineration of the collected particulates. Various means for conducting burning mixture to ignite the particulates in the filter are disclosed.

  2. Method and apparatus for controlling gas evolution from chemical reactions

    DOEpatents

    Skorpik, James R.; Dodson, Michael G.

    1999-01-01

    The present invention is directed toward monitoring a thermally driven gas evolving chemical reaction with an acoustic apparatus. Signals from the acoustic apparatus are used to control a heater to prevent a run-away condition. A digestion module in combination with a robotic arm further automate physical handling of sample material reaction vessels. The invention is especially useful for carrying out sample procedures defined in EPA Methods SW-846.

  3. Active control: an investigation method for combustion instabilities

    NASA Astrophysics Data System (ADS)

    Poinsot, T.; Yip, B.; Veynante, D.; Trouvé, A.; Samaniego, J. M.; Candel, S.

    1992-07-01

    Closed-loop active control methods and their application to combustion instabilities are discussed. In these methods the instability development is impeded with a feedback control loop: the signal provided by a sensor monitoring the flame or pressure oscillations is processed and sent back to actuators mounted on the combustor or on the feeding system. Different active control systems tested on a non-premixed multiple-flame turbulent combustor are described. These systems can suppress all unstable plane modes of oscillation (i.e. low frequency modes). The active instability control (AIC) also constitutes an original and powerful technique for studies of mechanisms leading to instability or resulting from the instability. Two basic applications of this kind are described. In the first case the flame is initially controlled with AIC, the feedback loop is then switched off and the growth of the instability is analysed through high speed Schlieren cinematography and simultaneous sound pressure and reaction rate measurements. Three phases are identified during th growth of the oscillations: (1) a linear phase where acoustic waves induce a flapping motion of the flame sheets without interaction between sheets, (2) a modulation phase, where flame sheets interact randomly and (3) a nonlinear phase where the flame sheets are broken and a limit cycle is reached. In the second case we investigate different types of flame extinctions associated with combustion instability. It is shown that pressure oscillations may lead to partial or total extinctions. Extinctions occur in various forms but usually follow a rapid growth of pressure oscillations. The flame is extinguished during the modulation phase observed in the initiation experiments. In these studies devoted to transient instability phenomena, the control system constitutes a unique investigation tool because it is difficult to obtain the same information by other means. Implications for modelling and prediction of

  4. Methods of Controlling the Loop Heat Pipe Operating Temperature

    NASA Technical Reports Server (NTRS)

    Ku, Jentung

    2008-01-01

    The operating temperature of a loop heat pipe (LHP) is governed by the saturation temperature of its compensation chamber (CC); the latter is in turn determined by the balance among the heat leak from the evaporator to the CC, the amount of subcooling carried by the liquid returning to the CC, and the amount of heat exchanged between the CC and ambient. The LHP operating temperature can be controlled at a desired set point by actively controlling the CC temperature. The most common method is to cold bias the CC and use electric heater power to maintain the CC set point temperature. The required electric heater power can be large when the condenser sink is very cold. Several methods have been developed to reduce the control heater power, including coupling block, heat exchanger and separate subcooler, variable conductance heat pipe, by-pass valve with pressure regulator, secondary evaporator, and thermoelectric converter. The paper discusses the operating principles, advantages and disadvantages of each method.

  5. Reviewing birth control methods for new clinic patients.

    PubMed

    1980-01-01

    The DHEW guidelines governing funding for family planning services specify that each new patient be educated about the commonly used birth control methods on the first visit. Pills, IUDs, the diaphragm, condoms, foam, natural family planning, and sterilization plus any additional methods offered by the clinic should be explained in terms of how it is used, effectiveness, contraindications, and side effects. Patients need to be able to compare effectiveness rates for the the methods. The 2 rates should include the level of effectiveness to be expected if you used the method right all the time and the level of effectiveness if you make the average number of mistakes. Suggestions for setting the tone of a group discussion are minimimize interruptions; maximize physical comfort; watch body language; encourage questions and reading. A patient who has made up her mind to a method and finds she has a contraindication to a method may be upset and have difficulty choosing another method. Other first visit topics which should be explained either in discussion or literature are why family planning is important; reproductive anatomy and physiology; locations for emergency medical care; clinic procedures, including fees; vaginities and sexually transmitted infections; pregnancy options; and, list of services available. PMID:12336138

  6. Evaluating methods for controlling depth perception in stereoscopic cinematography

    NASA Astrophysics Data System (ADS)

    Sun, Geng; Holliman, Nick

    2009-02-01

    Existing stereoscopic imaging algorithms can create static stereoscopic images with perceived depth control function to ensure a compelling 3D viewing experience without visual discomfort. However, current algorithms do not normally support standard Cinematic Storytelling techniques. These techniques, such as object movement, camera motion, and zooming, can result in dynamic scene depth change within and between a series of frames (shots) in stereoscopic cinematography. In this study, we empirically evaluate the following three types of stereoscopic imaging approaches that aim to address this problem. (1) Real-Eye Configuration: set camera separation equal to the nominal human eye interpupillary distance. The perceived depth on the display is identical to the scene depth without any distortion. (2) Mapping Algorithm: map the scene depth to a predefined range on the display to avoid excessive perceived depth. A new method that dynamically adjusts the depth mapping from scene space to display space is presented in addition to an existing fixed depth mapping method. (3) Depth of Field Simulation: apply Depth of Field (DOF) blur effect to stereoscopic images. Only objects that are inside the DOF are viewed in full sharpness. Objects that are far away from the focus plane are blurred. We performed a human-based trial using the ITU-R BT.500-11 Recommendation to compare the depth quality of stereoscopic video sequences generated by the above-mentioned imaging methods. Our results indicate that viewers' practical 3D viewing volumes are different for individual stereoscopic displays and viewers can cope with much larger perceived depth range in viewing stereoscopic cinematography in comparison to static stereoscopic images. Our new dynamic depth mapping method does have an advantage over the fixed depth mapping method in controlling stereo depth perception. The DOF blur effect does not provide the expected improvement for perceived depth quality control in 3D cinematography

  7. Robust control methods for nonlinear systems with uncertain dynamics and unknown control direction

    NASA Astrophysics Data System (ADS)

    Ton, Chau T.

    Robust nonlinear control design strategies using sliding mode control (SMC) and integral SMC (ISMC) are developed, which are capable of achieving reliable and accurate tracking control for systems containing dynamic uncertainty, unmodeled disturbances, and actuator anomalies that result in an unknown and time-varying control direction. In order to ease readability of this dissertation, detailed explanations of the relevant mathematical tools is provided, including stability denitions, Lyapunov-based stability analysis methods, SMC and ISMC fundamentals, and other basic nonlinear control tools. The contributions of the dissertation are three novel control algorithms for three different classes of nonlinear systems: single-input multipleoutput (SIMO) systems, systems with model uncertainty and bounded disturbances, and systems with unknown control direction. Control design for SIMO systems is challenging due to the fact that such systems have fewer actuators than degrees of freedom to control (i.e., they are underactuated systems). While traditional nonlinear control methods can be utilized to design controllers for certain classes of cascaded underactuated systems, more advanced methods are required to develop controllers for parallel systems, which are not in a cascade structure. A novel control technique is proposed in this dissertation, which is shown to achieve asymptotic tracking for dual parallel systems, where a single scalar control input directly aects two subsystems. The result is achieved through an innovative sequential control design algorithm, whereby one of the subsystems is indirectly stabilized via the desired state trajectory that is commanded to the other subsystem. The SIMO system under consideration does not contain uncertainty or disturbances. In dealing with systems containing uncertainty in the dynamic model, a particularly challenging situation occurs when uncertainty exists in the input-multiplicative gain matrix. Moreover, special

  8. Highly efficient and controllable method to fabricate ultrafine metallic nanostructures

    NASA Astrophysics Data System (ADS)

    Cai, Hongbing; Zhang, Kun; Yu, Xinxin; Pan, Nan; Tian, Yangchao; Luo, Yi; Wang, Xiaoping

    2015-11-01

    We report a highly efficient, controllable and scalable method to fabricate various ultrafine metallic nanostructures in this paper. The method starts with the negative poly-methyl-methacrylate (PMMA) resist pattern with line-width superior to 20 nm, which is obtained from overexposing of the conventionally positive PMMA under a low energy electron beam. The pattern is further shrunk to sub-10 nm line-width through reactive ion etching. Using the patter as a mask, we can fabricate various ultrafine metallic nanostructures with the line-width even less than 10 nm. This ion tailored mask lithography (ITML) method enriches the top-down fabrication strategy and provides potential opportunity for studying quantum effects in a variety of materials.

  9. Overview of Krylov subspace methods with applications to control problems

    NASA Technical Reports Server (NTRS)

    Saad, Youcef

    1989-01-01

    An overview of projection methods based on Krylov subspaces are given with emphasis on their application to solving matrix equations that arise in control problems. The main idea of Krylov subspace methods is to generate a basis of the Krylov subspace Span and seek an approximate solution the the original problem from this subspace. Thus, the original matrix problem of size N is approximated by one of dimension m typically much smaller than N. Krylov subspace methods have been very successful in solving linear systems and eigenvalue problems and are now just becoming popular for solving nonlinear equations. It is shown how they can be used to solve partial pole placement problems, Sylvester's equation, and Lyapunov's equation.

  10. Population-dynamics method with a multicanonical feedback control

    NASA Astrophysics Data System (ADS)

    Nemoto, Takahiro; Bouchet, Freddy; Jack, Robert L.; Lecomte, Vivien

    2016-06-01

    We discuss the Giardinà-Kurchan-Peliti population dynamics method for evaluating large deviations of time-averaged quantities in Markov processes [Phys. Rev. Lett. 96, 120603 (2006), 10.1103/PhysRevLett.96.120603]. This method exhibits systematic errors which can be large in some circumstances, particularly for systems with weak noise, with many degrees of freedom, or close to dynamical phase transitions. We show how these errors can be mitigated by introducing control forces within the algorithm. These forces are determined by an iteration-and-feedback scheme, inspired by multicanonical methods in equilibrium sampling. We demonstrate substantially improved results in a simple model, and we discuss potential applications to more complex systems.

  11. A Method to Keep Cushion Pressure under Control

    NASA Astrophysics Data System (ADS)

    Senba, Hiromitsu; Matsuo, Hideo; Matsuo, Kensuke; Kanazawa, Koji; Hiroe, Tetsuyuki; Fujiwara, Kazuhito

    An effective method to keep cushion pressure constant under fluctuation of cushion volume of SES is proposed and examined experimentally. In general, the fluctuation is induced by wave pumping. In the method an air jet with the length equal to the width of the air cushion is adapted. The air cushion is formed by this jet and sealed at one side. On the other hand, the opposite side is sealed with a material like as a skirt. The air nozzle that supplies the air jet can revolve to control the cushion pressure. In experiments a two-dimensional air cushion model of SES was used, where the wave pumping was simulated by a piston. Angle of the air nozzle was changed dynamically to eliminate the fluctuation of cushion pressure occurred by the piston. The experimental results show that the fluctuation of the cushion pressure became drastically extinct. The availability of this method was cleared and proved.

  12. Population-dynamics method with a multicanonical feedback control.

    PubMed

    Nemoto, Takahiro; Bouchet, Freddy; Jack, Robert L; Lecomte, Vivien

    2016-06-01

    We discuss the Giardinà-Kurchan-Peliti population dynamics method for evaluating large deviations of time-averaged quantities in Markov processes [Phys. Rev. Lett. 96, 120603 (2006)PRLTAO0031-900710.1103/PhysRevLett.96.120603]. This method exhibits systematic errors which can be large in some circumstances, particularly for systems with weak noise, with many degrees of freedom, or close to dynamical phase transitions. We show how these errors can be mitigated by introducing control forces within the algorithm. These forces are determined by an iteration-and-feedback scheme, inspired by multicanonical methods in equilibrium sampling. We demonstrate substantially improved results in a simple model, and we discuss potential applications to more complex systems. PMID:27415224

  13. Highly efficient and controllable method to fabricate ultrafine metallic nanostructures

    SciTech Connect

    Cai, Hongbing; Zhang, Kun; Pan, Nan E-mail: xpwang@ustc.edu.cn; Luo, Yi; Wang, Xiaoping E-mail: xpwang@ustc.edu.cn; Yu, Xinxin; Tian, Yangchao

    2015-11-15

    We report a highly efficient, controllable and scalable method to fabricate various ultrafine metallic nanostructures in this paper. The method starts with the negative poly-methyl-methacrylate (PMMA) resist pattern with line-width superior to 20 nm, which is obtained from overexposing of the conventionally positive PMMA under a low energy electron beam. The pattern is further shrunk to sub-10 nm line-width through reactive ion etching. Using the patter as a mask, we can fabricate various ultrafine metallic nanostructures with the line-width even less than 10 nm. This ion tailored mask lithography (ITML) method enriches the top-down fabrication strategy and provides potential opportunity for studying quantum effects in a variety of materials.

  14. Accelerometer method and apparatus for integral display and control functions

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J., Jr. (Inventor)

    1992-01-01

    Vibration analysis has been used for years to provide a determination of the proper functioning of different types of machinery, including rotating machinery and rocket engines. A determination of a malfunction, if detected at a relatively early stage in its development, will allow changes in operating mode or a sequenced shutdown of the machinery prior to a total failure. Such preventative measures result in less extensive and/or less expensive repairs, and can also prevent a sometimes catastrophic failure of equipment. Standard vibration analyzers are generally rather complex, expensive, and of limited portability. They also usually result in displays and controls being located remotely from the machinery being monitored. Consequently, a need exists for improvements in accelerometer electronic display and control functions which are more suitable for operation directly on machines and which are not so expensive and complex. The invention includes methods and apparatus for detecting mechanical vibrations and outputting a signal in response thereto. The apparatus includes an accelerometer package having integral display and control functions. The accelerometer package is suitable for mounting upon the machinery to be monitored. Display circuitry provides signals to a bar graph display which may be used to monitor machine condition over a period of time. Control switches may be set which correspond to elements in the bar graph to provide an alert if vibration signals increase over the selected trip point. The circuitry is shock mounted within the accelerometer housing. The method provides for outputting a broadband analog accelerometer signal, integrating this signal to produce a velocity signal, integrating and calibrating the velocity signal before application to a display driver, and selecting a trip point at which a digitally compatible output signal is generated. The benefits of a vibration recording and monitoring system with controls and displays readily

  15. A Statistical Process Control Method for Semiconductor Manufacturing

    NASA Astrophysics Data System (ADS)

    Kubo, Tomoaki; Ino, Tomomi; Minami, Kazuhiro; Minami, Masateru; Homma, Tetsuya

    To maintain stable operation of semiconductor fabrication lines, statistical process control (SPC) methods are recognized to be effective. However, in semiconductor fabrication lines, there exist a huge number of process state signals to be monitored, and these signals contain both normally and non-normally distributed data. Therefore, if we try to apply SPC methods to those signals, we need one which satisfies three requirements: 1) It can deal with both normally distributed data, and non-normally distributed data, 2) It can be set up automatically, 3) It can be easily understood by engineers and technicians. In this paper, we propose a new SPC method which satisfies these three requirements at the same time. This method uses similar rules to the Shewhart chart, but can deal with non-normally distributed data by introducing “effective standard deviations”. Usefulness of this method is demonstrated by comparing false alarm ratios to that of the Shewhart chart method. In the demonstration, we use various kinds of artificially generated data, and real data observed in a chemical vapor deposition (CVD) process tool in a semiconductor fabrication line.

  16. Battery control system for hybrid vehicle and method for controlling a hybrid vehicle battery

    DOEpatents

    Bockelmann, Thomas R.; Beaty, Kevin D.; Zou, Zhanijang; Kang, Xiaosong

    2009-07-21

    A battery control system for controlling a state of charge of a hybrid vehicle battery includes a detecting arrangement for determining a vehicle operating state or an intended vehicle operating state and a controller for setting a target state of charge level of the battery based on the vehicle operating state or the intended vehicle operating state. The controller is operable to set a target state of charge level at a first level during a mobile vehicle operating state and at a second level during a stationary vehicle operating state or in anticipation of the vehicle operating in the stationary vehicle operating state. The invention further includes a method for controlling a state of charge of a hybrid vehicle battery.

  17. [Analytical methods for control of foodstuffs made from bioengineered plants].

    PubMed

    Chernysheva, O N; Sorokina, E Iu

    2013-01-01

    Foodstuffs made by modern biotechnology are requiring for special control. Analytical methods used for these purposes are being constantly perfected. When choosing a strategy for the analysis, several factors have to be assessed: specificity, sensitivity, practically of the method and time efficiency. To date, the GMO testing methods are mainly based on the inserted DNA sequences and newly produced proteins in GMOs. Protein detection methods are based mainly on ELISA. The specific detection of a novel protein synthesized by gene introduced during transformation constitutes an alternative approach for the identification of GMO. The genetic modification is not always specifically directed at the production of a novel protein and does not always result in protein expression levels sufficient for detection purposes. In addition, some proteins may be expressed only in specific parts of the plant or expressed at different levels in distinct parts of plant. As DNA is a rather stable molecule relative to proteins, it is preferred target for any kind of sample. These methods are more sensitive and specific than protein detection methods. PCR-based test can be categorized into several levels of specificity. The least specific methods are commonly called "screening methods" and relate to target DNA elements, such as promoters and terminators that are present in many different GMOs. For routine screening purpose regulatory elements 35S promoter, derived from the Cauliflower Mosaic Virus and the NOS terminator, derived from the nopaline synthase gene of Agrobacterium tumefaciens, are used as target sequences. The second level is "gene-specific methods". These methods target a part of the DNA harbouring the active gene associated with the specific genetic modification. The highest specificity is seen when the target is the unique junction found at the integration locus between the inserted DNA and the recipient genome. These are called "event-specific methods". For a

  18. Digital reconstructed radiography quality control with software methods

    NASA Astrophysics Data System (ADS)

    Denis, Eloise; Beaumont, Stephane; Guedon, JeanPierre

    2005-04-01

    Nowadays, most of treatments for external radiotherapy are prepared with Treatment Planning Systems (TPS) which uses a virtual patient generated by a set of transverse slices acquired with a CT scanner of the patient in treatment position 1 2 3. In the first step of virtual simulation, the TPS is used to define a ballistic allowing a good target covering and the lowest irradiation for normal tissues. This parameters optimisation of the treatment with the TPS is realised with particular graphic tools allowing to: ×Contour the target, ×Expand the limit of the target in order to take into account contouring uncertainties, patient set up errors, movements of the target during the treatment (internal movement of the target and external movement of the patient), and beam's penumbra, ×Determine beams orientation and define dimensions and forms of the beams, ×Visualize beams on the patient's skin and calculate some characteristic points which will be tattooed on the patient to assist the patient set up before treating, ×Calculate for each beam a Digital Reconstructed Radiography (DRR) consisting in projecting the 3D CT virtual patient and beam limits with a cone beam geometry onto a plane. These DRR allow one for insuring the patient positioning during the treatment, essentially bone structures alignment by comparison with real radiography realized with the treatment X-ray source in the same geometric conditions (portal imaging). Then DRR are preponderant to insure the geometric accuracy of the treatment. For this reason quality control of its computation is mandatory4 . Until now, this control is realised with real test objects including some special inclusions4 5 . This paper proposes to use some numerical test objects to control the quality DRR calculation in terms of computation time, beam angle, divergence and magnification precision, spatial and contrast resolutions. The main advantage of this proposed method is to avoid a real test object CT acquisition

  19. Event-related brain potentials, bilateral electrodermal activity and Mangina-Test performance in learning disabled/ADHD pre-adolescents with severe behavioral disorders as compared to age-matched normal controls.

    PubMed

    Mangina, C A; Beuzeron-Mangina, J H; Grizenko, N

    2000-07-01

    The most frequently encountered developmental problems of learning disabilities/ADHD often co-exist with severe behavioral disorders. As a direct consequence, this condition opens the way to delinquency, school drop-out, depression, suicide, substance abuse, work absenteeism, and other psycho-social complications. In this paper, we are presenting a selective overview of our previous research and its clinical applications in this field as it relates to our present research data pertaining to the effects of our original Memory Workload Paradigm on the event-related brain potentials in differentiating normal and pathological pre-adolescents (learning disabled/ADHD with concomitant severe behavioral disorders such as oppositional and conduct). In addition, it provides data on the bilateral electrodermal activity during cognitive workload and Mangina-Test performance of pathological and normal pre-adolescents conducted in separate sessions. The results of our present research indicate that a significant memory load effect for the P450 latency (F(3,27)=4.98, P<0.01) and the P450 amplitude (F(3,27)=3.57, P<0.05) was present for normal pre-adolescents which was absent in pathological pre-adolescents. Moreover, enhanced N450 ERP amplitudes to our Memory Workload Paradigm in pre-frontal and frontal regions clearly differentiated normal from pathological pre-adolescents (F(1, 18)=12.21, P<0.004). Furthermore, significant differences between normal and pathological groups were found in bilateral electrodermal activity (F(1,18)=23.86, P<0.001) and on the Mangina-Test performance (F(1,18)=75.35, P<0.001). Our present research findings provide an original and valuable demonstration of an integrative and effective clinical psychophysiological application of central (ERPs), autonomic (bilateral electrodermal activity) and neuro-psychometric aspects (Mangina-Test) which characterize normal and pathological pre-adolescents and underpin the neurophysiological basis of learning disabled/ADHD with severe behavioral disorders as opposed to normal subjects. PMID:10828376

  20. Urban drainage control applying rational method and geographic information technologies

    NASA Astrophysics Data System (ADS)

    Aldalur, Beatriz; Campo, Alicia; Fernández, Sandra

    2013-09-01

    The objective of this study is to develop a method of controlling urban drainages in the town of Ingeniero White motivated by the problems arising as a result of floods, water logging and the combination of southeasterly and high tides. A Rational Method was applied to control urban watersheds and used tools of Geographic Information Technology (GIT). A Geographic Information System was developed on the basis of 28 panchromatic aerial photographs of 2005. They were georeferenced with control points measured with Global Positioning Systems (basin: 6 km2). Flow rates of basins and sub-basins were calculated and it was verified that the existing open channels have a low slope with the presence of permanent water and generate stagnation of water favored by the presence of trash. It is proposed for the output of storm drains, the use of an existing channel to evacuate the flow. The solution proposed in this work is complemented by the placement of three pumping stations: one on a channel to drain rain water which will allow the drain of the excess water from the lower area where is located the Ingeniero White city and the two others that will drain the excess liquid from the port area.

  1. Galerkin method for feedback controlled Rayleigh Bénard convection

    NASA Astrophysics Data System (ADS)

    Münch, A.; Wagner, B.

    2008-11-01

    The problem of feedback controlled Rayleigh-Bénard convection is considered. For this problem with the simple flow structure in the vertical direction, a Galerkin method that uses only a few basis functions in this direction is presented. This approximation yields considerable simplification of the problem, explicitly incorporates the non-classical boundary conditions at the horizontal boundaries of the fluid layer resulting from feedback control and reduces the dimension of the original problem by one. This method is in spirit very similar to lubrication theory, where the simple laminar flow in the vertical direction is integrated out across the height of the fluid layer. Using a minimal set of appropriate basis functions to capture the nonlinear behaviour of the flow, we investigate the effects of feedback control on amplitude, wavelength and selection of patterns via weakly nonlinear analysis and numerical simulations of the resulting dimension-reduced problems in two and three dimensions. In the second part of this study we discuss the derivation of the appropriate basis functions and prove convergence of the Galerkin scheme. This paper is published as part of a collection in honour of Todd Dupont's 65th birthday.

  2. Control system and method for a universal power conditioning system

    DOEpatents

    Lai, Jih-Sheng; Park, Sung Yeul; Chen, Chien-Liang

    2014-09-02

    A new current loop control system method is proposed for a single-phase grid-tie power conditioning system that can be used under a standalone or a grid-tie mode. This type of inverter utilizes an inductor-capacitor-inductor (LCL) filter as the interface in between inverter and the utility grid. The first set of inductor-capacitor (LC) can be used in the standalone mode, and the complete LCL can be used for the grid-tie mode. A new admittance compensation technique is proposed for the controller design to avoid low stability margin while maintaining sufficient gain at the fundamental frequency. The proposed current loop controller system and admittance compensation technique have been simulated and tested. Simulation results indicate that without the admittance path compensation, the current loop controller output duty cycle is largely offset by an undesired admittance path. At the initial simulation cycle, the power flow may be erratically fed back to the inverter causing catastrophic failure. With admittance path compensation, the output power shows a steady-state offset that matches the design value. Experimental results show that the inverter is capable of both a standalone and a grid-tie connection mode using the LCL filter configuration.

  3. Sensitivity method for integrated structure/active control law design

    NASA Technical Reports Server (NTRS)

    Gilbert, Michael G.

    1987-01-01

    The development is described of an integrated structure/active control law design methodology for aeroelastic aircraft applications. A short motivating introduction to aeroservoelasticity is given along with the need for integrated structures/controls design algorithms. Three alternative approaches to development of an integrated design method are briefly discussed with regards to complexity, coordination and tradeoff strategies, and the nature of the resulting solutions. This leads to the formulation of the proposed approach which is based on the concepts of sensitivity of optimum solutions and multi-level decompositions. The concept of sensitivity of optimum is explained in more detail and compared with traditional sensitivity concepts of classical control theory. The analytical sensitivity expressions for the solution of the linear, quadratic cost, Gaussian (LQG) control problem are summarized in terms of the linear regulator solution and the Kalman Filter solution. Numerical results for a state space aeroelastic model of the DAST ARW-II vehicle are given, showing the changes in aircraft responses to variations of a structural parameter, in this case first wing bending natural frequency.

  4. Methods of Measurement for Semiconductor Materials, Process Control, and Devices

    NASA Technical Reports Server (NTRS)

    Bullis, W. M. (Editor)

    1973-01-01

    The development of methods of measurement for semiconductor materials, process control, and devices is reported. Significant accomplishments include: (1) Completion of an initial identification of the more important problems in process control for integrated circuit fabrication and assembly; (2) preparations for making silicon bulk resistivity wafer standards available to the industry; and (3) establishment of the relationship between carrier mobility and impurity density in silicon. Work is continuing on measurement of resistivity of semiconductor crystals; characterization of generation-recombination-trapping centers, including gold, in silicon; evaluation of wire bonds and die attachment; study of scanning electron microscopy for wafer inspection and test; measurement of thermal properties of semiconductor devices; determination of S-parameters and delay time in junction devices; and characterization of noise and conversion loss of microwave detector diodes.

  5. Systems and methods for controlling diesel engine emissions

    DOEpatents

    Webb, Cynthia Chaffin; Weber, Phillip Anthony; Khair, Magdi K.

    2004-06-01

    Systems and methods for controlling diesel engine emissions, including, for example, oxides of nitrogen emissions, particulate matter emissions, and the like. The emission control system according to this invention is provided in the exhaust passageway of a diesel engine and includes a catalyst-based particulate filter; and first and second lean NO.sub.x trap systems coupled to the catalyst-based particulate filter. The first and second lean NO.sub.x trap systems are arranged in a parallel flow configuration with each other. Each of the first and second lean NO.sub.x trap systems include a carbon monoxide generating catalyst device, a sulfur trap device, a lean NO.sub.x device, a supplemental fuel injector device, and a plurality of flow diverter devices.

  6. Dynamically controlled crystallization method and apparatus and crystals obtained thereby

    NASA Technical Reports Server (NTRS)

    Arnowitz, Leonard (Inventor); Steinberg, Emanuel (Inventor)

    1999-01-01

    A method and apparatus for dynamically controlling the crystallization of proteins including a crystallization chamber or chambers for holding a protein in a salt solution, one or more salt solution chambers, two communication passages respectively coupling the crystallization chamber with each of the salt solution chambers, and transfer mechanisms configured to respectively transfer salt solution between each of the salt solution chambers and the crystallization chamber. The transfer mechanisms are interlocked to maintain the volume of salt solution in the crystallization chamber substantially constant. Salt solution of different concentrations is transferred into and out of the crystallization chamber to adjust the salt concentration in the crystallization chamber to achieve precise control of the crystallization process.

  7. Method and device for controlling plume during laser welding

    SciTech Connect

    Fuerschbach, P.W.; Jellison, J.L.; Keicher, D.M.; Oberkampf, W.L.

    1989-08-25

    A method and apparatus for enhancing the weldment of a laser welding system is provided. The laser weld plume control device is provided as a cylindrical body defining an upside-down cone cavity, the upper surface of the body circumscribing the base of the cone cavity, the vertex of the cavity forming an orifice which converts the flow of gas, directed through inlets in the upper surface of the body through channels in the wall of the body, from radial flow to an axisymmetric gas jet perpendicular to the surface of the weldment in a direction opposite to the direction of the laser beam. The orifice of the control device is concentrically located with respect to the laser beam and the plume which forms as a result of the welding operation. 6 figs.

  8. COMSAC: Computational Methods for Stability and Control. Part 2

    NASA Technical Reports Server (NTRS)

    Fremaux, C. Michael (Compiler); Hall, Robert M. (Compiler)

    2004-01-01

    The unprecedented advances being made in computational fluid dynamic (CFD) technology have demonstrated the powerful capabilities of codes in applications to civil and military aircraft. Used in conjunction with wind-tunnel and flight investigations, many codes are now routinely used by designers in diverse applications such as aerodynamic performance predictions and propulsion integration. Typically, these codes are most reliable for attached, steady, and predominantly turbulent flows. As a result of increasing reliability and confidence in CFD, wind-tunnel testing for some new configurations has been substantially reduced in key areas, such as wing trade studies for mission performance guarantees. Interest is now growing in the application of computational methods to other critical design challenges. One of the most important disciplinary elements for civil and military aircraft is prediction of stability and control characteristics. CFD offers the potential for significantly increasing the basic understanding, prediction, and control of flow phenomena associated with requirements for satisfactory aircraft handling characteristics.

  9. Combustor air flow control method for fuel cell apparatus

    DOEpatents

    Clingerman, Bruce J.; Mowery, Kenneth D.; Ripley, Eugene V.

    2001-01-01

    A method for controlling the heat output of a combustor in a fuel cell apparatus to a fuel processor where the combustor has dual air inlet streams including atmospheric air and fuel cell cathode effluent containing oxygen depleted air. In all operating modes, an enthalpy balance is provided by regulating the quantity of the air flow stream to the combustor to support fuel cell processor heat requirements. A control provides a quick fast forward change in an air valve orifice cross section in response to a calculated predetermined air flow, the molar constituents of the air stream to the combustor, the pressure drop across the air valve, and a look up table of the orifice cross sectional area and valve steps. A feedback loop fine tunes any error between the measured air flow to the combustor and the predetermined air flow.

  10. Method, apparatus and system for controlling fluid flow

    DOEpatents

    McMurtrey, Ryan D.; Ginosar, Daniel M.; Burch, Joesph V.

    2007-10-30

    A system, apparatus and method of controlling the flow of a fluid are provided. In accordance with one embodiment of the present invention, a flow control device includes a valve having a flow path defined therethrough and a valve seat in communication with the flow path with a valve stem disposed in the valve seat. The valve stem and valve seat are cooperatively configured to cause mutual relative linear displacement thereof in response to rotation of the valve stem. A gear member is coupled with the rotary stem and a linear positioning member includes a portion which complementarily engages the gear member. Upon displacement of the linear positioning member along a first axis, the gear member and rotary valve stem are rotated about a second axis and the valve stem and valve seat are mutually linearly displaced to alter the flow of fluid through the valve.

  11. Methods and apparatus for controlling dispersions of nanoparticles

    SciTech Connect

    Lavrentovich, Oleg D; Golovin, Andrii B

    2014-10-21

    Electrically reconfigurable metamaterial with spatially varied refractive index is proposed for applications such as optical devices and lenses. The apparatus and method comprises a metamaterial in which the refractive indices are modified in space and time by applying one or more electric fields. The metamaterials are electrically controllable and reconfigurable, and consist of metal (gold, silver, etc.) particles of different shapes, such as rods, with dimension much smaller than the wavelength of light, dispersed in a dielectric medium. The metamaterial is controlled by applying a non-uniform electric field that causes two effects: (1) It aligns the metallic anisometric particles with respect to the direction of the applied electric field and (2) It redistributes particles in space, making their local concentration position dependent.

  12. Gas migration modeling improves volumetric method of well control

    SciTech Connect

    Leach, C.P.; Quentin, K.M. )

    1994-12-26

    In the volumetric method, gas expansion during gas migration is allowed for by bleeding small quantities of fluid through the choke. When gas first reaches the choke, the influx is distributed near the surface in the annulus. Rapid gas migration then occurs, and mud and gas may need to be bled to maintain constant bottom hole pressure. The volumetric method is a technique for controlling gas kicks when circulation is not possible. The industry-recognized method is based on simple calculations which assume a single bubble of gas, the classic kick. This technique can now be evaluated by using more realistic, deterministic kick models. The results from such models cast double on some of the conventional procedures taught and used in the industry. This article details the analysis of influx behavior following a typical volumetric method. Numerical modeling of fluid losses as the surface pressure rises, gas migration, and dispersion are included to correspond accurately with field observations of kicks. Revised procedures are suggested to deal with these events better, such that the goals of the volumetric method are still attained.

  13. A Sensorless Starting Method for Self-Controlled Synchronous Motors

    NASA Astrophysics Data System (ADS)

    Hasegawa, Chihiro; Nishikata, Shoji

    A self-controlled synchronous motor is being used as a variable speed motor in industries to date, and nowadays it is also used for propelling a ship. In this type of motor, the information of rotor position is needed to achieve stable operations. A simple sensorless starting method for this motor is studied in this paper. An initial rotor position detecting method without any position sensor is first discussed. It is shown that the position can be detected easily by observing the electromotive forces induced in the armature windings due to the change in the field current. Then, a new starting method for the motor is proposed on the basis of the DC link current chopping during the starting period. It is clarified that based on the proposed method the starting of the motor can be realized independently of the load conditions, supporting the usefulness of the proposed method. Finally, the effects of various parameters in the system on the responses of dc input current and motor speed during starting up are discussed.

  14. Method and system for controlling a permanent magnet machine

    DOEpatents

    Walters, James E.

    2003-05-20

    Method and system for controlling the start of a permanent magnet machine are provided. The method allows to assign a parameter value indicative of an estimated initial rotor position of the machine. The method further allows to energize the machine with a level of current being sufficiently high to start rotor motion in a desired direction in the event the initial rotor position estimate is sufficiently close to the actual rotor position of the machine. A sensing action allows to sense whether any incremental changes in rotor position occur in response to the energizing action. In the event no changes in rotor position are sensed, the method allows to incrementally adjust the estimated rotor position by a first set of angular values until changes in rotor position are sensed. In the event changes in rotor position are sensed, the method allows to provide a rotor alignment signal as rotor motion continues. The alignment signal allows to align the estimated rotor position relative to the actual rotor position. This alignment action allows for operating the machine over a wide speed range.

  15. Adaptive model-based control systems and methods for controlling a gas turbine

    NASA Technical Reports Server (NTRS)

    Brunell, Brent Jerome (Inventor); Mathews, Jr., Harry Kirk (Inventor); Kumar, Aditya (Inventor)

    2004-01-01

    Adaptive model-based control systems and methods are described so that performance and/or operability of a gas turbine in an aircraft engine, power plant, marine propulsion, or industrial application can be optimized under normal, deteriorated, faulted, failed and/or damaged operation. First, a model of each relevant system or component is created, and the model is adapted to the engine. Then, if/when deterioration, a fault, a failure or some kind of damage to an engine component or system is detected, that information is input to the model-based control as changes to the model, constraints, objective function, or other control parameters. With all the information about the engine condition, and state and directives on the control goals in terms of an objective function and constraints, the control then solves an optimization so the optimal control action can be determined and taken. This model and control may be updated in real-time to account for engine-to-engine variation, deterioration, damage, faults and/or failures using optimal corrective control action command(s).

  16. Solving inverse problems of identification type by optimal control methods

    SciTech Connect

    Lenhart, S.; Protopopescu, V.; Yong, J.

    1997-05-01

    Inverse problems of identification type for nonlinear equations are considered within the framework of optimal control theory. The rigorous solution of any particular problem depends on the functional setting, type of equation, and unknown quantity (or quantities) to be determined. Here we present only the general articulations of the formalism. Compared to classical regularization methods (e.g. Tikhonov coupled with optimization schemes), our approach presents several advantages, namely: (i) a systematic procedure to solve inverse problems of identification type; (ii) an explicit expression for the approximations of the solution; and (iii) a convenient numerical solution of these approximations. {copyright} {ital 1997 American Institute of Physics.}

  17. Solving inverse problems of identification type by optimal control methods

    SciTech Connect

    Lenhart, S.; Protopopescu, V.; Jiongmin Yong

    1997-06-01

    Inverse problems of identification type for nonlinear equations are considered within the framework of optimal control theory. The rigorous solution of any particular problem depends on the functional setting, type of equation, and unknown quantity (or quantities) to be determined. Here the authors present only the general articulations of the formalism. Compared to classical regularization methods (e.g. Tikhonov coupled with optimization schemes), their approach presents several advantages, namely: (i) a systematic procedure to solve inverse problems of identification type; (ii) an explicit expression for the approximations of the solution; and (iii) a convenient numerical solution of these approximations.

  18. Cooperative Control Technology with ITP Method for SCADA Systems

    NASA Astrophysics Data System (ADS)

    Kosakaya, Juichi; Tadokoro, Hideyuki; Inazumi, Yasuhiro

    Introducing multi-agent (MA) technology into a SCADA (Supervisory Control and Data Acquisition) system can improve the serviceability and enhance maintenance-free operation with the inter-terminal parameter (ITP) method. In addition, the system's distributed intelligent field terminals (IFTs) use a common algorithm that is unaffected by any changes to the system specifications. As a result of these innovations, the proposed system has much better serviceability because it is much easier to make modifications compared to that of conventional systems. This system has been implemented for practical purposes at over 60 sites.

  19. Methods of measurement for semiconductor materials, process control, and devices

    NASA Technical Reports Server (NTRS)

    Bullis, W. M. (Editor)

    1972-01-01

    Activities directed toward the development of methods of measurement for semiconductor materials, process control, and devices are described. Topics investigated include: measurements of transistor delay time; application of the infrared response technique to the study of radiation-damaged, lithium-drifted silicon detectors; and identification of a condition that minimizes wire flexure and reduces the failure rate of wire bonds in transistors and integrated circuits under slow thermal cycling conditions. Supplementary data concerning staff, standards committee activities, technical services, and publications are included as appendixes.

  20. An Effective Mobile Sensor Control Method for Sparse Sensor Networks

    PubMed Central

    Treeprapin, Kriengsak; Kanzaki, Akimitsu; Hara, Takahiro; Nishio, Shojiro

    2009-01-01

    In this paper, we propose an effective mobile sensor control method, named DATFM (Data Acquisition and Transmission with Fixed and Mobile node) for sparse sensor networks. DATFM uses two types of sensor nodes, fixed node and mobile node. The data acquired by nodes are accumulated on a fixed node before being transferred to the sink node. In addition, DATFM transfers the accumulated data efficiently by constructing a communication route of multiple mobile nodes between fixed nodes. We also conduct simulation experiments to evaluate the performance of DATFM. PMID:22389602

  1. Enhanced Temperature Control Method Using ANFIS with FPGA

    PubMed Central

    Zhou, Jun-Tin

    2014-01-01

    Temperature control in etching process is important for semiconductor manufacturing technology. However, pressure variations in vacuum chamber results in a change in temperature, worsening the accuracy of the temperature of the wafer and the speed and quality of the etching process. This work develops an adaptive network-based fuzzy inference system (ANFIS) using a field-programmable gate array (FPGA) to improve the effectiveness. The proposed method adjusts every membership function to keep the temperature in the chamber stable. The improvement of the proposed algorithm is confirmed using a medium vacuum (MV) inductively-coupled plasma- (ICP-) type etcher. PMID:24715808

  2. Enhanced temperature control method using ANFIS with FPGA.

    PubMed

    Huang, Chiung-Wei; Pan, Shing-Tai; Zhou, Jun-Tin; Chang, Cheng-Yuan

    2014-01-01

    Temperature control in etching process is important for semiconductor manufacturing technology. However, pressure variations in vacuum chamber results in a change in temperature, worsening the accuracy of the temperature of the wafer and the speed and quality of the etching process. This work develops an adaptive network-based fuzzy inference system (ANFIS) using a field-programmable gate array (FPGA) to improve the effectiveness. The proposed method adjusts every membership function to keep the temperature in the chamber stable. The improvement of the proposed algorithm is confirmed using a medium vacuum (MV) inductively-coupled plasma- (ICP-) type etcher. PMID:24715808

  3. Method of forming cavitated objects of controlled dimension

    DOEpatents

    Anderson, P.R.; Miller, W.J.

    1981-02-11

    A method is disclosed of controllably varying the dimensions of cavitated objects such as hollow spherical shells wherein a precursor shell is heated to a temperature above the shell softening temperature in an ambient atmosphere wherein the ratio of gases which are permeable through the shell wall at that temperature to gases which are impermeable through the shell wall is substantially greater than the corresponding ratio for gases contained within the precursor shell. As the shell expands, the partial pressures of permeable gases internally and externally of the shell approach and achieve equilibrium, so that the final shell size depends solely upon the difference in impermeable gas partial pressures and shell surface tension.

  4. The controlled growth method - A tool for structural optimization

    NASA Technical Reports Server (NTRS)

    Hajela, P.; Sobieszczanski-Sobieski, J.

    1981-01-01

    An adaptive design variable linking scheme in a NLP based optimization algorithm is proposed and evaluated for feasibility of application. The present scheme, based on an intuitive effectiveness measure for each variable, differs from existing methodology in that a single dominant variable controls the growth of all others in a prescribed optimization cycle. The proposed method is implemented for truss assemblies and a wing box structure for stress, displacement and frequency constraints. Substantial reduction in computational time, even more so for structures under multiple load conditions, coupled with a minimal accompanying loss in accuracy, vindicates the algorithm.

  5. System and method for controlling a combustor assembly

    DOEpatents

    York, William David; Ziminsky, Willy Steve; Johnson, Thomas Edward; Stevenson, Christian Xavier

    2013-03-05

    A system and method for controlling a combustor assembly are disclosed. The system includes a combustor assembly. The combustor assembly includes a combustor and a fuel nozzle assembly. The combustor includes a casing. The fuel nozzle assembly is positioned at least partially within the casing and includes a fuel nozzle. The fuel nozzle assembly further defines a head end. The system further includes a viewing device configured for capturing an image of at least a portion of the head end, and a processor communicatively coupled to the viewing device, the processor configured to compare the image to a standard image for the head end.

  6. Dolomite magnesium oxychloride cement properties control method during its production

    NASA Astrophysics Data System (ADS)

    Chernykh, T. N.; Nosov, A. V.; Kramar, L. Ya

    2015-01-01

    The work considers the possibility of reducing the decomposition temperature of MgCO3 in dolomite rock, provides the results of studies of the effect of various additives and enhancers on the decomposition of magnesium and calcium components of dolomite. Chlorides additives are the most promising for dolomite rocks roast intensification. They allow shifting the MgCO3 decomposition to lower temperatures, without exerting a significant influence on the decomposition of CaCO3. Introduction of additives-enhancers is found to be an effective method of controlling the properties of dolomite MOC during roasting, producing high-strength dolomite magnesium oxychloride cements with change in volume during solidification.

  7. Method of forming cavitated objects of controlled dimension

    DOEpatents

    Anderson, Paul R.; Miller, Wayne J.

    1982-01-01

    A method of controllably varying the dimensions of cavitated objects such as hollow spherical shells wherein a precursor shell is heated to a temperature above the shell softening temperature in an ambient atmosphere wherein the ratio of gases which are permeable through the shell wall at that temperature to gases which are impermeable through the shell wall is substantially greater than the corresponding ratio for gases contained within the precursor shell. As the shell expands, the partial pressures of permeable gases internally and externally of the shell approach and achieve equilibrium, so that the final shell size depends solely upon the difference in impermeable gas partial pressures and shell surface tension.

  8. Method for consolidating sand or water control in subterranean formations

    SciTech Connect

    Golinkin, H.S.

    1980-03-18

    A description is given of a method and composition for fracturing a subterranean formation which comprises (1) contacting a subterranean formation with an aqueous liquid comprising a propping agent and a composition containing water, acrylamide:methacrylate copolymer cross-linked with chromium (III) ion, in presence of carbonate ion, oxalate ion, and, optionally, persulfate ion, (2) applying pressure to said liquid, (3) maintaining said pressure to fracture said formation, (4) and said gel breaking within 24 hours of gel formation. The composition without the persulfate gel breaking is also useful for sand consolidation and fluid control.

  9. Methods of measurement for semiconductor materials, process control, and devices

    NASA Technical Reports Server (NTRS)

    Bullis, W. M. (Editor)

    1971-01-01

    The development of methods of measurement for semiconductor materials, process control, and devices is discussed. The following subjects are also presented: (1) demonstration of the high sensitivity of the infrared response technique by the identification of gold in a germanium diode, (2) verification that transient thermal response is significantly more sensitive to the presence of voids in die attachment than steady-state thermal resistance, and (3) development of equipment for determining susceptibility of transistors to hot spot formation by the current-gain technique.

  10. Efficient model learning methods for actor-critic control.

    PubMed

    Grondman, Ivo; Vaandrager, Maarten; Buşoniu, Lucian; Babuska, Robert; Schuitema, Erik

    2012-06-01

    We propose two new actor-critic algorithms for reinforcement learning. Both algorithms use local linear regression (LLR) to learn approximations of the functions involved. A crucial feature of the algorithms is that they also learn a process model, and this, in combination with LLR, provides an efficient policy update for faster learning. The first algorithm uses a novel model-based update rule for the actor parameters. The second algorithm does not use an explicit actor but learns a reference model which represents a desired behavior, from which desired control actions can be calculated using the inverse of the learned process model. The two novel methods and a standard actor-critic algorithm are applied to the pendulum swing-up problem, in which the novel methods achieve faster learning than the standard algorithm. PMID:22156998

  11. Method and device for controlling plume during laser welding

    SciTech Connect

    Fuerschbach, P.W.; Jellison, J.L.; Keicher, D.M.; Oberkampf, W.L.

    1991-02-12

    This patent describes a method and apparatus for enhancing the weldment of a laser welding system. The laser weld plume control device includes a cylindrical body defining an upside-down cone cavity; the upper surface of the body circumscribes the base of the cone cavity, and the vertex of the cone cavity forms an orifice concentrically located with respect to the laser beam and the plume which forms as a result of the welding operation. According to the method of the invention, gas is directed radially inward through inlets in the upper surface of the body into and through channels in the wall of the body and finally through the orifice of the body, and downward onto the surface of the weldment.

  12. Method and device for controlling plume during laser welding

    DOEpatents

    Fuerschbach, Phillip W.; Jellison, James L.; Keicher, David M.; Oberkampf, William L.

    1991-01-01

    A method and apparatus for enhancing the weldment of a laser welding system is provided. The laser weld plume control device includes a cylindrical body defining an upside-down cone cavity; the upper surface of the body circumscribes the base of the cone cavity, and the vertex of the cone cavity forms an orifice concentrically located with respect to the laser beam and the plume which forms as a result of the welding operation. According to the method of the invention, gas is directed radially inward through inlets in the upper surface of the body into and through channels in the wall of the body and finally through the orifice of the body, and downward onto the surface of the weldment. The gas flow is then converted by the orifice of the device from radial flow to an axisymmetric gas jet flowing away from the weldment surface in a direction perpendicular to the surface and opposite to that of the laser.

  13. Development of motion control method for laser soldering process

    SciTech Connect

    Yerganian, S.S.

    1997-05-01

    Development of a method to generate the motion control data for sealing an electronic housing using laser soldering is described. The motion required to move the housing under the laser is a nonstandard application and was performed with a four-axis system using the timed data streaming mode capabilities of a Compumotor AT6400 indexer. A Microsoft Excel 5.0 spreadsheet (named Israuto.xls) was created to calculate the movement of the part under the laser, and macros were written into the spreadsheet to allow the user to easily create this data. A data verification method was developed for simulating the motion data. The geometry of the assembly was generated using Parametric Technology Corporation Pro/E version 15. This geometry was then converted using Pro/DADS version 3.1 from Computer Aided Design Software Inc. (CADSI), and the simulation was carried out using DADS version 8.0 from CADSI.

  14. Linear transformation method to control flexural waves in thin plates.

    PubMed

    Liu, Yongquan; Ma, Zhaoyang; Su, Xianyue

    2016-08-01

    In this paper, the linear transformation method (LTM) to control flexural waves propagating in thin plates is presented. Unlike earlier studies, only a small number of homogeneous materials with no requirement of in-plane forces or pre-stress are needed, which tremendously simplifies the implementation of devices for flexural waves. An invisibility cloak with homogeneous materials is studied to confirm the validity of the present approach, and to show its imperfection due to impedance mismatch at interfaces. Required materials can be further simplified as layered isotropic materials using the effective medium theory. Finally, the LTM can be extended to the case of flexural waves propagating in anisotropic thin plates. The present method opens a promising avenue toward the realization of advanced structured shields and other devices. PMID:27586744

  15. A demonstrated method for upgrading existing control room interiors

    SciTech Connect

    Brice, R.M. ); Terrill, D. ); Brice, R.M.

    1991-01-01

    The main control room (MCR) of any nuclear power plant can justifiably be called the most important area staffed by personnel in the entire facility. The interior workstation configuration, equipment arrangement, and staff placement all affect the efficiency and habitability of the room. There are many guidelines available that describe various human factor principles to use when upgrading the environment of the MCR. These involve anthropometric standards and rules for placement of peripheral equipment. Due to the variations in plant design, however, hard-and-fast rules have not and cannot be standardized for retrofits in any significant way. How then does one develop criteria for the improvement of a MCR The purpose of this paper is to discuss, from the designer's point of view, a method for the collection of information, development of criteria, and creation of a final design for a MCR upgrade. This method is best understood by describing the successful implementation at Tennessee Valley Authority's Sequoyah nuclear plant.

  16. Modeling and simulation of aeroservoelastic control with multiple control surfaces using mu-method

    NASA Astrophysics Data System (ADS)

    Teng, Ying

    A modeling and simulation approach to predicting the robust stability of a nonlinear aeroservoelastic system via the mu-method is presented. Mathematical models and implementation issues for the multi-input/multi-output (MIMO) aeroservoelastic system simulation developed for a flexible prototypical wing with leading and trailing edge control surfaces are described. The improvements in the aeroservoelastic analysis and the active flutter suppression (AFS) of a flexible wing structure with multiple control surfaces is accomplished using the mu-method with the uncertainty parameters/perturbations associated with unsteady dynamic pressure, variable structural damping and nonlinear structural stiffness. The motivation of this research is to develop an effective and more accurate methodology in aeroservoelastic analysis by improving the current analysis methods so that it can be readily applied to an aeroservoelastic system design with the validation of test data, and to determine the dynamic performance of an aeroservoelastic system which includes time and frequency responses, system modal properties, critical flutter airspeeds and stability margins. The mu-control law and algorithms for an aeroservoelastic system with leading and trailing edge control surfaces are developed by combining the MIMO analytical aeroservoelastic model with test data by means of the linear fractional transformation (LFT) and a set of norm-bounded operators (perturbations) Delta that describe modeling errors and uncertainties in the mu-framework. The relevant theories of structural dynamics, aerodynamics, and modern feedback control, as well as flutter, frequency response, poles and stability, aeroservoelasticity/structural-coupling, and mu-based analysis applied to derive the mu-control law for the aeroservoelastic control system are examined. Simulation results are presented for comparisons of the following: (a) the uncontrolled flexible wing, (b) the active flexible wing with a single

  17. Variable Camber Continuous Aerodynamic Control Surfaces and Methods for Active Wing Shaping Control

    NASA Technical Reports Server (NTRS)

    Nguyen, Nhan T. (Inventor)

    2016-01-01

    An aerodynamic control apparatus for an air vehicle improves various aerodynamic performance metrics by employing multiple spanwise flap segments that jointly form a continuous or a piecewise continuous trailing edge to minimize drag induced by lift or vortices. At least one of the multiple spanwise flap segments includes a variable camber flap subsystem having multiple chordwise flap segments that may be independently actuated. Some embodiments also employ a continuous leading edge slat system that includes multiple spanwise slat segments, each of which has one or more chordwise slat segment. A method and an apparatus for implementing active control of a wing shape are also described and include the determination of desired lift distribution to determine the improved aerodynamic deflection of the wings. Flap deflections are determined and control signals are generated to actively control the wing shape to approximate the desired deflection.

  18. Electrical energy consumption control apparatuses and electrical energy consumption control methods

    DOEpatents

    Hammerstrom, Donald J.

    2012-09-04

    Electrical energy consumption control apparatuses and electrical energy consumption control methods are described. According to one aspect, an electrical energy consumption control apparatus includes processing circuitry configured to receive a signal which is indicative of current of electrical energy which is consumed by a plurality of loads at a site, to compare the signal which is indicative of current of electrical energy which is consumed by the plurality of loads at the site with a desired substantially sinusoidal waveform of current of electrical energy which is received at the site from an electrical power system, and to use the comparison to control an amount of the electrical energy which is consumed by at least one of the loads of the site.

  19. Method for removing tilt control in adaptive optics systems

    DOEpatents

    Salmon, J.T.

    1998-04-28

    A new adaptive optics system and method of operation are disclosed, whereby the method removes tilt control, and includes the steps of using a steering mirror to steer a wavefront in the desired direction, for aiming an impinging aberrated light beam in the direction of a deformable mirror. The deformable mirror has its surface deformed selectively by means of a plurality of actuators, and compensates, at least partially, for existing aberrations in the light beam. The light beam is split into an output beam and a sample beam, and the sample beam is sampled using a wavefront sensor. The sampled signals are converted into corresponding electrical signals for driving a controller, which, in turn, drives the deformable mirror in a feedback loop in response to the sampled signals, for compensating for aberrations in the wavefront. To this purpose, a displacement error (gradient) of the wavefront is measured, and adjusted by a modified gain matrix, which satisfies the following equation: G{prime} = (I{minus}X(X{sup T} X){sup {minus}1}X{sup T})G(I{minus}A). 3 figs.

  20. Method for removing tilt control in adaptive optics systems

    DOEpatents

    Salmon, Joseph Thaddeus

    1998-01-01

    A new adaptive optics system and method of operation, whereby the method removes tilt control, and includes the steps of using a steering mirror to steer a wavefront in the desired direction, for aiming an impinging aberrated light beam in the direction of a deformable mirror. The deformable mirror has its surface deformed selectively by means of a plurality of actuators, and compensates, at least partially, for existing aberrations in the light beam. The light beam is split into an output beam and a sample beam, and the sample beam is sampled using a wavefront sensor. The sampled signals are converted into corresponding electrical signals for driving a controller, which, in turn, drives the deformable mirror in a feedback loop in response to the sampled signals, for compensating for aberrations in the wavefront. To this purpose, a displacement error (gradient) of the wavefront is measured, and adjusted by a modified gain matrix, which satisfies the following equation: G'=(I-X(X.sup.T X).sup.-1 X.sup.T)G(I-A)

  1. Methods to sustain drug efficacy in helminth control programmes.

    PubMed

    Albonico, M

    2003-05-01

    Assessment of the efficacy of anthelminthic treatment in public health is a broad concept, which goes beyond parasitological methods and should be clearly defined according to several indicators of morbidity. Several factors may influence the efficacy of anthelminthic drugs. The quality of drug is an issue of great importance, especially when produced locally as a generic product and used in large-scale chemotherapy-based control programmes. Other factors include the drug-patient interaction, the host-parasite relationship, the diagnostic method used, genetic variations between parasite strains and induced drug resistance. Veterinary scientists have warned that drug resistance can be selected through frequent mass treatment of sheep and goats and have developed a body of knowledge on evaluation of efficacy and detection of resistance in nematodes of veterinary importance. In soil-transmitted nematodes infections of humans, the egg reduction rate (ERR), the egg hatch assay (EHA) and novel molecular biological techniques may be used to monitor drug efficacy in helminth control programmes and to detect early occurrence of resistance. Evidence of reduced drug efficacy of some anthelminthics has been suggested by recent studies and strategies to prevent or delay the emergence of drug resistance in human soil-transmitted nematodes. PMID:12745140

  2. Dynamically controlled crystallization method and apparatus and crystals obtained thereby

    NASA Technical Reports Server (NTRS)

    Arnowitz, Leonard (Inventor); Steinberg, Emanuel (Inventor)

    2003-01-01

    A method and apparatus for dynamically controlling the crystallization of molecules including a crystallization chamber (14) or chambers for holding molecules in a precipitant solution, one or more precipitant solution reservoirs (16, 18), communication passages (17, 19) respectively coupling the crystallization chamber(s) with each of the precipitant solution reservoirs, and transfer mechanisms (20, 21, 22, 24, 26, 28) configured to respectively transfer precipitant solution between each of the precipitant solution reservoirs and the crystallization chamber(s). The transfer mechanisms are interlocked to maintain a constant volume of precipitant solution in the crystallization chamber(s). Precipitant solutions of different concentrations are transferred into and out of the crystallization chamber(s) to adjust the concentration of precipitant in the crystallization chamber(s) to achieve precise control of the crystallization process. The method and apparatus can be used effectively to grow crystals under reduced gravity conditions such as microgravity conditions of space, and under conditions of reduced or enhanced effective gravity as induced by a powerful magnetic field.

  3. Hydraulic fracturing method employing a fines control technique

    SciTech Connect

    Stowe, L.R.

    1986-11-18

    A method is described for controlling fines or sand in an unconsolidated or loosely consolidated formation or reservoir penetrated by at least one wellbore where hydraulic fracturing is used in combination with control of the critical salinity rate and the critical fluid flow velocity. The method comprises: (a) placing at least one wellbore in the reservoir; (b) hydraulically fracturing the formation via the wellbore with a fracturing fluid which creates at least one fracture; (c) placing a proppant comprising a gravel pack into the fracture; (d) determining the critical salinity rate and the critical fluid flow velocity of the formation or reservoir surrounding the wellbore; (e) injecting a saline solution into the formation or reservoir at a velocity exceeding the critical fluid flow velocity and at a saline concentration sufficient to cause the fines or particles to be transferred and fixed deep wihtin the formation or reservoir without plugging the formation, fracture, or wellbore; and (f) producing a hydrocarbonaceous fluid from the formation or reservoir at a velocity such that the critical flow velocity is not exceeded deep within the formation, fracture, or wellbore.

  4. Quality control and analytical methods for baculovirus-based products.

    PubMed

    Roldão, António; Vicente, Tiago; Peixoto, Cristina; Carrondo, Manuel J T; Alves, Paula M

    2011-07-01

    Recombinant baculoviruses (rBac) are used for many different applications, ranging from bio-insecticides to the production of heterologous proteins, high-throughput screening of gene functions, drug delivery, in vitro assembly studies, design of antiviral drugs, bio-weapons, building blocks for electronics, biosensors and chemistry, and recently as a delivery system in gene therapy. Independent of the application, the quality, quantity and purity of rBac-based products are pre-requisites demanded by regulatory authorities for product licensing. To guarantee maximization utility, it is necessary to delineate optimized production schemes either using trial-and-error experimental setups ("brute force" approach) or rational design of experiments by aid of in silico mathematical models (Systems Biology approach). For that, one must define all of the main steps in the overall process, identify the main bioengineering issues affecting each individual step and implement, if required, accurate analytical methods for product characterization. In this review, current challenges for quality control (QC) technologies for up- and down-stream processing of rBac-based products are addressed. In addition, a collection of QC methods for monitoring/control of the production of rBac derived products are presented as well as innovative technologies for faster process optimization and more detailed product characterization. PMID:21784235

  5. Teaching Thermal Hydraulics & Numerical Methods: An Introductory Control Volume Primer

    SciTech Connect

    D. S. Lucas

    2004-10-01

    A graduate level course for Thermal Hydraulics (T/H) was taught through Idaho State University in the spring of 2004. A numerical approach was taken for the content of this course since the students were employed at the Idaho National Laboratory and had been users of T/H codes. The majority of the students had expressed an interest in learning about the Courant Limit, mass error, semi-implicit and implicit numerical integration schemes in the context of a computer code. Since no introductory text was found the author developed notes taught from his own research and courses taught for Westinghouse on the subject. The course started with a primer on control volume methods and the construction of a Homogeneous Equilibrium Model (HEM) (T/H) code. The primer was valuable for giving the students the basics behind such codes and their evolution to more complex codes for Thermal Hydraulics and Computational Fluid Dynamics (CFD). The course covered additional material including the Finite Element Method and non-equilibrium (T/H). The control volume primer and the construction of a three-equation (mass, momentum and energy) HEM code are the subject of this paper . The Fortran version of the code covered in this paper is elementary compared to its descendants. The steam tables used are less accurate than the available commercial version written in C Coupled to a Graphical User Interface (GUI). The Fortran version and input files can be downloaded at www.microfusionlab.com.

  6. Tradeoff methods in multiobjective insensitive design of airplane control systems

    NASA Technical Reports Server (NTRS)

    Schy, A. A.; Giesy, D. P.

    1984-01-01

    The latest results of an ongoing study of computer-aided design of airplane control systems are given. Constrained minimization algorithms are used, with the design objectives in the constraint vector. The concept of Pareto optimiality is briefly reviewed. It is shown how an experienced designer can use it to find designs which are well-balanced in all objectives. Then the problem of finding designs which are insensitive to uncertainty in system parameters are discussed, introducing a probabilistic vector definition of sensitivity which is consistent with the deterministic Pareto optimal problem. Insensitivity is important in any practical design, but it is particularly important in the design of feedback control systems, since it is considered to be the most important distinctive property of feedback control. Methods of tradeoff between deterministic and stochastic-insensitive (SI) design are described, and tradeoff design results are presented for the example of the a Shuttle lateral stability augmentation system. This example is used because careful studies have been made of the uncertainty in Shuttle aerodynamics. Finally, since accurate statistics of uncertain parameters are usually not available, the effects of crude statistical models on SI designs are examined.

  7. Sway control method and system for rotary cranes

    DOEpatents

    Robinett, Rush D.; Parker, Gordon G.; Feddema, John T.; Dohrmann, Clark R.; Petterson, Ben J.

    1999-01-01

    Methods and apparatuses for reducing the oscillatory motion of rotary crane payloads during operator-commanded or computer-controlled maneuvers. An Input-shaping filter receives input signals from multiple operator input devices and converts them into output signals readable by the crane controller to dampen the payload tangential and radial sway associated with rotation of the jib. The input signals are characterized by a hub rotation trajectory .gamma.(t), which includes a jib angular acceleration .gamma., a trolley acceleration x, and a load-line length velocity L. The system state variables are characterized by a tangential rotation angle .theta.(t) and a radial rotation angle .phi.(t) of the load-line. The coupled equations of motion governing the filter are non-linear and configuration-dependent. In one embodiment, a filter is provided between the operator and the crane for filtering undesired frequencies from the angular .gamma. and trolley x velocities to suppress payload oscillation. In another embodiment, crane commands are computer generated and controlled to suppress vibration of the payload using a postulated asymmetrical shape for the acceleration profiles of the jib, which profiles are uniquely determined by a set of parameters (including the acceleration pulse amplitude and the duration and coast time between pulses), or a dynamic programming approach.

  8. Sway control method and system for rotary cranes

    DOEpatents

    Robinett, R.D.; Parker, G.G.; Feddema, J.T.; Dohrmann, C.R.; Petterson, B.J.

    1999-06-01

    Methods and apparatuses are disclosed for reducing the oscillatory motion of rotary crane payloads during operator-commanded or computer-controlled maneuvers. An Input-shaping filter receives input signals from multiple operator input devices and converts them into output signals readable by the crane controller to dampen the payload tangential and radial sway associated with rotation of the jib. The input signals are characterized by a hub rotation trajectory [gamma](t), which includes a jib angular acceleration [gamma], a trolley acceleration x, and a load-line length velocity L. The system state variables are characterized by a tangential rotation angle [theta](t) and a radial rotation angle [phi](t) of the load-line. The coupled equations of motion governing the filter are non-linear and configuration-dependent. In one embodiment, a filter is provided between the operator and the crane for filtering undesired frequencies from the angular [gamma] and trolley x velocities to suppress payload oscillation. In another embodiment, crane commands are computer generated and controlled to suppress vibration of the payload using a postulated asymmetrical shape for the acceleration profiles of the jib, which profiles are uniquely determined by a set of parameters (including the acceleration pulse amplitude and the duration and coast time between pulses), or a dynamic programming approach. 25 figs.

  9. Control methods and thresholds of acceptability for antibrucella vaccines.

    PubMed

    Bosseray, N

    1992-01-01

    Protection against brucellosis involves both cellular and humoral effectors not yet fully appreciated. Living or killed vaccines can protect against the infection itself or only against abortion. For official controls, vaccines (or new procedures of vaccination) must first be characterized pharmacologically and tested for innocuity. Protection must be tested on natural hosts with a reference vaccine (S19 or Rev. 1) by the agreed method which reproduces the natural infection and measures immunity in toto. Control and vaccinated females are challenged by the conjunctival route at mid-pregnancy under standard conditions (strain, dose) to measure the resulting infection by bacteriological analysis of excretion at parturition and of infection in target organs at slaughter. Results are principally expressed by the infection rate which should be +/- 95% in the control group. In the new vaccine group the rate should be equivalent to, or lower than, the reference vaccine group. To be statistically valid, at least 30 animals per group are required. For routine controls, laboratory models using guinea pigs, not well standardized, inaccurate and expensive, have long been proposed. The mouse model, extensively studied and standardized, should now be preferred to the guinea pig model. In the mouse model, residual virulence of a living vaccine is estimated by the time required by 50% of the mice to eradicate the strain from their spleen (Recovery Time 50%). Immunogenicity is measured by the ability of mice to restrict their splenic infection after a virulent i.p. challenge at a dose (B. abortus 544; 2 x 10(5) cfu) chosen in order that all mice were still infected 15 days post challenge.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1286747

  10. Method for controlling exhaust gas heat recovery systems in vehicles

    DOEpatents

    Spohn, Brian L.; Claypole, George M.; Starr, Richard D

    2013-06-11

    A method of operating a vehicle including an engine, a transmission, an exhaust gas heat recovery (EGHR) heat exchanger, and an oil-to-water heat exchanger providing selective heat-exchange communication between the engine and transmission. The method includes controlling a two-way valve, which is configured to be set to one of an engine position and a transmission position. The engine position allows heat-exchange communication between the EGHR heat exchanger and the engine, but does not allow heat-exchange communication between the EGHR heat exchanger and the oil-to-water heat exchanger. The transmission position allows heat-exchange communication between the EGHR heat exchanger, the oil-to-water heat exchanger, and the engine. The method also includes monitoring an ambient air temperature and comparing the monitored ambient air temperature to a predetermined cold ambient temperature. If the monitored ambient air temperature is greater than the predetermined cold ambient temperature, the two-way valve is set to the transmission position.

  11. Method and apparatus for recirculation with control of synchrotron radiation

    DOEpatents

    Douglas, David R.; Tennant, Christopher

    2016-08-02

    A method for controlling beam quality degradation from ISR and CSR and stabilizing the microbunching instability (.mu.BI) in a high brightness electron beam. The method includes providing a super-periodic second order achromat line with each super period being individually linearly achromatic and isochronous, setting individual superperiod tunes to rational fractions of an integer (such as 4.sup.th or 6.sup.th integers), setting individual bend angles to be as small as practical to reduce driving terms due to dispersion and dispersive angle, and setting bend radii as large enough to suppress ISR but not negatively affect the radial dependence of CSR. The method includes setting the structure of the individual superperiods to minimize bend plane beam envelope values in the dipoles to reduce betatron response to a CSR event at a dispersed location, increasing beam angular divergence, and creating dispersion nodes in the dipoles to similarly reduce response to CSR events, and limit R.sub.56 modulation in order to mitigate .mu.BI.

  12. A Controlled Study on the Correlation between Tear Film Volume and Tear Film Stability in Diabetic Patients

    PubMed Central

    Khalil, Noha M.; El-Gendy, Heba A.

    2016-01-01

    Purpose. To assess the tear film quantity and correlate it with the quality and stability of the tear film in diabetics and compare them to age matched controls. Introduction. Diabetes affects tear film parameters in multiple ways. Poor metabolic control and neuropathy are postulated factors. To further understand how diabetes affects tear film parameters this study was conducted. Subjects and Methods. Tear meniscus height was measured by anterior segment OCT, along with tear thinning time, a subtype of noninvasive tear break-up time, and blinking rate per minute which were all recorded for 22 diabetic patients. Correlations between these tear film parameters were studied and then compared to 16 age matched controls. Results. A statistically significant difference was found in blinking rate between the diabetic and the control group (P = 0.002), with higher blinking rate among diabetics. All tear film parameters were negatively correlated with duration of diabetes. A positive correlation was found between tear film volume and stability. Conclusion. Diabetes affects the tear film in various ways. Diabetics should be examined for dry eye signs even in absence of symptoms which may be masked by associated neuropathy. Duration of diabetes has an impact on tear film status. PMID:27034823

  13. Battery control system for hybrid vehicle and method for controlling a hybrid vehicle battery

    DOEpatents

    Bockelmann, Thomas R.; Hope, Mark E.; Zou, Zhanjiang; Kang, Xiaosong

    2009-02-10

    A battery control system for hybrid vehicle includes a hybrid powertrain battery, a vehicle accessory battery, and a prime mover driven generator adapted to charge the vehicle accessory battery. A detecting arrangement is configured to monitor the vehicle accessory battery's state of charge. A controller is configured to activate the prime mover to drive the generator and recharge the vehicle accessory battery in response to the vehicle accessory battery's state of charge falling below a first predetermined level, or transfer electrical power from the hybrid powertrain battery to the vehicle accessory battery in response to the vehicle accessory battery's state of charge falling below a second predetermined level. The invention further includes a method for controlling a hybrid vehicle powertrain system.

  14. Driving Torque Control Method for Electric Vehicle with In-Wheel Motors

    NASA Astrophysics Data System (ADS)

    Yoshimura, Masataka; Fujimoto, Hiroshi

    Anti-slip control or slip ratio control can help improve the stability of EVs on a low-µ road. However, these control methods cannot control the driving torque. In this paper, we propose a driving torque control method for EVs with in-wheel motors. By using this method, we can control the driving torque directly. Simulations and experiments are carried out to demonstrate the effectiveness of the proposed method.

  15. Method of repairing a wellbore liner for sand control

    SciTech Connect

    Dees, J.M.

    1992-10-13

    This patent describes a method of repairing a damaged wellbore liner for controlling sand and other fine materials. It comprises: positioning a quantity of fluid resin material in alignment with the portion of the wellbore liner to be repaired; positioning a gas generator in proximity with the fluid resin material; actuating the gas generator to increase wellbore pressure in a substantially instantaneous manner to a pressure substantially in excess of well pressure to force the fluid resin material from the wellbore into the damaged area of the wellbore liner; and subsequently polymerizing the resin material to form a consolidated, porous permeable matrix that allows the flow of production fluid into the well while preventing the flow of sand, or other fine materials into the well through the previously damaged area of the wellbore liner.

  16. Human gastrointestinal nematode infections: are new control methods required?

    PubMed Central

    Stepek, Gillian; Buttle, David J; Duce, Ian R; Behnke, Jerzy M

    2006-01-01

    Gastrointestinal (GI) nematode infections affect 50% of the human population worldwide, and cause great morbidity as well as hundreds of thousands of deaths. Despite modern medical practices, the proportion of the population infected with GI nematodes is not falling. This is due to a number of factors, the most important being the lack of good healthcare, sanitation and health education in many developing countries. A relatively new problem is the development of resistance to the small number of drugs available to treat GI nematode infections. Here we review the most important parasitic GI nematodes and the methods available to control them. In addition, we discuss the current status of new anthelmintic treatments, particularly the plant cysteine proteinases from various sources of latex-bearing plants and fruits. PMID:16965561

  17. Methods of control for hospital quality assurance systems.

    PubMed Central

    Restuccia, J D; Holloway, D C

    1982-01-01

    The major failure of hospital quality assurance systems is the failure to influence physicians' therapeutic decision making in a way that will ensure their ordering necessary and only necessary services. The primary reason for this is insufficient recognition of the "intensive" technology used to treat acute patients, a technology characterized by the interdependence of therapeutic services and the patient's response to these services. In such situations, the appropriate method of achieving quality control is to provide performance feedback to the physician on a regular basis. To the extent that there is uncertainty about the impact of therapeutic services on the patient's response, the physician should be allowed discretion over the therapeutic process. In contrast, when process-outcome relations in the therapeutic process are relatively certain, feedback should be reinforced with sanctions. PMID:7118544

  18. PARTICLE ACCELERATOR AND METHOD OF CONTROLLING THE TEMPERATURE THEREOF

    DOEpatents

    Neal, R.B.; Gallagher, W.J.

    1960-10-11

    A method and means for controlling the temperature of a particle accelerator and more particularly to the maintenance of a constant and uniform temperature throughout a particle accelerator is offered. The novel feature of the invention resides in the provision of two individual heating applications to the accelerator structure. The first heating application provided is substantially a duplication of the accelerator heat created from energization, this first application being employed only when the accelerator is de-energized thereby maintaining the accelerator temperature constant with regard to time whether the accelerator is energized or not. The second heating application provided is designed to add to either the first application or energization heat in a manner to create the same uniform temperature throughout all portions of the accelerator.

  19. Apparatus and method for controlling the secondary injection of fuel

    DOEpatents

    Martin, Scott M.; Cai, Weidong; Harris, Jr., Arthur J.

    2013-03-05

    A combustor (28) for a gas turbine engine is provided comprising a primary combustion chamber (30) for combusting a first fuel to form a combustion flow stream (50) and a transition piece (32) located downstream from the primary combustion chamber (30). The transition piece (32) comprises a plurality of injectors (66) located around a circumference of the transition piece (32) for injecting a second fuel into the combustion flow stream (50). The injectors (66) are effective to create a radial temperature profile (74) at an exit (58) of the transition piece (32) having a reduced coefficient of variation relative to a radial temperature profile (64) at an inlet (54) of the transition piece (32). Methods for controlling the temperature profile of a secondary injection are also provided.

  20. Apparatus and methods for controlling electron microscope stages

    SciTech Connect

    Duden, Thomas

    2015-08-11

    Methods and apparatus for generating an image of a specimen with a microscope (e.g., TEM) are disclosed. In one aspect, the microscope may generally include a beam generator, a stage, a detector, and an image generator. A plurality of crystal parameters, which describe a plurality of properties of a crystal sample, are received. In a display associated with the microscope, an interactive control sphere based at least in part on the received crystal parameters and that is rotatable by a user to different sphere orientations is presented. The sphere includes a plurality of stage coordinates that correspond to a plurality of positions of the stage and a plurality of crystallographic pole coordinates that correspond to a plurality of polar orientations of the crystal sample. Movement of the sphere causes movement of the stage, wherein the stage coordinates move in conjunction with the crystallographic coordinates represented by pole positions so as to show a relationship between stage positions and the pole positions.

  1. Landslide Geohazard Monitoring, Early Warning and Stabilization Control Methods

    NASA Astrophysics Data System (ADS)

    Bednarczyk, Zbigniew

    2014-03-01

    This paper is a presentation of landslide monitoring, early warning and remediation methods recommended for the Polish Carpathians. Instrumentation included standard and automatic on-line measurements with the real-time transfer of data to an Internet web server. The research was funded through EU Innovative Economy Programme and also by the SOPO Landslide Counteraction Project. The landslides investigated were characterized by relatively low rates of the displacements. These ranged from a few millimetres to several centimetres per year. Colluviums of clayey flysch deposits were of a soil-rock type with a very high plasticity and moisture content. The instrumentation consisted of 23 standard inclinometers set to depths of 5-21 m. The starting point of monitoring measurements was in January 2006. These were performed every 1-2 months over the period of 8 years. The measurements taken detected displacements from several millimetres to 40 cm set at a depth of 1-17 m. The modern, on-line monitoring and early warning system was installed in May 2010. The system is the first of its kind in Poland and only one of several such real-time systems in the world. The installation was working with the Local Road Authority in Gorlice. It contained three automatic field stations for investigation of landslide parameters to depths of 12-16 m and weather station. In-place tilt transducers and innovative 3D continuous inclinometer systems with sensors located every 0.5 m were used. It has the possibility of measuring a much greater range of movements compared to standard systems. The conventional and real-time data obtained provided a better recognition of the triggering parameters and the control of geohazard stabilizations. The monitoring methods chosen supplemented by numerical modelling could lead to more reliable forecasting of such landslides and could thus provide better control and landslide remediation possibilities also to stabilization works which prevent landslides.

  2. Current methods of controlling post-operative pain.

    PubMed Central

    Sinatra, R. S.

    1991-01-01

    Until recently, the clinical significance of post-surgical pain and its undertreatment were for the most part unappreciated. Recognition that inadequate analgesia adversely affects the patient's cardiovascular, pulmonary, and emotional status has spurred development of new and highly effective methods of controlling pain. With the introduction of spinal opioid and patient-controlled analgesia (PCA) came the realization that, while such forms of therapy provided superior pain relief, they were not without their own unique and occasionally serious side effects. For this reason, both techniques are more safely provided by highly trained members of a dedicated acute/post-surgical pain service. Although spinal opioid (epidural, intrathecal) techniques are invasive and require patient cooperation, they have a high degree of safety in low-risk populations (ASA 1 and 2). The major therapeutic advantage of spinal opioids is their ability to prevent pain from being perceived. PCA permits patients to titrate intravenous opioids in proportion to their particular level of pain intensity. Although PCA provides effective pain "relief," the technique is incapable of preventing pain from being appreciated. A number of studies have observed that pain scores in patients successfully employing PCA were significantly higher than those noted in individuals treated with epidural opioids. Nevertheless, the control gained by self-administration, uniformity of analgesia, and low level of adverse results associated with PCA provides higher patient satisfaction and decreased sedation when compared with traditional intramuscular dosing. The effectiveness of PCA may be improved by adjusting for patient variables, utilizing opioids having rapid onset, the addition of a basal infusion, and supplementation with non-steroidal anti-inflammatory agents. Interpleural analgesia represents an important therapeutic option in patients sensitive to opioid-induced respiratory depression. The technique is

  3. Method for controlling a laser additive process using intrinsic illumination

    NASA Astrophysics Data System (ADS)

    Tait, Robert; Cai, Guoshuang; Azer, Magdi; Chen, Xiaobin; Liu, Yong; Harding, Kevin

    2015-05-01

    One form of additive manufacturing is to use a laser to generate a melt pool from powdered metal that is sprayed from a nozzle. The laser net-shape machining system builds the part a layer at a time by following a predetermined path. However, because the path may need to take many turns, maintaining a constant melt pool may not be easy. A straight section may require one speed and power while a sharp bend would over melt the metal at the same settings. This paper describes a process monitoring method that uses the intrinsic IR radiation from the melt pool along with a process model configured to establish target values for the parameters associated with the manufacture or repair. This model is based upon known properties of the metal being used as well as the properties of the laser beam. An adaptive control technique is then employed to control process parameters of the machining system based upon the real-time weld pool measurement. Since the system uses the heat radiant from the melt pool, other previously deposited metal does not confuse the system as only the melted material is seen by the camera.

  4. Virtual Design Method for Controlled Failure in Foldcore Sandwich Panels

    NASA Astrophysics Data System (ADS)

    Sturm, Ralf; Fischer, S.

    2015-12-01

    For certification, novel fuselage concepts have to prove equivalent crashworthiness standards compared to the existing metal reference design. Due to the brittle failure behaviour of CFRP this requirement can only be fulfilled by a controlled progressive crash kinematics. Experiments showed that the failure of a twin-walled fuselage panel can be controlled by a local modification of the core through-thickness compression strength. For folded cores the required change in core properties can be integrated by a modification of the fold pattern. However, the complexity of folded cores requires a virtual design methodology for tailoring the fold pattern according to all static and crash relevant requirements. In this context a foldcore micromodel simulation method is presented to identify the structural response of a twin-walled fuselage panels with folded core under crash relevant loading condition. The simulations showed that a high degree of correlation is required before simulation can replace expensive testing. In the presented studies, the necessary correlation quality could only be obtained by including imperfections of the core material in the micromodel simulation approach.

  5. Systems and methods for autonomously controlling agricultural machinery

    DOEpatents

    Hoskinson, Reed L.; Bingham, Dennis N.; Svoboda, John M.; Hess, J. Richard

    2003-07-08

    Systems and methods for autonomously controlling agricultural machinery such as a grain combine. The operation components of a combine that function to harvest the grain have characteristics that are measured by sensors. For example, the combine speed, the fan speed, and the like can be measured. An important sensor is the grain loss sensor, which may be used to quantify the amount of grain expelled out of the combine. The grain loss sensor utilizes the fluorescence properties of the grain kernels and the plant residue to identify when the expelled plant material contains grain kernels. The sensor data, in combination with historical and current data stored in a database, is used to identify optimum operating conditions that will result in increased crop yield. After the optimum operating conditions are identified, an on-board computer can generate control signals that will adjust the operation of the components identified in the optimum operating conditions. The changes result in less grain loss and improved grain yield. Also, because new data is continually generated by the sensor, the system has the ability to continually learn such that the efficiency of the agricultural machinery is continually improved.

  6. Phase change thermal control materials, method and apparatus

    NASA Technical Reports Server (NTRS)

    Buckley, Theresa M. (Inventor)

    2001-01-01

    An apparatus and method for metabolic cooling and insulation of a user in a cold environment. In its preferred embodiment the apparatus is a highly flexible composite material having a flexible matrix containing a phase change thermal storage material. The apparatus can be made to heat or cool the body or to act as a thermal buffer to protect the wearer from changing environmental conditions. The apparatus may also include an external thermal insulation layer and/or an internal thermal control layer to regulate the rate of heat exchange between the composite and the skin of the wearer. Other embodiments of the apparatus also provide 1) a path for evaporation or direct absorption of perspiration from the skin of the wearer for improved comfort and thermal control, 2) heat conductive pathways within the material for thermal equalization, 3) surface treatments for improved absorption or rejection of heat by the material, and 4) means for quickly regenerating the thermal storage capacity for reuse of the material. Applications of the composite materials are also described which take advantage of the composite's thermal characteristics. The examples described include a diver's wet suit, ski boot liners, thermal socks, gloves and a face mask for cold weather activities, and a metabolic heating or cooling blanket useful for treating hypothermia or fever patients in a medical setting and therapeutic heating or cooling orthopedic joint supports.

  7. Does Reducing Physician Uncertainty Improve Hypertension Control? Rationale and Methods

    PubMed Central

    Pavlik, Valory N.; Greisinger, Anthony J.; Pool, James; Haidet, Paul; Hyman, David J.

    2009-01-01

    Background Hypertension affects nearly one-third of the U.S. population overall, and the prevalence rises sharply with age. In spite of public educational campaigns and professional education programs to encourage blood pressure measurement and control of both systolic and diastolic control to < 140/90 mmHg (or 130/80 mmHg if diabetic), 43% of treated hypertensives do not achieve the recommended JNC VII target. Among African-Americans, 48% are uncontrolled on treatment. The majority of persons classified as poorly controlled hypertensives have mild systolic blood pressure elevation (in the range of 140–160 mmHg). We hypothesized that physician uncertainty regarding the patient’s usual blood pressure, as well as uncertainty regarding the extent of medication non-adherence represent an important barrier to further reductions in the proportion of uncontrolled hypertensives in the U.S. Methods Using cluster randomization, ten primary care clinics (six from a public health care system and four from a private clinic system) were randomized to either the uncertainty reduction intervention condition or to usual care. An average of 68 patients per clinic were recruited to serve as units of observation. Physicians in the five intervention clinics were provided with a specially designed study form that included a graph of recent blood pressure measurements in their study patients, a check box to indicate their assessment of the adequacy of the patient’s blood pressure control, and a menu of services they could order to aid in patient management. These menu options included: 24-hour ambulatory blood pressure monitoring (ABPM); electronic bottle cap assessment of medication adherence, followed by medication adherence counseling in patients found to be non-adherent; and lifestyle assessment and counseling followed by 24-hour ABPM. Physicians in the five usual practice clinics did not have access to these services, but were informed of which patients had been enrolled in

  8. Implementation of a near-optimal global set point control method in a DDC controller

    SciTech Connect

    Cascia, M.A.

    2000-07-01

    A near-optimal global set point control method that can be implemented in an energy management system's (EMS) DDC controller is described in this paper. Mathematical models are presented for the power consumption of electric chillers, hot water boilers, chilled and hot water pumps, and air handler fans, which allow the calculation of near-optimal chilled water, hot water, and coil discharge air set points to minimize power consumption, based on data collected by the EMS. Also optimized are the differential and static pressure set points for the variable speed pumps and fans. A pilot test of this control methodology was implemented for a cooling plant at a pharmaceutical manufacturing facility near Dallas, Texas. Data collected at this site showed good agreement between the actual power consumed by the chillers, chilled water pumps, and air handlers and that predicted by the models. An approximate model was developed to calculate real-time power savings in the DDC controller. A third-party energy accounting program was used to track savings due to the near-optimal control, and results show a monthly KWH reduction ranging from 3% to 14%.

  9. Control of hydroxyapatite crystallinity by mechanical grinding method.

    PubMed

    Nakano, T; Tokumura, A; Umakoshi, Y; Imazato, S; Ehara, A; Ebisu, S

    2001-08-01

    Crystallinity of hydroxyapatite reflecting crystal size and crystal elastic strain was controlled by the mechanical grinding (MG) technique using a set of container and balls made of SUS304 stainless steel or agate. Variation in the crystallinity through MG was monitored by the XRD method and represented by the broadening of the diffraction peak. Effect of changes in crystallite size and strain on the crystallinity was also examined using the Hall-plot method. Crystallinity rapidly decreased with milling time. Significant crystallographic diffraction peaks disappeared and a broad diffraction around 2theta=32 degrees was observed after MG for 72 h. The broadening was dominantly due to an increase in crystal strain in addition to fine crystallite size. Contamination from the container and balls during MG was more suppressed using agate than SUS304 stainless steel. The recovery process of crystallinity during heating between 300 degrees C and 1200 degrees C was examined focusing on the decrease in residual elastic strain. Low crystallinity was maintained at annealing temperatures below 800 degrees C but lattice defects were recovered above 1000 degrees C. PMID:15348242

  10. Terrestrial Method for Airborne Lidar Quality Control and Assessment

    NASA Astrophysics Data System (ADS)

    Alsubaie, N. M.; Badawy, H. M.; Elhabiby, M. M.; El-Sheimy, N.

    2014-11-01

    Most of LiDAR systems do not provide the end user with the calibration and acquisition procedures that can use to validate the quality of the data acquired by the airborne system. Therefore, this system needs data Quality Control (QC) and assessment procedures to verify the accuracy of the laser footprints and mainly at building edges. This research paper introduces an efficient method for validating the quality of the airborne LiDAR point clouds data using terrestrial laser scanning data integrated with edge detection techniques. This method will be based on detecting the edge of buildings from these two independent systems. Hence, the building edges are extracted from the airborne data using an algorithm that is based on the standard deviation of neighbour point's height from certain threshold with respect to centre points using radius threshold. The algorithm is adaptive to different point densities. The approach is combined with another innovative edge detection technique from terrestrial laser scanning point clouds that is based on the height and point density constraints. Finally, statistical analysis and assessment will be applied to compare these two systems in term of edge detection extraction precision, which will be a priori step for 3D city modelling generated from heterogeneous LiDAR systems

  11. System identification methods for aircraft flight control development and validation

    NASA Technical Reports Server (NTRS)

    Tischler, Mark B.

    1995-01-01

    System-identification methods compose a mathematical model, or series of models, from measurements of inputs and outputs of dynamic systems. The extracted models allow the characterization of the response of the overall aircraft or component subsystem behavior, such as actuators and on-board signal processing algorithms. This paper discusses the use of frequency-domain system-identification methods for the development and integration of aircraft flight-control systems. The extraction and analysis of models of varying complexity from nonparametric frequency-responses to transfer-functions and high-order state-space representations is illustrated using the Comprehensive Identification from FrEquency Responses (CIFER) system-identification facility. Results are presented for test data of numerous flight and simulation programs at the Ames Research Center including rotorcraft, fixed-wing aircraft, advanced short takeoff and vertical landing (ASTOVL), vertical/short takeoff and landing (V/STOL), tiltrotor aircraft, and rotor experiments in the wind tunnel. Excellent system characterization and dynamic response prediction is achieved for this wide class of systems. Examples illustrate the role of system-identification technology in providing an integrated flow of dynamic response data around the entire life-cycle of aircraft development from initial specifications, through simulation and bench testing, and into flight-test optimization.

  12. Systems and Methods for Derivative-Free Adaptive Control

    NASA Technical Reports Server (NTRS)

    Yucelen, Tansel (Inventor); Kim, Kilsoo (Inventor); Calise, Anthony J. (Inventor)

    2015-01-01

    An adaptive control system is disclosed. The control system can control uncertain dynamic systems. The control system can employ one or more derivative-free adaptive control architectures. The control system can further employ one or more derivative-free weight update laws. The derivative-free weight update laws can comprise a time-varying estimate of an ideal vector of weights. The control system of the present invention can therefore quickly stabilize systems that undergo sudden changes in dynamics, caused by, for example, sudden changes in weight. Embodiments of the present invention can also provide a less complex control system than existing adaptive control systems. The control system can control aircraft and other dynamic systems, such as, for example, those with non-minimum phase dynamics.

  13. Biological Stability of Drinking Water: Controlling Factors, Methods, and Challenges.

    PubMed

    Prest, Emmanuelle I; Hammes, Frederik; van Loosdrecht, Mark C M; Vrouwenvelder, Johannes S

    2016-01-01

    Biological stability of drinking water refers to the concept of providing consumers with drinking water of same microbial quality at the tap as produced at the water treatment facility. However, uncontrolled growth of bacteria can occur during distribution in water mains and premise plumbing, and can lead to hygienic (e.g., development of opportunistic pathogens), aesthetic (e.g., deterioration of taste, odor, color) or operational (e.g., fouling or biocorrosion of pipes) problems. Drinking water contains diverse microorganisms competing for limited available nutrients for growth. Bacterial growth and interactions are regulated by factors, such as (i) type and concentration of available organic and inorganic nutrients, (ii) type and concentration of residual disinfectant, (iii) presence of predators, such as protozoa and invertebrates, (iv) environmental conditions, such as water temperature, and (v) spatial location of microorganisms (bulk water, sediment, or biofilm). Water treatment and distribution conditions in water mains and premise plumbing affect each of these factors and shape bacterial community characteristics (abundance, composition, viability) in distribution systems. Improved understanding of bacterial interactions in distribution systems and of environmental conditions impact is needed for better control of bacterial communities during drinking water production and distribution. This article reviews (i) existing knowledge on biological stability controlling factors and (ii) how these factors are affected by drinking water production and distribution conditions. In addition, (iii) the concept of biological stability is discussed in light of experience with well-established and new analytical methods, enabling high throughput analysis and in-depth characterization of bacterial communities in drinking water. We discussed, how knowledge gained from novel techniques will improve design and monitoring of water treatment and distribution systems in order

  14. Biological Stability of Drinking Water: Controlling Factors, Methods, and Challenges

    PubMed Central

    Prest, Emmanuelle I.; Hammes, Frederik; van Loosdrecht, Mark C. M.; Vrouwenvelder, Johannes S.

    2016-01-01

    Biological stability of drinking water refers to the concept of providing consumers with drinking water of same microbial quality at the tap as produced at the water treatment facility. However, uncontrolled growth of bacteria can occur during distribution in water mains and premise plumbing, and can lead to hygienic (e.g., development of opportunistic pathogens), aesthetic (e.g., deterioration of taste, odor, color) or operational (e.g., fouling or biocorrosion of pipes) problems. Drinking water contains diverse microorganisms competing for limited available nutrients for growth. Bacterial growth and interactions are regulated by factors, such as (i) type and concentration of available organic and inorganic nutrients, (ii) type and concentration of residual disinfectant, (iii) presence of predators, such as protozoa and invertebrates, (iv) environmental conditions, such as water temperature, and (v) spatial location of microorganisms (bulk water, sediment, or biofilm). Water treatment and distribution conditions in water mains and premise plumbing affect each of these factors and shape bacterial community characteristics (abundance, composition, viability) in distribution systems. Improved understanding of bacterial interactions in distribution systems and of environmental conditions impact is needed for better control of bacterial communities during drinking water production and distribution. This article reviews (i) existing knowledge on biological stability controlling factors and (ii) how these factors are affected by drinking water production and distribution conditions. In addition, (iii) the concept of biological stability is discussed in light of experience with well-established and new analytical methods, enabling high throughput analysis and in-depth characterization of bacterial communities in drinking water. We discussed, how knowledge gained from novel techniques will improve design and monitoring of water treatment and distribution systems in order

  15. Systems and Methods for Parameter Dependent Riccati Equation Approaches to Adaptive Control

    NASA Technical Reports Server (NTRS)

    Kim, Kilsoo (Inventor); Yucelen, Tansel (Inventor); Calise, Anthony J. (Inventor)

    2015-01-01

    Systems and methods for adaptive control are disclosed. The systems and methods can control uncertain dynamic systems. The control system can comprise a controller that employs a parameter dependent Riccati equation. The controller can produce a response that causes the state of the system to remain bounded. The control system can control both minimum phase and non-minimum phase systems. The control system can augment an existing, non-adaptive control design without modifying the gains employed in that design. The control system can also avoid the use of high gains in both the observer design and the adaptive control law.

  16. Method for continuous control of composition and doping of pulsed laser deposited films by pressure control

    DOEpatents

    Lowndes, Douglas H.; McCamy, James W.

    1996-01-01

    A method for growing a deposit upon a substrate of semiconductor material involves the utilization of pulsed laser deposition techniques within a low-pressure gas environment. The substrate and a target of a first material are positioned within a deposition chamber and a low-pressure gas atmosphere is developed within the chamber. The substrate is then heated, and the target is irradiated, so that atoms of the target material are ablated from the remainder of the target, while atoms of the gas simultaneously are adsorbed on the substrate/film surface. The ablated atoms build up upon the substrate, together with the adsorbed gas atoms to form the thin-film deposit on the substrate. By controlling the pressure of the gas of the chamber atmosphere, the composition of the formed deposit can be controlled, and films of continuously variable composition or doping can be grown from a single target of fixed composition.

  17. A grid spacing control technique for algebraic grid generation methods

    NASA Technical Reports Server (NTRS)

    Smith, R. E.; Kudlinski, R. A.; Everton, E. L.

    1982-01-01

    A technique which controls the spacing of grid points in algebraically defined coordinate transformations is described. The technique is based on the generation of control functions which map a uniformly distributed computational grid onto parametric variables defining the physical grid. The control functions are smoothed cubic splines. Sets of control points are input for each coordinate directions to outline the control functions. Smoothed cubic spline functions are then generated to approximate the input data. The technique works best in an interactive graphics environment where control inputs and grid displays are nearly instantaneous. The technique is illustrated with the two-boundary grid generation algorithm.

  18. Comparison of Advanced Distillation Control Methods, Final Technical Report

    SciTech Connect

    Dr. James B. Riggs

    2000-11-30

    Detailed dynamic simulations of three industrial distillation columns (a propylene/propane splitter, a xylene/toluene column, and a depropanizer) have been used to evaluate configuration selections for single-ended and dual-composition control, as well as to compare conventional and advanced control approaches. In addition, a simulator of a main fractionator was used to compare the control performance of conventional and advanced control. For each case considered, the controllers were tuned by using setpoint changes and tested using feed composition upsets. Proportional Integral (PI) control performance was used to evaluate the configuration selection problem. For single ended control, the energy balance configuration was found to yield the best performance. For dual composition control, nine configurations were considered. It was determined that the use of dynamic simulations is required in order to identify the optimum configuration from among the nine possible choices. The optimum configurations were used to evaluate the relative control performance of conventional PI controllers, MPC (Model Predictive Control), PMBC (Process Model-Based Control), and ANN (Artificial Neural Networks) control. It was determined that MPC works best when one product is much more important than the other, while PI was superior when both products were equally important. PMBC and ANN were not found to offer significant advantages over PI and MPC. MPC was found to outperform conventional PI control for the main fractionator. MPC was applied to three industrial columns: one at Phillips Petroleum and two at Union Carbide. In each case, MPC was found to significantly outperform PI controls. The major advantage of the MPC controller is its ability to effectively handle a complex set of constraints and control objectives.

  19. Wavelet Methods Developed to Detect and Control Compressor Stall

    NASA Technical Reports Server (NTRS)

    Le, Dzu K.

    1997-01-01

    A "wavelet" is, by definition, an amplitude-varying, short waveform with a finite bandwidth (e.g., that shown in the first two graphs). Naturally, wavelets are more effective than the sinusoids of Fourier analysis for matching and reconstructing signal features. In wavelet transformation and inversion, all transient or periodic data features (as in compressor-inlet pressures) can be detected and reconstructed by stretching or contracting a single wavelet to generate the matching building blocks. Consequently, wavelet analysis provides many flexible and effective ways to reduce noise and extract signals which surpass classical techniques - making it very attractive for data analysis, modeling, and active control of stall and surge in high-speed turbojet compressors. Therefore, fast and practical wavelet methods are being developed in-house at the NASA Lewis Research Center to assist in these tasks. This includes establishing user-friendly links between some fundamental wavelet analysis ideas and the classical theories (or practices) of system identification, data analysis, and processing.

  20. Development of Active Control Method for Supercooling Releasing of Water

    NASA Astrophysics Data System (ADS)

    Mito, Daisuke; Kozawa, Yoshiyuki; Tanino, Masayuki; Inada, Takaaki

    We have tested the prototype ice-slurry generator that enables both production of supercooled water (-2°C) and releasing of its supercooling simultaneously and continuously in a closed piping system. In the experiment, we adopted the irradiation of ultrasonic wave as an active control method of triggering for supercooling releasing, and evaluated the reliability for a practical use compared with the seed ice-crystal trigger. As the results, it has been confirmed that the ultrasonic wave trigger acts assuredly at the same level of degree of supercooling as that by using the seed ice-crystal Trigger. Moreover, it can be found that the ultrasonic wave trigger has the advantage of removing the growing ice-crystals on the pipe wall at the same time. Finally, we have specified the bombardment condition of ultrasonic wave enough to make continuously the ice-slurry in a closed system as the output surface power density > 31.4kW/m2 and the superficial bombardment time > 4.1sec. We have also demonstrated the continuous ice-slurry making for more than 6hours by using the refrigerator system with the practical scale of 88kW.

  1. Applications of Computational Methods for Dynamic Stability and Control Derivatives

    NASA Technical Reports Server (NTRS)

    Green, Lawrence L.; Spence, Angela M.

    2004-01-01

    Initial steps in the application o f a low-order panel method computational fluid dynamic (CFD) code to the calculation of aircraft dynamic stability and control (S&C) derivatives are documented. Several capabilities, unique to CFD but not unique to this particular demonstration, are identified and demonstrated in this paper. These unique capabilities complement conventional S&C techniques and they include the ability to: 1) perform maneuvers without the flow-kinematic restrictions and support interference commonly associated with experimental S&C facilities, 2) easily simulate advanced S&C testing techniques, 3) compute exact S&C derivatives with uncertainty propagation bounds, and 4) alter the flow physics associated with a particular testing technique from those observed in a wind or water tunnel test in order to isolate effects. Also presented are discussions about some computational issues associated with the simulation of S&C tests and selected results from numerous surface grid resolution studies performed during the course of the study.

  2. Method of achieving the controlled release of thermonuclear energy

    DOEpatents

    Brueckner, Keith A.

    1986-01-01

    A method of achieving the controlled release of thermonuclear energy by illuminating a minute, solid density, hollow shell of a mixture of material such as deuterium and tritium with a high intensity, uniformly converging laser wave to effect an extremely rapid build-up of energy in inwardly traveling shock waves to implode the shell creating thermonuclear conditions causing a reaction of deuterons and tritons and a resultant high energy thermonuclear burn. Utilizing the resulting energy as a thermal source and to breed tritium or plutonium. The invention also contemplates a laser source wherein the flux level is increased with time to reduce the initial shock heating of fuel and provide maximum compression after implosion; and, in addition, computations and an equation are provided to enable the selection of a design having a high degree of stability and a dependable fusion performance by establishing a proper relationship between the laser energy input and the size and character of the selected material for the fusion capsule.

  3. Comparison of Predictive Control Methods for High Consumption Industrial Furnace

    PubMed Central

    2013-01-01

    We describe several predictive control approaches for high consumption industrial furnace control. These furnaces are major consumers in production industries, and reducing their fuel consumption and optimizing the quality of the products is one of the most important engineer tasks. In order to demonstrate the benefits from implementation of the advanced predictive control algorithms, we have compared several major criteria for furnace control. On the basis of the analysis, some important conclusions have been drawn. PMID:24319354

  4. METHOD AND APPARATUS FOR CONTROLLING DIRECT-CYCLE NEUTRONIC REACTORS

    DOEpatents

    Reed, G.A.

    1961-01-10

    A control arrangement is offered for a boiling-water reactor. Boric acid is maintained in the water in the reactor and the amount in the reactor is controlled by continuously removing a portion of the water from the reactor, concentrating the boric acid by evaporating the water therefrom, returning a controlled amount of the acid to the reactor, and simultaneously controlling the water level by varying the rate of spent steam return to the reactor.

  5. Systems and Methods for Collaboratively Controlling at Least One Aircraft

    NASA Technical Reports Server (NTRS)

    Estkowski, Regina I. (Inventor)

    2016-01-01

    An unmanned vehicle management system includes an unmanned aircraft system (UAS) control station controlling one or more unmanned vehicles (UV), a collaborative routing system, and a communication network connecting the UAS and the collaborative routing system. The collaborative routing system being configured to receive flight parameters from an operator of the UAS control station and, based on the received flight parameters, automatically present the UAS control station with flight plan options to enable the operator to operate the UV in a defined airspace.

  6. Time-Varying Characteristics Analysis and Fuzzy Controller Systematic Design Method for Pressurized Water Reactor Power Control

    SciTech Connect

    Liu Shengzhi; Zhang Naiyao; Cui Zhenhua

    2004-11-15

    In this paper a systematic design method of fuzzy control systems is applied to the pressurized water reactor's (PWR) power control. The paper includes three parts. In the first part, a simplified time-varying linear model of the PWR power system is constructed, and its inner structure and time-varying characteristics are analyzed. That provides a solid basis for study and design of the nuclear reactor power control system. In the second part, a systematic design method of fuzzy control systems is introduced and applied to control the nuclear reactor power process. The design procedures and parameters are given in detail. This systematic design method has some notable advantages. The control of a global fuzzy model can be decomposed into controlling a set of linear submodels. Each submodel controller can be independently designed by using a linear quadratic regulator approach. This systematic design method gives a sufficient and necessary condition to guarantee the stability of fuzzy control systems; thus, better control performance can be obtained due to the accurate control gains. In the third part, the control performance of the nuclear reactor fuzzy control system is examined by simulation experiments, including nuclear reactor power shutdown, start-up, and adjustment operations. The satisfactory experiment results have shown that the systematic design method for fuzzy control systems is effective and feasible.

  7. System comprising interchangeable electronic controllers and corresponding methods

    NASA Technical Reports Server (NTRS)

    Steele, Glen F. (Inventor); Salazar, George A. (Inventor)

    2009-01-01

    A system comprising an interchangeable electronic controller is provided with programming that allows the controller to adapt a behavior that is dependent upon the particular type of function performed by a system or subsystem component. The system reconfigures the controller when the controller is moved from one group of subsystem components to another. A plurality of application programs are provided by a server from which the application program for a particular electronic controller is selected. The selection is based on criteria such as a subsystem component group identifier that identifies the particular type of function associated with the system or subsystem group of components.

  8. Patient-controlled analgesia: an appropriate method of pain control in children.

    PubMed

    McDonald, A J; Cooper, M G

    2001-01-01

    Patient-controlled analgesia (PCA) is an analgesic technique originally used in adults but now with an established role in paediatric practice. It is well tolerated in children as young as 5 years and has uses in postoperative pain as well as burns, oncology and palliative care. The use of background infusions is more frequent in children and improves efficacy; however, it may increase the occurrence of adverse effects such as nausea and respiratory depression. Monitoring involves measurement of respiratory rate, level of sedation and oxygen saturation. Efficacy is assessed by self-reporting, visual analogue scales, faces pain scales and usage patterns. This is optimally performed both at rest and on movement. The selection of opioid used in PCA is perhaps less critical than the appropriate selection of parameters such as bolus dose, lockout and background infusion rate. Moreover, opioid choice may be based on adverse effect profile rather than efficacy. The concept of PCA continues to be developed in children, with patient-controlled epidural analgesia, subcutaneous PCA and intranasal PCA being recent extensions of the method. There may also be a role for patient-controlled sedation. PCA, when used with adequate monitoring, is a well tolerated technique with high patient and staff acceptance. It can now be regarded as a standard for the delivery of postoperative analgesia in children aged >5 years. PMID:11354699

  9. `Earth-ionosphere' mode controlled source electromagnetic method

    NASA Astrophysics Data System (ADS)

    Li, Diquan; Di, Qingyun; Wang, Miaoyue; Nobes, David

    2015-09-01

    In traditional artificial-source electromagnetic exploration, the effects of the ionosphere and displacement current (DC) in the air were neglected, and only the geoelectrical structure of the earth's crust and upper mantle was considered, such as for controlled source audio-frequency magnetotelluric (CSAMT). By employing a transmitter (less than 30 kW) to generate source fields, the CSAMT method overcomes the problems associated with weak natural electromagnetic (EM) fields used in magnetotellurics. However, the transmitter is moved and the source-receiver offset is approximately less than 20 km, because of the limitation of emission energy. We put forward a new idea, that is, a fixed artificial source (greater than 200 kW) is used and the source location selected at a high resistivity region (to ensure a high emission efficiency), so there may be a possibility that as long as the source strength magnitude is strong enough, the artificial EM signal can be easily observed within a distance of several thousand kilometres. Previous studies have provided the evidence to support this idea; they used the `earth-ionosphere' mode in modeling the EM fields with the offset up to a thousand kilometres. Such EM fields still have a signal/noise ratio over 10-20 dB; this means that a new EM method with fixed source is feasible. However, in their calculations, the DC which plays a very important role for large offsets was neglected. This paper pays much attention to derive the formulae of the `earth-ionosphere' mode with a horizontal electric dipole source, and the DC is not neglected. We present some three layers modeling results to illustrate the basic EM field characteristics under the `earth-ionosphere' mode. As the offset increases, the contribution of the conduction current decreases, DC and ionosphere were taken into account, and the EM field attenuation decreases. We also quantitatively compare the predicted and observed data. The comparison of these results with the

  10. A simple method to control nanotribology behaviors of monocrystalline silicon

    NASA Astrophysics Data System (ADS)

    Wang, X. D.; Guo, J.; Chen, C.; Chen, L.; Qian, L. M.

    2016-01-01

    A simple method was proposed to control the nanotribology behaviors of monocrystalline silicon against SiO2 microsphere by adjusting relative humidity (RH). Experimental results indicated that adhesion work, friction coefficient, and nanowear of silicon against SiO2 microsphere significantly varied between 60% and 90% RH. Under 60% RH, adhesion work was 119 mN/m, and friction coefficient was about 0.53. However, adhesion work and friction coefficient decreased to ˜70 mN/m and ˜0.3 under 90% RH, respectively. An apparent wear track ˜13 nm deep formed on the silicon surface under 60% RH, whereas no obvious wear scar was observed on the silicon surface under 90% RH. Analysis indicated that such tribological behaviors were due to different water condensations on the silicon surface under 60% and 90% RH. Under 60% RH, the water that condensed on the surfaces of the silicon sample and SiO2 tip mainly consisted of ice-like water. As a result, adhesion work was enlarged by the breaking force of the ice-like water bridge in the contact area. Given that a ≡Si-O-Si≡ bonding bridge easily formed between the silicon surface and the SiO2 tip with the help of water condensation under 60% RH instead of 90% RH, the friction coefficient was large and the nanowear of the silicon sample was severe under 60% RH. These results may help elucidate the nanotribology behaviors of silicon and facilitate the tribological design of dynamic microelectromechanical systems working under humid conditions.

  11. Haar wavelet operational matrix method for solving constrained nonlinear quadratic optimal control problem

    NASA Astrophysics Data System (ADS)

    Swaidan, Waleeda; Hussin, Amran

    2015-10-01

    Most direct methods solve finite time horizon optimal control problems with nonlinear programming solver. In this paper, we propose a numerical method for solving nonlinear optimal control problem with state and control inequality constraints. This method used quasilinearization technique and Haar wavelet operational matrix to convert the nonlinear optimal control problem into a quadratic programming problem. The linear inequality constraints for trajectories variables are converted to quadratic programming constraint by using Haar wavelet collocation method. The proposed method has been applied to solve Optimal Control of Multi-Item Inventory Model. The accuracy of the states, controls and cost can be improved by increasing the Haar wavelet resolution.

  12. Control and optimization system and method for chemical looping processes

    DOEpatents

    Lou, Xinsheng; Joshi, Abhinaya; Lei, Hao

    2014-06-24

    A control system for optimizing a chemical loop system includes one or more sensors for measuring one or more parameters in a chemical loop. The sensors are disposed on or in a conduit positioned in the chemical loop. The sensors generate one or more data signals representative of an amount of solids in the conduit. The control system includes a data acquisition system in communication with the sensors and a controller in communication with the data acquisition system. The data acquisition system receives the data signals and the controller generates the control signals. The controller is in communication with one or more valves positioned in the chemical loop. The valves are configured to regulate a flow of the solids through the chemical loop.

  13. Control and optimization system and method for chemical looping processes

    DOEpatents

    Lou, Xinsheng; Joshi, Abhinaya; Lei, Hao

    2015-02-17

    A control system for optimizing a chemical loop system includes one or more sensors for measuring one or more parameters in a chemical loop. The sensors are disposed on or in a conduit positioned in the chemical loop. The sensors generate one or more data signals representative of an amount of solids in the conduit. The control system includes a data acquisition system in communication with the sensors and a controller in communication with the data acquisition system. The data acquisition system receives the data signals and the controller generates the control signals. The controller is in communication with one or more valves positioned in the chemical loop. The valves are configured to regulate a flow of the solids through the chemical loop.

  14. Control system and method for a hybrid electric vehicle

    DOEpatents

    Phillips, Anthony Mark; Blankenship, John Richard; Bailey, Kathleen Ellen; Jankovic, Miroslava

    2001-01-01

    A vehicle system controller (20) is presented for a LSR parallel hybrid electric vehicle having an engine (10), a motor (12), wheels (14), a transmission (16) and a battery (18). The vehicle system controller (20) has a state machine having a plurality of predefined states (22-32) that represent operating modes for the vehicle. A set of rules is defined for controlling the transition between any two states in the state machine. The states (22-32) are prioritized according to driver demands, energy management concerns and system fault occurrences. The vehicle system controller (20) controls the transitions from a lower priority state to a higher priority state based on the set of rules. In addition, the vehicle system controller (20) will control a transition to a lower state from a higher state when the conditions no longer warrant staying in the current state. A unique set of output commands is defined for each state for the purpose of controlling lower level subsystem controllers. These commands serve to achieve the desire vehicle functionality within each state and insure smooth transitions between states.

  15. Proposal of Current Control Method for High-Speed AC Motor System

    NASA Astrophysics Data System (ADS)

    Furutani, Shinichi; Satake, Akira

    In this paper, current control method for High-Speed AC Motor System is proposed. In High-Speed driving operation, Current controller tends to lose stability because of dead time caused by computational delay and Electromagnetic coupling included AC Motor Model. The Main purpose of the proposed method is reduction of dead time on current controller. Proposed method based model predictive control and optimizing of start timing. The Effectiveness of proposed method is confirmed by simulation results.

  16. A Simple Design Method Based on Vector Control of AC Machines with LC Filter

    NASA Astrophysics Data System (ADS)

    Saito, Ryosuke; Kubota, Hisao

    This paper presents a simple voltage control system of AC machines using PWM voltage source inverter with output LC filters. By assuming a motor as a current source, the voltage is controlled by a simple proportional differential (PD) control. The vector control and PD control can be separately controlled in this system. A method for disturbance rejection is also described. The effectiveness of the proposed method is verified by simulations and experiments.

  17. A Design Method of Force Dependent Velocity Bilateral Control Based on Gyrator Property

    NASA Astrophysics Data System (ADS)

    Mizoguchi, Takahiro; Kuwahara, Hiroaki; Ohnishi, Kouhei

    This paper proposes a bilateral control method for a teleoperation system with different sizes and work volumes. In the proposed controller, transformer-type bilateral control and gyrator-type bilateral control are integrated. The proposed control method can be used for the control of the motion of a slave robot; this involves intuitive manipulation of the master robot despite the structural difference between the master and slave.

  18. Control methods for high-speed supercavitating vehicles

    NASA Astrophysics Data System (ADS)

    Vanek, Balint

    Supercavitation is an emerging technology that enables underwater vehicles to reach unprecedented speed. With proper design of cavitator attached to the vehicle nose, the vehicle body is surrounded by water vapor cavity, eliminating skin friction drag. This technology offers unprecedented drag reduction, though poses problems for vehicle design. The gas bubble surrounding the hull introduces highly coupled dynamic behavior, representing a challenge for the control designer. Development of stable, controllable supercavitating vehicles requires solution for several open problems. This dissertation addresses the problem of control oriented modeling, stability augmentation, and reference tracking using parameter dependent control techniques for supercavitating vehicles. The thesis is divided into three parts. A nonlinear dynamical model capturing the most important properties of the vehicle motion is developed from a control design perspective. The model includes memory effects associated with the time evolution of the cavity and uses lookup tables to determine forces. To aid understanding the cavity-vehicle interaction, a longitudinal control scenario is developed for a simplified longitudinal dynamical model with guaranteed properties. Significant insight is gained on planing behavior and operating envelope using constrained control inputs. Extending the longitudinal control problem, a linear parameter varying model of the coupled motion is developed to provide a platform for parameter dependent control synthesis. The mathematical model is scheduled with aerodynamic angles, uses steady-state approximation of the cavity, leading to uncertainty in the governing equations. Two Linear Parameter Varying (LPV) controllers are synthesized for the angle rate tracking problem, taking uncertainty into account. One uses traditional decoupled loops for pitch-, roll- and yaw-rate tracking. Ignoring the cross coupling, leads to more tractable subproblems. A controller, taking

  19. Force control compensation method with variable load stiffness and damping of the hydraulic drive unit force control system

    NASA Astrophysics Data System (ADS)

    Kong, Xiangdong; Ba, Kaixian; Yu, Bin; Cao, Yuan; Zhu, Qixin; Zhao, Hualong

    2016-05-01

    Each joint of hydraulic drive quadruped robot is driven by the hydraulic drive unit (HDU), and the contacting between the robot foot end and the ground is complex and variable, which increases the difficulty of force control inevitably. In the recent years, although many scholars researched some control methods such as disturbance rejection control, parameter self-adaptive control, impedance control and so on, to improve the force control performance of HDU, the robustness of the force control still needs improving. Therefore, how to simulate the complex and variable load characteristics of the environment structure and how to ensure HDU having excellent force control performance with the complex and variable load characteristics are key issues to be solved in this paper. The force control system mathematic model of HDU is established by the mechanism modeling method, and the theoretical models of a novel force control compensation method and a load characteristics simulation method under different environment structures are derived, considering the dynamic characteristics of the load stiffness and the load damping under different environment structures. Then, simulation effects of the variable load stiffness and load damping under the step and sinusoidal load force are analyzed experimentally on the HDU force control performance test platform, which provides the foundation for the force control compensation experiment research. In addition, the optimized PID control parameters are designed to make the HDU have better force control performance with suitable load stiffness and load damping, under which the force control compensation method is introduced, and the robustness of the force control system with several constant load characteristics and the variable load characteristics respectively are comparatively analyzed by experiment. The research results indicate that if the load characteristics are known, the force control compensation method presented in this

  20. Force control compensation method with variable load stiffness and damping of the hydraulic drive unit force control system

    NASA Astrophysics Data System (ADS)

    Kong, Xiangdong; Ba, Kaixian; Yu, Bin; Cao, Yuan; Zhu, Qixin; Zhao, Hualong

    2016-04-01

    Each joint of hydraulic drive quadruped robot is driven by the hydraulic drive unit (HDU), and the contacting between the robot foot end and the ground is complex and variable, which increases the difficulty of force control inevitably. In the recent years, although many scholars researched some control methods such as disturbance rejection control, parameter self-adaptive control, impedance control and so on, to improve the force control performance of HDU, the robustness of the force control still needs improving. Therefore, how to simulate the complex and variable load characteristics of the environment structure and how to ensure HDU having excellent force control performance with the complex and variable load characteristics are key issues to be solved in this paper. The force control system mathematic model of HDU is established by the mechanism modeling method, and the theoretical models of a novel force control compensation method and a load characteristics simulation method under different environment structures are derived, considering the dynamic characteristics of the load stiffness and the load damping under different environment structures. Then, simulation effects of the variable load stiffness and load damping under the step and sinusoidal load force are analyzed experimentally on the HDU force control performance test platform, which provides the foundation for the force control compensation experiment research. In addition, the optimized PID control parameters are designed to make the HDU have better force control performance with suitable load stiffness and load damping, under which the force control compensation method is introduced, and the robustness of the force control system with several constant load characteristics and the variable load characteristics respectively are comparatively analyzed by experiment. The research results indicate that if the load characteristics are known, the force control compensation method presented in this

  1. CONTROL ROD FOR A NUCLEAR REACTOR AND METHOD OF PREPARATION

    DOEpatents

    Hausner, H.H.

    1958-12-30

    BS>An improved control rod is presented for a nuclear reactor. This control rod is comprised of a rare earth metal oxide or rare earth metal carbide such as gadolinium oxide or gadolinium carbide, uniformly distributed in a metal matrix having a low cross sectional area of absorption for thermal neutrons, such as aluminum, beryllium, and zirconium.

  2. METHODS FOR OPTIMIZING URBAN WET-WEATHER CONTROL SYSTEM

    EPA Science Inventory

    To minimize impacts of urban nonpoint source pollution and associated costs of control (storage and treatment) associated with wet-weather flows (WWFs), stormwater runoff volumes and pollutant loads must be reduced. A number of control strategies, so-called “best management pract...

  3. Apparatus for and method of controlling sputter coating

    SciTech Connect

    Boys, R.

    1985-02-19

    The magnetic field of a magnetron sputter coating apparatus is controlled in response to measurements of plasma parameters to control deposition parameters, such as sputter deposition rate and material deposition thickness profile. From time to time the apparatus is standardized to change preset values for parameters of the plasma to manage the deposition parameters.

  4. Computational methods for the control of distributed parameter systems

    NASA Technical Reports Server (NTRS)

    Burns, J. A.; Cliff, E. M.; Powers, R. K.

    1986-01-01

    Finite dimensional approximation schemes that work well for distributed parameter systems are often not suitable for the analysis and implementation of feedback control systems. The relationship between approximation schemes for distributed parameter systems and their application to optimal control problems is discussed. A numerical example is given.

  5. Method of electrochemical etching of tungsten tips with controllable profiles

    NASA Astrophysics Data System (ADS)

    Chang, Wei-Tse; Hwang, Ing-Shouh; Chang, Mu-Tung; Lin, Chung-Yueh; Hsu, Wei-Hao; Hou, Jin-Long

    2012-08-01

    We demonstrate a new and simple process to fabricate tungsten tips with good control of the tip profile. In this process, we use a commercial function generator without any electronic cutoff circuit or complex mechanical setup. The tip length can be varied from 160 μm to 10 mm, corresponding to an aspect ratio of 1.6-100. The radius of curvature of the tip apex can be controlled to a size <10 nm. Surface roughness and the taper angle can be controlled independently. Through control of the etching parameters, the tip length, the radius of curvature, surface roughness, and the taper angle can be controlled to suit different requirements of various applications. The possible etching mechanisms are also discussed.

  6. Comparison of advanced distillation control methods. Third annual report

    SciTech Connect

    Riggs, J.B.

    1997-07-01

    Detailed dynamic simulations of three industrial distillation columns (a propylene/propane splitter, a xylene/toluene column, and a depropanizer) have been used to study the issue of configuration selection for diagonal PI dual composition controls, feedforward from a feed composition analyzer, and decouplers. Auto Tune Variation (ATV) identification with on-line detuning for setpoint changes was used for tuning the diagonal proportional integral (PI) composition controls. In addition, robustness tests were conducted by inducting reboiler duty upsets. For single composition control, the (L, V) configuration was found to be best. For dual composition control, the optimum configuration changes from one column to another. Moreover, the use of analysis tools, such as RGA, appears to be of little value in identifying the optimum configuration for dual composition control. Using feedforward from a feed composition analyzer and using decouplers are shown to offer significant advantages for certain specific cases.

  7. Theory and applications survey of decentralized control methods

    NASA Technical Reports Server (NTRS)

    Athans, M.

    1975-01-01

    A nonmathematical overview is presented of trends in the general area of decentralized control strategies which are suitable for hierarchical systems. Advances in decentralized system theory are closely related to advances in the so-called stochastic control problem with nonclassical information pattern. The basic assumptions and mathematical tools pertaining to the classical stochastic control problem are outlined. Particular attention is devoted to pitfalls in the mathematical problem formulation for decentralized control. Major conclusions are that any purely deterministic approach to multilevel hierarchical dynamic systems is unlikely to lead to realistic theories or designs, that the flow of measurements and decisions in a decentralized system should not be instantaneous and error-free, and that delays in information exchange in a decentralized system lead to reasonable approaches to decentralized control. A mathematically precise notion of aggregating information is not yet available.

  8. Method for spinning up a three-axis controlled spacecraft

    NASA Technical Reports Server (NTRS)

    Vorlicek, Preston L. (Inventor)

    1988-01-01

    A three-axis controlled spacecraft (1), typically a satellite, is spun up about its roll axis (20) prior to firing a motor (2), i.e., a perigee kick motor, to achieve the requisite degree of angular momentum stiffness. Thrusters (21) for imparting rotation about the roll axis (20) are activated in open-loop fashion, typically at less than full duty cycle. Cross-axis torques induced by this rotational motion are compensated for by means of closed control loops for each of the pitch and yaw axes (30, 40, respectively). Each closed control loop combines a prebias torque (72) with torques (75, 74) representative of position and rate feedback information, respectively. A deadband (52) within each closed control loop can be widened during the spinup, to conserve fuel. Position feedback information (75) in each of the control loops is disabled upon saturation of the gyroscope associated with the roll axis (20).

  9. Method for controlling density and permeability of sintered powdered metals

    NASA Technical Reports Server (NTRS)

    Todd, H. H.

    1968-01-01

    Improved, relatively low-cost method has been developed to produce porous metals with predetermined pore size, pore spacing, and density, utilizing powder-metal processes. The method uses angular not spherical tungsten powder.

  10. Tandem robot control system and method for controlling mobile robots in tandem

    DOEpatents

    Hayward, David R.; Buttz, James H.; Shirey, David L.

    2002-01-01

    A control system for controlling mobile robots provides a way to control mobile robots, connected in tandem with coupling devices, to navigate across difficult terrain or in closed spaces. The mobile robots can be controlled cooperatively as a coupled system in linked mode or controlled individually as separate robots.

  11. Frequency response modeling and control of flexible structures: Computational methods

    NASA Technical Reports Server (NTRS)

    Bennett, William H.

    1989-01-01

    The dynamics of vibrations in flexible structures can be conventiently modeled in terms of frequency response models. For structural control such models capture the distributed parameter dynamics of the elastic structural response as an irrational transfer function. For most flexible structures arising in aerospace applications the irrational transfer functions which arise are of a special class of pseudo-meromorphic functions which have only a finite number of right half place poles. Computational algorithms are demonstrated for design of multiloop control laws for such models based on optimal Wiener-Hopf control of the frequency responses. The algorithms employ a sampled-data representation of irrational transfer functions which is particularly attractive for numerical computation. One key algorithm for the solution of the optimal control problem is the spectral factorization of an irrational transfer function. The basis for the spectral factorization algorithm is highlighted together with associated computational issues arising in optimal regulator design. Options for implementation of wide band vibration control for flexible structures based on the sampled-data frequency response models is also highlighted. A simple flexible structure control example is considered to demonstrate the combined frequency response modeling and control algorithms.

  12. Overview of control design methods for smart structural system

    NASA Astrophysics Data System (ADS)

    Rao, Vittal S.; Sana, Sridhar

    2001-08-01

    Smart structures are a result of effective integration of control system design and signal processing with the structural systems to maximally utilize the new advances in materials for structures, actuation and sensing to obtain the best performance for the application at hand. The research in smart structures is constantly driving towards attaining self adaptive and diagnostic capabilities that biological systems possess. This has been manifested in the number of successful applications in many areas of engineering such as aerospace, civil and automotive systems. Instrumental in the development of such systems are smart materials such as piezo-electric, shape memory alloys, electrostrictive, magnetostrictive and fiber-optic materials and various composite materials for use as actuators, sensors and structural members. The need for development of control systems that maximally utilize the smart actuators and sensing materials to design highly distributed and highly adaptable controllers has spurred research in the area of smart structural modeling, identification, actuator/sensor design and placement, control systems design such as adaptive and robust controllers with new tools such a neural networks, fuzzy logic, genetic algorithms, linear matrix inequalities and electronics for controller implementation such as analog electronics, micro controllers, digital signal processors (DSPs) and application specific integrated circuits (ASICs) such field programmable gate arrays (FPGAs) and Multichip modules (MCMs) etc. In this paper, we give a brief overview of the state of control in smart structures. Different aspects of the development of smart structures such as applications, technology and theoretical advances especially in the area of control systems design and implementation will be covered.

  13. Survey of decentralized control methods. [for large scale dynamic systems

    NASA Technical Reports Server (NTRS)

    Athans, M.

    1975-01-01

    An overview is presented of the types of problems that are being considered by control theorists in the area of dynamic large scale systems with emphasis on decentralized control strategies. Approaches that deal directly with decentralized decision making for large scale systems are discussed. It is shown that future advances in decentralized system theory are intimately connected with advances in the stochastic control problem with nonclassical information pattern. The basic assumptions and mathematical tools associated with the latter are summarized, and recommendations concerning future research are presented.

  14. Automatic transmission control system and method of operation

    SciTech Connect

    Lemon, R.W.; Arzoian, J.

    1991-04-16

    This patent describes a control system for an automatic transmission of a vehicle with a fluid torque converter having a bypass clutch, and a change gear assembly providing a variety of ratio changes on selective actuation of a plurality of friction engaging elements of the change gear assembly. The control system provides the selective engagement of three friction elements and the bypass clutch through the selective energization and de-energization of two solenoid operated valves and the selective actuation and de-actuation of three shift control valves.

  15. Modeling of a PVDF based gesture controller using energy methods

    NASA Astrophysics Data System (ADS)

    Van Volkinburg, Kyle R.; Washington, Gregory N.

    2014-03-01

    In this paper the concept of a PVDF based gesture controller is introduced and accompanied by a supporting model derived using Hamilton's principle. The model incorporates strain contributions from two loading situations: beam subject to transverse loading and axial loading. The prototype gesture controller is comprised of a compression sleeve with a spatially shaded PVDF element situated above the extensor muscles of the right forearm. The goal of the gesture controller, at this stage, is to be able to measure and discern forearm muscle activity for three distinct hand gestures. In this study the system was modeled and simulated. Test data was then collected for each hand gesture and compared to simulations.

  16. Automatic method of measuring silicon-controlled-rectifier holding current

    NASA Technical Reports Server (NTRS)

    Maslowski, E. A.

    1972-01-01

    Development of automated silicon controlled rectifier circuit for measuring minimum anode current required to maintain rectifiers in conducting state is discussed. Components of circuit are described and principles of operation are explained. Illustration of circuit is provided.

  17. Method of controlling defect orientation in silicon crystal ribbon growth

    NASA Technical Reports Server (NTRS)

    Leipold, M. H. (Inventor)

    1978-01-01

    The orientation of twinning and other effects in silicon crystal ribbon growth is controlled by use of a starting seed crystal having a specific (110) crystallographic plane and (112) crystallographic growth direction.

  18. Effectiveness-weighted control method for a cooling system

    DOEpatents

    Campbell, Levi A.; Chu, Richard C.; David, Milnes P.; Ellsworth Jr., Michael J.; Iyengar, Madhusudan K.; Schmidt, Roger R.; Simons, Robert E.

    2015-12-15

    Energy efficient control of cooling system cooling of an electronic system is provided based, in part, on weighted cooling effectiveness of the components. The control includes automatically determining speed control settings for multiple adjustable cooling components of the cooling system. The automatically determining is based, at least in part, on weighted cooling effectiveness of the components of the cooling system, and the determining operates to limit power consumption of at least the cooling system, while ensuring that a target temperature associated with at least one of the cooling system or the electronic system is within a desired range by provisioning, based on the weighted cooling effectiveness, a desired target temperature change among the multiple adjustable cooling components of the cooling system. The provisioning includes provisioning applied power to the multiple adjustable cooling components via, at least in part, the determined control settings.

  19. Method and apparatus for controlling carrier envelope phase

    DOEpatents

    Chang, Zenghu; Li, Chengquan; Moon, Eric

    2011-12-06

    A chirped pulse amplification laser system. The system generally comprises a laser source, a pulse modification apparatus including first and second pulse modification elements separated by a separation distance, a positioning element, a measurement device, and a feedback controller. The laser source is operable to generate a laser pulse and the pulse modification apparatus operable to modify at least a portion of the laser pulse. The positioning element is operable to reposition at least a portion of the pulse modification apparatus to vary the separation distance. The measurement device is operable to measure the carrier envelope phase of the generated laser pulse and the feedback controller is operable to control the positioning element based on the measured carrier envelope phase to vary the separation distance of the pulse modification elements and control the carrier envelope phase of laser pulses generated by the laser source.

  20. Quench monitoring and control system and method of operating same

    DOEpatents

    Ryan, David Thomas; Laskaris, Evangelos Trifon; Huang, Xianrui

    2006-05-30

    A rotating machine comprising a superconductive coil and a temperature sensor operable to provide a signal representative of superconductive coil temperature. The rotating machine may comprise a control system communicatively coupled to the temperature sensor. The control system may be operable to reduce electric current in the superconductive coil when a signal representative of a defined superconducting coil temperature is received from the temperature sensor.

  1. Computational methods for the control of distributed parameter systems

    NASA Technical Reports Server (NTRS)

    Burns, J. A.; Cliff, E. M.; Powers, R. K.

    1985-01-01

    It is shown that care must be taken to ensure that finite dimensional approximations of distributed parameter systems preserve important system properties (i.e., controllability, observability, stabilizability, detectability, etc.). It is noted that, if the particular scheme used to construct the finite dimensional model does not take into account these system properties, the model may not be suitable for control design and analysis. These ideas are illustrated by a simple example, i.e., a cable-spring-mass system.

  2. Computer control of large accelerators, design concepts and methods

    NASA Astrophysics Data System (ADS)

    Beck, F.; Gormley, M.

    1985-03-01

    Unlike most of the specialities treated in this volume, control system design is still an art, not a science. This presentation is an attempt to produce a primer for prospective practitioners of this art. A large modern accelerator requires a comprehensive control system for commissioning, machine studies, and day-to-day operation. Faced with the requirement to design a control system for such a machine, the control system architect has a bewildering array of technical devices and techniques at his disposal, and it is our aim in the following chapters to lead him through the characteristics of the problems he will have to face and the practical alternatives available for solving them. We emphasize good system architecture using commercially available hardware and software components, but in addition we discuss the actual control strategies which are to be implemented, since it is at the point of deciding what facilities shall be available that the complexity of the control system and its cost are implicitly decided.

  3. Computer control of large accelerators design concepts and methods

    SciTech Connect

    Beck, F.; Gormley, M.

    1984-05-01

    Unlike most of the specialities treated in this volume, control system design is still an art, not a science. These lectures are an attempt to produce a primer for prospective practitioners of this art. A large modern accelerator requires a comprehensive control system for commissioning, machine studies and day-to-day operation. Faced with the requirement to design a control system for such a machine, the control system architect has a bewildering array of technical devices and techniques at his disposal, and it is our aim in the following chapters to lead him through the characteristics of the problems he will have to face and the practical alternatives available for solving them. We emphasize good system architecture using commercially available hardware and software components, but in addition we discuss the actual control strategies which are to be implemented since it is at the point of deciding what facilities shall be available that the complexity of the control system and its cost are implicitly decided. 19 references.

  4. Systems and methods for data quality control and cleansing

    DOEpatents

    Wenzel, Michael; Boettcher, Andrew; Drees, Kirk; Kummer, James

    2016-05-31

    A method for detecting and cleansing suspect building automation system data is shown and described. The method includes using processing electronics to automatically determine which of a plurality of error detectors and which of a plurality of data cleansers to use with building automation system data. The method further includes using processing electronics to automatically detect errors in the data and cleanse the data using a subset of the error detectors and a subset of the cleansers.

  5. Physician payment methods: a focus on quality and cost control.

    PubMed

    Rudmik, Luke; Wranik, Dominika; Rudisill-Michaelsen, Caroline

    2014-08-01

    With rising health care costs, governments must develop innovative methods to deliver efficient and equitable health care services. With physician remuneration being the third largest health care expense, the design of remuneration methods is a priority in health care policy. Otolaryngology-Head and Neck surgeons should have an understanding of the behavioural incentives associated with different physician payment methods. This article will outline the different physician payment methods with a focus on discussing the impact on quality of care and health care costs. PMID:25219382

  6. Vibration and control of a flexible rotor in magnetic bearings using hybrid method and H{sup {infinity}} control theory

    SciTech Connect

    Shiau, T.N.; Sheu, G.J.; Yang, C.D.

    1997-01-01

    The vibration and active control of a flexible rotor system with magnetic bearings are investigated using Hybrid Method (HM) and H{sup {infinity}} control theory with consideration of gyroscopic effect. The hybrid method, which combines the merits of the finite element method (FEM) and generalized polynomial expansion method (GPEM) is employed to model the flexible rotor system with small order of plant. The mixed sensitivity problem of H{sup {infinity}} control theory is applied to design the control of system vibration with spillover phenomena for the reduced order plant. The H{sub 2} control design is also employed for comparison with the H{sup {infinity}} design. The experimental simulation is used to illustrate the effects of control design. It is shown that the H{sup {infinity}} controller design can be very effective to suppress spillover phenomena. In addition, the H{sup {infinity}} control design has robustness to the variation of the model parameters. The application of the hybrid method (HM) together with H{sup {infinity}} control design is highly recommended for vibration control of flexible rotor systems with magnetic bearings.

  7. Automated control of hierarchical systems using value-driven methods

    NASA Technical Reports Server (NTRS)

    Pugh, George E.; Burke, Thomas E.

    1990-01-01

    An introduction is given to the Value-driven methodology, which has been successfully applied to solve a variety of difficult decision, control, and optimization problems. Many real-world decision processes (e.g., those encountered in scheduling, allocation, and command and control) involve a hierarchy of complex planning considerations. For such problems it is virtually impossible to define a fixed set of rules that will operate satisfactorily over the full range of probable contingencies. Decision Science Applications' value-driven methodology offers a systematic way of automating the intuitive, common-sense approach used by human planners. The inherent responsiveness of value-driven systems to user-controlled priorities makes them particularly suitable for semi-automated applications in which the user must remain in command of the systems operation. Three examples of the practical application of the approach in the automation of hierarchical decision processes are discussed: the TAC Brawler air-to-air combat simulation is a four-level computerized hierarchy; the autonomous underwater vehicle mission planning system is a three-level control system; and the Space Station Freedom electrical power control and scheduling system is designed as a two-level hierarchy. The methodology is compared with rule-based systems and with other more widely-known optimization techniques.

  8. Locomotor adaptation to a powered ankle-foot orthosis depends on control method

    PubMed Central

    Cain, Stephen M; Gordon, Keith E; Ferris, Daniel P

    2007-01-01

    Background We studied human locomotor adaptation to powered ankle-foot orthoses with the intent of identifying differences between two different orthosis control methods. The first orthosis control method used a footswitch to provide bang-bang control (a kinematic control) and the second orthosis control method used a proportional myoelectric signal from the soleus (a physiological control). Both controllers activated an artificial pneumatic muscle providing plantar flexion torque. Methods Subjects walked on a treadmill for two thirty-minute sessions spaced three days apart under either footswitch control (n = 6) or myoelectric control (n = 6). We recorded lower limb electromyography (EMG), joint kinematics, and orthosis kinetics. We compared stance phase EMG amplitudes, correlation of joint angle patterns, and mechanical work performed by the powered orthosis between the two controllers over time. Results During steady state at the end of the second session, subjects using proportional myoelectric control had much lower soleus and gastrocnemius activation than the subjects using footswitch control. The substantial decrease in triceps surae recruitment allowed the proportional myoelectric control subjects to walk with ankle kinematics close to normal and reduce negative work performed by the orthosis. The footswitch control subjects walked with substantially perturbed ankle kinematics and performed more negative work with the orthosis. Conclusion These results provide evidence that the choice of orthosis control method can greatly alter how humans adapt to powered orthosis assistance during walking. Specifically, proportional myoelectric control results in larger reductions in muscle activation and gait kinematics more similar to normal compared to footswitch control. PMID:18154649

  9. A Method for Controlling Skew on Linked Surfaces

    SciTech Connect

    BENZLEY,STEVEN E.; KERR,ROBERT A.; MITCHELL,SCOTT A.; WHITE,DAVID R.

    1999-09-27

    A new method for lessening skew in mapped meshes is presented. This new method involves progressive subdivision of a surface into loops consisting of four sides. Using these loops, constraints can then be set on the curves of the surface, which will propagate interval assignments across the surface, allowing a mesh with a better skew metric to be generated.

  10. Methods of controlling hydrogen fluoride pressure during chemical fabrication processes

    SciTech Connect

    Solovyov, Vyacheslav; Wiesmann, Harold

    2009-11-24

    The present invention is a method for producing a crystalline end-product. The method comprising exposing a fluoride-containing precursor to a hydrogen fluoride absorber under conditions suitable for the conversion of the precursor into the crystalline end-product.

  11. Methods of Statistical Control for Groundwater Quality Indicators

    NASA Astrophysics Data System (ADS)

    Yankovich, E.; Nevidimova, O.; Yankovich, K.

    2016-06-01

    The article describes the results of conducted groundwater quality control. Controlled quality indicators included the following microelements - barium, manganese, iron, mercury, iodine, chromium, strontium, etc. Quality control charts - X-bar chart and R chart - were built. For the upper and the lower threshold limits, maximum permissible concentration of components in water and the lower limit of their biologically significant concentration, respectively, were selected. The charts analysis has shown that the levels of microelements content in water at the area of study are stable. Most elements in the underground water are contained in concentrations, significant for human organisms consuming the water. For example, such elements as Ba, Mn, Fe have concentrations that exceed maximum permissible levels for drinking water.

  12. Automatic Mode Switching Method for Torque Priority Control of IPMSM by Considering Voltage Saturation

    NASA Astrophysics Data System (ADS)

    Nakama, Takao; Hanada, Toshihiro; Ohishi, Kiyoshi; Makishima, Shingo; Uezono, Keiichi; Yasukawa, Shinobu

    This paper proposes a new current control method for interior permanent magnet synchronous motor (IPMSM). In the case of AC motor control, two axis current feedback control is performed to control the voltage amplitude and phase. When the inverter voltage is saturated, current control is achieved by controlling the voltage phase. Conventional techniques require switching the mode of the control system from variable-voltage mode to voltage-saturation mode. However, in conventional techniques, the transient voltage saturation occurs by switching the control system. The proposed method achieves the current control in variable voltage mode and voltage saturation mode without switching the control system. Moreover, the current response is not affected by the rotor speed. The numerical simulation results and experimental results confirm the effectiveness of proposed current control method.

  13. Method and apparatus for controlling accidental releases of tritium

    DOEpatents

    Galloway, Terry R. [Berkeley, CA

    1980-04-01

    An improvement in a tritium control system based on a catalytic oxidation reactor wherein accidental releases of tritium into room air are controlled by flooding the catalytic oxidation reactor with hydrogen when the tritium concentration in the room air exceeds a specified limit. The sudden flooding with hydrogen heats the catalyst to a high temperature within seconds, thereby greatly increasing the catalytic oxidation rate of tritium to tritiated water vapor. Thus, the catalyst is heated only when needed. In addition to the heating effect, the hydrogen flow also swamps the tritium and further reduces the tritium release.

  14. Method and apparatus for controlling accidental releases of tritium

    DOEpatents

    Galloway, T.R.

    1980-04-01

    An improvement is described in a tritium control system based on a catalytic oxidation reactor wherein accidental releases of tritium into room air are controlled by flooding the catalytic oxidation reactor with hydrogen when the tritium concentration in the room air exceeds a specified limit. The sudden flooding with hydrogen heats the catalyst to a high temperature within seconds, thereby greatly increasing the catalytic oxidation rate of tritium to tritiated water vapor. Thus, the catalyst is heated only when needed. In addition to the heating effect, the hydrogen flow also swamps the tritium and further reduces the tritium release. 1 fig.

  15. Introduction to Computational Methods for Stability and Control (COMSAC)

    NASA Technical Reports Server (NTRS)

    Hall, Robert M.; Fremaux, C. Michael; Chambers, Joseph R.

    2004-01-01

    This Symposium is intended to bring together the often distinct cultures of the Stability and Control (S&C) community and the Computational Fluid Dynamics (CFD) community. The COMSAC program is itself a new effort by NASA Langley to accelerate the application of high end CFD methodologies to the demanding job of predicting stability and control characteristics of aircraft. This talk is intended to set the stage for needing a program like COMSAC. It is not intended to give details of the program itself. The topics include: 1) S&C Challenges; 2) Aero prediction methodology; 3) CFD applications; 4) NASA COMSAC planning; 5) Objectives of symposium; and 6) Closing remarks.

  16. Progress Towards Computational Method for Circulation Control Airfoils

    NASA Technical Reports Server (NTRS)

    Swanson, R. C.; Rumsey, C. L.; Anders, S. G.

    2005-01-01

    The compressible Reynolds-averaged Navier-Stokes equations are solved for circulation control airfoil flows. Numerical solutions are computed with both structured and unstructured grid solvers. Several turbulence models are considered, including the Spalart-Allmaras model with and without curvature corrections, the shear stress transport model of Menter, and the k-enstrophy model. Circulation control flows with jet momentum coefficients of 0.03, 0.10, and 0.226 are considered. Comparisons are made between computed and experimental pressure distributions, velocity profiles, Reynolds stress profiles, and streamline patterns. Including curvature effects yields the closest agreement with the measured data.

  17. All-optical flip-flop and control methods thereof

    DOEpatents

    Maywar, Drew; Agrawal, Govind P.

    2010-03-23

    Embodiments of the invention pertain to remote optical control of holding beam-type, optical flip-flop devices, as well as to the devices themselves. All-optical SET and RE-SET control signals operate on a cw holding beam in a remote manner to vary the power of the holding beam between threshold switching values to enable flip-flop operation. Cross-gain modulation and cross-polarization modulation processes can be used to change the power of the holding beam.

  18. Method and apparatus for decoupled thermo-catalytic pollution control

    DOEpatents

    Tabatabaie-Raissi, Ali; Muradov, Nazim Z.; Martin, Eric

    2006-07-11

    A new method for design and scale-up of thermocatalytic processes is disclosed. The method is based on optimizing process energetics by decoupling of the process energetics from the DRE for target contaminants. The technique is applicable to high temperature thermocatalytic reactor design and scale-up. The method is based on the implementation of polymeric and other low-pressure drop support for thermocatalytic media as well as the multifunctional catalytic media in conjunction with a novel rotating fluidized particle bed reactor.

  19. A general method for selecting quantum channel for bidirectional controlled state teleportation and other schemes of controlled quantum communication

    NASA Astrophysics Data System (ADS)

    Thapliyal, Kishore; Verma, Amit; Pathak, Anirban

    2015-12-01

    Recently, a large number of protocols for bidirectional controlled state teleportation (BCST) have been proposed using n-qubit entangled states (nin {5,6,7}) as quantum channel. Here, we propose a general method of selecting multiqubit (n>4) quantum channels suitable for BCST and show that all the channels used in the existing protocols of BCST can be obtained using the proposed method. Further, it is shown that the quantum channels used in the existing protocols of BCST form only a negligibly small subset of the set of all the quantum channels that can be constructed using the proposed method to implement BCST. It is also noted that all these quantum channels are also suitable for controlled bidirectional remote state preparation. Following the same logic, methods for selecting quantum channels for other controlled quantum communication tasks, such as controlled bidirectional joint remote state preparation and controlled quantum dialogue, are also provided.

  20. Organic weed control for cantaloupe methods comparison trial

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Effective weed control is needed for successful melon production. Synthetic herbicides that are available for non-organic melon production cannot be used in organic production. In addition to organic producers' needs, herbicide use is not always practical in many garden situations, whether organic o...

  1. Unexpected Finding Suggests Method for Controlling Pollen Dispersal

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two studies on the genetic inheritance of a wheat genomic DNA fragment in transgenic corn conclude that this DNA fragment is inherited maternally because it functions as a pollen specific gametocide. The authors of these studies illustrate that this transgene can but used to control transfer of a s...

  2. Geospatial methods for monitoring alternative control technology sites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Monitoring alternative feedlot runoff control technology effectiveness, especially vegetative treatment systems (VTS), is of interest to both cattlemen and regulatory agencies. Producers have constructed VTS in several mid-western states under an agreement with the Iowa Cattlemen Association and the...

  3. Method of controlling crystallite size in nuclear-reactor fuels

    DOEpatents

    Lloyd, Milton H.; Collins, Jack L.; Shell, Sam E.

    1985-01-01

    Improved spherules for making enhanced forms of nuclear-reactor fuels are prepared by internal gelation procedures within a sol-gel operation and are accomplished by first boiling the concentrated HMTA-urea feed solution before engaging in the spherule-forming operation thereby effectively controlling crystallite size in the product spherules.

  4. Students' Attitudes towards Control Methods in Computer-Assisted Instruction.

    ERIC Educational Resources Information Center

    Hintze, Hanne; And Others

    1988-01-01

    Describes study designed to investigate dental students' attitudes toward computer-assisted teaching as applied in programs for oral radiology in Denmark. Programs using personal computers and slide projectors with varying degrees of learner and teacher control are described, and differences in attitudes between male and female students are…

  5. Method of controlling crystallite size in nuclear-reactor fuels

    DOEpatents

    Lloyd, M.H.; Collins, J.L.; Shell, S.E.

    Improved spherules for making enhanced forms of nuclear-reactor fuels are prepared by internal gelation procedures within a sol-gel operation and are accomplished by first boiling the concentrated HMTA-urea feed solution before engaging in the spherule-forming operation thereby effectively controlling crystallite size in the product spherules.

  6. Temperature Control Method in the Snow Road Construction

    NASA Astrophysics Data System (ADS)

    Serebrenikova, Yu; Lysyannikov, A.; Kaizer, Yu; Zhelykevich, R.; Plakhotnikova, M.; Lysyannikova, N.; Merko, M.; Merko, I.

    2016-06-01

    The paper substantiates the process of heat treatment before the snow compaction in snow road construction. The methods to measure the temperature of snow as a moving dispersed material have been considered in the paper.

  7. Novel plasma control method in PECVD for preparing microcrystalline silicon

    SciTech Connect

    Nishimiya, T.; Kondo, M.; Matsuda, A.

    1997-07-01

    A novel plasma enhanced vapor deposition (PECVD) technique employing biased wall (BW) method has been developed for the enhanced growth rate of the hydrogenated microcrystalline silicon ({micro}c-Si:H) films. Using this method, the authors have achieved a growth rate of more than 6{angstrom}/sec for the formation of {micro}c-Si:H having an average grain size of 200{angstrom} at 350 C.

  8. Nanomaterials and nanotechnologies: methods of analysis and control

    NASA Astrophysics Data System (ADS)

    Gmoshinski, I. V.; Khotimchenko, S. A.; Popov, V. O.; Dzantiev, B. B.; Zherdev, A. V.; Demin, V. F.; Buzulukov, Yu P.

    2013-01-01

    The methods for isolation and identification of nanoparticles and for quantitative determination of nanoparticles in complex multicomponent mixed-phase systems are considered. These systems include most environmental objects, in particular, animal and plant organisms, agricultural raw materials, foodstuffs and various sorts of consumer goods. The published data and the results of authors' research concerning determination of various types of nanoparticles in biological samples by electron microscopy, chromatography and radioactive tracer method are generalized. The bibliography includes 161 references.

  9. Simple method of designing centralized PI controllers for multivariable systems based on SSGM.

    PubMed

    Dhanya Ram, V; Chidambaram, M

    2015-05-01

    A method is given to design multivariable PI/PID controllers for stable and unstable multivariable systems. The method needs only the steady state gain matrix (SSGM). The method is based on the static decoupler design followed by SISO PI/PID controllers design and combining the resulted decoupler and the diagonal PI(D) controllers as the centralized controllers. The result of the present method is shown to be equivalent to the empirical method proposed by Davison EJ. Multivariable tuning regulators: the feed-forward and robust control of general servo-mechanism problem. IEEE Trans Autom Control 1976;21:35-41. Three simulation examples are given. The performance of the controllers is compared with that of the reported centralized controller based on the multivariable transfer function matrix. PMID:25530257

  10. The Application of Parameter Space Design Method for Generator Excitation Control

    NASA Astrophysics Data System (ADS)

    Iki, Hiroyuki; Yoshimura, Shyuta; Uriu, Yosihisa

    Recently, control engineering changes from classical control theory to modern control theory, and analogue to digital. However, as a matter of fact, the sensitivity adjustment of the parameters using Bode diagram require many time and works. In this paper, the tool of Matlab/Simulink that adjusted the AVR control parameter of the PI control type brushless and Thyristor excitation method by using the technique for based on the parameter space planning method by QE was made. Moreover, the adjustment of the sensitivity parameter of the excitation control method intended for the dynamic stability level area in Single Machine Infinite Bus is examined with the tool.

  11. Advanced Control and Protection system Design Methods for Modular HTGRs

    SciTech Connect

    Ball, Sydney J; Wilson Jr, Thomas L; Wood, Richard Thomas

    2012-06-01

    The project supported the Nuclear Regulatory Commission (NRC) in identifying and evaluating the regulatory implications concerning the control and protection systems proposed for use in the Department of Energy's (DOE) Next-Generation Nuclear Plant (NGNP). The NGNP, using modular high-temperature gas-cooled reactor (HTGR) technology, is to provide commercial industries with electricity and high-temperature process heat for industrial processes such as hydrogen production. Process heat temperatures range from 700 to 950 C, and for the upper range of these operation temperatures, the modular HTGR is sometimes referred to as the Very High Temperature Reactor or VHTR. Initial NGNP designs are for operation in the lower temperature range. The defining safety characteristic of the modular HTGR is that its primary defense against serious accidents is to be achieved through its inherent properties of the fuel and core. Because of its strong negative temperature coefficient of reactivity and the capability of the fuel to withstand high temperatures, fast-acting active safety systems or prompt operator actions should not be required to prevent significant fuel failure and fission product release. The plant is designed such that its inherent features should provide adequate protection despite operational errors or equipment failure. Figure 1 shows an example modular HTGR layout (prismatic core version), where its inlet coolant enters the reactor vessel at the bottom, traversing up the sides to the top plenum, down-flow through an annular core, and exiting from the lower plenum (hot duct). This research provided NRC staff with (a) insights and knowledge about the control and protection systems for the NGNP and VHTR, (b) information on the technologies/approaches under consideration for use in the reactor and process heat applications, (c) guidelines for the design of highly integrated control rooms, (d) consideration for modeling of control and protection system designs for

  12. Method and apparatus for controlling LCL converters using asymmetric voltage cancellation techniques

    DOEpatents

    Wu, Hunter; Sealy, Kylee Devro; Sharp, Bryan Thomas; Gilchrist, Aaron

    2016-01-26

    A method and apparatus for LCL resonant converter control utilizing Asymmetric Voltage Cancellation is described. The methods to determine the optimal trajectory of the control variables are discussed. Practical implementations of sensing load parameters are included. Simple PI, PID and fuzzy logic controllers are included with AVC for achieving good transient response characteristics with output current regulation.

  13. Definition of Method of Measurement of Supporting and Control Surface Areas, Special Report

    NASA Technical Reports Server (NTRS)

    1931-01-01

    Definitions of methods of measurements of supporting and control surface areas are presented. Methods for measuring the supporting surface, i.e., the wing area, and the control surfaces, i.e., the horizontal tail area, the vertical tail area, and the trailing control surface areas are defined. Illustrations of each of the areas are included.

  14. Method and apparatus for monitoring and controlling well drilling parameters

    SciTech Connect

    Moorehead, R. M.; Anderson, M. V.; Eppler, S. G.

    1985-03-26

    A mud logging system for receiving and displaying conditions measured during the drilling of a well includes a plurality of units for receiving and processing signals from sensors responsive to the values of the conditions. A/D convertors in each of said units produce digital representations of signals received from the sensors and the digital representations are utilized with visual display means in the units for digitally displaying values of the conditions. A slave computer of the digital type is interfaced with the A/D converters and a file disk. Under control of said slave computer the digital representatives are transferred to the file disk, and a recorder also under control of the slave computer displays selected ones of the conditions. The system also includes a master computer of the digital type connected to access data on the file disk, to utilize the accessed data to provide for analysis of drilling conditions.

  15. Ultrafast laser based coherent control methods for explosives detection

    SciTech Connect

    Moore, David Steven

    2010-12-06

    The detection of explosives is a notoriously difficult problem, especially at stand-off, due to their (generally) low vapor pressure, environmental and matrix interferences, and packaging. We are exploring Optimal Dynamic Detection of Explosives (ODD-Ex), which exploits the best capabilities of recent advances in laser technology and recent discoveries in optimal shaping of laser pulses for control of molecular processes to significantly enhance the standoff detection of explosives. The core of the ODD-Ex technique is the introduction of optimally shaped laser pulses to simultaneously enhance sensitivity to explosives signatures while dramatically improving specificity, particularly against matrix materials and background interferences. These goals are being addressed by operating in an optimal non-linear fashion, typically with a single shaped laser pulse inherently containing within it coherently locked control and probe subpulses. Recent results will be presented.

  16. Method and system for providing autonomous control of a platform

    NASA Technical Reports Server (NTRS)

    Seelinger, Michael J. (Inventor); Yoder, John-David (Inventor)

    2012-01-01

    The present application provides a system for enabling instrument placement from distances on the order of five meters, for example, and increases accuracy of the instrument placement relative to visually-specified targets. The system provides precision control of a mobile base of a rover and onboard manipulators (e.g., robotic arms) relative to a visually-specified target using one or more sets of cameras. The system automatically compensates for wheel slippage and kinematic inaccuracy ensuring accurate placement (on the order of 2 mm, for example) of the instrument relative to the target. The system provides the ability for autonomous instrument placement by controlling both the base of the rover and the onboard manipulator using a single set of cameras. To extend the distance from which the placement can be completed to nearly five meters, target information may be transferred from navigation cameras (used for long-range) to front hazard cameras (used for positioning the manipulator).

  17. Method and apparatus for heat extraction by controlled spray cooling

    DOEpatents

    Edwards, Christopher Francis; Meeks, Ellen; Kee, Robert; McCarty, Kevin

    1999-01-01

    Two solutions to the problem of cooling a high temperature, high heat flux surface using controlled spray cooling are presented for use on a mandrel. In the first embodiment, spray cooling is used to provide a varying isothermal boundary layer on the side portions of a mandrel by providing that the spray can be moved axially along the mandrel. In the second embodiment, a spray of coolant is directed to the lower temperature surface of the mandrel. By taking advantage of super-Leidenfrost cooling, the temperature of the high temperature surface of the mandrel can be controlled by varying the mass flux rate of coolant droplets. The invention has particular applicability to the field of diamond synthesis using chemical vapor deposition techniques.

  18. Methods of Verification, Accountability and Control of Special Nuclear Material

    SciTech Connect

    Stewart, J.E.

    1999-05-03

    This session demonstrates nondestructive assay (NDA) measurement, surveillance and analysis technology required to protect, control and account (MPC and A) for special nuclear materials (SNM) in sealed containers. These measurements, observations and analyses comprise state-of-the art, strengthened, SNM safeguards systems. Staff member specialists, actively involved in research, development, training and implementation worldwide, will present six NDA verification systems and two software tools for integration and analysis of facility MPC and A data.

  19. Comparison of advanced distillation control methods. Second annual report

    SciTech Connect

    Riggs, J.B.

    1996-11-01

    Detailed dynamic simulations of two industrial distillation columns (a propylene/propane splitter and a xylene/toluene column) have been used to study the issue of configuration selection for diagonal PI dual composition controls. Auto Tune Variation (ATV) identification with on-line detuning was used for tuning the diagonal proportional integral (PI) composition controls. Each configuration was evaluated with respect to steady-state relative gain array (RGA) values, sensitivity to feed composition changes, and open loop dynamic performance. Each configuration was tuned using setpoint changes over a wider range of operation for robustness and tested for feed composition upsets. Overall, configuration selection was shown to have a dominant effect upon control performance. Configuration analysis tools (e.g., RGA, condition number, disturbance sensitivity) were found to reject configuration choices that are obviously poor choices, but were unable to critically differentiate between the remaining viable choices. Configuration selection guidelines are given although it is demonstrated that the most reliable configuration selection approach is based upon testing the viable configurations using dynamic column simulators.

  20. Proactive control of proactive interference using the method of loci

    PubMed Central

    Bass, Willa S.; Oswald, Karl M.

    2014-01-01

    Proactive interferencebuilds up with exposure to multiple lists of similar items with a resulting reduction in recall. This study examined the effectiveness of using a proactive strategy of the method of loci to reduce proactive interference in a list recall paradigm of categorically similar words. While all participants reported using some form of strategy to recall list words, this study demonstrated that young adults were able to proactively use the method of loci after 25 min of instruction to reduce proactive interference as compared with other personal spontaneous strategies. The implications of this study are that top-down proactive strategies such as the method of loci can significantly reduce proactive interference, and that the use of image and sequence or location are especially useful in this regard. PMID:25157300

  1. Proactive control of proactive interference using the method of loci.

    PubMed

    Bass, Willa S; Oswald, Karl M

    2014-01-01

    Proactive interferencebuilds up with exposure to multiple lists of similar items with a resulting reduction in recall. This study examined the effectiveness of using a proactive strategy of the method of loci to reduce proactive interference in a list recall paradigm of categorically similar words. While all participants reported using some form of strategy to recall list words, this study demonstrated that young adults were able to proactively use the method of loci after 25 min of instruction to reduce proactive interference as compared with other personal spontaneous strategies. The implications of this study are that top-down proactive strategies such as the method of loci can significantly reduce proactive interference, and that the use of image and sequence or location are especially useful in this regard. PMID:25157300

  2. Synthetic Methods for Nanomaterials of Controlled Composition and Morphology

    NASA Astrophysics Data System (ADS)

    Tienes, Bryan Matthew

    Novel heterogeneous catalysts are required to meet the energy needs of future generations and reduce emissions of carbon dioxide. Many of the recent advances in catalysis have been in the study of nanoparticles. The catalytic activity of nanoparticles relies heavily on their composition, crystal morphology, and surface structure. The best approach for the discovery of new catalysts is to first identify the most catalytically active elemental compositions and then synthesize nanoparticles of those compositions in the most active morphology. This dissertation covers three projects, each with the goal of addressing deficiencies the methods currently available for that catalyst discovery approach. The work presented in Chapter 2 addressed deficiencies in the current synthetic methods used to discover materials with the most active composition. Presented is a method for synthesizing combinatorial catalysts arrays from precursor nanoparticles. Many researchers have turned to combinatorial methods to identify heterogeneous catalysts due to the difficultly in predicting active catalytic compositions a priori. First the synthetic method was demonstrated for generating arrays of gold and silver alloy nanoparticles, and then platinum and ruthenium nanoparticles were used to demonstrate the ability of the synthetic method to generate arrays for a combinatorial study. The final two chapters focused on understanding the role of capping ligands in nanoparticle synthesis and then utilizing their functionality to direct the synthesis of nanoparticles to produce a desired surface structure. Chapter 3 discusses the role of the popular capping ligands, alkyl phosphonic acids, in the synthesis of anisotropic zinc oxide nanoparticles. Chapter 4 describes work with the goal of using in vitro selection procedures to select RNA capable of directing the growth of platinum nanoparticles so that the desired surface structure is exposed on the surface of the nanoparticle product.

  3. Power control apparatus and methods for electric vehicles

    DOEpatents

    Gadh, Rajit; Chung, Ching-Yen; Chu, Chi-Cheng; Qiu, Li

    2016-03-22

    Electric vehicle (EV) charging apparatus and methods are described which allow the sharing of charge current between multiple vehicles connected to a single source of charging energy. In addition, this charge sharing can be performed in a grid-friendly manner by lowering current supplied to EVs when necessary in order to satisfy the needs of the grid, or building operator. The apparatus and methods can be integrated into charging stations or can be implemented with a middle-man approach in which a multiple EV charging box, which includes an EV emulator and multiple pilot signal generation circuits, is coupled to a single EV charge station.

  4. Control of irradiated food: Recent developments in analytical detection methods.

    NASA Astrophysics Data System (ADS)

    Delincée, H.

    1993-07-01

    An overview of recent international efforts, i.e. programmes of "ADMIT" (FAO/IAEA) and of BCR (EC) towards the development of analytical detection methods for radiation processed foods will be given. Some larger collaborative studies have already taken place, e.g. ESR of bones from chicken, prok, beef, frog legs and fish, thermoluminescence of insoluble minerals isolated from herbs and spices, GC analysis of long-chain hydrocarbons derived from the lipid fraction of chicken and other meats, and the microbiological APC/DEFT procedure for spices. These methods could soon be implemented in international standard protocols.

  5. Method for controlling viscosity of organic liquid and compositions

    SciTech Connect

    Kitano, K.; Duvdevani, I.; Schulz, D.N.

    1989-11-14

    This patent describes a method of viscosifying an organic liquid from about 10 to about 10,000 cps for polymer concentrations of less than about 10.0 wt.%. The method comprises adding a sufficient quantity of a hydrolyzed ester containing copolymer of an alpha-olefin and a vinyl alkylenecarboxylil acid copolymerized in the presence of a Ziegler-Natta catalyst having an acid content of from about 0.01 to 10 mole percent and a molecular weight of about 100,000 to about 10,000,000.

  6. Tensor Product Model Transformation Based Adaptive Integral-Sliding Mode Controller: Equivalent Control Method

    PubMed Central

    Zhao, Guoliang; Li, Hongxing

    2013-01-01

    This paper proposes new methodologies for the design of adaptive integral-sliding mode control. A tensor product model transformation based adaptive integral-sliding mode control law with respect to uncertainties and perturbations is studied, while upper bounds on the perturbations and uncertainties are assumed to be unknown. The advantage of proposed controllers consists in having a dynamical adaptive control gain to establish a sliding mode right at the beginning of the process. Gain dynamics ensure a reasonable adaptive gain with respect to the uncertainties. Finally, efficacy of the proposed controller is verified by simulations on an uncertain nonlinear system model. PMID:24453897

  7. Vehicle yaw stability control using active limited-slip differential via model predictive control methods

    NASA Astrophysics Data System (ADS)

    Rubin, Daniel; Arogeti, Shai A.

    2015-09-01

    In this paper, the problem of vehicle yaw control using an active limited-slip differential (ALSD) applied on the rear axle is addressed. The controller objective is to minimise yaw-rate and body slip-angle errors, with respect to target values. A novel model predictive controller is designed, using a linear parameter-varying (LPV) vehicle model, which takes into account the ALSD dynamics and its constraints. The controller is simulated using a 10DOF Matlab/Simulink simulation model and a CarSim model. These simulations exemplify the controller yaw-rate and slip-angle tracking performances, under challenging manoeuvres and road conditions. The model predictive controller performances surpass those of a reference sliding mode controller, and can narrow the loss of performances due to the ALSD's inability to transfer torque regardless of driving conditions.

  8. Controlling white sweetclover with herbicides and non-chemical methods

    Technology Transfer Automated Retrieval System (TEKTRAN)

    White sweetclover is spreading in urban areas, roadsides and glacial floodplains in Alaska and effective methods are needed to limit competition and to eradicate new populations. White sweetclover is a biennial and populations can contain either all 1st-year, all-2nd-year or mixed-age plants. We stu...

  9. THE CRITICAL-PATH METHOD OF CONSTRUCTION CONTROL.

    ERIC Educational Resources Information Center

    DOMBROW, RODGER T.; MAUCHLY, JOHN

    THIS DISCUSSION PRESENTS A DEFINITION AND BRIEF DESCRIPTION OF THE CRITICAL-PATH METHOD AS APPLIED TO BUILDING CONSTRUCTION. INTRODUCING REMARKS CONSIDER THE MOST PERTINENT QUESTIONS PERTAINING TO CPM AND THE NEEDS ASSOCIATED WITH MINIMIZING TIME AND COST ON CONSTRUCTION PROJECTS. SPECIFIC DISCUSSION INCLUDES--(1) ADVANTAGES OF NETWORK TECHNIQUES,…

  10. DEVELOP NEW TOC/DOC METHOD WITH EXPANDED QUALITY CONTROL

    EPA Science Inventory

    The purpose of this project is to provide a total organic carbon (TOC)/specific ultraviolet absorbance (SUVA) method that will be used by the Office of Ground Water and Drinking Water (OGWDW) to support monitoring requirements of the Stage 2 Disinfectant/Disinfection By-products ...

  11. Geospatial methods for monitoring alternative control technology sites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soils data can be used to establish nutrient distribution at a selected site; however, soil sampling is labor intensive, costly, and selection of sampling sites may be difficult. This study was conducted to determine if methods developed for the management of saline soils can be applied to a vegetat...

  12. NEUTRONIC REACTOR CONTROL ROD AND METHOD OF FABRICATION

    DOEpatents

    Porembka, S.W. Jr.

    1961-06-27

    A reactor control rod formed from a compacted powder dispersion is patented. The rod consists of titanium sheathed with a cladding alloy. The cladding alloy contains 1.3% to 1.6% by weight of tin, 0.07% to 0.12% by weight of chromium, 0.04% to 0.08% by weight of nickel, 0.09% to 0.16% by weight of iron, carbon not exceeding 0.05%, less than 0.5% by weight of incidental impurities, and the balance zirconium.

  13. Optimal management strategies in variable environments: Stochastic optimal control methods

    USGS Publications Warehouse

    Williams, B.K.

    1985-01-01

    Dynamic optimization was used to investigate the optimal defoliation of salt desert shrubs in north-western Utah. Management was formulated in the context of optimal stochastic control theory, with objective functions composed of discounted or time-averaged biomass yields. Climatic variability and community patterns of salt desert shrublands make the application of stochastic optimal control both feasible and necessary. A primary production model was used to simulate shrub responses and harvest yields under a variety of climatic regimes and defoliation patterns. The simulation results then were used in an optimization model to determine optimal defoliation strategies. The latter model encodes an algorithm for finite state, finite action, infinite discrete time horizon Markov decision processes. Three questions were addressed: (i) What effect do changes in weather patterns have on optimal management strategies? (ii) What effect does the discounting of future returns have? (iii) How do the optimal strategies perform relative to certain fixed defoliation strategies? An analysis was performed for the three shrub species, winterfat (Ceratoides lanata), shadscale (Atriplex confertifolia) and big sagebrush (Artemisia tridentata). In general, the results indicate substantial differences among species in optimal control strategies, which are associated with differences in physiological and morphological characteristics. Optimal policies for big sagebrush varied less with variation in climate, reserve levels and discount rates than did either shadscale or winterfat. This was attributed primarily to the overwintering of photosynthetically active tissue and to metabolic activity early in the growing season. Optimal defoliation of shadscale and winterfat generally was more responsive to differences in plant vigor and climate, reflecting the sensitivity of these species to utilization and replenishment of carbohydrate reserves. Similarities could be seen in the influence of both

  14. A comparison between IMSC, PI and MIMSC methods in controlling the vibration of flexible systems

    NASA Technical Reports Server (NTRS)

    Baz, A.; Poh, S.

    1987-01-01

    A comparative study is presented between three active control algorithms which have proven to be successful in controlling the vibrations of large flexible systems. These algorithms are: the Independent Modal Space Control (IMSC), the Pseudo-inverse (PI), and the Modified Independent Modal Space Control (MIMSC). Emphasis is placed on demonstrating the effectiveness of the MIMSC method in controlling the vibration of large systems with small number of actuators by using an efficient time sharing strategy. Such a strategy favors the MIMSC over the IMSC method, which requires a large number of actuators to control equal number of modes, and also over the PI method which attempts to control large number of modes with smaller number of actuators through the use of an in-exact statistical realization of a modal controller. Numerical examples are presented to illustrate the main features of the three algorithms and the merits of the MIMSC method.

  15. Method and apparatus for controlling hybrid powertrain system in response to engine temperature

    SciTech Connect

    Martini, Ryan D; Spohn, Brian L; Lehmen, Allen J; Cerbolles, Teresa L

    2014-10-07

    A method for controlling a hybrid powertrain system including an internal combustion engine includes controlling operation of the hybrid powertrain system in response to a preferred minimum coolant temperature trajectory for the internal combustion engine.

  16. Method and apparatus for adaptive force and position control of manipulators

    NASA Technical Reports Server (NTRS)

    Seraji, Homayoun (Inventor)

    1989-01-01

    The present invention discloses systematic methods and apparatus for the design of real time controllers. Real-time control employs adaptive force/position by use of feedforward and feedback controllers, with the feedforward controller being the inverse of the linearized model of robot dynamics and containing only proportional-double-derivative terms is disclosed. The feedback controller, of the proportional-integral-derivative type, ensures that manipulator joints follow reference trajectories and the feedback controller achieves robust tracking of step-plus-exponential trajectories, all in real time. The adaptive controller includes adaptive force and position control within a hybrid control architecture. The adaptive controller, for force control, achieves tracking of desired force setpoints, and the adaptive position controller accomplishes tracking of desired position trajectories. Circuits in the adaptive feedback and feedforward controllers are varied by adaptation laws.

  17. Fuel control valve construction, parts therefor and methods

    SciTech Connect

    Kelly, S.T.; Katchka, J.R.

    1990-05-29

    This patent describes a fuel control valve construction. It comprises: a housing means having an inlet means adapted to be interconnected to a main burner means, the housing means having a main valve seat for interconnecting the inlet means with the main outlet means, the housing means having a movable main valve member for opening and closing the main valve seat, the housing means having a movable lever carrying the main valve member and having a manually operable actuator means for controlling the operating positions of the lever, the lever having an intermediate cam follower portion and opposed ends disposed on each side of the cam follower portion with one end of the opposed ends being pivotally mounted to the housing means and with the other end of the opposed ends carrying the main valve member, the housing means having biasing means operatively interconnected to the lever to tend to pivot the lever in one direction that opens the main valve member away from its main valve seat.

  18. Automated alignment method for coherence-controlled holographic microscope

    NASA Astrophysics Data System (ADS)

    Dostal, Zbynek; Slaby, Tomas; Kvasnica, Lukas; Lostak, Martin; Krizova, Aneta; Chmelik, Radim

    2015-11-01

    A coherence-controlled holographic microscope (CCHM) was developed particularly for quantitative phase imaging and measurement of live cell dynamics, which is the proper subject of digital holographic microscopy (DHM). CCHM in low-coherence mode extends DHM in the study of living cells. However, this advantage is compensated by sensitivity of the system to easily become misaligned, which is a serious hindrance to wanted performance. Therefore, it became clear that introduction of a self-correcting system is inevitable. Accordingly, we had to devise a theory of a suitable control and design an automated alignment system for CCHM. The modulus of the reconstructed holographic signal was identified as a significant variable for guiding the alignment procedures. From this, we derived the original basic realignment three-dimensional algorithm, which encompasses a unique set of procedures for automated alignment that contains processes for initial and advanced alignment as well as long-term maintenance of microscope tuning. All of these procedures were applied to a functioning microscope and the tested processes were successfully validated. Finally, in such a way, CCHM is enabled to substantially contribute to study of biology, particularly of cancer cells in vitro.

  19. Method for forming porous sintered bodies with controlled pore structure

    DOEpatents

    Whinnery, LeRoy Louis; Nichols, Monte Carl

    2000-01-01

    The present invention is based, in part, on a method for combining a mixture of hydroxide and hydride functional siloxanes to form a polysiloxane polymer foam, that leaves no residue (zero char yield) upon thermal decomposition, with ceramic and/or metal powders and appropriate catalysts to produce porous foam structures having compositions, densities, porosities and structures not previously attainable. The siloxanes are mixed with the ceramic and/or metal powder, wherein the powder has a particle size of about 400 .mu.m or less, a catalyst is added causing the siloxanes to foam and crosslink, thereby forming a polysiloxane polymer foam having the metal or ceramic powder dispersed therein. The polymer foam is heated to thermally decompose the polymer foam and sinter the powder particles together. Because the system is completely nonaqueous, this method further provides for incorporating reactive metals such as magnesium and aluminum, which can be further processed, into the foam structure.

  20. Analysis methods for wind turbine control and electrical system dynamics

    NASA Technical Reports Server (NTRS)

    Hinrichsen, E. N.

    1995-01-01

    The integration of new energy technologies into electric power systems requires methods which recognize the full range of dynamic events in both the new generating unit and the power system. Since new energy technologies are initially perceived as small contributors to large systems, little attention is generally paid to system integration, i.e. dynamic events in the power system are ignored. As a result, most new energy sources are only capable of base-load operation, i.e. they have no load following or cycling capability. Wind turbines are no exception. Greater awareness of this implicit (and often unnecessary) limitation is needed. Analysis methods are recommended which include very low penetration (infinite bus) as well as very high penetration (stand-alone) scenarios.

  1. Computational Methods for Dynamic Stability and Control Derivatives

    NASA Technical Reports Server (NTRS)

    Green, Lawrence L.; Spence, Angela M.; Murphy, Patrick C.

    2003-01-01

    Force and moment measurements from an F-16XL during forced pitch oscillation tests result in dynamic stability derivatives, which are measured in combinations. Initial computational simulations of the motions and combined derivatives are attempted via a low-order, time-dependent panel method computational fluid dynamics code. The code dynamics are shown to be highly questionable for this application and the chosen configuration. However, three methods to computationally separate such combined dynamic stability derivatives are proposed. One of the separation techniques is demonstrated on the measured forced pitch oscillation data. Extensions of the separation techniques to yawing and rolling motions are discussed. In addition, the possibility of considering the angles of attack and sideslip state vector elements as distributed quantities, rather than point quantities, is introduced.

  2. Computational Methods for Dynamic Stability and Control Derivatives

    NASA Technical Reports Server (NTRS)

    Green, Lawrence L.; Spence, Angela M.; Murphy, Patrick C.

    2004-01-01

    Force and moment measurements from an F-16XL during forced pitch oscillation tests result in dynamic stability derivatives, which are measured in combinations. Initial computational simulations of the motions and combined derivatives are attempted via a low-order, time-dependent panel method computational fluid dynamics code. The code dynamics are shown to be highly questionable for this application and the chosen configuration. However, three methods to computationally separate such combined dynamic stability derivatives are proposed. One of the separation techniques is demonstrated on the measured forced pitch oscillation data. Extensions of the separation techniques to yawing and rolling motions are discussed. In addition, the possibility of considering the angles of attack and sideslip state vector elements as distributed quantities, rather than point quantities, is introduced.

  3. Hybrid architecture active wavefront sensing and control system, and method

    NASA Technical Reports Server (NTRS)

    Feinberg, Lee D. (Inventor); Dean, Bruce H. (Inventor); Hyde, Tristram T. (Inventor)

    2011-01-01

    According to various embodiments, provided herein is an optical system and method that can be configured to perform image analysis. The optical system can comprise a telescope assembly and one or more hybrid instruments. The one or more hybrid instruments can be configured to receive image data from the telescope assembly and perform a fine guidance operation and a wavefront sensing operation, simultaneously, on the image data received from the telescope assembly.

  4. Method and apparatus for control of a magnetic structure

    DOEpatents

    Challenger, Michael P.; Valla, Arthur S.

    1996-06-18

    A method and apparatus for independently adjusting the spacing between opposing magnet arrays in charged particle based light sources. Adjustment mechanisms between each of the magnet arrays and the supporting structure allow the gap between the two magnet arrays to be independently adjusted. In addition, spherical bearings in the linkages to the magnet arrays permit the transverse angular orientation of the magnet arrays to also be adjusted. The opposing magnet arrays can be supported above the ground by the structural support.

  5. A Coefficient Diagram Method Controller with Backstepping Methodology for Robotic Manipulators

    NASA Astrophysics Data System (ADS)

    Haouari, Fouad; Nourdine, Bali; Boucherit, Mohamed Segir; Tadjine, Mohamed

    2015-09-01

    A new robust control procedure for robot manipulators is proposed in this paper. Coefficients diagram method controllers CDM and Backstepping methodology are combined to create the novel control law. Two steps of backstepping on the resulting system are used to design a nonlinear CDM-Backstepping controller. Simulations on a PUMA robot including external disturbances, parametric uncertainties and noises are performed to show the effectiveness and feasibility of the proposed method.

  6. Application of optical controlling methods for plants under external influence

    NASA Astrophysics Data System (ADS)

    Timchenko, E. V.; Taskina, L. A.

    2012-10-01

    The experimental study results of spectral characteristic change of different types of plants influenced by external factors (synthetic superficially active substances, salts of heavy metals and nitrate fertilizers) are presented. Differential optical factor was used as the monitored optical parameter that characterizes the chlorophyll concentration change. The differential backscatter method which has high test-sensitivity and provides with the most complete information on the plant condition was the main optical monitoring method. For understanding the mechanisms of external factor accumulation and influence on plants the confocal fluorescent microscopy method providing contrast micrographs of high resolution was used for microscopic analysis in the study. It was revealed that synthetic superficially active substances and heavy metal presence lead to quasilinear decrease of differential backscatter factor with time. It was shown that the presence of salts of heavy metals in a water solution leads to chlorophyll "binding" which is microscopically shown as their «adhesion» near the cell membranes. On the contrary, the presence of synthetic superficially active substances maintains the uniformity of chlorophyll distribution in a cell, but its concentration falls with increasing the concentration in a major emission. The latter depends on the fact that synthetic superficially active substances solubilize the cell membrane proteins, increasing its penetrability. It causes pigment release ("washing away") from a plant, thereby leading to differential optical factor change. It was shown that nitrate fertilizer presence leads to increase of differential backscatter factor with time which is microscopically connected to increase in chlorophyll concentration.

  7. The Kinesio Taping Method for Myofascial Pain Control

    PubMed Central

    Wu, Wei-Ting; Hong, Chang-Zern; Chou, Li-Wei

    2015-01-01

    Many people continue suffering from myofascial pain syndrome (MPS) defined as a regional pain syndrome characterized by muscle pain caused by myofascial trigger points (MTrPs) clinically. Muscle spasm and block of blood circulation can be noticed in the taut bands. In the MTrP region, nociceptors can be sensitized by the peripheral inflammatory factors and contracture of fascia can also be induced. Traditional treatments of MPS include stretching therapy, thermal treatment, electrical stimulation, massage, manipulation, trigger points injection, acupuncture, and medicine. However, the pain syndrome may not be relieved even under multiple therapies. Recently, the Kinesio Taping (KT) method is popularly used in sports injuries, postoperative complications, and various pain problems, but little research is focused on MPS with KT method. In this paper, we review the research studies on the application to KT in treating MPS and other related issues. It appears that the KT application can elevate the subcutaneous space and then increase the blood circulation and lymph fluid drainage to reduce the chemical factors around the MTrP region. Therefore, it is suggested that KT method can be used as a regular treatment or added to the previous treatment for myofascial pain. PMID:26185522

  8. Controlled method of reducing electrophoretic mobility of various substances

    NASA Technical Reports Server (NTRS)

    Vanalstine, James M. (Inventor)

    1989-01-01

    A method of reducing electrophoretic mobility of macromolecules, particles, cells, and the like is provided. The method comprises interacting the particles or cells with a polymer-linked affinity compound composed of: a hydrophilic neutral polymer such as polyethylene glycol, and an affinity component consisting of a hydrophobic compound such as a fatty acid ester, an immunocompound such as an antibody or active fragment thereof or simular macromolecule, or other ligands. The reduction of electrophoretic mobility achieved is directly proportional to the concentration of the polymer-linked affinity compound employed, and the mobility reduction obtainable is up to 100 percent for particular particles and cells. The present invention is advantageous in that analytical electrophoretic separation can not be achieved for macromolecules, particles, and cells whose native surface charge structure had prevented them from being separated by normal electrophoretic means. Depending on the affinity component utilized, separation can be achieved on the basis of specific/irreversible, specific/reversible, semi-specific/reversible, relatively nonspecific/reversible, or relatively nonspecific/irreversible ligand-substance interactions. The present method is also advantageous in that it can be used in a variety of standard laboratory electrophoresis equipment.

  9. The Kinesio Taping Method for Myofascial Pain Control.

    PubMed

    Wu, Wei-Ting; Hong, Chang-Zern; Chou, Li-Wei

    2015-01-01

    Many people continue suffering from myofascial pain syndrome (MPS) defined as a regional pain syndrome characterized by muscle pain caused by myofascial trigger points (MTrPs) clinically. Muscle spasm and block of blood circulation can be noticed in the taut bands. In the MTrP region, nociceptors can be sensitized by the peripheral inflammatory factors and contracture of fascia can also be induced. Traditional treatments of MPS include stretching therapy, thermal treatment, electrical stimulation, massage, manipulation, trigger points injection, acupuncture, and medicine. However, the pain syndrome may not be relieved even under multiple therapies. Recently, the Kinesio Taping (KT) method is popularly used in sports injuries, postoperative complications, and various pain problems, but little research is focused on MPS with KT method. In this paper, we review the research studies on the application to KT in treating MPS and other related issues. It appears that the KT application can elevate the subcutaneous space and then increase the blood circulation and lymph fluid drainage to reduce the chemical factors around the MTrP region. Therefore, it is suggested that KT method can be used as a regular treatment or added to the previous treatment for myofascial pain. PMID:26185522

  10. Magnetic agglomeration method for size control in the synthesis of magnetic nanoparticles

    DOEpatents

    Huber, Dale L.

    2011-07-05

    A method for controlling the size of chemically synthesized magnetic nanoparticles that employs magnetic interaction between particles to control particle size and does not rely on conventional kinetic control of the reaction to control particle size. The particles are caused to reversibly agglomerate and precipitate from solution; the size at which this occurs can be well controlled to provide a very narrow particle size distribution. The size of particles is controllable by the size of the surfactant employed in the process; controlling the size of the surfactant allows magnetic control of the agglomeration and precipitation processes. Agglomeration is used to effectively stop particle growth to provide a very narrow range of particle sizes.

  11. Alternate method for achieving temperature control in the -160 to +90 Celcius range

    NASA Technical Reports Server (NTRS)

    Johnson, Kenneth R. (Inventor)

    1995-01-01

    A single-pass method for accurate and precise temperature control in the -160 to +90 C range is discussed. The method exhibited minimal set-point overshoot during temperature transitions. Control to +/-2 C with transitions between set-points of 7 C per minute were achieved. The method uses commercially available temperature controllers and a gaseous nitrogen/liquid nitrogen mixer to dampen the amplitude of cold temperature spikes caused by liquid nitrogen pulsing.

  12. Methods and systems for seed planting management and control

    DOEpatents

    Svoboda, John M.; Hess, J. Richard; Hoskinson, Reed L.; Harker, David J.

    2002-01-01

    A seed planting system providing optimal seed spacing in an agricultural field. The seed planting system includes a mobile seed planter having one or more planting shoes, or members being adapted for towing by a farm vehicle or being self-propelled. Sensors, disposed proximate to respective planting shoes, detect seed planting events and send corresponding signals to a computer. Contemporaneously, a geospatial locator acquires, and transmits to the computer, the geospatial location of each planted seed. The computer correlates the geospatial location data with the seed deposition data and generates a seed distribution profile indicating the location of each seed planted in a zone of interest to enable the control of speed spacing.

  13. Method of controlling cyclic variation in engine combustion

    DOEpatents

    Davis, L.I. Jr.; Daw, C.S.; Feldkamp, L.A.; Hoard, J.W.; Yuan, F.; Connolly, F.T.

    1999-07-13

    Cyclic variation in combustion of a lean burning engine is reduced by detecting an engine combustion event output such as torsional acceleration in a cylinder (i) at a combustion event (k), using the detected acceleration to predict a target acceleration for the cylinder at the next combustion event (k+1), modifying the target output by a correction term that is inversely proportional to the average phase of the combustion event output of cylinder (i) and calculating a control output such as fuel pulse width or spark timing necessary to achieve the target acceleration for cylinder (i) at combustion event (k+1) based on anti-correlation with the detected acceleration and spill-over effects from fueling. 27 figs.

  14. Method of controlling cyclic variation in engine combustion

    DOEpatents

    Davis, Jr., Leighton Ira; Daw, Charles Stuart; Feldkamp, Lee Albert; Hoard, John William; Yuan, Fumin; Connolly, Francis Thomas

    1999-01-01

    Cyclic variation in combustion of a lean burning engine is reduced by detecting an engine combustion event output such as torsional acceleration in a cylinder (i) at a combustion event (k), using the detected acceleration to predict a target acceleration for the cylinder at the next combustion event (k+1), modifying the target output by a correction term that is inversely proportional to the average phase of the combustion event output of cylinder (i) and calculating a control output such as fuel pulse width or spark timing necessary to achieve the target acceleration for cylinder (i) at combustion event (k+1) based on anti-correlation with the detected acceleration and spill-over effects from fueling.

  15. Advanced methods of microscope control using μManager software

    PubMed Central

    Edelstein, Arthur D.; Tsuchida, Mark A.; Amodaj, Nenad; Pinkard, Henry; Vale, Ronald D.; Stuurman, Nico

    2014-01-01

    μManager is an open-source, cross-platform desktop application, to control a wide variety of motorized microscopes, scientific cameras, stages, illuminators, and other microscope accessories. Since its inception in 2005, μManager has grown to support a wide range of microscopy hardware and is now used by thousands of researchers around the world. The application provides a mature graphical user interface and offers open programming interfaces to facilitate plugins and scripts. Here, we present a guide to using some of the recently added advanced μManager features, including hardware synchronization, simultaneous use of multiple cameras, projection of patterned light onto a specimen, live slide mapping, imaging with multi-well plates, particle localization and tracking, and high-speed imaging. PMID:25606571

  16. Quality-control analytical methods: continuous quality improvement.

    PubMed

    Venti, Eden M

    2006-01-01

    It is vital that all compounding pharmacies have a continuous quality improvement program in place by way of standard operating procedures to assure that patients receive high-quality preparations. The program should take into consideration any federal and state regulatory requirements, as well as professional association expectations. Quality control measurements and regular review of those measurements are the foundations of a good quality plan. All pharmacy personnel should be aware of the importance of reporting potential internal quality concerns or problems and should be encouraged to do so without fear of repercussions. Ideally, an error-free compounding pracitice would be the goal. Since this is not practical, quality issues should not be viewed as problems, but as opportunities to improve compounding practices by correcting, before they become pervasive, the processes used in the preparation of prescriptions. PMID:23974418

  17. Analysis of control methods: mercury and cadmium pollution.

    PubMed Central

    MacGregor, A

    1975-01-01

    Physical system conceptual models are developed to illustrate the various interconnecting pathways of metal flow. Economic use of mercury and cadmium, as representative toxic heavy metals, is inventoried, and the losses of each from the pathways of economic use are compared. Distinctions are made between high volume consumers and industries that are responsible for a large percent of total emissions or effluent loads. The pathways of the metals in the environment are traced via the conceptual models. A global mass balance is presented for mercury. The problem of high local concentrations vs. global metal flow is reviewed. Impacts of the metals on human health are categorized by type of effect. Available control strategies and abatement measures are evaluated with respect to the effectiveness of each on the problems of metal pollution, as illustrated by the physical models. PMID:1227855

  18. Thermoelectric generator cooling system and method of control

    SciTech Connect

    Prior, Gregory P; Meisner, Gregory P; Glassford, Daniel B

    2012-10-16

    An apparatus is provided that includes a thermoelectric generator and an exhaust gas system operatively connected to the thermoelectric generator to heat a portion of the thermoelectric generator with exhaust gas flow through the thermoelectric generator. A coolant system is operatively connected to the thermoelectric generator to cool another portion of the thermoelectric generator with coolant flow through the thermoelectric generator. At least one valve is controllable to cause the coolant flow through the thermoelectric generator in a direction that opposes a direction of the exhaust gas flow under a first set of operating conditions and to cause the coolant flow through the thermoelectric generator in the direction of exhaust gas flow under a second set of operating conditions.

  19. EVALUATION OF A NEW METHOD OF DUST CONTROL

    PubMed Central

    Harris, M. Coleman; Shure, Norman

    1952-01-01

    Microscopic dust sampling was done to determine the amount of dust in the homes of six patients who were sensitive to house dust and who had allergic disease that was intractable to treatment. One case was subsequently excluded from the study because of extraordinary circumstances. The remaining five cases were studied with repeated dust counts before and after a water-and-oil emulsion was sprayed in the patient's bedroom to immobilize house dust. In all five cases, the patients had dramatic relief of symptoms after the spraying was done. In four out of five, there was concomitant reduction of the amount of dust in the air as determined by microscopic counting of the dust particles on a glycerincoated slide. In the fifth case, relief of symptoms was not accompanied by reduction of dust on slides, but investigation revealed an error in control of exposure of the slides. PMID:14886758

  20. Power conversion and control methods for renewable energy sources

    NASA Astrophysics Data System (ADS)

    Yu, Dachuan

    2005-07-01

    In recent years, there has been an increase in the use of renewable energy due to the growing concern over the pollution caused by fossil-fuel-based energy. Renewable energy sources, such as photovoltaic (PV) and fuel cell, can be used to enhance the safety, reliability, sustainability, and transmission efficiency of a power system. This dissertation focuses on the power conversion and control for two major renewable-energy sources: PV and fuel cell. Firstly, a current-based, maximum power-point tracking (MPPT) algorithm is proposed for PV energy. An economical converter system using the above scheme for converting the output from PV panels into 60 Hz AC voltage is developed and built. Secondly, a novel circuit model for the Proton Exchange Membrane (PEM) fuel-cell stack that is useful in the design and analysis of fuel-cell-based power systems is proposed. This Pspice-based model uses elements available in the Pspice library with some modifications to represent both the static and dynamic responses of a PEM fuel-cell module. The accuracy of the model is verified by comparing the simulation and experimental results. Thirdly, a DSP-controlled three-phase induction-motor drive using constant voltage over frequency is built and can be used in a fuel-cell automobile. A hydrogen sensor is used in the drive to both sound an alarm and shut down the inverter trigger pulses through the DSP. Finally, a hybrid power system consisting of PV panels and fuel cell is proposed and built. In the proposed system, PV panels can supply most of the power when the sunlight is available, and the excess power required by the load is supplied by a fuel cell. Load sharing between a fuel cell (FC) and the PV panel is investigated by both simulation and experiments.

  1. Method of controlling scale in oil recovery operations

    DOEpatents

    Krajicek, Richard W.

    1981-01-01

    Disclosed is a method of producing highly viscous minerals from a subterranean formation by injection of an acidic, thermal vapor stream without substantial scale buildup in downstream piping, pumps and well bore. The process comprises heating the formation by injection of heat, preferably in the form of a thermal vapor stream composed of combustion gases and steam and injecting an acidic compound simultaneously with the thermal vapor stream into the formation at a temperature above the dew point of the thermal vapor stream. The acidic, thermal vapor stream increases the solubility of metal ions in connate water and thus reduces scaling in the downstream equipment during the production of viscous hydrocarbons.

  2. METHOD OF CONTROLLING CORROSION IN A NEUTRONIC REACTOR

    DOEpatents

    Kidder, C.P.; Sloan, C.K.

    1959-10-01

    A method is described for reducing or removing corrosion and iron deposits on aluminum surfaces from coolant water comprising adding to the coolant alkali metal dichromate in a concentration of between 1.8 and 2.2 ppm, adjusting the pH to between 7.3 and 7.8 by adding CaCO/sub 3/ or other similar material, and adding a silicious material such as diatomaceous earth of a particle size of 5 to 15 microns to effect a suspension of between 2 and 300 ppm and circulating it through the reactor.

  3. Method for detecting engine misfire and for fuel control

    SciTech Connect

    Tang, D.L.; Chang, M.F.; Sultan, M.C.

    1990-06-12

    This patent describes the method of detecting misfire in an internal combustion engine during start up. It comprises: sensing first engine speeds at positions midway between top dead center positions and second engine speeds at positions between each midway position and the previous top dead center position, during initial cranking, storing first speeds as cranking speed, and comparing the first speed with the second speed during the combustion period of each cylinder and with the cranking speed.A failure to increase speed over the cranking speed and over the second speed denotes misfire for that cylinder.

  4. A Facial Control Method Using Emotional Parameters in Sensibility Robot

    NASA Astrophysics Data System (ADS)

    Shibata, Hiroshi; Kanoh, Masayoshi; Kato, Shohei; Kunitachi, Tsutomu; Itoh, Hidenori

    The “Ifbot” robot communicates with people by considering its own “emotions”. Ifbot has many facial expressions to communicate enjoyment. These are used to express its internal emotions, purposes, reactions caused by external stimulus, and entertainment such as singing songs. All these facial expressions are developed by designers manually. Using this approach, we must design all facial motions, if we want Ifbot to express them. It, however, is not realistic. We have therefore developed a system which convert Ifbot's emotions to its facial expressions automatically. In this paper, we propose a method for creating Ifbot's facial expressions from parameters, emotional parameters, which handle its internal emotions computationally.

  5. Control Banding Nanotool: Evaluation of a qualitative risk assessment method for the control of nanoparticulate exposures

    SciTech Connect

    Zalk, D; Paik, S; Swuste, P

    2009-01-27

    Control Banding strategies offer a simplified control of worker exposures when there is an absence of firm toxicological and exposure information. The nanotechnology industry fits this classification as there are overwhelming uncertainties of work-related health risks posed by nanomaterials. Many experts have suggested Control Banding as a solution for these issues. A recent survey shows a majority of nanomaterial users are not performing a basic risk assessment of their product in use. A Control Banding Nanotool has been developed and implemented to afford a qualitative risk assessment toward the control of nanoparticle exposures. The international use of the Control Banding Nanotool reflects on both its need and its possibilities. By developing this dynamic Control Banding Nanotool within the realm of the scientific information available, this application of Control Banding appears to be a useful approach for assessing the risk of nanomaterial operations. This success can be seen in providing recommendations for appropriate engineering controls, facilitating the allocation of resources to the activities that most need them, and initiating an appropriate discussion of these risks with nonexperts. Experts have requested standardization of toxicological parameters, affording better utility and consistency of research. This database of toxicological research findings should be harnessed and presented in a format feeding directly into the Control Banding Nanotool severity and probability risk matrix. Making the latest research available for experts and practitioners alike will provide the best protection of workers in the nanotechnology industries. This presentation will also show the science behind the simplified Control Banding Nanotool approach, its structure, weighting of risks, utility for exposure mitigation, and the research needs to bolster its effectiveness.

  6. Methods of Si based ceramic components volatilization control in a gas turbine engine

    DOEpatents

    Garcia-Crespo, Andres Jose; Delvaux, John; Dion Ouellet, Noemie

    2016-09-06

    A method of controlling volatilization of silicon based components in a gas turbine engine includes measuring, estimating and/or predicting a variable related to operation of the gas turbine engine; correlating the variable to determine an amount of silicon to control volatilization of the silicon based components in the gas turbine engine; and injecting silicon into the gas turbine engine to control volatilization of the silicon based components. A gas turbine with a compressor, combustion system, turbine section and silicon injection system may be controlled by a controller that implements the control method.

  7. Linear motion device and method for inserting and withdrawing control rods

    DOEpatents

    Smith, J.E.

    Disclosed is a linear motion device and more specifically a control rod drive mechanism (CRDM) for inserting and withdrawing control rods into a reactor core. The CRDM and method disclosed is capable of independently and sequentially positioning two sets of control rods with a single motor stator and rotor. The CRDM disclosed can control more than one control rod lead screw without incurring a substantial increase in the size of the mechanism.

  8. An Adaptive Instability Suppression Controls Method for Aircraft Gas Turbine Engine Combustors

    NASA Technical Reports Server (NTRS)

    Kopasakis, George; DeLaat, John C.; Chang, Clarence T.

    2008-01-01

    An adaptive controls method for instability suppression in gas turbine engine combustors has been developed and successfully tested with a realistic aircraft engine combustor rig. This testing was part of a program that demonstrated, for the first time, successful active combustor instability control in an aircraft gas turbine engine-like environment. The controls method is called Adaptive Sliding Phasor Averaged Control. Testing of the control method has been conducted in an experimental rig with different configurations designed to simulate combustors with instabilities of about 530 and 315 Hz. Results demonstrate the effectiveness of this method in suppressing combustor instabilities. In addition, a dramatic improvement in suppression of the instability was achieved by focusing control on the second harmonic of the instability. This is believed to be due to a phenomena discovered and reported earlier, the so called Intra-Harmonic Coupling. These results may have implications for future research in combustor instability control.

  9. Rotating vector methods for smooth torque control of a switched reluctance motor drive

    SciTech Connect

    Nagel, N.J.; Lorenz, R.D.

    2000-04-01

    This paper has two primary contributions to switched reluctance motor (SRM) control: a systematic approach to smooth torque production and a high-performance technique for sensorless motion control. The systematic approach to smooth torque production is based on development of novel rotating spatial vectors methods that can be used to predict the torque produced in an arbitrary SRM. This analysis directly leads to explicit, insightful methods to provide smooth torque control of SRM's. The high-performance technique for sensorless motion control is based on a rotating vector method for high bandwidth, high resolution, position, and velocity estimation suitable for both precise torque and motion control. The sensorless control and smooth torque control methods are both verified experimentally.

  10. Method and apparatus for laser-controlled proton beam radiology

    DOEpatents

    Johnstone, Carol J.

    1998-01-01

    A proton beam radiology system provides cancer treatment and proton radiography. The system includes an accelerator for producing an H.sup.- beam and a laser source for generating a laser beam. A photodetachment module is located proximate the periphery of the accelerator. The photodetachment module combines the H.sup.- beam and laser beam to produce a neutral beam therefrom within a subsection of the H.sup.- beam. The photodetachment module emits the neutral beam along a trajectory defined by the laser beam. The photodetachment module includes a stripping foil which forms a proton beam from the neutral beam. The proton beam is delivered to a conveyance segment which transports the proton beam to a patient treatment station. The photodetachment module further includes a laser scanner which moves the laser beam along a path transverse to the cross-section of the H.sup.- beam in order to form the neutral beam in subsections of the H.sup.- beam. As the scanning laser moves across the H.sup.- beam, it similarly varies the trajectory of the proton beam emitted from the photodetachment module and in turn varies the target location of the proton beam upon the patient. Intensity modulation of the proton beam can also be achieved by controlling the output of the laser.

  11. Bathymetry, electromagnetic streamlines and the marine controlled source electromagnetic method

    NASA Astrophysics Data System (ADS)

    Pethick, Andrew 12Harris, Brett

    2014-07-01

    Seafloor topography must influence the strength and direction of electromagnetic fields generated during deep ocean controlled source electromagnetic surveying. Neither mathematical equation nor rules of thumb provide a clear perspective of how changes in water column thickness alters electromagnetic fields that engulf hundreds of cubic kilometres of air, ocean, host and reservoir. We use streamline visualisation to provide a generalised representation of how electromagnetic fields propagate into a 2D geo-electrical setting that includes strong bathymetry. Of particular interest are: (i)' dead zones' where electric fields at the ocean floor are demonstrated to be weak and (ii) the 'airwave' that appears in the electric field streamlines as circulating vortices with a shape that is clearly influenced by changes in ocean depth. Our analysis of the distribution of electric fields for deep and shallow water examples alludes to potential benefits from placement of receivers and/or transmitters higher in the water column as is the case for towed receiver geometries. Real-time streamline representation probably holds the most value at the survey planning stage, especially for shallow water marine EM surveys where ocean bottom topography is likely to be consequential.

  12. Analysis of modified SMI method for adaptive array weight control

    NASA Technical Reports Server (NTRS)

    Dilsavor, R. L.; Moses, R. L.

    1989-01-01

    An adaptive array is applied to the problem of receiving a desired signal in the presence of weak interference signals which need to be suppressed. A modification, suggested by Gupta, of the sample matrix inversion (SMI) algorithm controls the array weights. In the modified SMI algorithm, interference suppression is increased by subtracting a fraction F of the noise power from the diagonal elements of the estimated covariance matrix. Given the true covariance matrix and the desired signal direction, the modified algorithm is shown to maximize a well-defined, intuitive output power ratio criterion. Expressions are derived for the expected value and variance of the array weights and output powers as a function of the fraction F and the number of snapshots used in the covariance matrix estimate. These expressions are compared with computer simulation and good agreement is found. A trade-off is found to exist between the desired level of interference suppression and the number of snapshots required in order to achieve that level with some certainty. The removal of noise eigenvectors from the covariance matrix inverse is also discussed with respect to this application. Finally, the type and severity of errors which occur in the covariance matrix estimate are characterized through simulation.

  13. A Proposal for a Mist Cooling Control and Measurement Methods

    NASA Astrophysics Data System (ADS)

    Farnham, Craig; Nakao, Masaki; Nishioka, Masatoshi; Nabeshima, Minako; Mizuno, Takeo

    Fine water mist sprays with average droplet diameters around 20 microns are being increasingly used as an energy-efficient means of cooling outdoor and semi-enclosed spaces such as rail platforms and shopping arcades. At high relative humidity there is a higher risk of wetting people and the ground beneath mist nozzles. Automated control systems are often set to run above a set dry bulb temperature and below a set relative humidity. Experiments show that mist evaporation rates before reaching the ground are closely related to the difference between the dry bulb and wet bulb temperatures, here labeled ΔTWB. Changing the operating parameters to include a minimum ΔTWB can allow use at higher relative humidity levels. If a common 28°C, 70% condition is sufficient to prevent floor-wetting, then a condition of 28°C with a ΔTWB > 4.3K should still prevent floor-wetting. This would allow operation at 75% relative humidity near 39°C.

  14. Method and apparatus for laser-controlled proton beam radiology

    DOEpatents

    Johnstone, C.J.

    1998-06-02

    A proton beam radiology system provides cancer treatment and proton radiography. The system includes an accelerator for producing an H{sup {minus}} beam and a laser source for generating a laser beam. A photodetachment module is located proximate the periphery of the accelerator. The photodetachment module combines the H{sup {minus}} beam and laser beam to produce a neutral beam therefrom within a subsection of the H{sup {minus}} beam. The photodetachment module emits the neutral beam along a trajectory defined by the laser beam. The photodetachment module includes a stripping foil which forms a proton beam from the neutral beam. The proton beam is delivered to a conveyance segment which transports the proton beam to a patient treatment station. The photodetachment module further includes a laser scanner which moves the laser beam along a path transverse to the cross-section of the H{sup {minus}} beam in order to form the neutral beam in subsections of the H{sup {minus}} beam. As the scanning laser moves across the H{sup {minus}} beam, it similarly varies the trajectory of the proton beam emitted from the photodetachment module and in turn varies the target location of the proton beam upon the patient. Intensity modulation of the proton beam can also be achieved by controlling the output of the laser. 9 figs.

  15. Blading System and Method For Controlling Structural Vibrations

    NASA Technical Reports Server (NTRS)

    Nguyen, Nhan (Inventor)

    2000-01-01

    A new blading system for controlling the structural vibrations in axial-flow compressors, turbines, or fans, as in aircraft engines and like turbomachines including a stator disc and a rotor disc is presented. The rotor disc defines several radial hubs that retain the rotor blading systems. Each blading system includes a blade formed of an airfoil, and a root attachment which is dimensioned to fit within, and to engage a corresponding hub. Viscoelastic dampers are selectively applied to the outer surfaces of the root attachment on which compressive or shear forces are likely to develop, intermediate the root attachment and the hub, for compression therebetween upon rotation of the rotor disc, in order to dampen structural vibrations. One advantage presented by the viscoelastic dampers lies in its simplicity, efficiency, cost effectiveness, and its ability to be retrofitted into existing turbomachines with minor surface treatment of the root attachments. Furthermore, since the dampers are not exposed to the inflowing airstream, they do not affect the aerodynamic performance of the turbomachine. Another feature of the damping system is that it provides a significant source of damping to minimize destructive structural vibrations, thereby increasing the durability of the turbomachine, and reducing acoustic noise accompanying high amplitude vibrations.

  16. Control and monitoring method and system for electromagnetic forming process

    DOEpatents

    Kunerth, Dennis C.; Lassahn, Gordon D.

    1990-01-01

    A process, system, and improvement for a process for electromagnetic forming of a workpiece in which characteristics of the workpiece such as its geometry, electrical conductivity, quality, and magnetic permeability can be determined by monitoring the current and voltage in the workcoil. In an electromagnet forming process in which a power supply provides current to a workcoil and the electromagnetic field produced by the workcoil acts to form the workpiece, the dynamic interaction of the electromagnetic fields produced by the workcoil with the geometry, electrical conductivity, and magnetic permeability of the workpiece, provides information pertinent to the physical condition of the workpiece that is available for determination of quality and process control. This information can be obtained by deriving in real time the first several time derivatives of the current and voltage in the workcoil. In addition, the process can be extended by injecting test signals into the workcoil during the electromagnetic forming and monitoring the response to the test signals in the workcoil.

  17. Rapid microbiological methods with hazard analysis critical control point.

    PubMed

    Griffiths, M W

    1997-01-01

    The proactive approach to ensuring food safety termed hazard analysis critical control point (HACCP) was introduced in the 1960s by the Pillsbury Company, in collaboration with the U.S. Army Natick Laboratories and National Aeronautics and Space Administration, to help guarantee that astronauts would not be incapacitated by the trauma of foodborne illness during space flights. The approach has subsequently been adopted as the standard food safety management system world-wide and is seen as forming the basis for harmonization of food inspection regulations necessitated by trade agreements such as General Agreement on Tariffs and Trade and North American Free Trade Agreement as the move toward globalization of trade in food products gains momentum. The new U.S. Department of Agriculture Mega-Reg requires mandatory introduction of HACCP, and the Food Safety Enhancement Program of Agriculture and Agri-food Canada, as well as the "due diligence" legislation of the European Union, is centered on HACCP principles. PMID:9419852

  18. Compositions and method for controlling precipitation when acidizing sour wells

    SciTech Connect

    Dill, W.R.; Walker, M.L.

    1990-08-21

    This patent describes a method of treating a sour well penetrating a subterranean formation. It comprises: introducing into the well a treating fluid comprising an acid solution having a pH below 1.9, an iron sequestering agent comprising at least one compound selected from the group consisting of aminopolycarboxylic acids, hydroxycarboxylic acids, cyclic polyethers and derivatives of the acids and ethers, present in an amount of from about 0.25 to about 5 percent by weight of the acid solution, and a sulfide modifier comprising at least one compound selected from the group consisting of an aldehyde, acetal, hemiacetal and any other compound capable of forming aldehydes in the acid solution, present in an amount of from about 0.25 to about 5 percent of the acid solution; and treating the subterranean formation with the treating fluid.

  19. Method and apparatus for wind turbine air gap control

    DOEpatents

    Grant, James Jonathan; Bagepalli, Bharat Sampathkumaran; Jansen, Patrick Lee; DiMascio, Paul Stephen; Gadre, Aniruddha Dattatraya; Qu, Ronghai

    2007-02-20

    Methods and apparatus for assembling a wind turbine generator are provided. The wind turbine generator includes a core and a plurality of stator windings circumferentially spaced about a generator longitudinal axis, a rotor rotatable about the generator longitudinal axis wherein the rotor includes a plurality of magnetic elements coupled to a radially outer periphery of the rotor such that an airgap is defined between the stator windings and the magnetic elements and the plurality of magnetic elements including a radially inner periphery having a first diameter. The wind turbine generator also includes a bearing including a first member in rotatable engagement with a radially inner second member, the first member including a radially outer periphery, a diameter of the radially outer periphery of the first member being substantially equal to the first diameter, the rotor coupled to the stator through the bearing such that a substantially uniform airgap is maintained.

  20. An investigation of longwall gob gas behavior and control methods

    SciTech Connect

    Schatzel, S.J.; Diamond, W.P.; Garcia, F.; LaScola, J.C.; McCall, F.E.; Jeran, P.W.; Mucho, T.P.

    1999-07-01

    The National Inst. for Occupational Safety and Health (NIOSH) has initiated the use of a tracer gas in field studies to characterize geologic and mining factors influencing the migration of longwall gob gas. Three studies have been conducted using sulfur hexafluoride (SF{sub 6}) at a coal mine in the Northern Appalachian Basin operating in the Pittsburgh Coalbed. Eight underground tracer gas releases and one gob gas venthole release are summarized. The results indicate that the gas flow in the bleeder network and in the interior regions of longwall panel gobs do not strongly interact and that the negative pressure provided by gob gas venthole exhausters is very significant in maintaining this behavior. The data also show that ventilation practices employed in a large multi-panel gob area are functioning in accordance with the intent of the engineering design, a fact which would be difficult to evaluate using conventional mine ventilation measurement methods.